File: auth.c

package info (click to toggle)
sipsak 0.9.6+git20170713-1
  • links: PTS, VCS
  • area: main
  • in suites: buster
  • size: 396 kB
  • ctags: 466
  • sloc: ansic: 5,910; makefile: 78
file content (402 lines) | stat: -rw-r--r-- 13,779 bytes parent folder | download | duplicates (2)
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
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
/*
 * