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
|
/*
* File: digest.c
*
* Copyright 2009 Justus Winter <4winter@informatik.uni-hamburg.de>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 3 of the License, or
* (at your option) any later version.
*/
#include <stdlib.h>
#include "digest.h"
#include "md5.h"
#include "msg.h"
#include "../dlib/dlib.h"
static const char *ALGORITHM2STR[] = { NULL, "MD5", "MD5-sess" };
static const char *QOP2STR[] = { NULL, "auth", "auth-int" };
static const char hexchars[] = "0123456789abcdef";
static Dstr *md5hexdigest(const Dstr *data)
{
md5_state_t state;
md5_byte_t digest[16];
Dstr *result = dStr_sized_new(33);
int i;
md5_init(&state);
md5_append(&state, (const md5_byte_t *)data->str, data->len);
md5_finish(&state, digest);
for (i = 0; i < 16; i++)
dStr_sprintfa(result, "%02x", digest[i]);
return result;
}
/*
* Returns a pointer to a newly allocated string containing a cnonce
*/
char *a_Digest_create_cnonce(void)
{
int i;
char *result = dNew(char, 33);
for (i = 0; i < 32; i++)
result[i] = hexchars[rand() % 16];
result[32] = 0;
return result;
}
/*
* This portion only has to be calculated once.
*/
int a_Digest_compute_digest(AuthRealm_t *realm, const char *username,
const char *passwd)
{
Dstr *a1;
Dstr *digest;
if (realm->algorithm == MD5 || realm->algorithm == ALGORITHMNOTSET) {
/* A1 = unq(username-value) ":" unq(realm-value) ":" passwd */
a1 = dStr_new(NULL);
dStr_sprintf(a1, "%s:%s:%s", username, realm->name, passwd);
} else if (realm->algorithm == MD5SESS) {
/* A1 = H( unq(username-value) ":" unq(realm-value)
** ":" passwd )
** ":" unq(nonce-value) ":" unq(cnonce-value)
*/
Dstr *a0 = dStr_new(NULL);
dStr_sprintf(a0, "%s:%s:%s", username, realm->name, passwd);
Dstr *ha0 = md5hexdigest(a0);
a1 = dStr_new(NULL);
dStr_sprintf(a1, "%s:%s:%s", ha0, realm->nonce, realm->cnonce);
dStr_free(a0, 1);
dStr_free(ha0, 1);
} else {
MSG("a_Digest_create_auth: Unknown algorithm.\n");
return 0;
}
digest = md5hexdigest(a1);
realm->authorization = digest->str;
dStr_shred(a1);
dStr_free(a1, 1);
dStr_free(digest, 0);
return 1;
}
/*
* This portion is calculatd for each request.
*/
static Dstr *Digest_create_response(AuthRealm_t *realm, const char *method,
const char *digest_uri,
const Dstr *entity_body)
{
Dstr *ha2;
Dstr *result;
if (realm->qop == QOPNOTSET || realm->qop == AUTH) {
/* A2 = Method ":" digest-uri-value */
Dstr *a2 = dStr_new(NULL);
dStr_sprintf(a2, "%s:%s", method, digest_uri);
ha2 = md5hexdigest(a2);
dStr_free(a2, 1);
} else if (realm->qop == AUTHINT) {
/* A2 = Method ":" digest-uri-value ":" H(entity-body) */
Dstr *hentity = md5hexdigest(entity_body);
Dstr *a2 = dStr_new(NULL);
dStr_sprintf(a2, "%s:%s:%s", method, digest_uri, hentity->str);
ha2 = md5hexdigest(a2);
dStr_free(hentity, 1);
dStr_free(a2, 1);
} else {
MSG("a_Digest_create_auth: Unknown qop value.\n");
return NULL;
}
result = dStr_new(NULL);
if (realm->qop == AUTH || realm->qop == AUTHINT) {
dStr_sprintf(result,
"%s:%s:%08x:%s:%s:%s",
realm->authorization,
realm->nonce,
realm->nonce_count,
realm->cnonce,
QOP2STR[realm->qop],
ha2->str);
} else {
dStr_sprintf(result,
"%s:%s:%s",
realm->authorization,
realm->nonce,
ha2->str);
}
Dstr *request_digest = md5hexdigest(result);
dStr_free(result, 1);
dStr_free(ha2, 1);
return request_digest;
}
static void Digest_Dstr_append_token_value(Dstr *str, int delimiter,
const char *token,
const char *value, int quoted)
{
char c;
dStr_sprintfa(str, "%s%s=", (delimiter ? ", " : ""), token);
if (quoted) {
dStr_append_c(str, '"');
while ((c = *value++)) {
if (c == '"')
dStr_append_c(str, '\\');
dStr_append_c(str, c);
}
dStr_append_c(str, '"');
} else {
dStr_append(str, value);
}
}
/*
* Construct Digest Authorization header.
*/
char *a_Digest_authorization_hdr(AuthRealm_t *realm, const DilloUrl *url,
const char *digest_uri)
{
char *ret;
Dstr *response, *result;
const char *method = URL_FLAGS(url) & URL_Post ? "POST" : "GET";
realm->nonce_count++;
response = Digest_create_response(realm, method, digest_uri, URL_DATA(url));
if (!response)
return NULL;
result = dStr_new("Authorization: Digest ");
Digest_Dstr_append_token_value(result, 0, "username", realm->username, 1);
Digest_Dstr_append_token_value(result, 1, "realm", realm->name, 1);
Digest_Dstr_append_token_value(result, 1, "nonce", realm->nonce, 1);
Digest_Dstr_append_token_value(result, 1, "uri", digest_uri, 0);
if (realm->algorithm != ALGORITHMNOTSET) {
Digest_Dstr_append_token_value(result, 1, "algorithm",
ALGORITHM2STR[realm->algorithm], 0);
}
Digest_Dstr_append_token_value(result, 1, "response", response->str, 1);
if (realm->opaque)
Digest_Dstr_append_token_value(result, 1, "opaque", realm->opaque, 1);
if (realm->qop != QOPNOTSET) {
Digest_Dstr_append_token_value(result, 1, "qop", QOP2STR[realm->qop], 1);
dStr_sprintfa(result, ", nc=%08x", realm->nonce_count);
Digest_Dstr_append_token_value(result, 1, "cnonce", realm->cnonce, 1);
}
dStr_sprintfa(result, "\r\n");
dStr_free(response, 1);
ret = result->str;
dStr_free(result, 0);
return ret;
}
|
