Annotation of embedaddon/curl/lib/hmac.c, revision 1.1
1.1 ! misho 1: /***************************************************************************
! 2: * _ _ ____ _
! 3: * Project ___| | | | _ \| |
! 4: * / __| | | | |_) | |
! 5: * | (__| |_| | _ <| |___
! 6: * \___|\___/|_| \_\_____|
! 7: *
! 8: * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
! 9: *
! 10: * This software is licensed as described in the file COPYING, which
! 11: * you should have received as part of this distribution. The terms
! 12: * are also available at https://curl.haxx.se/docs/copyright.html.
! 13: *
! 14: * You may opt to use, copy, modify, merge, publish, distribute and/or sell
! 15: * copies of the Software, and permit persons to whom the Software is
! 16: * furnished to do so, under the terms of the COPYING file.
! 17: *
! 18: * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
! 19: * KIND, either express or implied.
! 20: *
! 21: * RFC2104 Keyed-Hashing for Message Authentication
! 22: *
! 23: ***************************************************************************/
! 24:
! 25: #include "curl_setup.h"
! 26:
! 27: #ifndef CURL_DISABLE_CRYPTO_AUTH
! 28:
! 29: #include <curl/curl.h>
! 30:
! 31: #include "curl_hmac.h"
! 32: #include "curl_memory.h"
! 33: #include "warnless.h"
! 34:
! 35: /* The last #include file should be: */
! 36: #include "memdebug.h"
! 37:
! 38: /*
! 39: * Generic HMAC algorithm.
! 40: *
! 41: * This module computes HMAC digests based on any hash function. Parameters
! 42: * and computing procedures are set-up dynamically at HMAC computation
! 43: * context initialisation.
! 44: */
! 45:
! 46: static const unsigned char hmac_ipad = 0x36;
! 47: static const unsigned char hmac_opad = 0x5C;
! 48:
! 49:
! 50:
! 51: HMAC_context *
! 52: Curl_HMAC_init(const HMAC_params * hashparams,
! 53: const unsigned char *key,
! 54: unsigned int keylen)
! 55: {
! 56: size_t i;
! 57: HMAC_context *ctxt;
! 58: unsigned char *hkey;
! 59: unsigned char b;
! 60:
! 61: /* Create HMAC context. */
! 62: i = sizeof(*ctxt) + 2 * hashparams->hmac_ctxtsize +
! 63: hashparams->hmac_resultlen;
! 64: ctxt = malloc(i);
! 65:
! 66: if(!ctxt)
! 67: return ctxt;
! 68:
! 69: ctxt->hmac_hash = hashparams;
! 70: ctxt->hmac_hashctxt1 = (void *) (ctxt + 1);
! 71: ctxt->hmac_hashctxt2 = (void *) ((char *) ctxt->hmac_hashctxt1 +
! 72: hashparams->hmac_ctxtsize);
! 73:
! 74: /* If the key is too long, replace it by its hash digest. */
! 75: if(keylen > hashparams->hmac_maxkeylen) {
! 76: (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
! 77: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, key, keylen);
! 78: hkey = (unsigned char *) ctxt->hmac_hashctxt2 + hashparams->hmac_ctxtsize;
! 79: (*hashparams->hmac_hfinal)(hkey, ctxt->hmac_hashctxt1);
! 80: key = hkey;
! 81: keylen = hashparams->hmac_resultlen;
! 82: }
! 83:
! 84: /* Prime the two hash contexts with the modified key. */
! 85: (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
! 86: (*hashparams->hmac_hinit)(ctxt->hmac_hashctxt2);
! 87:
! 88: for(i = 0; i < keylen; i++) {
! 89: b = (unsigned char)(*key ^ hmac_ipad);
! 90: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &b, 1);
! 91: b = (unsigned char)(*key++ ^ hmac_opad);
! 92: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &b, 1);
! 93: }
! 94:
! 95: for(; i < hashparams->hmac_maxkeylen; i++) {
! 96: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &hmac_ipad, 1);
! 97: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &hmac_opad, 1);
! 98: }
! 99:
! 100: /* Done, return pointer to HMAC context. */
! 101: return ctxt;
! 102: }
! 103:
! 104: int Curl_HMAC_update(HMAC_context * ctxt,
! 105: const unsigned char *data,
! 106: unsigned int len)
! 107: {
! 108: /* Update first hash calculation. */
! 109: (*ctxt->hmac_hash->hmac_hupdate)(ctxt->hmac_hashctxt1, data, len);
! 110: return 0;
! 111: }
! 112:
! 113:
! 114: int Curl_HMAC_final(HMAC_context *ctxt, unsigned char *result)
! 115: {
! 116: const HMAC_params * hashparams = ctxt->hmac_hash;
! 117:
! 118: /* Do not get result if called with a null parameter: only release
! 119: storage. */
! 120:
! 121: if(!result)
! 122: result = (unsigned char *) ctxt->hmac_hashctxt2 +
! 123: ctxt->hmac_hash->hmac_ctxtsize;
! 124:
! 125: (*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt1);
! 126: (*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2,
! 127: result, hashparams->hmac_resultlen);
! 128: (*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt2);
! 129: free((char *) ctxt);
! 130: return 0;
! 131: }
! 132:
! 133: /*
! 134: * Curl_hmacit()
! 135: *
! 136: * This is used to generate a HMAC hash, for the specified input data, given
! 137: * the specified hash function and key.
! 138: *
! 139: * Parameters:
! 140: *
! 141: * hashparams [in] - The hash function (Curl_HMAC_MD5).
! 142: * key [in] - The key to use.
! 143: * keylen [in] - The length of the key.
! 144: * data [in] - The data to encrypt.
! 145: * datalen [in] - The length of the data.
! 146: * output [in/out] - The output buffer.
! 147: *
! 148: * Returns CURLE_OK on success.
! 149: */
! 150: CURLcode Curl_hmacit(const HMAC_params *hashparams,
! 151: const unsigned char *key, const size_t keylen,
! 152: const unsigned char *data, const size_t datalen,
! 153: unsigned char *output)
! 154: {
! 155: HMAC_context *ctxt = Curl_HMAC_init(hashparams, key, curlx_uztoui(keylen));
! 156:
! 157: if(!ctxt)
! 158: return CURLE_OUT_OF_MEMORY;
! 159:
! 160: /* Update the digest with the given challenge */
! 161: Curl_HMAC_update(ctxt, data, curlx_uztoui(datalen));
! 162:
! 163: /* Finalise the digest */
! 164: Curl_HMAC_final(ctxt, output);
! 165:
! 166: return CURLE_OK;
! 167: }
! 168:
! 169: #endif /* CURL_DISABLE_CRYPTO_AUTH */
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to hmac.c CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / curl / lib