version 1.1.1.1, 2014/06/15 16:31:38
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version 1.1.1.3, 2021/03/17 00:56:46
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/* dnssec.c is Copyright (c) 2012 Giovanni Bajo <rasky@develer.com> |
/* dnssec.c is Copyright (c) 2012 Giovanni Bajo <rasky@develer.com> |
and Copyright (c) 2012-2014 Simon Kelley | and Copyright (c) 2012-2020 Simon Kelley |
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This program is free software; you can redistribute it and/or modify |
This program is free software; you can redistribute it and/or modify |
it under the terms of the GNU General Public License as published by |
it under the terms of the GNU General Public License as published by |
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#ifdef HAVE_DNSSEC |
#ifdef HAVE_DNSSEC |
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#include <nettle/rsa.h> |
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#include <nettle/dsa.h> |
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#ifndef NO_NETTLE_ECC |
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# include <nettle/ecdsa.h> |
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# include <nettle/ecc-curve.h> |
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#endif |
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#include <nettle/nettle-meta.h> |
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#include <gmp.h> |
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#define SERIAL_UNDEF -100 |
#define SERIAL_UNDEF -100 |
#define SERIAL_EQ 0 |
#define SERIAL_EQ 0 |
#define SERIAL_LT -1 |
#define SERIAL_LT -1 |
#define SERIAL_GT 1 |
#define SERIAL_GT 1 |
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/* http://www.iana.org/assignments/ds-rr-types/ds-rr-types.xhtml */ |
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static char *ds_digest_name(int digest) |
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{ |
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switch (digest) |
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{ |
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case 1: return "sha1"; |
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case 2: return "sha256"; |
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case 3: return "gosthash94"; |
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case 4: return "sha384"; |
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default: return NULL; |
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} |
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} |
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/* http://www.iana.org/assignments/dns-sec-alg-numbers/dns-sec-alg-numbers.xhtml */ |
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static char *algo_digest_name(int algo) |
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{ |
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switch (algo) |
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{ |
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case 1: return "md5"; |
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case 3: return "sha1"; |
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case 5: return "sha1"; |
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case 6: return "sha1"; |
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case 7: return "sha1"; |
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case 8: return "sha256"; |
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case 10: return "sha512"; |
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case 12: return "gosthash94"; |
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case 13: return "sha256"; |
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case 14: return "sha384"; |
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default: return NULL; |
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} |
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} |
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/* Find pointer to correct hash function in nettle library */ |
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static const struct nettle_hash *hash_find(char *name) |
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{ |
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int i; |
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if (!name) |
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return NULL; |
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for (i = 0; nettle_hashes[i]; i++) |
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{ |
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if (strcmp(nettle_hashes[i]->name, name) == 0) |
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return nettle_hashes[i]; |
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} |
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return NULL; |
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} |
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/* expand ctx and digest memory allocations if necessary and init hash function */ |
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static int hash_init(const struct nettle_hash *hash, void **ctxp, unsigned char **digestp) |
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{ |
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static void *ctx = NULL; |
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static unsigned char *digest = NULL; |
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static unsigned int ctx_sz = 0; |
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static unsigned int digest_sz = 0; |
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void *new; |
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if (ctx_sz < hash->context_size) |
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{ |
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if (!(new = whine_malloc(hash->context_size))) |
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return 0; |
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if (ctx) |
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free(ctx); |
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ctx = new; |
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ctx_sz = hash->context_size; |
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} |
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if (digest_sz < hash->digest_size) |
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{ |
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if (!(new = whine_malloc(hash->digest_size))) |
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return 0; |
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if (digest) |
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free(digest); |
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digest = new; |
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digest_sz = hash->digest_size; |
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} |
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*ctxp = ctx; |
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*digestp = digest; |
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hash->init(ctx); |
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return 1; |
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} |
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static int rsa_verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
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unsigned char *digest, int algo) |
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{ |
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unsigned char *p; |
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size_t exp_len; |
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static struct rsa_public_key *key = NULL; |
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static mpz_t sig_mpz; |
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if (key == NULL) |
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{ |
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if (!(key = whine_malloc(sizeof(struct rsa_public_key)))) |
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return 0; |
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nettle_rsa_public_key_init(key); |
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mpz_init(sig_mpz); |
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} |
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if ((key_len < 3) || !(p = blockdata_retrieve(key_data, key_len, NULL))) |
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return 0; |
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key_len--; |
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if ((exp_len = *p++) == 0) |
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{ |
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GETSHORT(exp_len, p); |
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key_len -= 2; |
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} |
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if (exp_len >= key_len) |
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return 0; |
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key->size = key_len - exp_len; |
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mpz_import(key->e, exp_len, 1, 1, 0, 0, p); |
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mpz_import(key->n, key->size, 1, 1, 0, 0, p + exp_len); |
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mpz_import(sig_mpz, sig_len, 1, 1, 0, 0, sig); |
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switch (algo) |
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{ |
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case 1: |
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return nettle_rsa_md5_verify_digest(key, digest, sig_mpz); |
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case 5: case 7: |
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return nettle_rsa_sha1_verify_digest(key, digest, sig_mpz); |
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case 8: |
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return nettle_rsa_sha256_verify_digest(key, digest, sig_mpz); |
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case 10: |
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return nettle_rsa_sha512_verify_digest(key, digest, sig_mpz); |
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} |
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return 0; |
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} |
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static int dsa_verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
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unsigned char *digest, int algo) |
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{ |
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unsigned char *p; |
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unsigned int t; |
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static struct dsa_public_key *key = NULL; |
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static struct dsa_signature *sig_struct; |
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if (key == NULL) |
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{ |
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if (!(sig_struct = whine_malloc(sizeof(struct dsa_signature))) || |
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!(key = whine_malloc(sizeof(struct dsa_public_key)))) |
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return 0; |
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nettle_dsa_public_key_init(key); |
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nettle_dsa_signature_init(sig_struct); |
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} |
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if ((sig_len < 41) || !(p = blockdata_retrieve(key_data, key_len, NULL))) |
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return 0; |
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t = *p++; |
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if (key_len < (213 + (t * 24))) |
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return 0; |
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mpz_import(key->q, 20, 1, 1, 0, 0, p); p += 20; |
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mpz_import(key->p, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); |
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mpz_import(key->g, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); |
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mpz_import(key->y, 64 + (t*8), 1, 1, 0, 0, p); p += 64 + (t*8); |
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mpz_import(sig_struct->r, 20, 1, 1, 0, 0, sig+1); |
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mpz_import(sig_struct->s, 20, 1, 1, 0, 0, sig+21); |
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(void)algo; |
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return nettle_dsa_sha1_verify_digest(key, digest, sig_struct); |
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} |
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#ifndef NO_NETTLE_ECC |
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static int dnsmasq_ecdsa_verify(struct blockdata *key_data, unsigned int key_len, |
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unsigned char *sig, size_t sig_len, |
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unsigned char *digest, size_t digest_len, int algo) |
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{ |
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unsigned char *p; |
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unsigned int t; |
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struct ecc_point *key; |
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static struct ecc_point *key_256 = NULL, *key_384 = NULL; |
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static mpz_t x, y; |
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static struct dsa_signature *sig_struct; |
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if (!sig_struct) |
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{ |
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if (!(sig_struct = whine_malloc(sizeof(struct dsa_signature)))) |
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return 0; |
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nettle_dsa_signature_init(sig_struct); |
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mpz_init(x); |
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mpz_init(y); |
