1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165
|
/*********************************************************************
* Copyright 2018, UCAR/Unidata
* See netcdf/COPYRIGHT file for copying and redistribution conditions.
* ********************************************************************/
/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) Daniel Stenberg, <daniel@haxx.se>, et al.
*
* This software is licensed as described in the file COPYING, which
* you should have received as part of this distribution. The terms
* are also available at https://curl.se/docs/copyright.html.
*
* You may opt to use, copy, modify, merge, publish, distribute and/or sell
* copies of the Software, and permit persons to whom the Software is
* furnished to do so, under the terms of the COPYING file.
*
* This software is distributed on an "AS IS" basis, WITHOUT WARRANTY OF ANY
* KIND, either express or implied.
*
* SPDX-License-Identifier: curl
*
* RFC2104 Keyed-Hashing for Message Authentication
*
***************************************************************************/
#include "nccurl_setup.h"
#include "nccurl_hmac.h"
/*
* Generic HMAC algorithm.
*
* This module computes HMAC digests based on any hash function. Parameters
* and computing procedures are set-up dynamically at HMAC computation context
* initialization.
*/
static const unsigned char hmac_ipad = 0x36;
static const unsigned char hmac_opad = 0x5C;
struct HMAC_context *
Curl_HMAC_init(const struct HMAC_params *hashparams,
const unsigned char *key,
unsigned int keylen)
{
size_t i;
struct HMAC_context *ctxt;
unsigned char *hkey;
unsigned char b;
/* Create HMAC context. */
i = sizeof(*ctxt) + 2 * hashparams->hmac_ctxtsize +
hashparams->hmac_resultlen;
ctxt = malloc(i);
if(!ctxt)
return ctxt;
ctxt->hmac_hash = hashparams;
ctxt->hmac_hashctxt1 = (void *) (ctxt + 1);
ctxt->hmac_hashctxt2 = (void *) ((char *) ctxt->hmac_hashctxt1 +
hashparams->hmac_ctxtsize);
/* If the key is too long, replace it by its hash digest. */
if(keylen > hashparams->hmac_maxkeylen) {
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, key, keylen);
hkey = (unsigned char *) ctxt->hmac_hashctxt2 + hashparams->hmac_ctxtsize;
(*hashparams->hmac_hfinal)(hkey, ctxt->hmac_hashctxt1);
key = hkey;
keylen = hashparams->hmac_resultlen;
}
/* Prime the two hash contexts with the modified key. */
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt1);
(*hashparams->hmac_hinit)(ctxt->hmac_hashctxt2);
for(i = 0; i < keylen; i++) {
b = (unsigned char)(*key ^ hmac_ipad);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &b, 1);
b = (unsigned char)(*key++ ^ hmac_opad);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &b, 1);
}
for(; i < hashparams->hmac_maxkeylen; i++) {
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt1, &hmac_ipad, 1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2, &hmac_opad, 1);
}
/* Done, return pointer to HMAC context. */
return ctxt;
}
int Curl_HMAC_update(struct HMAC_context *ctxt,
const unsigned char *data,
unsigned int len)
{
/* Update first hash calculation. */
(*ctxt->hmac_hash->hmac_hupdate)(ctxt->hmac_hashctxt1, data, len);
return 0;
}
int Curl_HMAC_final(struct HMAC_context *ctxt, unsigned char *result)
{
const struct HMAC_params *hashparams = ctxt->hmac_hash;
/* Do not get result if called with a null parameter: only release
storage. */
if(!result)
result = (unsigned char *) ctxt->hmac_hashctxt2 +
ctxt->hmac_hash->hmac_ctxtsize;
(*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt1);
(*hashparams->hmac_hupdate)(ctxt->hmac_hashctxt2,
result, hashparams->hmac_resultlen);
(*hashparams->hmac_hfinal)(result, ctxt->hmac_hashctxt2);
free((char *) ctxt);
return 0;
}
/*
* Curl_hmacit()
*
* This is used to generate a HMAC hash, for the specified input data, given
* the specified hash function and key.
*
* Parameters:
*
* hashparams [in] - The hash function (Curl_HMAC_MD5).
* key [in] - The key to use.
* keylen [in] - The length of the key.
* data [in] - The data to encrypt.
* datalen [in] - The length of the data.
* output [in/out] - The output buffer.
*
* Returns CURLE_OK on success.
*/
CURLcode
Curl_hmacit(const struct HMAC_params *hashparams,
const unsigned char *key, const size_t keylen,
const unsigned char *data, const size_t datalen,
unsigned char *output)
{
struct HMAC_context *ctxt =
Curl_HMAC_init(hashparams, key, nccurlx_uztoui(keylen));
if(!ctxt)
return CURLE_OUT_OF_MEMORY;
/* Update the digest with the given challenge */
Curl_HMAC_update(ctxt, data, nccurlx_uztoui(datalen));
/* Finalise the digest */
Curl_HMAC_final(ctxt, output);
return CURLE_OK;
}
|