1 | /*************************************************************************** |
2 | * _ _ ____ _ |
3 | * Project ___| | | | _ \| | |
4 | * / __| | | | |_) | | |
5 | * | (__| |_| | _ <| |___ |
6 | * \___|\___/|_| \_\_____| |
7 | * |
8 | * Copyright (C) 1998 - 2019, 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 | * RFC2195 CRAM-MD5 authentication |
22 | * |
23 | ***************************************************************************/ |
24 | |
25 | #include "curl_setup.h" |
26 | |
27 | #if !defined(CURL_DISABLE_CRYPTO_AUTH) |
28 | |
29 | #include <curl/curl.h> |
30 | #include "urldata.h" |
31 | |
32 | #include "vauth/vauth.h" |
33 | #include "curl_base64.h" |
34 | #include "curl_hmac.h" |
35 | #include "curl_md5.h" |
36 | #include "warnless.h" |
37 | #include "curl_printf.h" |
38 | |
39 | /* The last #include files should be: */ |
40 | #include "curl_memory.h" |
41 | #include "memdebug.h" |
42 | |
43 | /* |
44 | * Curl_auth_decode_cram_md5_message() |
45 | * |
46 | * This is used to decode an already encoded CRAM-MD5 challenge message. |
47 | * |
48 | * Parameters: |
49 | * |
50 | * chlg64 [in] - The base64 encoded challenge message. |
51 | * outptr [in/out] - The address where a pointer to newly allocated memory |
52 | * holding the result will be stored upon completion. |
53 | * outlen [out] - The length of the output message. |
54 | * |
55 | * Returns CURLE_OK on success. |
56 | */ |
57 | CURLcode Curl_auth_decode_cram_md5_message(const char *chlg64, char **outptr, |
58 | size_t *outlen) |
59 | { |
60 | CURLcode result = CURLE_OK; |
61 | size_t chlg64len = strlen(chlg64); |
62 | |
63 | *outptr = NULL; |
64 | *outlen = 0; |
65 | |
66 | /* Decode the challenge if necessary */ |
67 | if(chlg64len && *chlg64 != '=') |
68 | result = Curl_base64_decode(chlg64, (unsigned char **) outptr, outlen); |
69 | |
70 | return result; |
71 | } |
72 | |
73 | /* |
74 | * Curl_auth_create_cram_md5_message() |
75 | * |
76 | * This is used to generate an already encoded CRAM-MD5 response message ready |
77 | * for sending to the recipient. |
78 | * |
79 | * Parameters: |
80 | * |
81 | * data [in] - The session handle. |
82 | * chlg [in] - The challenge. |
83 | * userp [in] - The user name. |
84 | * passwdp [in] - The user's password. |
85 | * outptr [in/out] - The address where a pointer to newly allocated memory |
86 | * holding the result will be stored upon completion. |
87 | * outlen [out] - The length of the output message. |
88 | * |
89 | * Returns CURLE_OK on success. |
90 | */ |
91 | CURLcode Curl_auth_create_cram_md5_message(struct Curl_easy *data, |
92 | const char *chlg, |
93 | const char *userp, |
94 | const char *passwdp, |
95 | char **outptr, size_t *outlen) |
96 | { |
97 | CURLcode result = CURLE_OK; |
98 | size_t chlglen = 0; |
99 | HMAC_context *ctxt; |
100 | unsigned char digest[MD5_DIGEST_LEN]; |
101 | char *response; |
102 | |
103 | if(chlg) |
104 | chlglen = strlen(chlg); |
105 | |
106 | /* Compute the digest using the password as the key */ |
107 | ctxt = Curl_HMAC_init(Curl_HMAC_MD5, |
108 | (const unsigned char *) passwdp, |
109 | curlx_uztoui(strlen(passwdp))); |
110 | if(!ctxt) |
111 | return CURLE_OUT_OF_MEMORY; |
112 | |
113 | /* Update the digest with the given challenge */ |
114 | if(chlglen > 0) |
115 | Curl_HMAC_update(ctxt, (const unsigned char *) chlg, |
116 | curlx_uztoui(chlglen)); |
117 | |
118 | /* Finalise the digest */ |
119 | Curl_HMAC_final(ctxt, digest); |
120 | |
121 | /* Generate the response */ |
122 | response = aprintf( |
123 | "%s %02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x" , |
124 | userp, digest[0], digest[1], digest[2], digest[3], digest[4], |
125 | digest[5], digest[6], digest[7], digest[8], digest[9], digest[10], |
126 | digest[11], digest[12], digest[13], digest[14], digest[15]); |
127 | if(!response) |
128 | return CURLE_OUT_OF_MEMORY; |
129 | |
130 | /* Base64 encode the response */ |
131 | result = Curl_base64_encode(data, response, 0, outptr, outlen); |
132 | |
133 | free(response); |
134 | |
135 | return result; |
136 | } |
137 | |
138 | #endif /* !CURL_DISABLE_CRYPTO_AUTH */ |
139 | |