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} |
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switch (algo) |
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{ |
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case 13: |
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if (!key_256) |
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{ |
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if (!(key_256 = whine_malloc(sizeof(struct ecc_point)))) |
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return 0; |
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nettle_ecc_point_init(key_256, &nettle_secp_256r1); |
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} |
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key = key_256; |
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t = 32; |
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break; |
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case 14: |
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if (!key_384) |
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{ |
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if (!(key_384 = whine_malloc(sizeof(struct ecc_point)))) |
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return 0; |
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nettle_ecc_point_init(key_384, &nettle_secp_384r1); |
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} |
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key = key_384; |
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t = 48; |
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break; |
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default: |
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return 0; |
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} |
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if (sig_len != 2*t || key_len != 2*t || |
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(p = blockdata_retrieve(key_data, key_len, NULL))) |
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return 0; |
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mpz_import(x, t , 1, 1, 0, 0, p); |
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mpz_import(y, t , 1, 1, 0, 0, p + t); |
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if (!ecc_point_set(key, x, y)) |
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return 0; |
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mpz_import(sig_struct->r, t, 1, 1, 0, 0, sig); |
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mpz_import(sig_struct->s, t, 1, 1, 0, 0, sig + t); |
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return nettle_ecdsa_verify(key, digest_len, digest, sig_struct); |
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} |
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#endif |
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static int verify(struct blockdata *key_data, unsigned int key_len, unsigned char *sig, size_t sig_len, |
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unsigned char *digest, size_t digest_len, int algo) |
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{ |
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(void)digest_len; |
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switch (algo) |
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{ |
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case 1: case 5: case 7: case 8: case 10: |
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return rsa_verify(key_data, key_len, sig, sig_len, digest, algo); |
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case 3: case 6: |
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return dsa_verify(key_data, key_len, sig, sig_len, digest, algo); |
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#ifndef NO_NETTLE_ECC |
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case 13: case 14: |
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return dnsmasq_ecdsa_verify(key_data, key_len, sig, sig_len, digest, digest_len, algo); |
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#endif |
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} |
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return 0; |
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} |
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/* Convert from presentation format to wire format, in place. |
/* Convert from presentation format to wire format, in place. |
Also map UC -> LC. |
Also map UC -> LC. |
Note that using extract_name to get presentation format |
Note that using extract_name to get presentation format |
Line 313 static int verify(struct blockdata *key_data, unsigned
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Line 31 static int verify(struct blockdata *key_data, unsigned
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thus generating names in canonical form. |
thus generating names in canonical form. |
Calling to_wire followed by from_wire is almost an identity, |
Calling to_wire followed by from_wire is almost an identity, |
except that the UC remains mapped to LC. |
except that the UC remains mapped to LC. |
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Note that both /000 and '.' are allowed within labels. These get |
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represented in presentation format using NAME_ESCAPE as an escape |
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character. In theory, if all the characters in a name were /000 or |
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'.' or NAME_ESCAPE then all would have to be escaped, so the |
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presentation format would be twice as long as the spec (1024). |
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The buffers are all declared as 2049 (allowing for the trailing zero) |
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for this reason. |
*/ |
*/ |
static int to_wire(char *name) |
static int to_wire(char *name) |
{ |
{ |
unsigned char *l, *p, term; | unsigned char *l, *p, *q, term; |
int len; |
int len; |
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for (l = (unsigned char*)name; *l != 0; l = p) |
for (l = (unsigned char*)name; *l != 0; l = p) |
Line 324 static int to_wire(char *name)
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Line 50 static int to_wire(char *name)
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for (p = l; *p != '.' && *p != 0; p++) |
for (p = l; *p != '.' && *p != 0; p++) |
if (*p >= 'A' && *p <= 'Z') |
if (*p >= 'A' && *p <= 'Z') |
*p = *p - 'A' + 'a'; |
*p = *p - 'A' + 'a'; |
| else if (*p == NAME_ESCAPE) |
| { |
| for (q = p; *q; q++) |
| *q = *(q+1); |
| (*p)--; |
| } |
term = *p; |
term = *p; |
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if ((len = p - l) != 0) |
if ((len = p - l) != 0) |
Line 343 static int to_wire(char *name)
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Line 74 static int to_wire(char *name)
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/* Note: no compression allowed in input. */ |
/* Note: no compression allowed in input. */ |
static void from_wire(char *name) |
static void from_wire(char *name) |
{ |
{ |
unsigned char *l; | unsigned char *l, *p, *last; |
int len; |
int len; |
| |
| for (last = (unsigned char *)name; *last != 0; last += *last+1); |
| |
for (l = (unsigned char *)name; *l != 0; l += len+1) |
for (l = (unsigned char *)name; *l != 0; l += len+1) |
{ |
{ |
len = *l; |
len = *l; |
memmove(l, l+1, len); |
memmove(l, l+1, len); |
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for (p = l; p < l + len; p++) |
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if (*p == '.' || *p == 0 || *p == NAME_ESCAPE) |
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{ |
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memmove(p+1, p, 1 + last - p); |
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len++; |
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*p++ = NAME_ESCAPE; |
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(*p)++; |
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} |
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l[len] = '.'; |
l[len] = '.'; |
} |
} |
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Line 361 static void from_wire(char *name)
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Line 103 static void from_wire(char *name)
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static int count_labels(char *name) |
static int count_labels(char *name) |
{ |
{ |
int i; |
int i; |
| char *p; |
| |
if (*name == 0) |
if (*name == 0) |
return 0; |
return 0; |
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for (i = 0; *name; name++) | for (p = name, i = 0; *p; p++) |
if (*name == '.') | if (*p == '.') |
i++; |
i++; |
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return i+1; | /* Don't count empty first label. */ |
| return *name == '.' ? i : i+1; |
} |
} |
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/* Implement RFC1982 wrapped compare for 32-bit numbers */ |
/* Implement RFC1982 wrapped compare for 32-bit numbers */ |
static int serial_compare_32(unsigned long s1, unsigned long s2) | static int serial_compare_32(u32 s1, u32 s2) |
{ |
{ |
if (s1 == s2) |
if (s1 == s2) |
return SERIAL_EQ; |
return SERIAL_EQ; |
Line 387 static int serial_compare_32(unsigned long s1, unsigne
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Line 131 static int serial_compare_32(unsigned long s1, unsigne
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return SERIAL_UNDEF; |
return SERIAL_UNDEF; |
} |
} |
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/* Check whether today/now is between date_start and date_end */ | /* Called at startup. If the timestamp file is configured and exists, put its mtime on |
static int check_date_range(unsigned long date_start, unsigned long date_end) | timestamp_time. If it doesn't exist, create it, and set the mtime to 1-1-2015. |
{ | return -1 -> Cannot create file. |
unsigned long curtime; | 0 -> not using timestamp, or timestamp exists and is in past. |
| 1 -> timestamp exists and is in future. |
| */ |
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/* Checking timestamps may be temporarily disabled */ | static time_t timestamp_time; |
if (option_bool(OPT_DNSSEC_TIME)) | |
return 1; | |
| |
curtime = time(0); | |
| |
/* We must explicitly check against wanted values, because of SERIAL_UNDEF */ | |
return serial_compare_32(curtime, date_start) == SERIAL_GT | |
&& serial_compare_32(curtime, date_end) == SERIAL_LT; | |
} | |
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static u16 *get_desc(int type) | int setup_timestamp(void) |
{ |
{ |
/* List of RRtypes which include domains in the data. | struct stat statbuf; |
0 -> domain | |
integer -> no of plain bytes | |
-1 -> end | |
| |
zero is not a valid RRtype, so the final entry is returned for | |
anything which needs no mangling. | |
*/ | |
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static u16 rr_desc[] = | daemon->back_to_the_future = 0; |
{ | |
T_NS, 0, -1, | |
T_MD, 0, -1, | |
T_MF, 0, -1, | |
T_CNAME, 0, -1, | |
T_SOA, 0, 0, -1, | |
T_MB, 0, -1, | |
T_MG, 0, -1, | |
T_MR, 0, -1, | |
T_PTR, 0, -1, | |
T_MINFO, 0, 0, -1, | |
T_MX, 2, 0, -1, | |
T_RP, 0, 0, -1, | |
T_AFSDB, 2, 0, -1, | |
T_RT, 2, 0, -1, | |
T_SIG, 18, 0, -1, | |
T_PX, 2, 0, 0, -1, | |
T_NXT, 0, -1, | |
T_KX, 2, 0, -1, | |
T_SRV, 6, 0, -1, | |
T_DNAME, 0, -1, | |
0, -1 /* wildcard/catchall */ | |
}; | |
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u16 *p = rr_desc; | if (!daemon->timestamp_file) |
| return 0; |
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while (*p != type && *p != 0) | if (stat(daemon->timestamp_file, &statbuf) != -1) |
while (*p++ != (u16)-1); | { |
| timestamp_time = statbuf.st_mtime; |
| check_and_exit: |
| if (difftime(timestamp_time, time(0)) <= 0) |
| { |
| /* time already OK, update timestamp, and do key checking from the start. */ |
| if (utimes(daemon->timestamp_file, NULL) == -1) |
| my_syslog(LOG_ERR, _("failed to update mtime on %s: %s"), daemon->timestamp_file, strerror(errno)); |
| daemon->back_to_the_future = 1; |
| return 0; |
| } |
| return 1; |
| } |
| |
| if (errno == ENOENT) |
| { |
| /* NB. for explanation of O_EXCL flag, see comment on pidfile in dnsmasq.c */ |
| int fd = open(daemon->timestamp_file, O_WRONLY | O_CREAT | O_NONBLOCK | O_EXCL, 0666); |
| if (fd != -1) |
| { |
| struct timeval tv[2]; |
|
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return p+1; | close(fd); |
| |
| timestamp_time = 1420070400; /* 1-1-2015 */ |
| tv[0].tv_sec = tv[1].tv_sec = timestamp_time; |
| tv[0].tv_usec = tv[1].tv_usec = 0; |
| if (utimes(daemon->timestamp_file, tv) == 0) |
| goto check_and_exit; |
| } |
| } |
| |
| return -1; |
} |
} |
|
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/* Return bytes of canonicalised rdata, when the return value is zero, the remaining | /* Check whether today/now is between date_start and date_end */ |
data, pointed to by *p, should be used raw. */ | static int is_check_date(unsigned long curtime) |
static int get_rdata(struct dns_header *header, size_t plen, unsigned char *end, char *buff, | |
unsigned char **p, u16 **desc) | |
{ |
{ |
int d = **desc; | /* Checking timestamps may be temporarily disabled */ |
| |
(*desc)++; | /* If the current time if _before_ the timestamp |
| on our persistent timestamp file, then assume the |
/* No more data needs mangling */ | time if not yet correct, and don't check the |
if (d == (u16)-1) | key timestamps. As soon as the current time is |
return 0; | later then the timestamp, update the timestamp |
| and start checking keys */ |
if (d == 0 && extract_name(header, plen, p, buff, 1, 0)) | if (daemon->timestamp_file) |
/* domain-name, canonicalise */ | { |
return to_wire(buff); | if (daemon->back_to_the_future == 0 && difftime(timestamp_time, curtime) <= 0) |
else | |
{ | |
/* plain data preceding a domain-name, don't run off the end of the data */ | |
if ((end - *p) < d) | |
d = end - *p; | |
| |
if (d != 0) | |
{ |
{ |
memcpy(buff, *p, d); | if (utimes(daemon->timestamp_file, NULL) != 0) |
*p += d; | my_syslog(LOG_ERR, _("failed to update mtime on %s: %s"), daemon->timestamp_file, strerror(errno)); |
} | |
| my_syslog(LOG_INFO, _("system time considered valid, now checking DNSSEC signature timestamps.")); |
return d; | daemon->back_to_the_future = 1; |
| daemon->dnssec_no_time_check = 0; |
| queue_event(EVENT_RELOAD); /* purge cache */ |
| } |
| |
| return daemon->back_to_the_future; |
} |
} |
|
else |
|
return !daemon->dnssec_no_time_check; |
} |
} |
|
