xref: /curl/lib/vauth/cram.c (revision ad1c49bc)
1 /***************************************************************************
2  *                                  _   _ ____  _
3  *  Project                     ___| | | |  _ \| |
4  *                             / __| | | | |_) | |
5  *                            | (__| |_| |  _ <| |___
6  *                             \___|\___/|_| \_\_____|
7  *
8  * Copyright (C) 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.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  * SPDX-License-Identifier: curl
22  *
23  * RFC2195 CRAM-MD5 authentication
24  *
25  ***************************************************************************/
26 
27 #include "curl_setup.h"
28 
29 #ifndef CURL_DISABLE_DIGEST_AUTH
30 
31 #include <curl/curl.h>
32 #include "urldata.h"
33 
34 #include "vauth/vauth.h"
35 #include "curl_hmac.h"
36 #include "curl_md5.h"
37 #include "warnless.h"
38 #include "curl_printf.h"
39 
40 /* The last #include files should be: */
41 #include "curl_memory.h"
42 #include "memdebug.h"
43 
44 
45 /*
46  * Curl_auth_create_cram_md5_message()
47  *
48  * This is used to generate a CRAM-MD5 response message ready for sending to
49  * the recipient.
50  *
51  * Parameters:
52  *
53  * chlg    [in]     - The challenge.
54  * userp   [in]     - The username.
55  * passwdp [in]     - The user's password.
56  * out     [out]    - The result storage.
57  *
58  * Returns CURLE_OK on success.
59  */
Curl_auth_create_cram_md5_message(const struct bufref * chlg,const char * userp,const char * passwdp,struct bufref * out)60 CURLcode Curl_auth_create_cram_md5_message(const struct bufref *chlg,
61                                            const char *userp,
62                                            const char *passwdp,
63                                            struct bufref *out)
64 {
65   struct HMAC_context *ctxt;
66   unsigned char digest[MD5_DIGEST_LEN];
67   char *response;
68 
69   /* Compute the digest using the password as the key */
70   ctxt = Curl_HMAC_init(&Curl_HMAC_MD5,
71                         (const unsigned char *) passwdp,
72                         curlx_uztoui(strlen(passwdp)));
73   if(!ctxt)
74     return CURLE_OUT_OF_MEMORY;
75 
76   /* Update the digest with the given challenge */
77   if(Curl_bufref_len(chlg))
78     Curl_HMAC_update(ctxt, Curl_bufref_ptr(chlg),
79                      curlx_uztoui(Curl_bufref_len(chlg)));
80 
81   /* Finalise the digest */
82   Curl_HMAC_final(ctxt, digest);
83 
84   /* Generate the response */
85   response = aprintf(
86     "%s %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x",
87     userp, digest[0], digest[1], digest[2], digest[3], digest[4],
88     digest[5], digest[6], digest[7], digest[8], digest[9], digest[10],
89     digest[11], digest[12], digest[13], digest[14], digest[15]);
90   if(!response)
91     return CURLE_OUT_OF_MEMORY;
92 
93   Curl_bufref_set(out, response, strlen(response), curl_free);
94   return CURLE_OK;
95 }
96 
97 #endif /* !CURL_DISABLE_DIGEST_AUTH */
98