aboutsummaryrefslogtreecommitdiff
path: root/lib/http_digest.c
blob: 378424b9588e4f3b4a981b3995ba497a069ad0a2 (plain)
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
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
/***************************************************************************
 *                                  _   _ ____  _     
 *  Project                     ___| | | |  _ \| |    
 *                             / __| | | | |_) | |    
 *                            | (__| |_| |  _ <| |___ 
 *                             \___|\___/|_| \_\_____|
 *
 * Copyright (C) 1998 - 2003, 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 http://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.
 *
 * $Id$
 ***************************************************************************/
#include "setup.h"

#ifndef CURL_DISABLE_HTTP
/* -- WIN32 approved -- */
#include <stdio.h>
#include <string.h>
#include <stdarg.h>
#include <stdlib.h>
#include <ctype.h>

#include "urldata.h"
#include "sendf.h"
#include "strequal.h"

#include "md5.h"
#include "http_digest.h"

#define _MPRINTF_REPLACE /* use our functions only */
#include <curl/mprintf.h>

/* The last #include file should be: */
#ifdef CURLDEBUG
#include "memdebug.h"
#endif

/* Test example header:

WWW-Authenticate: Digest realm="testrealm", nonce="1053604598"

*/

CURLdigest Curl_input_digest(struct connectdata *conn,
                             char *header) /* rest of the www-authenticate:
                                              header */
{
  bool more = TRUE;
  struct SessionHandle *data=conn->data;

  /* skip initial whitespaces */
  while(*header && isspace((int)*header))
    header++;

  if(checkprefix("Digest", header)) {
    header += strlen("Digest");

    /* clear off any former leftovers and init to defaults */
    Curl_digest_cleanup(data);

    while(more) {
      char value[32];
      char content[128];
      int totlen=0;

      while(*header && isspace((int)*header))
        header++;
    
      /* how big can these strings be? */
      if(2 == sscanf(header, "%31[^=]=\"%127[^\"]\"",
                     value, content)) {
        if(strequal(value, "nonce")) {
          data->state.digest.nonce = strdup(content);
        }
        else if(strequal(value, "cnonce")) {
          data->state.digest.cnonce = strdup(content);
        }
        else if(strequal(value, "realm")) {
          data->state.digest.realm = strdup(content);
        }
        else if(strequal(value, "algorithm")) {
          if(strequal(content, "MD5-sess"))
            data->state.digest.algo = CURLDIGESTALGO_MD5SESS;
          /* else, remain using the default md5 */
        }
        else {
          /* unknown specifier, ignore it! */
        }
        totlen = strlen(value)+strlen(content)+3;
      }
      else 
        break; /* we're done here */
        
      header += totlen;
      if(',' == *header)
        /* allow the list to be comma-separated */
        header++; 
    }

    if(!data->state.digest.nonce)
      return CURLDIGEST_BAD;
  }
  else 
    /* else not a digest, get out */
    return CURLDIGEST_NONE;

  return CURLDIGEST_FINE;
}

/* convert md5 chunk to RFC2617 (section 3.1.3) -suitable ascii string*/
static void md5_to_ascii(unsigned char *source, /* 16 bytes */
                         unsigned char *dest) /* 33 bytes */
{
  int i;
  for(i=0; i<16; i++)
    sprintf((char *)&dest[i*2], "%02x", source[i]);
}

CURLcode Curl_output_digest(struct connectdata *conn,
                            unsigned char *request,
                            unsigned char *uripath)
{
  /* We have a Digest setup for this, use it!  Now, to get all the details for
     this sorted out, I must urge you dear friend to read up on the RFC2617
     section 3.2.2, */
  unsigned char md5buf[16]; /* 16 bytes/128 bits */
  unsigned char ha1[33]; /* 32 digits and 1 zero byte */
  unsigned char ha2[33];
  unsigned char request_digest[33];
  unsigned char *md5this;

  struct SessionHandle *data = conn->data;

  /*
    if the algorithm is "MD5" or unspecified (which then defaults to MD5):
    
    A1 = unq(username-value) ":" unq(realm-value) ":" passwd

    if the algorithm is "MD5-sess" then:

    A1 = H( unq(username-value) ":" unq(realm-value) ":" passwd )
         ":" unq(nonce-value) ":" unq(cnonce-value)
  */
  if(data->state.digest.algo == CURLDIGESTALGO_MD5SESS) {
    md5this = (unsigned char *)
      aprintf("%s:%s:%s:%s:%s",
              conn->user,
              data->state.digest.realm,
              conn->passwd,
              data->state.digest.nonce,
              data->state.digest.cnonce);
  }
  else {
    md5this = (unsigned char *)
      aprintf("%s:%s:%s",
              conn->user,
              data->state.digest.realm,
              conn->passwd);
  }
  Curl_md5it(md5buf, md5this);
  free(md5this); /* free this again */
  md5_to_ascii(md5buf, ha1);

  /*
    A2 = Method ":" digest-uri-value
    
    (The "Method" value is the HTTP request method as specified in section
    5.1.1 of RFC 2616)
  */

  md5this = (unsigned char *)aprintf("%s:%s", request, uripath);
  Curl_md5it(md5buf, md5this);
  free(md5this); /* free this again */
  md5_to_ascii(md5buf, ha2);
  
  md5this = (unsigned char *)aprintf("%s:%s:%s", ha1, data->state.digest.nonce,
                                     ha2);
  Curl_md5it(md5buf, md5this);
  free(md5this); /* free this again */
  md5_to_ascii(md5buf, request_digest);

  /* for test case 64 (snooped from a Mozilla 1.3a request)

    Authorization: Digest username="testuser", realm="testrealm", \
    nonce="1053604145", uri="/64", response="c55f7f30d83d774a3d2dcacf725abaca"
  */

  conn->allocptr.userpwd =
    aprintf( "Authorization: Digest "
             "username=\"%s\", "
             "realm=\"%s\", "
             "nonce=\"%s\", "
             "uri=\"%s\", "
             "response=\"%s\"\r\n",
             conn->user,
             data->state.digest.realm,
             data->state.digest.nonce,
             uripath, /* this is the PATH part of the URL */ 
             request_digest );

  return CURLE_OK;
}

void Curl_digest_cleanup(struct SessionHandle *data)
{
  if(data->state.digest.nonce)
    free(data->state.digest.nonce);
  data->state.digest.nonce = NULL;

  if(data->state.digest.cnonce)
    free(data->state.digest.cnonce);
  data->state.digest.cnonce = NULL;

  if(data->state.digest.realm)
    free(data->state.digest.realm);
  data->state.digest.realm = NULL;

  data->state.digest.algo = CURLDIGESTALGO_MD5; /* default algorithm */
}

#endif