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static int expand_workspace(unsigned char ***wkspc, int *sz, int new) | /* Check whether today/now is between date_start and date_end */ |
| static int check_date_range(unsigned long curtime, u32 date_start, u32 date_end) |
{ |
{ |
unsigned char **p; | /* We must explicitly check against wanted values, because of SERIAL_UNDEF */ |
int new_sz = *sz; | return serial_compare_32(curtime, date_start) == SERIAL_GT |
| && serial_compare_32(curtime, date_end) == SERIAL_LT; |
if (new_sz > new) | } |
return 1; | |
|
|
if (new >= 100) | /* Return bytes of canonicalised rrdata one by one. |
return 0; | Init state->ip with the RR, and state->end with the end of same. |
| Init state->op to NULL. |
| Init state->desc to RR descriptor. |
| Init state->buff with a MAXDNAME * 2 buffer. |
| |
| After each call which returns 1, state->op points to the next byte of data. |
| On returning 0, the end has been reached. |
| */ |
| struct rdata_state { |
| u16 *desc; |
| size_t c; |
| unsigned char *end, *ip, *op; |
| char *buff; |
| }; |
|
|
new_sz += 5; | static int get_rdata(struct dns_header *header, size_t plen, struct rdata_state *state) |
| { |
| int d; |
|
|
if (!(p = whine_malloc((new_sz) * sizeof(unsigned char **)))) | if (state->op && state->c != 1) |
return 0; | |
| |
if (*wkspc) | |
{ |
{ |
memcpy(p, *wkspc, *sz * sizeof(unsigned char **)); | state->op++; |
free(*wkspc); | state->c--; |
| return 1; |
} |
} |
|
|
*wkspc = p; |
|
*sz = new_sz; |
|
|
|
return 1; | while (1) |
| { |
| d = *(state->desc); |
| |
| if (d == (u16)-1) |
| { |
| /* all the bytes to the end. */ |
| if ((state->c = state->end - state->ip) != 0) |
| { |
| state->op = state->ip; |
| state->ip = state->end;; |
| } |
| else |
| return 0; |
| } |
| else |
| { |
| state->desc++; |
| |
| if (d == (u16)0) |
| { |
| /* domain-name, canonicalise */ |
| int len; |
| |
| if (!extract_name(header, plen, &state->ip, state->buff, 1, 0) || |
| (len = to_wire(state->buff)) == 0) |
| continue; |
| |
| state->c = len; |
| state->op = (unsigned char *)state->buff; |
| } |
| else |
| { |
| /* plain data preceding a domain-name, don't run off the end of the data */ |
| if ((state->end - state->ip) < d) |
| d = state->end - state->ip; |
| |
| if (d == 0) |
| continue; |
| |
| state->op = state->ip; |
| state->c = d; |
| state->ip += d; |
| } |
| } |
| |
| return 1; |
| } |
} |
} |
|
|
/* Bubble sort the RRset into the canonical order. | /* Bubble sort the RRset into the canonical order. */ |
Note that the byte-streams from two RRs may get unsynced: consider | |
RRs which have two domain-names at the start and then other data. | |
The domain-names may have different lengths in each RR, but sort equal | |
|
|
------------ | static int sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int rrsetidx, |
|abcde|fghi| | unsigned char **rrset, char *buff1, char *buff2) |
------------ | |
|abcd|efghi| | |
------------ | |
| |
leaving the following bytes as deciding the order. Hence the nasty left1 and left2 variables. | |
*/ | |
| |
static void sort_rrset(struct dns_header *header, size_t plen, u16 *rr_desc, int rrsetidx, | |
unsigned char **rrset, char *buff1, char *buff2) | |
{ |
{ |
int swap, quit, i; | int swap, i, j; |
|
|
do |
do |
{ |
{ |
for (swap = 0, i = 0; i < rrsetidx-1; i++) |
for (swap = 0, i = 0; i < rrsetidx-1; i++) |
{ |
{ |
int rdlen1, rdlen2, left1, left2, len1, len2, len, rc; | int rdlen1, rdlen2; |
u16 *dp1, *dp2; | struct rdata_state state1, state2; |
unsigned char *end1, *end2; | |
/* Note that these have been determined to be OK previously, |
/* Note that these have been determined to be OK previously, |
so we don't need to check for NULL return here. */ |
so we don't need to check for NULL return here. */ |
unsigned char *p1 = skip_name(rrset[i], header, plen, 10); | state1.ip = skip_name(rrset[i], header, plen, 10); |
unsigned char *p2 = skip_name(rrset[i+1], header, plen, 10); | state2.ip = skip_name(rrset[i+1], header, plen, 10); |
| state1.op = state2.op = NULL; |
| state1.buff = buff1; |
| state2.buff = buff2; |
| state1.desc = state2.desc = rr_desc; |
|
|
p1 += 8; /* skip class, type, ttl */ | state1.ip += 8; /* skip class, type, ttl */ |
GETSHORT(rdlen1, p1); | GETSHORT(rdlen1, state1.ip); |
end1 = p1 + rdlen1; | if (!CHECK_LEN(header, state1.ip, plen, rdlen1)) |
| return rrsetidx; /* short packet */ |
| state1.end = state1.ip + rdlen1; |
|
|
p2 += 8; /* skip class, type, ttl */ | state2.ip += 8; /* skip class, type, ttl */ |
GETSHORT(rdlen2, p2); | GETSHORT(rdlen2, state2.ip); |
end2 = p2 + rdlen2; | if (!CHECK_LEN(header, state2.ip, plen, rdlen2)) |
| return rrsetidx; /* short packet */ |
dp1 = dp2 = rr_desc; | state2.end = state2.ip + rdlen2; |
| |
for (quit = 0, left1 = 0, left2 = 0, len1 = 0, len2 = 0; !quit;) | /* If the RR has no names in it then canonicalisation |
| is the identity function and we can compare |
| the RRs directly. If not we compare the |
| canonicalised RRs one byte at a time. */ |
| if (*rr_desc == (u16)-1) |
{ |
{ |
if (left1 != 0) | int rdmin = rdlen1 > rdlen2 ? rdlen2 : rdlen1; |
memmove(buff1, buff1 + len1 - left1, left1); | int cmp = memcmp(state1.ip, state2.ip, rdmin); |
|
|
if ((len1 = get_rdata(header, plen, end1, buff1 + left1, &p1, &dp1)) == 0) | if (cmp > 0 || (cmp == 0 && rdlen1 > rdmin)) |
{ |
{ |
quit = 1; |
|
len1 = end1 - p1; |
|
memcpy(buff1 + left1, p1, len1); |
|
} |
|
len1 += left1; |
|
|
|
if (left2 != 0) |
|
memmove(buff2, buff2 + len2 - left2, left2); |
|
|
|
if ((len2 = get_rdata(header, plen, end2, buff2 + left2, &p2, &dp2)) == 0) |
|
{ |
|
quit = 1; |
|
len2 = end2 - p2; |
|
memcpy(buff2 + left2, p2, len2); |
|
} |
|
len2 += left2; |
|
|
|
if (len1 > len2) |
|
left1 = len1 - len2, left2 = 0, len = len2; |
|
else |
|
left2 = len2 - len1, left1 = 0, len = len1; |
|
|
|
rc = (len == 0) ? 0 : memcmp(buff1, buff2, len); |
|
|
|
if (rc > 0 || (rc == 0 && quit && len1 > len2)) |
|
{ |
|
unsigned char *tmp = rrset[i+1]; |
unsigned char *tmp = rrset[i+1]; |
rrset[i+1] = rrset[i]; |
rrset[i+1] = rrset[i]; |
rrset[i] = tmp; |
rrset[i] = tmp; |
swap = quit = 1; | swap = 1; |
} |
} |
else if (rc < 0) | else if (cmp == 0 && (rdlen1 == rdlen2)) |
quit = 1; | { |
| /* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */ |
| for (j = i+1; j < rrsetidx-1; j++) |
| rrset[j] = rrset[j+1]; |
| rrsetidx--; |
| i--; |
| } |
} |
} |
|
else |
|
/* Comparing canonicalised RRs, byte-at-a-time. */ |
|
while (1) |
|
{ |
|
int ok1, ok2; |
|
|
|
ok1 = get_rdata(header, plen, &state1); |
|
ok2 = get_rdata(header, plen, &state2); |
|
|
|
if (!ok1 && !ok2) |
|
{ |
|
/* Two RRs are equal, remove one copy. RFC 4034, para 6.3 */ |
|
for (j = i+1; j < rrsetidx-1; j++) |
|
rrset[j] = rrset[j+1]; |
|
rrsetidx--; |
|
i--; |
|
break; |
|
} |
|
else if (ok1 && (!ok2 || *state1.op > *state2.op)) |
|
{ |
|
unsigned char *tmp = rrset[i+1]; |
|
rrset[i+1] = rrset[i]; |
|
rrset[i] = tmp; |
|
swap = 1; |
|
break; |
|
} |
|
else if (ok2 && (!ok1 || *state2.op > *state1.op)) |
|
break; |
|
|
|
/* arrive here when bytes are equal, go round the loop again |
|
and compare the next ones. */ |
|
} |
} |
} |
} while (swap); |
} while (swap); |
|
|
|
return rrsetidx; |
} |
} |
|
|
/* Validate a single RRset (class, type, name) in the supplied DNS reply | static unsigned char **rrset = NULL, **sigs = NULL; |
Return code: | |
STAT_SECURE if it validates. | |
STAT_SECURE_WILDCARD if it validates and is the result of wildcard expansion. | |
STAT_NO_SIG no RRsigs found. | |
STAT_INSECURE RRset empty. | |
STAT_BOGUS signature is wrong, bad packet. | |
STAT_NEED_KEY need DNSKEY to complete validation (name is returned in keyname) | |
|
|
if key is non-NULL, use that key, which has the algo and tag given in the params of those names, | /* Get pointers to RRset members and signature(s) for same. |
otherwise find the key in the cache. | Check signatures, and return keyname associated in keyname. */ |
| static int explore_rrset(struct dns_header *header, size_t plen, int class, int type, |
name is unchanged on exit. keyname is used as workspace and trashed. | char *name, char *keyname, int *sigcnt, int *rrcnt) |
*/ | |
static int validate_rrset(time_t now, struct dns_header *header, size_t plen, int class, | |
int type, char *name, char *keyname, struct blockdata *key, int keylen, int algo_in, int keytag_in) | |
{ |
{ |
static unsigned char **rrset = NULL, **sigs = NULL; | static int rrset_sz = 0, sig_sz = 0; |
static int rrset_sz = 0, sig_sz = 0; | |
| |
unsigned char *p; |
unsigned char *p; |
int rrsetidx, sigidx, res, rdlen, j, name_labels; | int rrsetidx, sigidx, j, rdlen, res; |
struct crec *crecp = NULL; | int gotkey = 0; |
int type_covered, algo, labels, orig_ttl, sig_expiration, sig_inception, key_tag; | |
u16 *rr_desc = get_desc(type); | |
|
|
if (!(p = skip_questions(header, plen))) |
if (!(p = skip_questions(header, plen))) |
return STAT_BOGUS; | return 0; |
|
|
name_labels = count_labels(name); /* For 4035 5.3.2 check */ | /* look for RRSIGs for this RRset and get pointers to each RR in the set. */ |
| |
/* look for RRSIGs for this RRset and get pointers to each RR in the set. */ | |
for (rrsetidx = 0, sigidx = 0, j = ntohs(header->ancount) + ntohs(header->nscount); |
for (rrsetidx = 0, sigidx = 0, j = ntohs(header->ancount) + ntohs(header->nscount); |
j != 0; j--) |
j != 0; j--) |
{ |
{ |
unsigned char *pstart, *pdata; |
unsigned char *pstart, *pdata; |
int stype, sclass; | int stype, sclass, type_covered; |
|
|
pstart = p; |
pstart = p; |
|
|
if (!(res = extract_name(header, plen, &p, name, 0, 10))) |
if (!(res = extract_name(header, plen, &p, name, 0, 10))) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
GETSHORT(stype, p); |
GETSHORT(stype, p); |
GETSHORT(sclass, p); |
GETSHORT(sclass, p); |
p += 4; /* TTL */ | |
| |
pdata = p; |
pdata = p; |
|
|
|
p += 4; /* TTL */ |
GETSHORT(rdlen, p); |
GETSHORT(rdlen, p); |
|
|
if (!CHECK_LEN(header, p, plen, rdlen)) |
if (!CHECK_LEN(header, p, plen, rdlen)) |
return STAT_BOGUS; | return 0; |
|
|
if (res == 1 && sclass == class) |
if (res == 1 && sclass == class) |
{ |
{ |
if (stype == type) |
if (stype == type) |
{ |
{ |
if (!expand_workspace(&rrset, &rrset_sz, rrsetidx)) |
if (!expand_workspace(&rrset, &rrset_sz, rrsetidx)) |
return STAT_BOGUS; | return 0; |
|
|
rrset[rrsetidx++] = pstart; |
rrset[rrsetidx++] = pstart; |
} |
} |
Line 660 static int validate_rrset(time_t now, struct dns_heade
|
Line 449 static int validate_rrset(time_t now, struct dns_heade
|
if (stype == T_RRSIG) |
if (stype == T_RRSIG) |
{ |
{ |
if (rdlen < 18) |
if (rdlen < 18) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
GETSHORT(type_covered, p); |
GETSHORT(type_covered, p); |
|
p += 16; /* algo, labels, orig_ttl, sig_expiration, sig_inception, key_tag */ |
|
|
|
if (gotkey) |
|
{ |
|
/* If there's more than one SIG, ensure they all have same keyname */ |
|
if (extract_name(header, plen, &p, keyname, 0, 0) != 1) |
|
return 0; |
|
} |
|
else |
|
{ |
|
gotkey = 1; |
|
|
|
if (!extract_name(header, plen, &p, keyname, 1, 0)) |
|
return 0; |
|
|
|
/* RFC 4035 5.3.1 says that the Signer's Name field MUST equal |
|
the name of the zone containing the RRset. We can't tell that |
|
for certain, but we can check that the RRset name is equal to |
|
or encloses the signers name, which should be enough to stop |
|
an attacker using signatures made with the key of an unrelated |
|
zone he controls. Note that the root key is always allowed. */ |
|
if (*keyname != 0) |
|
{ |
|
char *name_start; |
|
for (name_start = name; !hostname_isequal(name_start, keyname); ) |
|
if ((name_start = strchr(name_start, '.'))) |
|
name_start++; /* chop a label off and try again */ |
|
else |
|
return 0; |
|
} |
|
} |
|
|
|
|
if (type_covered == type) |
if (type_covered == type) |
{ |
{ |
if (!expand_workspace(&sigs, &sig_sz, sigidx)) |
if (!expand_workspace(&sigs, &sig_sz, sigidx)) |
return STAT_BOGUS; | return 0; |
|
|
sigs[sigidx++] = pdata; |
sigs[sigidx++] = pdata; |
} |
} |
|
|
p = pdata + 2; /* restore for ADD_RDLEN */ | p = pdata + 6; /* restore for ADD_RDLEN */ |
} |
} |
} |
} |
|
|
if (!ADD_RDLEN(header, p, plen, rdlen)) |
if (!ADD_RDLEN(header, p, plen, rdlen)) |
return STAT_BOGUS; | return 0; |
} |
} |
|
|
/* RRset empty */ | *sigcnt = sigidx; |
if (rrsetidx == 0) | *rrcnt = rrsetidx; |
return STAT_INSECURE; | |
|
|
/* no RRSIGs */ | return 1; |
if (sigidx == 0) | } |
return STAT_NO_SIG; | |
| /* Validate a single RRset (class, type, name) in the supplied DNS reply |
| Return code: |
| STAT_SECURE if it validates. |
| STAT_SECURE_WILDCARD if it validates and is the result of wildcard expansion. |
| (In this case *wildcard_out points to the "body" of the wildcard within name.) |
| STAT_BOGUS signature is wrong, bad packet. |
| STAT_NEED_KEY need DNSKEY to complete validation (name is returned in keyname) |
| STAT_NEED_DS need DS to complete validation (name is returned in keyname) |
| |
| If key is non-NULL, use that key, which has the algo and tag given in the params of those names, |
| otherwise find the key in the cache. |
| |
| Name is unchanged on exit. keyname is used as workspace and trashed. |
| |
| Call explore_rrset first to find and count RRs and sigs. |
| |
| ttl_out is the floor on TTL, based on TTL and orig_ttl and expiration of sig used to validate. |
| */ |
| static int validate_rrset(time_t now, struct dns_header *header, size_t plen, int class, int type, int sigidx, int rrsetidx, |
| char *name, char *keyname, char **wildcard_out, struct blockdata *key, int keylen, |
| int algo_in, int keytag_in, unsigned long *ttl_out) |
| { |
| unsigned char *p; |
| int rdlen, j, name_labels, algo, labels, key_tag; |
| struct crec *crecp = NULL; |
| u16 *rr_desc = rrfilter_desc(type); |
| u32 sig_expiration, sig_inception; |
| |
| unsigned long curtime = time(0); |
| int time_check = is_check_date(curtime); |
|
|
|
if (wildcard_out) |
|
*wildcard_out = NULL; |
|
|
|
name_labels = count_labels(name); /* For 4035 5.3.2 check */ |
|
|
/* Sort RRset records into canonical order. |
/* Sort RRset records into canonical order. |
Note that at this point keyname and daemon->workspacename buffs are |
Note that at this point keyname and daemon->workspacename buffs are |
unused, and used as workspace by the sort. */ |
unused, and used as workspace by the sort. */ |
sort_rrset(header, plen, rr_desc, rrsetidx, rrset, daemon->workspacename, keyname); | rrsetidx = sort_rrset(header, plen, rr_desc, rrsetidx, rrset, daemon->workspacename, keyname); |
|
|
/* Now try all the sigs to try and find one which validates */ |
/* Now try all the sigs to try and find one which validates */ |
for (j = 0; j <sigidx; j++) |
for (j = 0; j <sigidx; j++) |
Line 701 static int validate_rrset(time_t now, struct dns_heade
|
Line 556 static int validate_rrset(time_t now, struct dns_heade
|
