Return to hmacmd5.c CVS log

Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / ntp / lib / isc

Annotation of embedaddon/ntp/lib/isc/hmacmd5.c, revision 1.1.1.1

1.1       misho       1: /*
                      2:  * Copyright (C) 2004-2007  Internet Systems Consortium, Inc. ("ISC")
                      3:  * Copyright (C) 2000, 2001  Internet Software Consortium.
                      4:  *
                      5:  * Permission to use, copy, modify, and/or distribute this software for any
                      6:  * purpose with or without fee is hereby granted, provided that the above
                      7:  * copyright notice and this permission notice appear in all copies.
                      8:  *
                      9:  * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH
                     10:  * REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
                     11:  * AND FITNESS.  IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT,
                     12:  * INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
                     13:  * LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
                     14:  * OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
                     15:  * PERFORMANCE OF THIS SOFTWARE.
                     16:  */
                     17: 
                     18: /* $Id: hmacmd5.c,v 1.14 2007/06/19 23:47:17 tbox Exp $ */
                     19: 
                     20: /*! \file
                     21:  * This code implements the HMAC-MD5 keyed hash algorithm
                     22:  * described in RFC2104.
                     23:  */
                     24: 
                     25: #include "config.h"
                     26: 
                     27: #include <isc/assertions.h>
                     28: #include <isc/hmacmd5.h>
                     29: #include <isc/md5.h>
                     30: #include <isc/string.h>
                     31: #include <isc/types.h>
                     32: #include <isc/util.h>
                     33: 
                     34: #define PADLEN 64
                     35: #define IPAD 0x36
                     36: #define OPAD 0x5C
                     37: 
                     38: /*!
                     39:  * Start HMAC-MD5 process.  Initialize an md5 context and digest the key.
                     40:  */
                     41: void
                     42: isc_hmacmd5_init(isc_hmacmd5_t *ctx, const unsigned char *key,
                     43:                 unsigned int len)
                     44: {
                     45:        unsigned char ipad[PADLEN];
                     46:        int i;
                     47: 
                     48:        memset(ctx->key, 0, sizeof(ctx->key));
                     49:        if (len > sizeof(ctx->key)) {
                     50:                isc_md5_t md5ctx;
                     51:                isc_md5_init(&md5ctx);
                     52:                isc_md5_update(&md5ctx, key, len);
                     53:                isc_md5_final(&md5ctx, ctx->key);
                     54:        } else
                     55:                memcpy(ctx->key, key, len);
                     56: 
                     57:        isc_md5_init(&ctx->md5ctx);
                     58:        memset(ipad, IPAD, sizeof(ipad));
                     59:        for (i = 0; i < PADLEN; i++)
                     60:                ipad[i] ^= ctx->key[i];
                     61:        isc_md5_update(&ctx->md5ctx, ipad, sizeof(ipad));
                     62: }
                     63: 
                     64: void
                     65: isc_hmacmd5_invalidate(isc_hmacmd5_t *ctx) {
                     66:        isc_md5_invalidate(&ctx->md5ctx);
                     67:        memset(ctx->key, 0, sizeof(ctx->key));
                     68: }
                     69: 
                     70: /*!
                     71:  * Update context to reflect the concatenation of another buffer full
                     72:  * of bytes.
                     73:  */
                     74: void
                     75: isc_hmacmd5_update(isc_hmacmd5_t *ctx, const unsigned char *buf,
                     76:                   unsigned int len)
                     77: {
                     78:        isc_md5_update(&ctx->md5ctx, buf, len);
                     79: }
                     80: 
                     81: /*!
                     82:  * Compute signature - finalize MD5 operation and reapply MD5.
                     83:  */
                     84: void
                     85: isc_hmacmd5_sign(isc_hmacmd5_t *ctx, unsigned char *digest) {
                     86:        unsigned char opad[PADLEN];
                     87:        int i;
                     88: 
                     89:        isc_md5_final(&ctx->md5ctx, digest);
                     90: 
                     91:        memset(opad, OPAD, sizeof(opad));
                     92:        for (i = 0; i < PADLEN; i++)
                     93:                opad[i] ^= ctx->key[i];
                     94: 
                     95:        isc_md5_init(&ctx->md5ctx);
                     96:        isc_md5_update(&ctx->md5ctx, opad, sizeof(opad));
                     97:        isc_md5_update(&ctx->md5ctx, digest, ISC_MD5_DIGESTLENGTH);
                     98:        isc_md5_final(&ctx->md5ctx, digest);
                     99:        isc_hmacmd5_invalidate(ctx);
                    100: }
                    101: 
                    102: /*!
                    103:  * Verify signature - finalize MD5 operation and reapply MD5, then
                    104:  * compare to the supplied digest.
                    105:  */
                    106: isc_boolean_t
                    107: isc_hmacmd5_verify(isc_hmacmd5_t *ctx, unsigned char *digest) {
                    108:        return (isc_hmacmd5_verify2(ctx, digest, ISC_MD5_DIGESTLENGTH));
                    109: }
                    110: 
                    111: isc_boolean_t
                    112: isc_hmacmd5_verify2(isc_hmacmd5_t *ctx, unsigned char *digest, size_t len) {
                    113:        unsigned char newdigest[ISC_MD5_DIGESTLENGTH];
                    114: 
                    115:        REQUIRE(len <= ISC_MD5_DIGESTLENGTH);
                    116:        isc_hmacmd5_sign(ctx, newdigest);
                    117:        return (ISC_TF(memcmp(digest, newdigest, len) == 0));
                    118: }