curl/lib/vauth/cram.c

139 строки
4.3 KiB
C

/***************************************************************************
* _ _ ____ _
* Project ___| | | | _ \| |
* / __| | | | |_) | |
* | (__| |_| | _ <| |___
* \___|\___/|_| \_\_____|
*
* Copyright (C) 1998 - 2020, 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.haxx.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.
*
* RFC2195 CRAM-MD5 authentication
*
***************************************************************************/
#include "curl_setup.h"
#if !defined(CURL_DISABLE_CRYPTO_AUTH)
#include <curl/curl.h>
#include "urldata.h"
#include "vauth/vauth.h"
#include "curl_base64.h"
#include "curl_hmac.h"
#include "curl_md5.h"
#include "warnless.h"
#include "curl_printf.h"
/* The last #include files should be: */
#include "curl_memory.h"
#include "memdebug.h"
/*
* Curl_auth_decode_cram_md5_message()
*
* This is used to decode an already encoded CRAM-MD5 challenge message.
*
* Parameters:
*
* chlg64 [in] - The base64 encoded challenge message.
* outptr [in/out] - The address where a pointer to newly allocated memory
* holding the result will be stored upon completion.
* outlen [out] - The length of the output message.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_auth_decode_cram_md5_message(const char *chlg64, char **outptr,
size_t *outlen)
{
CURLcode result = CURLE_OK;
size_t chlg64len = strlen(chlg64);
*outptr = NULL;
*outlen = 0;
/* Decode the challenge if necessary */
if(chlg64len && *chlg64 != '=')
result = Curl_base64_decode(chlg64, (unsigned char **) outptr, outlen);
return result;
}
/*
* Curl_auth_create_cram_md5_message()
*
* This is used to generate an already encoded CRAM-MD5 response message ready
* for sending to the recipient.
*
* Parameters:
*
* data [in] - The session handle.
* chlg [in] - The challenge.
* userp [in] - The user name.
* passwdp [in] - The user's password.
* outptr [in/out] - The address where a pointer to newly allocated memory
* holding the result will be stored upon completion.
* outlen [out] - The length of the output message.
*
* Returns CURLE_OK on success.
*/
CURLcode Curl_auth_create_cram_md5_message(struct Curl_easy *data,
const char *chlg,
const char *userp,
const char *passwdp,
char **outptr, size_t *outlen)
{
CURLcode result = CURLE_OK;
size_t chlglen = 0;
struct HMAC_context *ctxt;
unsigned char digest[MD5_DIGEST_LEN];
char *response;
if(chlg)
chlglen = strlen(chlg);
/* Compute the digest using the password as the key */
ctxt = Curl_HMAC_init(Curl_HMAC_MD5,
(const unsigned char *) passwdp,
curlx_uztoui(strlen(passwdp)));
if(!ctxt)
return CURLE_OUT_OF_MEMORY;
/* Update the digest with the given challenge */
if(chlglen > 0)
Curl_HMAC_update(ctxt, (const unsigned char *) chlg,
curlx_uztoui(chlglen));
/* Finalise the digest */
Curl_HMAC_final(ctxt, digest);
/* Generate the response */
response = aprintf(
"%s %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
userp, digest[0], digest[1], digest[2], digest[3], digest[4],
digest[5], digest[6], digest[7], digest[8], digest[9], digest[10],
digest[11], digest[12], digest[13], digest[14], digest[15]);
if(!response)
return CURLE_OUT_OF_MEMORY;
/* Base64 encode the response */
result = Curl_base64_encode(data, response, 0, outptr, outlen);
free(response);
return result;
}
#endif /* !CURL_DISABLE_CRYPTO_AUTH */