const struct nettle_hash *hash; |
const struct nettle_hash *hash; |
void *ctx; |
void *ctx; |
char *name_start; |
char *name_start; |
u32 nsigttl; | u32 nsigttl, ttl, orig_ttl; |
|
|
p = sigs[j]; |
p = sigs[j]; |
|
GETLONG(ttl, p); |
GETSHORT(rdlen, p); /* rdlen >= 18 checked previously */ |
GETSHORT(rdlen, p); /* rdlen >= 18 checked previously */ |
psav = p; |
psav = p; |
|
|
Line 718 static int validate_rrset(time_t now, struct dns_heade
|
Line 574 static int validate_rrset(time_t now, struct dns_heade
|
if (!extract_name(header, plen, &p, keyname, 1, 0)) |
if (!extract_name(header, plen, &p, keyname, 1, 0)) |
return STAT_BOGUS; |
return STAT_BOGUS; |
|
|
/* RFC 4035 5.3.1 says that the Signer's Name field MUST equal | if ((time_check && !check_date_range(curtime, sig_inception, sig_expiration)) || |
the name of the zone containing the RRset. We can't tell that | |
for certain, but we can check that the RRset name is equal to | |
or encloses the signers name, which should be enough to stop | |
an attacker using signatures made with the key of an unrelated | |
zone he controls. Note that the root key is always allowed. */ | |
if (*keyname != 0) | |
{ | |
int failed = 0; | |
| |
for (name_start = name; !hostname_isequal(name_start, keyname); ) | |
if ((name_start = strchr(name_start, '.'))) | |
name_start++; /* chop a label off and try again */ | |
else | |
{ | |
failed = 1; | |
break; | |
} | |
| |
/* Bad sig, try another */ | |
if (failed) | |
continue; | |
} | |
| |
/* Other 5.3.1 checks */ | |
if (!check_date_range(sig_inception, sig_expiration) || | |
labels > name_labels || |
labels > name_labels || |
!(hash = hash_find(algo_digest_name(algo))) || |
!(hash = hash_find(algo_digest_name(algo))) || |
!hash_init(hash, &ctx, &digest)) |
!hash_init(hash, &ctx, &digest)) |
continue; |
continue; |
| |
/* OK, we have the signature record, see if the relevant DNSKEY is in the cache. */ |
/* OK, we have the signature record, see if the relevant DNSKEY is in the cache. */ |
if (!key && !(crecp = cache_find_by_name(NULL, keyname, now, F_DNSKEY))) |
if (!key && !(crecp = cache_find_by_name(NULL, keyname, now, F_DNSKEY))) |
return STAT_NEED_KEY; |
return STAT_NEED_KEY; |
| |
| if (ttl_out) |
| { |
| /* 4035 5.3.3 rules on TTLs */ |
| if (orig_ttl < ttl) |
| ttl = orig_ttl; |
| |
| if (time_check && difftime(sig_expiration, curtime) < ttl) |
| ttl = difftime(sig_expiration, curtime); |
| |
| *ttl_out = ttl; |
| } |
| |
sig = p; |
sig = p; |
sig_len = rdlen - (p - psav); |
sig_len = rdlen - (p - psav); |
|
|
Line 762 static int validate_rrset(time_t now, struct dns_heade
|
Line 605 static int validate_rrset(time_t now, struct dns_heade
|
wire_len = to_wire(keyname); |
wire_len = to_wire(keyname); |
hash->update(ctx, (unsigned int)wire_len, (unsigned char*)keyname); |
hash->update(ctx, (unsigned int)wire_len, (unsigned char*)keyname); |
from_wire(keyname); |
from_wire(keyname); |
|
|
|
#define RRBUFLEN 128 /* Most RRs are smaller than this. */ |
|
|
for (i = 0; i < rrsetidx; ++i) |
for (i = 0; i < rrsetidx; ++i) |
{ |
{ |
int seg; | int j; |
unsigned char *end, *cp; | struct rdata_state state; |
u16 len, *dp; | u16 len; |
| unsigned char rrbuf[RRBUFLEN]; |
|
|
p = rrset[i]; |
p = rrset[i]; |
|
|
if (!extract_name(header, plen, &p, name, 1, 10)) |
if (!extract_name(header, plen, &p, name, 1, 10)) |
return STAT_BOGUS; |
return STAT_BOGUS; |
|
|
Line 778 static int validate_rrset(time_t now, struct dns_heade
|
Line 625 static int validate_rrset(time_t now, struct dns_heade
|
/* if more labels than in RRsig name, hash *.<no labels in rrsig labels field> 4035 5.3.2 */ |
/* if more labels than in RRsig name, hash *.<no labels in rrsig labels field> 4035 5.3.2 */ |
if (labels < name_labels) |
if (labels < name_labels) |
{ |
{ |
int k; | for (j = name_labels - labels; j != 0; j--) |
for (k = name_labels - labels; k != 0; k--) | { |
while (*name_start != '.' && *name_start != 0) | while (*name_start != '.' && *name_start != 0) |
name_start++; | name_start++; |
| if (j != 1 && *name_start == '.') |
| name_start++; |
| } |
| |
| if (wildcard_out) |
| *wildcard_out = name_start+1; |
| |
name_start--; |
name_start--; |
*name_start = '*'; |
*name_start = '*'; |
} |
} |
Line 790 static int validate_rrset(time_t now, struct dns_heade
|
Line 644 static int validate_rrset(time_t now, struct dns_heade
|
hash->update(ctx, (unsigned int)wire_len, (unsigned char *)name_start); |
hash->update(ctx, (unsigned int)wire_len, (unsigned char *)name_start); |
hash->update(ctx, 4, p); /* class and type */ |
hash->update(ctx, 4, p); /* class and type */ |
hash->update(ctx, 4, (unsigned char *)&nsigttl); |
hash->update(ctx, 4, (unsigned char *)&nsigttl); |
| |
p += 8; /* skip class, type, ttl */ | p += 8; /* skip type, class, ttl */ |
GETSHORT(rdlen, p); |
GETSHORT(rdlen, p); |
if (!CHECK_LEN(header, p, plen, rdlen)) |
if (!CHECK_LEN(header, p, plen, rdlen)) |
return STAT_BOGUS; |
return STAT_BOGUS; |
| |
end = p + rdlen; | /* Optimisation for RR types which need no cannonicalisation. |
| This includes DNSKEY DS NSEC and NSEC3, which are also long, so |
/* canonicalise rdata and calculate length of same, use name buffer as workspace */ | it saves lots of calls to get_rdata, and avoids the pessimal |
cp = p; | segmented insertion, even with a small rrbuf[]. |
dp = rr_desc; | |
for (len = 0; (seg = get_rdata(header, plen, end, name, &cp, &dp)) != 0; len += seg); | If canonicalisation is not needed, a simple insertion into the hash works. |
len += end - cp; | */ |
len = htons(len); | if (*rr_desc == (u16)-1) |
hash->update(ctx, 2, (unsigned char *)&len); | { |
| len = htons(rdlen); |
/* Now canonicalise again and digest. */ | hash->update(ctx, 2, (unsigned char *)&len); |
cp = p; | hash->update(ctx, rdlen, p); |
dp = rr_desc; | } |
while ((seg = get_rdata(header, plen, end, name, &cp, &dp))) | else |
hash->update(ctx, seg, (unsigned char *)name); | { |
if (cp != end) | /* canonicalise rdata and calculate length of same, use |
hash->update(ctx, end - cp, cp); | name buffer as workspace for get_rdata. */ |
| state.ip = p; |
| state.op = NULL; |
| state.desc = rr_desc; |
| state.buff = name; |
| state.end = p + rdlen; |
| |
| for (j = 0; get_rdata(header, plen, &state); j++) |
| if (j < RRBUFLEN) |
| rrbuf[j] = *state.op; |
| |
| len = htons((u16)j); |
| hash->update(ctx, 2, (unsigned char *)&len); |
| |
| /* If the RR is shorter than RRBUFLEN (most of them, in practice) |
| then we can just digest it now. If it exceeds RRBUFLEN we have to |
| go back to the start and do it in chunks. */ |
| if (j >= RRBUFLEN) |
| { |
| state.ip = p; |
| state.op = NULL; |
| state.desc = rr_desc; |
| |
| for (j = 0; get_rdata(header, plen, &state); j++) |
| { |
| rrbuf[j] = *state.op; |
| |
| if (j == RRBUFLEN - 1) |
| { |
| hash->update(ctx, RRBUFLEN, rrbuf); |
| j = -1; |
| } |
| } |
| } |
| |
| if (j != 0) |
| hash->update(ctx, j, rrbuf); |
| } |
} |
} |
|
|
hash->digest(ctx, hash->digest_size, digest); |
hash->digest(ctx, hash->digest_size, digest); |
Line 842 static int validate_rrset(time_t now, struct dns_heade
|
Line 733 static int validate_rrset(time_t now, struct dns_heade
|
return STAT_BOGUS; |
return STAT_BOGUS; |
} |
} |
|
|
|
|
/* The DNS packet is expected to contain the answer to a DNSKEY query. |
/* The DNS packet is expected to contain the answer to a DNSKEY query. |
Put all DNSKEYs in the answer which are valid into the cache. |
Put all DNSKEYs in the answer which are valid into the cache. |
return codes: |
return codes: |
STAT_INSECURE No DNSKEYs in reply. | STAT_OK Done, key(s) in cache. |
STAT_SECURE At least one valid DNSKEY found and in cache. | STAT_BOGUS No DNSKEYs found, which can be validated with DS, |
STAT_BOGUS No DNSKEYs found, which can be validated with DS, | or self-sign for DNSKEY RRset is not valid, bad packet. |
or self-sign for DNSKEY RRset is not valid, bad packet. | STAT_NEED_DS DS records to validate a key not found, name in keyname |
STAT_NEED_DS DS records to validate a key not found, name in keyname | STAT_NEED_KEY DNSKEY records to validate a key not found, name in keyname |
*/ |
*/ |
int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) |
int dnssec_validate_by_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) |
{ |
{ |
unsigned char *psave, *p = (unsigned char *)(header+1); |
unsigned char *psave, *p = (unsigned char *)(header+1); |
struct crec *crecp, *recp1; |
struct crec *crecp, *recp1; |
int rc, j, qtype, qclass, ttl, rdlen, flags, algo, valid, keytag, type_covered; | int rc, j, qtype, qclass, rdlen, flags, algo, valid, keytag; |
| unsigned long ttl, sig_ttl; |
struct blockdata *key; |
struct blockdata *key; |
struct all_addr a; | union all_addr a; |
|
|
if (ntohs(header->qdcount) != 1 || |
if (ntohs(header->qdcount) != 1 || |
|
RCODE(header) == SERVFAIL || RCODE(header) == REFUSED || |
!extract_name(header, plen, &p, name, 1, 4)) |
!extract_name(header, plen, &p, name, 1, 4)) |
return STAT_BOGUS; |
return STAT_BOGUS; |
|
|
GETSHORT(qtype, p); |
GETSHORT(qtype, p); |
GETSHORT(qclass, p); |
GETSHORT(qclass, p); |
|
|
if (qtype != T_DNSKEY || qclass != class) | if (qtype != T_DNSKEY || qclass != class || ntohs(header->ancount) == 0) |
return STAT_BOGUS; |
return STAT_BOGUS; |
|
|
if (ntohs(header->ancount) == 0) |
|
return STAT_INSECURE; |
|
|
|
/* See if we have cached a DS record which validates this key */ |
/* See if we have cached a DS record which validates this key */ |
if (!(crecp = cache_find_by_name(NULL, name, now, F_DS))) |
if (!(crecp = cache_find_by_name(NULL, name, now, F_DS))) |
Line 879 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 770 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
return STAT_NEED_DS; |
return STAT_NEED_DS; |
} |
} |
|
|
/* If we've cached that DS provably doesn't exist, result must be INSECURE */ |
|
if (crecp->flags & F_NEG) |
|
return STAT_INSECURE; |
|
|
|
/* NOTE, we need to find ONE DNSKEY which matches the DS */ |
/* NOTE, we need to find ONE DNSKEY which matches the DS */ |
for (valid = 0, j = ntohs(header->ancount); j != 0 && !valid; j--) |
for (valid = 0, j = ntohs(header->ancount); j != 0 && !valid; j--) |
{ |
{ |
Line 935 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 822 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
void *ctx; |
void *ctx; |
unsigned char *digest, *ds_digest; |
unsigned char *digest, *ds_digest; |
const struct nettle_hash *hash; |
const struct nettle_hash *hash; |
| int sigcnt, rrcnt; |
| |
if (recp1->addr.ds.algo == algo && |
if (recp1->addr.ds.algo == algo && |
recp1->addr.ds.keytag == keytag && |
recp1->addr.ds.keytag == keytag && |
recp1->uid == (unsigned int)class && |
recp1->uid == (unsigned int)class && |
Line 953 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 841 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
|
|
from_wire(name); |
from_wire(name); |
|
|
if (recp1->addr.ds.keylen == (int)hash->digest_size && | if (!(recp1->flags & F_NEG) && |
(ds_digest = blockdata_retrieve(recp1->addr.key.keydata, recp1->addr.ds.keylen, NULL)) && | recp1->addr.ds.keylen == (int)hash->digest_size && |
| (ds_digest = blockdata_retrieve(recp1->addr.ds.keydata, recp1->addr.ds.keylen, NULL)) && |
memcmp(ds_digest, digest, recp1->addr.ds.keylen) == 0 && |
memcmp(ds_digest, digest, recp1->addr.ds.keylen) == 0 && |
validate_rrset(now, header, plen, class, T_DNSKEY, name, keyname, key, rdlen - 4, algo, keytag) == STAT_SECURE) | explore_rrset(header, plen, class, T_DNSKEY, name, keyname, &sigcnt, &rrcnt) && |
| sigcnt != 0 && rrcnt != 0 && |
| validate_rrset(now, header, plen, class, T_DNSKEY, sigcnt, rrcnt, name, keyname, |
| NULL, key, rdlen - 4, algo, keytag, &sig_ttl) == STAT_SECURE) |
{ |
{ |
valid = 1; |
valid = 1; |
break; |
break; |
Line 968 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 860 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
|
|
if (valid) |
if (valid) |
{ |
{ |
/* DNSKEY RRset determined to be OK, now cache it and the RRsigs that sign it. */ | /* DNSKEY RRset determined to be OK, now cache it. */ |
cache_start_insert(); |
cache_start_insert(); |
|
|
p = skip_questions(header, plen); |
p = skip_questions(header, plen); |
Line 977 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 869 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
{ |
{ |
/* Ensure we have type, class TTL and length */ |
/* Ensure we have type, class TTL and length */ |
if (!(rc = extract_name(header, plen, &p, name, 0, 10))) |
if (!(rc = extract_name(header, plen, &p, name, 0, 10))) |
return STAT_INSECURE; /* bad packet */ | return STAT_BOGUS; /* bad packet */ |
|
|
GETSHORT(qtype, p); |
GETSHORT(qtype, p); |
GETSHORT(qclass, p); |
GETSHORT(qclass, p); |
GETLONG(ttl, p); |
GETLONG(ttl, p); |
GETSHORT(rdlen, p); |
GETSHORT(rdlen, p); |
|
|
|
/* TTL may be limited by sig. */ |
|
if (sig_ttl < ttl) |
|
ttl = sig_ttl; |
|
|
if (!CHECK_LEN(header, p, plen, rdlen)) |
if (!CHECK_LEN(header, p, plen, rdlen)) |
return STAT_BOGUS; /* bad packet */ |
return STAT_BOGUS; /* bad packet */ |
Line 1002 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 898 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
algo = *p++; |
algo = *p++; |
keytag = dnskey_keytag(algo, flags, p, rdlen - 4); |
keytag = dnskey_keytag(algo, flags, p, rdlen - 4); |
|
|
/* Cache needs to known class for DNSSEC stuff */ |
|
a.addr.dnssec.class = class; |
|
|
|
if ((key = blockdata_alloc((char*)p, rdlen - 4))) |
if ((key = blockdata_alloc((char*)p, rdlen - 4))) |
{ |
{ |
if (!(recp1 = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DNSSECOK))) | a.key.keylen = rdlen - 4; |
blockdata_free(key); | a.key.keydata = key; |
else | a.key.algo = algo; |
| a.key.keytag = keytag; |
| a.key.flags = flags; |
| |
| if (!cache_insert(name, &a, class, now, ttl, F_FORWARD | F_DNSKEY | F_DNSSECOK)) |
{ |
{ |
a.addr.keytag = keytag; | blockdata_free(key); |
log_query(F_KEYTAG | F_UPSTREAM, name, &a, "DNSKEY keytag %u"); | return STAT_BOGUS; |
| |
recp1->addr.key.keylen = rdlen - 4; | |
recp1->addr.key.keydata = key; | |
recp1->addr.key.algo = algo; | |
recp1->addr.key.keytag = keytag; | |
recp1->addr.key.flags = flags; | |
} |
} |
} | else |
} | |
else if (qtype == T_RRSIG) | |
{ | |
/* RRSIG, cache if covers DNSKEY RRset */ | |
if (rdlen < 18) | |
return STAT_BOGUS; /* bad packet */ | |
| |
GETSHORT(type_covered, p); | |
| |
if (type_covered == T_DNSKEY) | |
{ | |
a.addr.dnssec.class = class; | |
a.addr.dnssec.type = type_covered; | |
| |
algo = *p++; | |
p += 13; /* labels, orig_ttl, expiration, inception */ | |
GETSHORT(keytag, p); | |
if ((key = blockdata_alloc((char*)psave, rdlen))) | |
{ |
{ |
if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DS))) | a.log.keytag = keytag; |
blockdata_free(key); | a.log.algo = algo; |
| if (algo_digest_name(algo)) |
