summaryrefslogtreecommitdiffstats
path: root/src/openvpn/httpdigest.c
blob: 78b8344d7c63081cdd61735a1ea3f8704936d26f (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
/*
 *  OpenVPN -- An application to securely tunnel IP networks
 *             over a single TCP/UDP port, with support for SSL/TLS-based
 *             session authentication and key exchange,
 *             packet encryption, packet authentication, and
 *             packet compression.
 *
 *  Copyright (C) 2002-2010 OpenVPN Technologies, Inc. <sales@openvpn.net>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License version 2
 *  as published by the Free Software Foundation.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program (see the file COPYING included with this
 *  distribution); if not, write to the Free Software Foundation, Inc.,
 *  59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef HAVE_CONFIG_H
#include "config.h"
#elif defined(_MSC_VER)
#include "config-msvc.h"
#endif

#include "syshead.h"

#if PROXY_DIGEST_AUTH

#include "crypto.h"
#include "httpdigest.h"

static void
CvtHex(
       IN HASH Bin,
       OUT HASHHEX Hex
       )
{
  unsigned short i;
  unsigned char j;

  for (i = 0; i < HASHLEN; i++) {
    j = (Bin[i] >> 4) & 0xf;
    if (j <= 9)
      Hex[i*2] = (j + '0');
    else
      Hex[i*2] = (j + 'a' - 10);
    j = Bin[i] & 0xf;
    if (j <= 9)
      Hex[i*2+1] = (j + '0');
    else
      Hex[i*2+1] = (j + 'a' - 10);
  };
  Hex[HASHHEXLEN] = '\0';
};

/* calculate H(A1) as per spec */
void
DigestCalcHA1(
	      IN char * pszAlg,
	      IN char * pszUserName,
	      IN char * pszRealm,
	      IN char * pszPassword,
	      IN char * pszNonce,
	      IN char * pszCNonce,
	      OUT HASHHEX SessionKey
	      )
{
  HASH HA1;
  md_ctx_t md5_ctx;
  const md_kt_t *md5_kt = md_kt_get("MD5");

  md_ctx_init(&md5_ctx, md5_kt);
  md_ctx_update(&md5_ctx, pszUserName, strlen(pszUserName));
  md_ctx_update(&md5_ctx, ":", 1);
  md_ctx_update(&md5_ctx, pszRealm, strlen(pszRealm));
  md_ctx_update(&md5_ctx, ":", 1);
  md_ctx_update(&md5_ctx, pszPassword, strlen(pszPassword));
  md_ctx_final(&md5_ctx, HA1);
  if (pszAlg && strcasecmp(pszAlg, "md5-sess") == 0)
    {
      md_ctx_init(&md5_ctx, md5_kt);
      md_ctx_update(&md5_ctx, HA1, HASHLEN);
      md_ctx_update(&md5_ctx, ":", 1);
      md_ctx_update(&md5_ctx, pszNonce, strlen(pszNonce));
      md_ctx_update(&md5_ctx, ":", 1);
      md_ctx_update(&md5_ctx, pszCNonce, strlen(pszCNonce));
      md_ctx_final(&md5_ctx, HA1);
    };
  md_ctx_cleanup(&md5_ctx);
  CvtHex(HA1, SessionKey);
}

/* calculate request-digest/response-digest as per HTTP Digest spec */
void
DigestCalcResponse(
		   IN HASHHEX HA1,           /* H(A1) */
		   IN char * pszNonce,       /* nonce from server */
		   IN char * pszNonceCount,  /* 8 hex digits */
		   IN char * pszCNonce,      /* client nonce */
		   IN char * pszQop,         /* qop-value: "", "auth", "auth-int" */
		   IN char * pszMethod,      /* method from the request */
		   IN char * pszDigestUri,   /* requested URL */
		   IN HASHHEX HEntity,       /* H(entity body) if qop="auth-int" */
		   OUT HASHHEX Response      /* request-digest or response-digest */
		   )
{
  HASH HA2;
  HASH RespHash;
  HASHHEX HA2Hex;

  md_ctx_t md5_ctx;
  const md_kt_t *md5_kt = md_kt_get("MD5");

  /* calculate H(A2) */
  md_ctx_init(&md5_ctx, md5_kt);
  md_ctx_update(&md5_ctx, pszMethod, strlen(pszMethod));
  md_ctx_update(&md5_ctx, ":", 1);
  md_ctx_update(&md5_ctx, pszDigestUri, strlen(pszDigestUri));
  if (strcasecmp(pszQop, "auth-int") == 0)
    {
      md_ctx_update(&md5_ctx, ":", 1);
      md_ctx_update(&md5_ctx, HEntity, HASHHEXLEN);
    };
  md_ctx_final(&md5_ctx, HA2);
  CvtHex(HA2, HA2Hex);

  /* calculate response */
  md_ctx_init(&md5_ctx, md5_kt);
  md_ctx_update(&md5_ctx, HA1, HASHHEXLEN);
  md_ctx_update(&md5_ctx, ":", 1);
  md_ctx_update(&md5_ctx, pszNonce, strlen(pszNonce));
  md_ctx_update(&md5_ctx, ":", 1);
  if (*pszQop)
    {
      md_ctx_update(&md5_ctx, pszNonceCount, strlen(pszNonceCount));
      md_ctx_update(&md5_ctx, ":", 1);
      md_ctx_update(&md5_ctx, pszCNonce, strlen(pszCNonce));
      md_ctx_update(&md5_ctx, ":", 1);
      md_ctx_update(&md5_ctx, pszQop, strlen(pszQop));
      md_ctx_update(&md5_ctx, ":", 1);
    };
  md_ctx_update(&md5_ctx, HA2Hex, HASHHEXLEN);
  md_ctx_final(&md5_ctx, RespHash);
  md_ctx_cleanup(&md5_ctx);
  CvtHex(RespHash, Response);
}

#endif