| log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DNSKEY keytag %hu, algo %hu"); |
else |
else |
{ | log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DNSKEY keytag %hu, algo %hu (not supported)"); |
crecp->addr.sig.keydata = key; | |
crecp->addr.sig.keylen = rdlen; | |
crecp->addr.sig.keytag = keytag; | |
crecp->addr.sig.type_covered = type_covered; | |
crecp->addr.sig.algo = algo; | |
} | |
} |
} |
} |
} |
} |
} |
| |
p = psave; |
p = psave; |
} |
} |
|
|
Line 1063 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
Line 932 int dnssec_validate_by_ds(time_t now, struct dns_heade
|
|
|
/* commit cache insert. */ |
/* commit cache insert. */ |
cache_end_insert(); |
cache_end_insert(); |
return STAT_SECURE; | return STAT_OK; |
} |
} |
|
|
log_query(F_UPSTREAM, name, NULL, "BOGUS DNSKEY"); | log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, "BOGUS DNSKEY"); |
return STAT_BOGUS; |
return STAT_BOGUS; |
} |
} |
|
|
/* The DNS packet is expected to contain the answer to a DS query |
/* The DNS packet is expected to contain the answer to a DS query |
Put all DSs in the answer which are valid into the cache. |
Put all DSs in the answer which are valid into the cache. |
|
Also handles replies which prove that there's no DS at this location, |
|
either because the zone is unsigned or this isn't a zone cut. These are |
|
cached too. |
return codes: |
return codes: |
STAT_INSECURE no DS in reply or not signed. | STAT_OK At least one valid DS found and in cache. |
STAT_SECURE At least one valid DS found and in cache. | STAT_BOGUS no DS in reply or not signed, fails validation, bad packet. |
STAT_NO_DS It's proved there's no DS here. | STAT_NEED_KEY DNSKEY records to validate a DS not found, name in keyname |
STAT_BOGUS At least one DS found, which fails validation, bad packet. | STAT_NEED_DS DS record needed. |
STAT_NEED_DNSKEY DNSKEY records to validate a DS not found, name in keyname | |
*/ |
*/ |
|
|
int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) |
int dnssec_validate_ds(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int class) |
{ |
{ |
unsigned char *p = (unsigned char *)(header+1); |
unsigned char *p = (unsigned char *)(header+1); |
int qtype, qclass, val, i, neganswer; | int qtype, qclass, rc, i, neganswer, nons, neg_ttl = 0; |
| int aclass, atype, rdlen; |
| unsigned long ttl; |
| union all_addr a; |
|
|
if (ntohs(header->qdcount) != 1 || |
if (ntohs(header->qdcount) != 1 || |
!(p = skip_name(p, header, plen, 4))) |
!(p = skip_name(p, header, plen, 4))) |
Line 1093 int dnssec_validate_ds(time_t now, struct dns_header *
|
Line 967 int dnssec_validate_ds(time_t now, struct dns_header *
|
GETSHORT(qclass, p); |
GETSHORT(qclass, p); |
|
|
if (qtype != T_DS || qclass != class) |
if (qtype != T_DS || qclass != class) |
val = STAT_BOGUS; | rc = STAT_BOGUS; |
else |
else |
val = dnssec_validate_reply(now, header, plen, name, keyname, NULL, &neganswer); | rc = dnssec_validate_reply(now, header, plen, name, keyname, NULL, 0, &neganswer, &nons, &neg_ttl); |
| |
if (val == STAT_NO_SIG) | |
val = STAT_INSECURE; | |
|
|
|
if (rc == STAT_INSECURE) |
|
{ |
|
my_syslog(LOG_WARNING, _("Insecure DS reply received for %s, check domain configuration and upstream DNS server DNSSEC support"), name); |
|
rc = STAT_BOGUS; |
|
} |
|
|
p = (unsigned char *)(header+1); |
p = (unsigned char *)(header+1); |
extract_name(header, plen, &p, name, 1, 4); |
extract_name(header, plen, &p, name, 1, 4); |
p += 4; /* qtype, qclass */ |
p += 4; /* qtype, qclass */ |
|
|
if (!(p = skip_section(p, ntohs(header->ancount), header, plen))) | /* If the key needed to validate the DS is on the same domain as the DS, we'll |
return STAT_BOGUS; | loop getting nowhere. Stop that now. This can happen of the DS answer comes |
| from the DS's zone, and not the parent zone. */ |
| if (rc == STAT_BOGUS || (rc == STAT_NEED_KEY && hostname_isequal(name, keyname))) |
| { |
| log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, "BOGUS DS"); |
| return STAT_BOGUS; |
| } |
|
|
if (val == STAT_BOGUS) | if (rc != STAT_SECURE) |
log_query(F_UPSTREAM, name, NULL, "BOGUS DS"); | return rc; |
| |
if ((val == STAT_SECURE || val == STAT_INSECURE) && neganswer) | if (!neganswer) |
{ |
{ |
int rdlen, flags = F_FORWARD | F_DS | F_NEG; | cache_start_insert(); |
unsigned long ttl, minttl = ULONG_MAX; | |
struct all_addr a; | |
| |
if (RCODE(header) == NXDOMAIN) | |
flags |= F_NXDOMAIN; | |
|
|
if (val == STAT_SECURE) | for (i = 0; i < ntohs(header->ancount); i++) |
flags |= F_DNSSECOK; | |
| |
for (i = ntohs(header->nscount); i != 0; i--) | |
{ |
{ |
if (!(p = skip_name(p, header, plen, 0))) | if (!(rc = extract_name(header, plen, &p, name, 0, 10))) |
return STAT_BOGUS; | return STAT_BOGUS; /* bad packet */ |
|
|
GETSHORT(qtype, p); | GETSHORT(atype, p); |
GETSHORT(qclass, p); | GETSHORT(aclass, p); |
GETLONG(ttl, p); |
GETLONG(ttl, p); |
GETSHORT(rdlen, p); |
GETSHORT(rdlen, p); |
| |
if (!CHECK_LEN(header, p, plen, rdlen)) |
if (!CHECK_LEN(header, p, plen, rdlen)) |
return STAT_BOGUS; /* bad packet */ |
return STAT_BOGUS; /* bad packet */ |
|
|
if (qclass != class || qtype != T_SOA) |
|
{ |
|
p += rdlen; |
|
continue; |
|
} |
|
|
|
if (ttl < minttl) |
|
minttl = ttl; |
|
|
|
/* MNAME */ | if (aclass == class && atype == T_DS && rc == 1) |
if (!(p = skip_name(p, header, plen, 0))) | { |
return STAT_BOGUS; | int algo, digest, keytag; |
/* RNAME */ | unsigned char *psave = p; |
if (!(p = skip_name(p, header, plen, 20))) | struct blockdata *key; |
return STAT_BOGUS; | |
p += 16; /* SERIAL REFRESH RETRY EXPIRE */ | if (rdlen < 4) |
| return STAT_BOGUS; /* bad packet */ |
GETLONG(ttl, p); /* minTTL */ | |
if (ttl < minttl) | GETSHORT(keytag, p); |
minttl = ttl; | algo = *p++; |
| digest = *p++; |
break; | |
| if ((key = blockdata_alloc((char*)p, rdlen - 4))) |
| { |
| a.ds.digest = digest; |
| a.ds.keydata = key; |
| a.ds.algo = algo; |
| a.ds.keytag = keytag; |
| a.ds.keylen = rdlen - 4; |
| |
| if (!cache_insert(name, &a, class, now, ttl, F_FORWARD | F_DS | F_DNSSECOK)) |
| { |
| blockdata_free(key); |
| return STAT_BOGUS; |
| } |
| else |
| { |
| a.log.keytag = keytag; |
| a.log.algo = algo; |
| a.log.digest = digest; |
| if (ds_digest_name(digest) && algo_digest_name(algo)) |
| log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DS keytag %hu, algo %hu, digest %hu"); |
| else |
| log_query(F_NOEXTRA | F_KEYTAG | F_UPSTREAM, name, &a, "DS keytag %hu, algo %hu, digest %hu (not supported)"); |
| } |
| } |
| |
| p = psave; |
| } |
| if (!ADD_RDLEN(header, p, plen, rdlen)) |
| return STAT_BOGUS; /* bad packet */ |
} |
} |
|
|
|
cache_end_insert(); |
|
|
|
} |
|
else |
|
{ |
|
int flags = F_FORWARD | F_DS | F_NEG | F_DNSSECOK; |
|
|
|
if (RCODE(header) == NXDOMAIN) |
|
flags |= F_NXDOMAIN; |
|
|
if (i != 0) | /* We only cache validated DS records, DNSSECOK flag hijacked |
{ | to store presence/absence of NS. */ |
cache_start_insert(); | if (nons) |
| flags &= ~F_DNSSECOK; |
| |
| cache_start_insert(); |
|
|
a.addr.dnssec.class = class; | /* Use TTL from NSEC for negative cache entries */ |
cache_insert(name, &a, now, ttl, flags); | if (!cache_insert(name, NULL, class, now, neg_ttl, flags)) |
| return STAT_BOGUS; |
cache_end_insert(); | |
} | cache_end_insert(); |
| |
return (val == STAT_SECURE) ? STAT_NO_DS : STAT_INSECURE; | log_query(F_NOEXTRA | F_UPSTREAM, name, NULL, nons ? "no DS/cut" : "no DS"); |
} |
} |
| |
return val; | return STAT_OK; |
} |
} |
|
|
|
|
/* 4034 6.1 */ |
/* 4034 6.1 */ |
static int hostname_cmp(const char *a, const char *b) |
static int hostname_cmp(const char *a, const char *b) |
{ |
{ |
Line 1234 static int hostname_cmp(const char *a, const char *b)
|
Line 1143 static int hostname_cmp(const char *a, const char *b)
|
if (sb == b) |
if (sb == b) |
return 1; |
return 1; |
|
|
ea = sa--; | ea = --sa; |
eb = sb--; | eb = --sb; |
} |
} |
} |
} |
|
|
/* Find all the NSEC or NSEC3 records in a reply. | static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsigned char **nsecs, unsigned char **labels, int nsec_count, |
return an array of pointers to them. */ | char *workspace1_in, char *workspace2, char *name, int type, int *nons) |
static int find_nsec_records(struct dns_header *header, size_t plen, unsigned char ***nsecsetp, int *nsecsetl, int class_reqd) | |
{ |
{ |
static unsigned char **nsecset = NULL; |
|
static int nsecset_sz = 0; |
|
|
|
int type_found = 0; |
|
unsigned char *p = skip_questions(header, plen); |
|
int type, class, rdlen, i, nsecs_found; |
|
|
|
/* Move to NS section */ |
|
if (!p || !(p = skip_section(p, ntohs(header->ancount), header, plen))) |
|
return 0; |
|
|
|
for (nsecs_found = 0, i = ntohs(header->nscount); i != 0; i--) |
|
{ |
|
unsigned char *pstart = p; |
|
|
|
if (!(p = skip_name(p, header, plen, 10))) |
|
return 0; |
|
|
|
GETSHORT(type, p); |
|
GETSHORT(class, p); |
|
p += 4; /* TTL */ |
|
GETSHORT(rdlen, p); |
|
|
|
if (class == class_reqd && (type == T_NSEC || type == T_NSEC3)) |
|
{ |
|
/* No mixed NSECing 'round here, thankyouverymuch */ |
|
if (type_found == T_NSEC && type == T_NSEC3) |
|
return 0; |
|
if (type_found == T_NSEC3 && type == T_NSEC) |
|
return 0; |
|
|
|
type_found = type; |
|
|
|
if (!expand_workspace(&nsecset, &nsecset_sz, nsecs_found)) |
|
return 0; |
|
|
|
nsecset[nsecs_found++] = pstart; |
|
} |
|
|
|
if (!ADD_RDLEN(header, p, plen, rdlen)) |
|
return 0; |
|
} |
|
|
|
*nsecsetp = nsecset; |
|
*nsecsetl = nsecs_found; |
|
|
|
return type_found; |
|
} |
|
|
|
static int prove_non_existence_nsec(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count, |
|
char *workspace1, char *workspace2, char *name, int type) |
|
{ |
|
int i, rc, rdlen; |
int i, rc, rdlen; |
unsigned char *p, *psave; |
unsigned char *p, *psave; |
int offset = (type & 0xff) >> 3; |
int offset = (type & 0xff) >> 3; |
int mask = 0x80 >> (type & 0x07); |
int mask = 0x80 >> (type & 0x07); |
|
|
|
if (nons) |
|
*nons = 1; |
|
|
/* Find NSEC record that proves name doesn't exist */ |
/* Find NSEC record that proves name doesn't exist */ |
for (i = 0; i < nsec_count; i++) |
for (i = 0; i < nsec_count; i++) |
{ |
{ |
|
char *workspace1 = workspace1_in; |
|
int sig_labels, name_labels; |
|
|
p = nsecs[i]; |
p = nsecs[i]; |
if (!extract_name(header, plen, &p, workspace1, 1, 10)) |
if (!extract_name(header, plen, &p, workspace1, 1, 10)) |
return STAT_BOGUS; | return 0; |
p += 8; /* class, type, TTL */ |
p += 8; /* class, type, TTL */ |
GETSHORT(rdlen, p); |
GETSHORT(rdlen, p); |
psave = p; |
psave = p; |
if (!extract_name(header, plen, &p, workspace2, 1, 10)) |
if (!extract_name(header, plen, &p, workspace2, 1, 10)) |
return STAT_BOGUS; | return 0; |
| |
| /* If NSEC comes from wildcard expansion, use original wildcard |
| as name for computation. */ |
| sig_labels = *labels[i]; |
| name_labels = count_labels(workspace1); |
| |
| if (sig_labels < name_labels) |
| { |
| int k; |
| for (k = name_labels - sig_labels; k != 0; k--) |
| { |
| while (*workspace1 != '.' && *workspace1 != 0) |
| workspace1++; |
| if (k != 1 && *workspace1 == '.') |
| workspace1++; |
| } |
| |
| workspace1--; |
| *workspace1 = '*'; |
| } |
| |
rc = hostname_cmp(workspace1, name); |
rc = hostname_cmp(workspace1, name); |
|
|
if (rc == 0) |
if (rc == 0) |
{ |
{ |
/* 4035 para 5.4. Last sentence */ |
/* 4035 para 5.4. Last sentence */ |
if (type == T_NSEC || type == T_RRSIG) |
if (type == T_NSEC || type == T_RRSIG) |
return STAT_SECURE; | return 1; |
|
|
/* NSEC with the same name as the RR we're testing, check |
/* NSEC with the same name as the RR we're testing, check |
that the type in question doesn't appear in the type map */ |
that the type in question doesn't appear in the type map */ |
rdlen -= p - psave; |
rdlen -= p - psave; |
/* rdlen is now length of type map, and p points to it */ |
/* rdlen is now length of type map, and p points to it */ |
|
|
|
/* If we can prove that there's no NS record, return that information. */ |
|
if (nons && rdlen >= 2 && p[0] == 0 && (p[2] & (0x80 >> T_NS)) != 0) |
|
*nons = 0; |
|
|
|
if (rdlen >= 2 && p[0] == 0) |
|
{ |
|
/* A CNAME answer would also be valid, so if there's a CNAME is should |
|
have been returned. */ |
|
if ((p[2] & (0x80 >> T_CNAME)) != 0) |
|
return 0; |
|
|
|
/* If the SOA bit is set for a DS record, then we have the |
|
DS from the wrong side of the delegation. For the root DS, |
|
this is expected. */ |
|
if (name_labels != 0 && type == T_DS && (p[2] & (0x80 >> T_SOA)) != 0) |
|
return 0; |
|
} |
|
|
while (rdlen >= 2) |
while (rdlen >= 2) |
{ |
{ |
if (!CHECK_LEN(header, p, plen, rdlen)) |
if (!CHECK_LEN(header, p, plen, rdlen)) |
return STAT_BOGUS; | return 0; |
|
|
if (p[0] == type >> 8) |
if (p[0] == type >> 8) |
{ |
{ |
/* Does the NSEC say our type exists? */ |
/* Does the NSEC say our type exists? */ |
if (offset < p[1] && (p[offset+2] & mask) != 0) |
if (offset < p[1] && (p[offset+2] & mask) != 0) |
return STAT_BOGUS; | return 0; |
|
|
break; /* finshed checking */ | break; /* finished checking */ |
} |
} |
|
|
rdlen -= p[1]; |
rdlen -= p[1]; |
p += p[1]; |
p += p[1]; |
} |
} |
|
|
return STAT_SECURE; | return 1; |
} |
} |
else if (rc == -1) |
else if (rc == -1) |
{ |
{ |
/* Normal case, name falls between NSEC name and next domain name, |
/* Normal case, name falls between NSEC name and next domain name, |
wrap around case, name falls between NSEC name (rc == -1) and end */ |
wrap around case, name falls between NSEC name (rc == -1) and end */ |
if (hostname_cmp(workspace2, name) == 1 || hostname_cmp(workspace1, workspace2) == 1) | if (hostname_cmp(workspace2, name) >= 0 || hostname_cmp(workspace1, workspace2) >= 0) |
return STAT_SECURE; | return 1; |
} |
} |
else |
else |
{ |
{ |
/* wrap around case, name falls between start and next domain name */ |
/* wrap around case, name falls between start and next domain name */ |
if (hostname_cmp(workspace1, workspace2) == 1 && hostname_cmp(workspace2, name) == 1) | if (hostname_cmp(workspace1, workspace2) >= 0 && hostname_cmp(workspace2, name) >=0 ) |
return STAT_SECURE; | return 1; |
} |
} |
} |
} |
|
|
return STAT_BOGUS; | return 0; |
} |
} |
|
|
/* return digest length, or zero on error */ |
/* return digest length, or zero on error */ |
Line 1425 static int base32_decode(char *in, unsigned char *out)
|
Line 1325 static int base32_decode(char *in, unsigned char *out)
|
return p - out; |
return p - out; |
} |
} |
|
|
|
static int check_nsec3_coverage(struct dns_header *header, size_t plen, int digest_len, unsigned char *digest, int type, |
|
char *workspace1, char *workspace2, unsigned char **nsecs, int nsec_count, int *nons, int name_labels) |
|
{ |
|
int i, hash_len, salt_len, base32_len, rdlen, flags; |
|
unsigned char *p, *psave; |
|
|
|
for (i = 0; i < nsec_count; i++) |
|
if ((p = nsecs[i])) |
|
{ |
|
if (!extract_name(header, plen, &p, workspace1, 1, 0) || |
|
!(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) |
|
return 0; |
|
|
|
p += 8; /* class, type, TTL */ |
|
GETSHORT(rdlen, p); |
|
psave = p; |
|
p++; /* algo */ |
|
flags = *p++; /* flags */ |
|
p += 2; /* iterations */ |
|
salt_len = *p++; /* salt_len */ |
|
p += salt_len; /* salt */ |
|
hash_len = *p++; /* p now points to next hashed name */ |
|
|
|
if (!CHECK_LEN(header, p, plen, hash_len)) |
|
return 0; |
|
|
|
if (digest_len == base32_len && hash_len == base32_len) |
|
{ |
|
int rc = memcmp(workspace2, digest, digest_len); |
|
|
|
if (rc == 0) |
|
{ |
|
/* We found an NSEC3 whose hashed name exactly matches the query, so |
|
we just need to check the type map. p points to the RR data for the record. */ |
|
|
|
int offset = (type & 0xff) >> 3; |
|
int mask = 0x80 >> (type & 0x07); |
|
|
|
p += hash_len; /* skip next-domain hash */ |
|
rdlen -= p - psave; |
|
|
|
if (!CHECK_LEN(header, p, plen, rdlen)) |
|
return 0; |
|
|
|
if (rdlen >= 2 && p[0] == 0) |
|
{ |
|
/* If we can prove that there's no NS record, return that information. */ |
|
if (nons && (p[2] & (0x80 >> T_NS)) != 0) |
|
*nons = 0; |
|
|
|
/* A CNAME answer would also be valid, so if there's a CNAME is should |
|
have been returned. */ |
|
if ((p[2] & (0x80 >> T_CNAME)) != 0) |
|
return 0; |
|
|
|
/* If the SOA bit is set for a DS record, then we have the |
|
DS from the wrong side of the delegation. For the root DS, |
|
this is expected. */ |
|
if (name_labels != 0 && type == T_DS && (p[2] & (0x80 >> T_SOA)) != 0) |
|
return 0; |
|
} |
|
|
|
while (rdlen >= 2) |
|
{ |
|
if (p[0] == type >> 8) |
|
{ |
|
/* Does the NSEC3 say our type exists? */ |
|
if (offset < p[1] && (p[offset+2] & mask) != 0) |
|
return 0; |
|
|
|
break; /* finished checking */ |
|
} |
|
|
|
rdlen -= p[1]; |
|
p += p[1]; |
|
} |
|
|
|
return 1; |
|
} |
|
else if (rc < 0) |
|
{ |
|
/* Normal case, hash falls between NSEC3 name-hash and next domain name-hash, |
|
wrap around case, name-hash falls between NSEC3 name-hash and end */ |
|
if (memcmp(p, digest, digest_len) >= 0 || memcmp(workspace2, p, digest_len) >= 0) |
|
{ |
|
if ((flags & 0x01) && nons) /* opt out */ |
|
*nons = 0; |
|
|
|
return 1; |
|
} |
|
} |
|
else |
|
{ |
|
/* wrap around case, name falls between start and next domain name */ |
|
if (memcmp(workspace2, p, digest_len) >= 0 && memcmp(p, digest, digest_len) >= 0) |
|
{ |
|
if ((flags & 0x01) && nons) /* opt out */ |
|
*nons = 0; |
|
|
|
return 1; |
|
} |
|
} |
|
} |
|
} |
|
|
|
return 0; |
|
} |
|
|
static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count, |
static int prove_non_existence_nsec3(struct dns_header *header, size_t plen, unsigned char **nsecs, int nsec_count, |
char *workspace1, char *workspace2, char *name, int type) | char *workspace1, char *workspace2, char *name, int type, char *wildname, int *nons) |
{ |
{ |
unsigned char *salt, *p, *digest; |
unsigned char *salt, *p, *digest; |
int digest_len, i, iterations, salt_len, hash_len, base32_len, algo = 0; | int digest_len, i, iterations, salt_len, base32_len, algo = 0; |
struct nettle_hash const *hash; |
struct nettle_hash const *hash; |
char *closest_encloser, *next_closest, *wildcard; |
char *closest_encloser, *next_closest, *wildcard; |
| |
| if (nons) |
| *nons = 1; |
| |
/* Look though the NSEC3 records to find the first one with |
/* Look though the NSEC3 records to find the first one with |
an algorithm we support (currently only algo == 1). | an algorithm we support. |
|
|
Take the algo, iterations, and salt of that record |
Take the algo, iterations, and salt of that record |
as the ones we're going to use, and prune any |
as the ones we're going to use, and prune any |
Line 1443 static int prove_non_existence_nsec3(struct dns_header
|
Line 1454 static int prove_non_existence_nsec3(struct dns_header
|
for (i = 0; i < nsec_count; i++) |
for (i = 0; i < nsec_count; i++) |
{ |
{ |
if (!(p = skip_name(nsecs[i], header, plen, 15))) |
if (!(p = skip_name(nsecs[i], header, plen, 15))) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
p += 10; /* type, class, TTL, rdlen */ |
p += 10; /* type, class, TTL, rdlen */ |
algo = *p++; |
algo = *p++; |
|
|
if (algo == 1) | if ((hash = hash_find(nsec3_digest_name(algo)))) |
break; /* known algo */ |
break; /* known algo */ |
} |
} |
|
|
/* No usable NSEC3s */ |
/* No usable NSEC3s */ |
if (i == nsec_count) |
if (i == nsec_count) |
return STAT_BOGUS; | return 0; |
|
|
p++; /* flags */ |
p++; /* flags */ |
|
|
GETSHORT (iterations, p); |
GETSHORT (iterations, p); |
|
/* Upper-bound iterations, to avoid DoS. |
|
Strictly, there are lower bounds for small keys, but |
|
since we don't have key size info here, at least limit |
|
to the largest bound, for 4096-bit keys. RFC 5155 10.3 */ |
|
if (iterations > 2500) |
|
return 0; |
|
|
salt_len = *p++; |
salt_len = *p++; |
salt = p; |
salt = p; |
if (!CHECK_LEN(header, salt, plen, salt_len)) |
if (!CHECK_LEN(header, salt, plen, salt_len)) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
/* Now prune so we only have NSEC3 records with same iterations, salt and algo */ |
/* Now prune so we only have NSEC3 records with same iterations, salt and algo */ |
for (i = 0; i < nsec_count; i++) |
for (i = 0; i < nsec_count; i++) |
{ |
{ |
unsigned char *nsec3p = nsecs[i]; |
unsigned char *nsec3p = nsecs[i]; |
int this_iter; | int this_iter, flags; |
|
|
nsecs[i] = NULL; /* Speculative, will be restored if OK. */ |
nsecs[i] = NULL; /* Speculative, will be restored if OK. */ |
|
|
if (!(p = skip_name(nsec3p, header, plen, 15))) |
if (!(p = skip_name(nsec3p, header, plen, 15))) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
p += 10; /* type, class, TTL, rdlen */ |
p += 10; /* type, class, TTL, rdlen */ |
|
|
if (*p++ != algo) |
if (*p++ != algo) |
continue; |
continue; |
|
|
p++; /* flags */ | flags = *p++; /* flags */ |
|
|
|
/* 5155 8.2 */ |
|
if (flags != 0 && flags != 1) |
|
continue; |
|
|
GETSHORT(this_iter, p); |
GETSHORT(this_iter, p); |
if (this_iter != iterations) |
if (this_iter != iterations) |
continue; |
continue; |
Line 1489 static int prove_non_existence_nsec3(struct dns_header
|
Line 1512 static int prove_non_existence_nsec3(struct dns_header
|
continue; |
continue; |
|
|
if (!CHECK_LEN(header, p, plen, salt_len)) |
if (!CHECK_LEN(header, p, plen, salt_len)) |
return STAT_BOGUS; /* bad packet */ | return 0; /* bad packet */ |
|
|
if (memcmp(p, salt, salt_len) != 0) |
if (memcmp(p, salt, salt_len) != 0) |
continue; |
continue; |
Line 1498 static int prove_non_existence_nsec3(struct dns_header
|
Line 1521 static int prove_non_existence_nsec3(struct dns_header
|
nsecs[i] = nsec3p; |
nsecs[i] = nsec3p; |
} |
} |
|
|
/* Algo is checked as 1 above */ | if ((digest_len = hash_name(name, &digest, hash, salt, salt_len, iterations)) == 0) |
if (!(hash = hash_find("sha1"))) | return 0; |
return STAT_BOGUS; | |
| if (check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, nons, count_labels(name))) |
| return 1; |
|
|
/* Now, we need the "closest encloser NSEC3" */ | /* Can't find an NSEC3 which covers the name directly, we need the "closest encloser NSEC3" |
| or an answer inferred from a wildcard record. */ |
closest_encloser = name; |
closest_encloser = name; |
next_closest = NULL; |
next_closest = NULL; |
|
|
Line 1511 static int prove_non_existence_nsec3(struct dns_header
|
Line 1537 static int prove_non_existence_nsec3(struct dns_header
|
if (*closest_encloser == '.') |
if (*closest_encloser == '.') |
closest_encloser++; |
closest_encloser++; |
|
|
|
if (wildname && hostname_isequal(closest_encloser, wildname)) |
|
break; |
|
|
if ((digest_len = hash_name(closest_encloser, &digest, hash, salt, salt_len, iterations)) == 0) |
if ((digest_len = hash_name(closest_encloser, &digest, hash, salt, salt_len, iterations)) == 0) |
return STAT_BOGUS; | return 0; |
|
|
for (i = 0; i < nsec_count; i++) |
for (i = 0; i < nsec_count; i++) |
if ((p = nsecs[i])) |
if ((p = nsecs[i])) |
{ |
{ |
if (!extract_name(header, plen, &p, workspace1, 1, 0) || |
if (!extract_name(header, plen, &p, workspace1, 1, 0) || |
!(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) |
!(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) |
return STAT_BOGUS; | return 0; |
|
|
if (digest_len == base32_len && |
if (digest_len == base32_len && |
memcmp(digest, workspace2, digest_len) == 0) |
memcmp(digest, workspace2, digest_len) == 0) |
Line 1533 static int prove_non_existence_nsec3(struct dns_header
|
Line 1562 static int prove_non_existence_nsec3(struct dns_header
|
} |
} |
while ((closest_encloser = strchr(closest_encloser, '.'))); |
while ((closest_encloser = strchr(closest_encloser, '.'))); |
|
|
/* No usable NSEC3s */ | if (!closest_encloser || !next_closest) |
if (i == nsec_count) | return 0; |
return STAT_BOGUS; | |
|
|
if (!next_closest) | /* Look for NSEC3 that proves the non-existence of the next-closest encloser */ |
| if ((digest_len = hash_name(next_closest, &digest, hash, salt, salt_len, iterations)) == 0) |
| return 0; |
| |
| if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL, 1)) |
| return 0; |
| |
| /* Finally, check that there's no seat of wildcard synthesis */ |
| if (!wildname) |
{ |
{ |
/* We found an NSEC3 whose hashed name exactly matches the query, so | if (!(wildcard = strchr(next_closest, '.')) || wildcard == next_closest) |
Now we just need to check the type map. p points to the RR data for the record. */ | return 0; |
int rdlen; | |
unsigned char *psave; | |
int offset = (type & 0xff) >> 3; | |
int mask = 0x80 >> (type & 0x07); | |
|
|
p += 8; /* class, type, TTL */ | wildcard--; |
GETSHORT(rdlen, p); | *wildcard = '*'; |
psave = p; | |
p += 5 + salt_len; /* algo, flags, iterations, salt_len, salt */ | |
hash_len = *p++; | |
if (!CHECK_LEN(header, p, plen, hash_len)) | |
return STAT_BOGUS; /* bad packet */ | |
p += hash_len; | |
rdlen -= p - psave; | |
|
|
while (rdlen >= 2) | if ((digest_len = hash_name(wildcard, &digest, hash, salt, salt_len, iterations)) == 0) |
| return 0; |
| |
| if (!check_nsec3_coverage(header, plen, digest_len, digest, type, workspace1, workspace2, nsecs, nsec_count, NULL, 1)) |
| return 0; |
| } |
| |
| return 1; |
| } |
| |
| static int prove_non_existence(struct dns_header *header, size_t plen, char *keyname, char *name, int qtype, int qclass, char *wildname, int *nons, int *nsec_ttl) |
| { |
| static unsigned char **nsecset = NULL, **rrsig_labels = NULL; |
| static int nsecset_sz = 0, rrsig_labels_sz = 0; |
| |
| int type_found = 0; |
| unsigned char *auth_start, *p = skip_questions(header, plen); |
| int type, class, rdlen, i, nsecs_found; |
| unsigned long ttl; |
| |
| /* Move to NS section */ |
| if (!p || !(p = skip_section(p, ntohs(header->ancount), header, plen))) |
| return 0; |
| |
| auth_start = p; |
| |
| for (nsecs_found = 0, i = 0; i < ntohs(header->nscount); i++) |
| { |
| unsigned char *pstart = p; |
| |
| if (!extract_name(header, plen, &p, daemon->workspacename, 1, 10)) |
| return 0; |
| |
| GETSHORT(type, p); |
| GETSHORT(class, p); |
| GETLONG(ttl, p); |
| GETSHORT(rdlen, p); |
| |
| if (class == qclass && (type == T_NSEC || type == T_NSEC3)) |
{ |
{ |
if (!CHECK_LEN(header, p, plen, rdlen)) | if (nsec_ttl) |
return STAT_BOGUS; | { |
| /* Limit TTL with sig TTL */ |
| if (daemon->rr_status[ntohs(header->ancount) + i] < ttl) |
| ttl = daemon->rr_status[ntohs(header->ancount) + i]; |
| *nsec_ttl = ttl; |
| } |
|
|
if (p[0] == type >> 8) | /* No mixed NSECing 'round here, thankyouverymuch */ |
| if (type_found != 0 && type_found != type) |
| return 0; |
| |
| type_found = type; |
| |
| if (!expand_workspace(&nsecset, &nsecset_sz, nsecs_found)) |
| return 0; |
| |
| if (type == T_NSEC) |
{ |
{ |
/* Does the NSEC3 say our type exists? */ | /* If we're looking for NSECs, find the corresponding SIGs, to |
if (offset < p[1] && (p[offset+2] & mask) != 0) | extract the labels value, which we need in case the NSECs |
return STAT_BOGUS; | are the result of wildcard expansion. |
| Note that the NSEC may not have been validated yet |
| so if there are multiple SIGs, make sure the label value |
| is the same in all, to avoid be duped by a rogue one. |
| If there are no SIGs, that's an error */ |
| unsigned char *p1 = auth_start; |
| int res, j, rdlen1, type1, class1; |
|
|
break; /* finshed checking */ | if (!expand_workspace(&rrsig_labels, &rrsig_labels_sz, nsecs_found)) |
| return 0; |
| |
| rrsig_labels[nsecs_found] = NULL; |
| |
| for (j = ntohs(header->nscount); j != 0; j--) |
| { |
| if (!(res = extract_name(header, plen, &p1, daemon->workspacename, 0, 10))) |
| return 0; |
| |
| GETSHORT(type1, p1); |
| GETSHORT(class1, p1); |
| p1 += 4; /* TTL */ |
| GETSHORT(rdlen1, p1); |
| |
| if (!CHECK_LEN(header, p1, plen, rdlen1)) |
| return 0; |
| |
| if (res == 1 && class1 == qclass && type1 == T_RRSIG) |
| { |
| int type_covered; |
| unsigned char *psav = p1; |
| |
| if (rdlen1 < 18) |
| return 0; /* bad packet */ |
| |
| GETSHORT(type_covered, p1); |
| |
| if (type_covered == T_NSEC) |
| { |
| p1++; /* algo */ |
| |
| /* labels field must be the same in every SIG we find. */ |
| if (!rrsig_labels[nsecs_found]) |
| rrsig_labels[nsecs_found] = p1; |
| else if (*rrsig_labels[nsecs_found] != *p1) /* algo */ |
| return 0; |
| } |
| p1 = psav; |
| } |
| |
| if (!ADD_RDLEN(header, p1, plen, rdlen1)) |
| return 0; |
| } |
| |
| /* Must have found at least one sig. */ |
| if (!rrsig_labels[nsecs_found]) |
| return 0; |
} |
} |
| |
rdlen -= p[1]; | nsecset[nsecs_found++] = pstart; |
p += p[1]; | |
} |
} |
|
|
return STAT_SECURE; | if (!ADD_RDLEN(header, p, plen, rdlen)) |
| return 0; |
} |
} |
|
|
|
if (type_found == T_NSEC) |
|
return prove_non_existence_nsec(header, plen, nsecset, rrsig_labels, nsecs_found, daemon->workspacename, keyname, name, qtype, nons); |
|
else if (type_found == T_NSEC3) |
|
return prove_non_existence_nsec3(header, plen, nsecset, nsecs_found, daemon->workspacename, keyname, name, qtype, wildname, nons); |
|
else |
|
return 0; |
|
} |
|
|
/* Look for NSEC3 that proves the non-existence of the next-closest encloser */ | /* Check signing status of name. |
if ((digest_len = hash_name(next_closest, &digest, hash, salt, salt_len, iterations)) == 0) | returns: |
return STAT_BOGUS; | STAT_SECURE zone is signed. |
| STAT_INSECURE zone proved unsigned. |
| STAT_NEED_DS require DS record of name returned in keyname. |
| STAT_NEED_KEY require DNSKEY record of name returned in keyname. |
| name returned unaltered. |
| */ |
| static int zone_status(char *name, int class, char *keyname, time_t now) |
| { |
| int name_start = strlen(name); /* for when TA is root */ |
| struct crec *crecp; |
| char *p; |
|
|
for (i = 0; i < nsec_count; i++) | /* First, work towards the root, looking for a trust anchor. |
if ((p = nsecs[i])) | This can either be one configured, or one previously cached. |
{ | We can assume, if we don't find one first, that there is |
if (!extract_name(header, plen, &p, workspace1, 1, 0) || | a trust anchor at the root. */ |
!(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) | for (p = name; p; p = strchr(p, '.')) |
return STAT_BOGUS; | { |
| if (*p == '.') |
p += 15 + salt_len; /* class, type, TTL, rdlen, algo, flags, iterations, salt_len, salt */ | p++; |
hash_len = *p++; /* p now points to next hashed name */ | |
| if (cache_find_by_name(NULL, p, now, F_DS)) |
if (!CHECK_LEN(header, p, plen, hash_len)) | { |
return STAT_BOGUS; | name_start = p - name; |
| break; |
if (digest_len == base32_len && hash_len == base32_len) | } |
{ | } |
if (memcmp(workspace2, digest, digest_len) <= 0) | |
{ | /* Now work away from the trust anchor */ |
/* Normal case, hash falls between NSEC3 name-hash and next domain name-hash, | while (1) |
wrap around case, name-hash falls between NSEC3 name-hash and end */ | { |
if (memcmp(p, digest, digest_len) > 0 || memcmp(workspace2, p, digest_len) > 0) | strcpy(keyname, &name[name_start]); |
return STAT_SECURE; | |
} | if (!(crecp = cache_find_by_name(NULL, keyname, now, F_DS))) |
else | return STAT_NEED_DS; |
{ | |
/* wrap around case, name falls between start and next domain name */ | /* F_DNSSECOK misused in DS cache records to non-existence of NS record. |
if (memcmp(workspace2, p, digest_len) > 0 && memcmp(p, digest, digest_len) > 0) | F_NEG && !F_DNSSECOK implies that we've proved there's no DS record here, |
return STAT_SECURE; | but that's because there's no NS record either, ie this isn't the start |
} | of a zone. We only prove that the DNS tree below a node is unsigned when |
} | we prove that we're at a zone cut AND there's no DS record. */ |
} | if (crecp->flags & F_NEG) |
| { |
/* Finally, check that there's no seat of wildcard synthesis */ | if (crecp->flags & F_DNSSECOK) |
if (!(wildcard = strchr(next_closest, '.')) || wildcard == next_closest) | return STAT_INSECURE; /* proved no DS here */ |
return STAT_BOGUS; | } |
| else |
wildcard--; | { |
*wildcard = '*'; | /* If all the DS records have digest and/or sig algos we don't support, |
| then the zone is insecure. Note that if an algo |
if ((digest_len = hash_name(wildcard, &digest, hash, salt, salt_len, iterations)) == 0) | appears in the DS, then RRSIGs for that algo MUST |
return STAT_BOGUS; | exist for each RRset: 4035 para 2.2 So if we find |
| a DS here with digest and sig we can do, we're entitled |
for (i = 0; i < nsec_count; i++) | to assume we can validate the zone and if we can't later, |
if ((p = nsecs[i])) | because an RRSIG is missing we return BOGUS. |
{ | */ |
if (!extract_name(header, plen, &p, workspace1, 1, 0) || | do |
!(base32_len = base32_decode(workspace1, (unsigned char *)workspace2))) | { |
return STAT_BOGUS; | if (crecp->uid == (unsigned int)class && |
| ds_digest_name(crecp->addr.ds.digest) && |
p += 15 + salt_len; /* class, type, TTL, rdlen, algo, flags, iterations, salt_len, salt */ | algo_digest_name(crecp->addr.ds.algo)) |
hash_len = *p++; /* p now points to next hashed name */ | break; |
| } |
if (!CHECK_LEN(header, p, plen, hash_len)) | while ((crecp = cache_find_by_name(crecp, keyname, now, F_DS))); |
return STAT_BOGUS; | |
| if (!crecp) |
if (digest_len == base32_len && hash_len == base32_len) | return STAT_INSECURE; |
{ | } |
if (memcmp(workspace2, digest, digest_len) <= 0) | |
{ | if (name_start == 0) |
/* Normal case, hash falls between NSEC3 name-hash and next domain name-hash, | break; |
wrap around case, name-hash falls between NSEC3 name-hash and end */ | |
if (memcmp(p, digest, digest_len) > 0 || memcmp(workspace2, p, digest_len) > 0) | for (p = &name[name_start-2]; (*p != '.') && (p != name); p--); |
return STAT_SECURE; | |
} | if (p != name) |
else | p++; |
{ | |
/* wrap around case, name falls between start and next domain name */ | name_start = p - name; |
if (memcmp(workspace2, p, digest_len) > 0 && memcmp(p, digest, digest_len) > 0) | } |
return STAT_SECURE; | |
} | return STAT_SECURE; |
} | |
} | |
| |
return STAT_BOGUS; | |
} |
} |
| |
/* Validate all the RRsets in the answer and authority sections of the reply (4035:3.2.3) */ | /* Validate all the RRsets in the answer and authority sections of the reply (4035:3.2.3) |
/* Returns are the same as validate_rrset, plus the class if the missing key is in *class */ | Return code: |
int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, int *class, int *neganswer) | STAT_SECURE if it validates. |
| STAT_INSECURE at least one RRset not validated, because in unsigned zone. |
| STAT_BOGUS signature is wrong, bad packet, no validation where there should be. |
| STAT_NEED_KEY need DNSKEY to complete validation (name is returned in keyname, class in *class) |
| STAT_NEED_DS need DS to complete validation (name is returned in keyname) |
| |
| daemon->rr_status points to a char array which corressponds to the RRs in the |
| answer and auth sections. This is set to 1 for each RR which is validated, and 0 for any which aren't. |
| |
| When validating replies to DS records, we're only interested in the NSEC{3} RRs in the auth section. |
| Other RRs in that section missing sigs will not cause am INSECURE reply. We determine this mode |
| is the nons argument is non-NULL. |
| */ |
| int dnssec_validate_reply(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname, |
| int *class, int check_unsigned, int *neganswer, int *nons, int *nsec_ttl) |
{ |
{ |
unsigned char *ans_start, *qname, *p1, *p2, **nsecs; | static unsigned char **targets = NULL; |
int type1, class1, rdlen1, type2, class2, rdlen2, qclass, qtype; | static int target_sz = 0; |
int i, j, rc, nsec_count, cname_count = CNAME_CHAIN; | |
int nsec_type = 0, have_answer = 0; | |
|
|
|
unsigned char *ans_start, *p1, *p2; |
|
int type1, class1, rdlen1 = 0, type2, class2, rdlen2, qclass, qtype, targetidx; |
|
int i, j, rc = STAT_INSECURE; |
|
int secure = STAT_SECURE; |
|
|
|
/* extend rr_status if necessary */ |
|
if (daemon->rr_status_sz < ntohs(header->ancount) + ntohs(header->nscount)) |
|
{ |
|
unsigned long *new = whine_malloc(sizeof(*daemon->rr_status) * (ntohs(header->ancount) + ntohs(header->nscount) + 64)); |
|
|
|
if (!new) |
|
return STAT_BOGUS; |
|
|
|
free(daemon->rr_status); |
|
daemon->rr_status = new; |
|
daemon->rr_status_sz = ntohs(header->ancount) + ntohs(header->nscount) + 64; |
|
} |
|
|
|
memset(daemon->rr_status, 0, sizeof(*daemon->rr_status) * daemon->rr_status_sz); |
|
|
if (neganswer) |
if (neganswer) |
*neganswer = 0; |
*neganswer = 0; |
|
|
Line 1674 int dnssec_validate_reply(time_t now, struct dns_heade
|
Line 1850 int dnssec_validate_reply(time_t now, struct dns_heade
|
if (RCODE(header) != NXDOMAIN && RCODE(header) != NOERROR) |
if (RCODE(header) != NXDOMAIN && RCODE(header) != NOERROR) |
return STAT_INSECURE; |
return STAT_INSECURE; |
|
|
qname = p1 = (unsigned char *)(header+1); | p1 = (unsigned char *)(header+1); |
|
|
|
/* Find all the targets we're looking for answers to. |
|
The zeroth array element is for the query, subsequent ones |
|
for CNAME targets, unless the query is for a CNAME. */ |
|
|
|
if (!expand_workspace(&targets, &target_sz, 0)) |
|
return STAT_BOGUS; |
|
|
|
targets[0] = p1; |
|
targetidx = 1; |
|
|
if (!extract_name(header, plen, &p1, name, 1, 4)) |
if (!extract_name(header, plen, &p1, name, 1, 4)) |
return STAT_BOGUS; |
return STAT_BOGUS; |
| |
GETSHORT(qtype, p1); |
GETSHORT(qtype, p1); |
GETSHORT(qclass, p1); |
GETSHORT(qclass, p1); |
ans_start = p1; |
ans_start = p1; |
|
|
if (qtype == T_ANY) |
|
have_answer = 1; |
|
|
|
/* Can't validate an RRISG query */ | /* Can't validate an RRSIG query */ |
if (qtype == T_RRSIG) |
if (qtype == T_RRSIG) |
return STAT_INSECURE; |
return STAT_INSECURE; |
|
|
cname_loop: |
|
for (j = ntohs(header->ancount); j != 0; j--) |
|
{ |
|
/* leave pointer to missing name in qname */ |
|
|
|
if (!(rc = extract_name(header, plen, &p1, name, 0, 10))) |
|
return STAT_BOGUS; /* bad packet */ |
|
|
|
GETSHORT(type2, p1); |
|
GETSHORT(class2, p1); |
|
p1 += 4; /* TTL */ |
|
GETSHORT(rdlen2, p1); |
|
|
|
if (rc == 1 && qclass == class2) |
|
{ |
|
/* Do we have an answer for the question? */ |
|
if (type2 == qtype) |
|
{ |
|
have_answer = 1; |
|
break; |
|
} |
|
else if (type2 == T_CNAME) |
|
{ |
|
qname = p1; |
|
|
|
/* looped CNAMES */ |
|
if (!cname_count-- || !extract_name(header, plen, &p1, name, 1, 0)) |
|
return STAT_BOGUS; |
|
|
|
p1 = ans_start; |
|
goto cname_loop; |
|
} |
|
} |
|
|
|
if (!ADD_RDLEN(header, p1, plen, rdlen2)) |
|
return STAT_BOGUS; |
|
} |
|
|
|
if (neganswer && !have_answer) |
|
*neganswer = 1; |
|
|
|
/* No data, therefore no sigs */ |
|
if (ntohs(header->ancount) + ntohs(header->nscount) == 0) |
|
return STAT_NO_SIG; |
|
|
|
|
if (qtype != T_CNAME) |
|
for (j = ntohs(header->ancount); j != 0; j--) |
|
{ |
|
if (!(p1 = skip_name(p1, header, plen, 10))) |
|
return STAT_BOGUS; /* bad packet */ |
|
|
|
GETSHORT(type2, p1); |
|
p1 += 6; /* class, TTL */ |
|
GETSHORT(rdlen2, p1); |
|
|
|
if (type2 == T_CNAME) |
|
{ |
|
if (!expand_workspace(&targets, &target_sz, targetidx)) |
|
return STAT_BOGUS; |
|
|
|
targets[targetidx++] = p1; /* pointer to target name */ |
|
} |
|
|
|
if (!ADD_RDLEN(header, p1, plen, rdlen2)) |
|
return STAT_BOGUS; |
|
} |
|
|
for (p1 = ans_start, i = 0; i < ntohs(header->ancount) + ntohs(header->nscount); i++) |
for (p1 = ans_start, i = 0; i < ntohs(header->ancount) + ntohs(header->nscount); i++) |
{ |
{ |
|
if (i != 0 && !ADD_RDLEN(header, p1, plen, rdlen1)) |
|
return STAT_BOGUS; |
|
|
if (!extract_name(header, plen, &p1, name, 1, 10)) |
if (!extract_name(header, plen, &p1, name, 1, 10)) |
return STAT_BOGUS; /* bad packet */ |
return STAT_BOGUS; /* bad packet */ |
|
|
Line 1746 int dnssec_validate_reply(time_t now, struct dns_heade
|
Line 1909 int dnssec_validate_reply(time_t now, struct dns_heade
|
GETSHORT(rdlen1, p1); |
GETSHORT(rdlen1, p1); |
|
|
/* Don't try and validate RRSIGs! */ |
/* Don't try and validate RRSIGs! */ |
if (type1 != T_RRSIG) | if (type1 == T_RRSIG) |
| continue; |
| |
| /* Check if we've done this RRset already */ |
| for (p2 = ans_start, j = 0; j < i; j++) |
{ |
{ |
/* Check if we've done this RRset already */ | if (!(rc = extract_name(header, plen, &p2, name, 0, 10))) |
for (p2 = ans_start, j = 0; j < i; j++) | return STAT_BOGUS; /* bad packet */ |
{ | |
if (!(rc = extract_name(header, plen, &p2, name, 0, 10))) | |
return STAT_BOGUS; /* bad packet */ | |
| |
GETSHORT(type2, p2); | |
GETSHORT(class2, p2); | |
p2 += 4; /* TTL */ | |
GETSHORT(rdlen2, p2); | |
| |
if (type2 == type1 && class2 == class1 && rc == 1) | |
break; /* Done it before: name, type, class all match. */ | |
| |
if (!ADD_RDLEN(header, p2, plen, rdlen2)) | |
return STAT_BOGUS; | |
} | |
|
|
|
GETSHORT(type2, p2); |
|
GETSHORT(class2, p2); |
|
p2 += 4; /* TTL */ |
|
GETSHORT(rdlen2, p2); |
|
|
|
if (type2 == type1 && class2 == class1 && rc == 1) |
|
break; /* Done it before: name, type, class all match. */ |
|
|
|
if (!ADD_RDLEN(header, p2, plen, rdlen2)) |
|
return STAT_BOGUS; |
|
} |
|
|
|
/* Done already: copy the validation status */ |
|
if (j != i) |
|
daemon->rr_status[i] = daemon->rr_status[j]; |
|
else |
|
{ |
/* Not done, validate now */ |
/* Not done, validate now */ |
if (j == i) | int sigcnt, rrcnt; |
| char *wildname; |
| |
| if (!explore_rrset(header, plen, class1, type1, name, keyname, &sigcnt, &rrcnt)) |
| return STAT_BOGUS; |
| |
| /* No signatures for RRset. We can be configured to assume this is OK and return an INSECURE result. */ |
| if (sigcnt == 0) |
{ |
{ |
int ttl, keytag, algo, digest, type_covered; | /* NSEC and NSEC3 records must be signed. We make this assumption elsewhere. */ |
unsigned char *psave; | if (type1 == T_NSEC || type1 == T_NSEC3) |
struct all_addr a; | rc = STAT_INSECURE; |
struct blockdata *key; | else if (nons && i >= ntohs(header->ancount)) |
struct crec *crecp; | /* If we're validating a DS reply, rather than looking for the value of AD bit, |
| we only care that NSEC and NSEC3 RRs in the auth section are signed. |
rc = validate_rrset(now, header, plen, class1, type1, name, keyname, NULL, 0, 0, 0); | Return SECURE even if others (SOA....) are not. */ |
| rc = STAT_SECURE; |
if (rc == STAT_SECURE_WILDCARD) | else |
{ |
{ |
/* An attacker replay a wildcard answer with a different | /* unsigned RRsets in auth section are not BOGUS, but do make reply insecure. */ |
answer and overlay a genuine RR. To prove this | if (check_unsigned && i < ntohs(header->ancount)) |
hasn't happened, the answer must prove that | { |
the gennuine record doesn't exist. Check that here. */ | rc = zone_status(name, class1, keyname, now); |
if (!nsec_type && !(nsec_type = find_nsec_records(header, plen, &nsecs, &nsec_count, class1))) | if (rc == STAT_SECURE) |
return STAT_BOGUS; /* No NSECs or bad packet */ | rc = STAT_BOGUS; |
| if (class) |
| *class = class1; /* Class for NEED_DS or NEED_KEY */ |
| } |
| else |
| rc = STAT_INSECURE; |
|
|
if (nsec_type == T_NSEC) | if (rc != STAT_INSECURE) |
rc = prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1); | |
else | |
rc = prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, type1); | |
| |
if (rc != STAT_SECURE) | |
return rc; |
return rc; |
} | } |
else if (rc != STAT_SECURE) | } |
| else |
| { |
| /* explore_rrset() gives us key name from sigs in keyname. |
| Can't overwrite name here. */ |
| strcpy(daemon->workspacename, keyname); |
| rc = zone_status(daemon->workspacename, class1, keyname, now); |
| |
| if (rc == STAT_BOGUS || rc == STAT_NEED_KEY || rc == STAT_NEED_DS) |
{ |
{ |
if (class) |
if (class) |
*class = class1; /* Class for DS or DNSKEY */ | *class = class1; /* Class for NEED_DS or NEED_KEY */ |
return rc; |
return rc; |
} |
} |
|
|
/* Cache RRsigs in answer section, and if we just validated a DS RRset, cache it */ | /* Zone is insecure, don't need to validate RRset */ |
cache_start_insert(); | if (rc == STAT_SECURE) |
| |
for (p2 = ans_start, j = 0; j < ntohs(header->ancount); j++) | |
{ |
{ |
if (!(rc = extract_name(header, plen, &p2, name, 0, 10))) | unsigned long sig_ttl; |
return STAT_BOGUS; /* bad packet */ | rc = validate_rrset(now, header, plen, class1, type1, sigcnt, |
| rrcnt, name, keyname, &wildname, NULL, 0, 0, 0, &sig_ttl); |
GETSHORT(type2, p2); | |
GETSHORT(class2, p2); | |
GETLONG(ttl, p2); | |
GETSHORT(rdlen2, p2); | |
| |
if (!CHECK_LEN(header, p2, plen, rdlen2)) | |
return STAT_BOGUS; /* bad packet */ | |
|
|
if (class2 == class1 && rc == 1) | if (rc == STAT_BOGUS || rc == STAT_NEED_KEY || rc == STAT_NEED_DS) |
{ | { |
psave = p2; | if (class) |
| *class = class1; /* Class for DS or DNSKEY */ |
if (type1 == T_DS && type2 == T_DS) | return rc; |
{ | } |
if (rdlen2 < 4) | |
return STAT_BOGUS; /* bad packet */ | |
| |
GETSHORT(keytag, p2); | |
algo = *p2++; | |
digest = *p2++; | |
| |
/* Cache needs to known class for DNSSEC stuff */ | |
a.addr.dnssec.class = class2; | |
| |
if ((key = blockdata_alloc((char*)p2, rdlen2 - 4))) | |
{ | |
if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DS | F_DNSSECOK))) | |
blockdata_free(key); | |
else | |
{ | |
a.addr.keytag = keytag; | |
log_query(F_KEYTAG | F_UPSTREAM, name, &a, "DS keytag %u"); | |
crecp->addr.ds.digest = digest; | |
crecp->addr.ds.keydata = key; | |
crecp->addr.ds.algo = algo; | |
crecp->addr.ds.keytag = keytag; | |
crecp->addr.ds.keylen = rdlen2 - 4; | |
} | |
} | |
} | |
else if (type2 == T_RRSIG) | |
{ | |
if (rdlen2 < 18) | |
return STAT_BOGUS; /* bad packet */ | |
| |
GETSHORT(type_covered, p2); | |
| |
if (type_covered == type1 && | |
(type_covered == T_A || type_covered == T_AAAA || | |
type_covered == T_CNAME || type_covered == T_DS || | |
type_covered == T_DNSKEY || type_covered == T_PTR)) | |
{ | |
a.addr.dnssec.type = type_covered; | |
a.addr.dnssec.class = class1; | |
| |
algo = *p2++; | |
p2 += 13; /* labels, orig_ttl, expiration, inception */ | |
GETSHORT(keytag, p2); | |
| |
if ((key = blockdata_alloc((char*)psave, rdlen2))) | |
{ | |
if (!(crecp = cache_insert(name, &a, now, ttl, F_FORWARD | F_DNSKEY | F_DS))) | |
blockdata_free(key); | |
else | |
{ | |
crecp->addr.sig.keydata = key; | |
crecp->addr.sig.keylen = rdlen2; | |
crecp->addr.sig.keytag = keytag; | |
crecp->addr.sig.type_covered = type_covered; | |
crecp->addr.sig.algo = algo; | |
} | |
} | |
} | |
} | |
| |
p2 = psave; | |
} | |
|
|
if (!ADD_RDLEN(header, p2, plen, rdlen2)) | /* rc is now STAT_SECURE or STAT_SECURE_WILDCARD */ |
return STAT_BOGUS; /* bad packet */ | |
} | |
|
|
cache_end_insert(); | /* Note that RR is validated */ |
| daemon->rr_status[i] = sig_ttl; |
| |
| /* Note if we've validated either the answer to the question |
| or the target of a CNAME. Any not noted will need NSEC or |
| to be in unsigned space. */ |
| for (j = 0; j <targetidx; j++) |
| if ((p2 = targets[j])) |
| { |
| int rc1; |
| if (!(rc1 = extract_name(header, plen, &p2, name, 0, 10))) |
| return STAT_BOGUS; /* bad packet */ |
| |
| if (class1 == qclass && rc1 == 1 && (type1 == T_CNAME || type1 == qtype || qtype == T_ANY )) |
| targets[j] = NULL; |
| } |
| |
| /* An attacker replay a wildcard answer with a different |
| answer and overlay a genuine RR. To prove this |
| hasn't happened, the answer must prove that |
| the genuine record doesn't exist. Check that here. |
| Note that we may not yet have validated the NSEC/NSEC3 RRsets. |
| That's not a problem since if the RRsets later fail |
| we'll return BOGUS then. */ |
| if (rc == STAT_SECURE_WILDCARD && |
| !prove_non_existence(header, plen, keyname, name, type1, class1, wildname, NULL, NULL)) |
| return STAT_BOGUS; |
| |
| rc = STAT_SECURE; |
| } |
} |
} |
} |
} |
|
|
if (!ADD_RDLEN(header, p1, plen, rdlen1)) | if (rc == STAT_INSECURE) |
return STAT_BOGUS; | secure = STAT_INSECURE; |
} |
} |
|
|
/* OK, all the RRsets validate, now see if we have a NODATA or NXDOMAIN reply */ | /* OK, all the RRsets validate, now see if we have a missing answer or CNAME target. */ |
if (have_answer) | if (secure == STAT_SECURE) |
return STAT_SECURE; | for (j = 0; j <targetidx; j++) |
| if ((p2 = targets[j])) |
/* NXDOMAIN or NODATA reply, prove that (name, class1, type1) can't exist */ | |
/* First marshall the NSEC records, if we've not done it previously */ | |
if (!nsec_type && !(nsec_type = find_nsec_records(header, plen, &nsecs, &nsec_count, qclass))) | |
return STAT_BOGUS; /* No NSECs */ | |
| |
/* Get name of missing answer */ | |
if (!extract_name(header, plen, &qname, name, 1, 0)) | |
return STAT_BOGUS; | |
| |
if (nsec_type == T_NSEC) | |
return prove_non_existence_nsec(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype); | |
else | |
return prove_non_existence_nsec3(header, plen, nsecs, nsec_count, daemon->workspacename, keyname, name, qtype); | |
} | |
| |
/* Chase the CNAME chain in the packet until the first record which _doesn't validate. | |
Needed for proving answer in unsigned space. | |
Return STAT_NEED_* | |
STAT_BOGUS - error | |
STAT_INSECURE - name of first non-secure record in name | |
*/ | |
int dnssec_chase_cname(time_t now, struct dns_header *header, size_t plen, char *name, char *keyname) | |
{ | |
unsigned char *p = (unsigned char *)(header+1); | |
int type, class, qclass, rdlen, j, rc; | |
int cname_count = CNAME_CHAIN; | |
| |
/* Get question */ | |
if (!extract_name(header, plen, &p, name, 1, 4)) | |
return STAT_BOGUS; | |
| |
p +=2; /* type */ | |
GETSHORT(qclass, p); | |
| |
while (1) | |
{ | |
for (j = ntohs(header->ancount); j != 0; j--) | |
{ |
{ |
if (!(rc = extract_name(header, plen, &p, name, 0, 10))) | if (neganswer) |
| *neganswer = 1; |
| |
| if (!extract_name(header, plen, &p2, name, 1, 10)) |
return STAT_BOGUS; /* bad packet */ |
return STAT_BOGUS; /* bad packet */ |
|
|
GETSHORT(type, p); | /* NXDOMAIN or NODATA reply, unanswered question is (name, qclass, qtype) */ |
GETSHORT(class, p); | |
p += 4; /* TTL */ | /* For anything other than a DS record, this situation is OK if either |
GETSHORT(rdlen, p); | the answer is in an unsigned zone, or there's a NSEC records. */ |
| if (!prove_non_existence(header, plen, keyname, name, qtype, qclass, NULL, nons, nsec_ttl)) |
/* Not target, loop */ | |
if (rc == 2 || qclass != class) | |
{ |
{ |
if (!ADD_RDLEN(header, p, plen, rdlen)) | /* Empty DS without NSECS */ |
| if (qtype == T_DS) |
return STAT_BOGUS; |
return STAT_BOGUS; |
continue; | |
| if ((rc = zone_status(name, qclass, keyname, now)) != STAT_SECURE) |
| { |
| if (class) |
| *class = qclass; /* Class for NEED_DS or NEED_KEY */ |
| return rc; |
| } |
| |
| return STAT_BOGUS; /* signed zone, no NSECs */ |
} |
} |
|
|
/* Got to end of CNAME chain. */ |
|
if (type != T_CNAME) |
|
return STAT_INSECURE; |
|
|
|
/* validate CNAME chain, return if insecure or need more data */ |
|
rc = validate_rrset(now, header, plen, class, type, name, keyname, NULL, 0, 0, 0); |
|
if (rc != STAT_SECURE) |
|
{ |
|
if (rc == STAT_NO_SIG) |
|
rc = STAT_INSECURE; |
|
return rc; |
|
} |
|
|
|
/* Loop down CNAME chain/ */ |
|
if (!cname_count-- || |
|
!extract_name(header, plen, &p, name, 1, 0) || |
|
!(p = skip_questions(header, plen))) |
|
return STAT_BOGUS; |
|
|
|
break; |
|
} |
} |
| |
/* End of CNAME chain */ | return secure; |
return STAT_INSECURE; | |
} | |
} |
} |
|
|
|
|
Line 2007 int dnskey_keytag(int alg, int flags, unsigned char *k
|
Line 2096 int dnskey_keytag(int alg, int flags, unsigned char *k
|
} |
} |
} |
} |
|
|
size_t dnssec_generate_query(struct dns_header *header, char *end, char *name, int class, int type, union mysockaddr *addr) | size_t dnssec_generate_query(struct dns_header *header, unsigned char *end, char *name, int class, |
| int type, int edns_pktsz) |
{ |
{ |
unsigned char *p; |
unsigned char *p; |
char *types = querystr("dnssec-query", type); | size_t ret; |
|
|
if (addr->sa.sa_family == AF_INET) |
|
log_query(F_DNSSEC | F_IPV4, name, (struct all_addr *)&addr->in.sin_addr, types); |
|
#ifdef HAVE_IPV6 |
|
else |
|
log_query(F_DNSSEC | F_IPV6, name, (struct all_addr *)&addr->in6.sin6_addr, types); |
|
#endif |
|
|
|
header->qdcount = htons(1); |
header->qdcount = htons(1); |
header->ancount = htons(0); |
header->ancount = htons(0); |
header->nscount = htons(0); |
header->nscount = htons(0); |
Line 2034 size_t dnssec_generate_query(struct dns_header *header
|
Line 2117 size_t dnssec_generate_query(struct dns_header *header
|
|
|
p = (unsigned char *)(header+1); |
p = (unsigned char *)(header+1); |
|
|
p = do_rfc1035_name(p, name); | p = do_rfc1035_name(p, name, NULL); |
*p++ = 0; |
*p++ = 0; |
PUTSHORT(type, p); |
PUTSHORT(type, p); |
PUTSHORT(class, p); |
PUTSHORT(class, p); |
|
|
return add_do_bit(header, p - (unsigned char *)header, end); | ret = add_do_bit(header, p - (unsigned char *)header, end); |
} | |
|
|
/* Go through a domain name, find "pointers" and fix them up based on how many bytes | if (find_pseudoheader(header, ret, NULL, &p, NULL, NULL)) |
we've chopped out of the packet, or check they don't point into an elided part. */ | PUTSHORT(edns_pktsz, p); |
static int check_name(unsigned char **namep, struct dns_header *header, size_t plen, int fixup, unsigned char **rrs, int rr_count) | |
{ | |
unsigned char *ansp = *namep; | |
|
|
while(1) | return ret; |
{ | |
unsigned int label_type; | |
| |
if (!CHECK_LEN(header, ansp, plen, 1)) | |
return 0; | |
| |
label_type = (*ansp) & 0xc0; | |
| |
if (label_type == 0xc0) | |
{ | |
/* pointer for compression. */ | |
unsigned int offset; | |
int i; | |
unsigned char *p; | |
| |
if (!CHECK_LEN(header, ansp, plen, 2)) | |
return 0; | |
| |
offset = ((*ansp++) & 0x3f) << 8; | |
offset |= *ansp++; | |
| |
p = offset + (unsigned char *)header; | |
| |
for (i = 0; i < rr_count; i++) | |
if (p < rrs[i]) | |
break; | |
else | |
if (i & 1) | |
offset -= rrs[i] - rrs[i-1]; | |
| |
/* does the pointer end up in an elided RR? */ | |
if (i & 1) | |
return 0; | |
| |
/* No, scale the pointer */ | |
if (fixup) | |
{ | |
ansp -= 2; | |
*ansp++ = (offset >> 8) | 0xc0; | |
*ansp++ = offset & 0xff; | |
} | |
break; | |
} | |
else if (label_type == 0x80) | |
return 0; /* reserved */ | |
else if (label_type == 0x40) | |
{ | |
/* Extended label type */ | |
unsigned int count; | |
| |
if (!CHECK_LEN(header, ansp, plen, 2)) | |
return 0; | |
| |
if (((*ansp++) & 0x3f) != 1) | |
return 0; /* we only understand bitstrings */ | |
| |
count = *(ansp++); /* Bits in bitstring */ | |
| |
if (count == 0) /* count == 0 means 256 bits */ | |
ansp += 32; | |
else | |
ansp += ((count-1)>>3)+1; | |
} | |
else | |
{ /* label type == 0 Bottom six bits is length */ | |
unsigned int len = (*ansp++) & 0x3f; | |
| |
if (!ADD_RDLEN(header, ansp, plen, len)) | |
return 0; | |
| |
if (len == 0) | |
break; /* zero length label marks the end. */ | |
} | |
} | |
| |
*namep = ansp; | |
| |
return 1; | |
} | |
| |
/* Go through RRs and check or fixup the domain names contained within */ | |
static int check_rrs(unsigned char *p, struct dns_header *header, size_t plen, int fixup, unsigned char **rrs, int rr_count) | |
{ | |
int i, type, class, rdlen; | |
unsigned char *pp; | |
| |
for (i = 0; i < ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount); i++) | |
{ | |
pp = p; | |
| |
if (!(p = skip_name(p, header, plen, 10))) | |
return 0; | |
| |
GETSHORT(type, p); | |
GETSHORT(class, p); | |
p += 4; /* TTL */ | |
GETSHORT(rdlen, p); | |
| |
if (type != T_NSEC && type != T_NSEC3 && type != T_RRSIG) | |
{ | |
/* fixup name of RR */ | |
if (!check_name(&pp, header, plen, fixup, rrs, rr_count)) | |
return 0; | |
| |
if (class == C_IN) | |
{ | |
u16 *d; | |
| |
for (pp = p, d = get_desc(type); *d != (u16)-1; d++) | |
{ | |
if (*d != 0) | |
pp += *d; | |
else if (!check_name(&pp, header, plen, fixup, rrs, rr_count)) | |
return 0; | |
} | |
} | |
} | |
| |
if (!ADD_RDLEN(header, p, plen, rdlen)) | |
return 0; | |
} | |
| |
return 1; | |
} | |
| |
| |
size_t filter_rrsigs(struct dns_header *header, size_t plen) | |
{ | |
static unsigned char **rrs; | |
static int rr_sz = 0; | |
| |
unsigned char *p = (unsigned char *)(header+1); | |
int i, rdlen, qtype, qclass, rr_found, chop_an, chop_ns, chop_ar; | |
| |
if (ntohs(header->qdcount) != 1 || | |
!(p = skip_name(p, header, plen, 4))) | |
return plen; | |
| |
GETSHORT(qtype, p); | |
GETSHORT(qclass, p); | |
| |
/* First pass, find pointers to start and end of all the records we wish to elide: | |
records added for DNSSEC, unless explicity queried for */ | |
for (rr_found = 0, chop_ns = 0, chop_an = 0, chop_ar = 0, i = 0; | |
i < ntohs(header->ancount) + ntohs(header->nscount) + ntohs(header->arcount); | |
i++) | |
{ | |
unsigned char *pstart = p; | |
int type, class; | |
| |
if (!(p = skip_name(p, header, plen, 10))) | |
return plen; | |
| |
GETSHORT(type, p); | |
GETSHORT(class, p); | |
p += 4; /* TTL */ | |
GETSHORT(rdlen, p); | |
| |
if ((type == T_NSEC || type == T_NSEC3 || type == T_RRSIG) && | |
(type != qtype || class != qclass)) | |
{ | |
if (!expand_workspace(&rrs, &rr_sz, rr_found + 1)) | |
return plen; | |
| |
rrs[rr_found++] = pstart; | |
| |
if (!ADD_RDLEN(header, p, plen, rdlen)) | |
return plen; | |
| |
rrs[rr_found++] = p; | |
| |
if (i < ntohs(header->ancount)) | |
chop_an++; | |
else if (i < (ntohs(header->nscount) + ntohs(header->ancount))) | |
chop_ns++; | |
else | |
chop_ar++; | |
} | |
else if (!ADD_RDLEN(header, p, plen, rdlen)) | |
return plen; | |
} | |
| |
/* Nothing to do. */ | |
if (rr_found == 0) | |
return plen; | |
| |
/* Second pass, look for pointers in names in the records we're keeping and make sure they don't | |
point to records we're going to elide. This is theoretically possible, but unlikely. If | |
it happens, we give up and leave the answer unchanged. */ | |
p = (unsigned char *)(header+1); | |
| |
/* question first */ | |
if (!check_name(&p, header, plen, 0, rrs, rr_found)) | |
return plen; | |
p += 4; /* qclass, qtype */ | |
| |
/* Now answers and NS */ | |
if (!check_rrs(p, header, plen, 0, rrs, rr_found)) | |
return plen; | |
| |
/* Third pass, elide records */ | |
for (p = rrs[0], i = 1; i < rr_found; i += 2) | |
{ | |
unsigned char *start = rrs[i]; | |
unsigned char *end = (i != rr_found - 1) ? rrs[i+1] : ((unsigned char *)(header+1)) + plen; | |
| |
memmove(p, start, end-start); | |
p += end-start; | |
} | |
| |
plen = p - (unsigned char *)header; | |
header->ancount = htons(ntohs(header->ancount) - chop_an); | |
header->nscount = htons(ntohs(header->nscount) - chop_ns); | |
header->arcount = htons(ntohs(header->arcount) - chop_ar); | |
| |
/* Fourth pass, fix up pointers in the remaining records */ | |
p = (unsigned char *)(header+1); | |
| |
check_name(&p, header, plen, 1, rrs, rr_found); | |
p += 4; /* qclass, qtype */ | |
| |
check_rrs(p, header, plen, 1, rrs, rr_found); | |
| |
return plen; | |
} | |
| |
unsigned char* hash_questions(struct dns_header *header, size_t plen, char *name) | |
{ | |
int q; | |
unsigned int len; | |
unsigned char *p = (unsigned char *)(header+1); | |
const struct nettle_hash *hash; | |
void *ctx; | |
unsigned char *digest; | |
| |
if (!(hash = hash_find("sha1")) || !hash_init(hash, &ctx, &digest)) | |
return NULL; | |
| |
for (q = ntohs(header->qdcount); q != 0; q--) | |
{ | |
if (!extract_name(header, plen, &p, name, 1, 4)) | |
break; /* bad packet */ | |
| |
len = to_wire(name); | |
hash->update(ctx, len, (unsigned char *)name); | |
/* CRC the class and type as well */ | |
hash->update(ctx, 4, p); | |
| |
p += 4; | |
if (!CHECK_LEN(header, p, plen, 0)) | |
break; /* bad packet */ | |
} | |
| |
hash->digest(ctx, hash->digest_size, digest); | |
return digest; | |
} |
} |
|
|
#endif /* HAVE_DNSSEC */ |
#endif /* HAVE_DNSSEC */ |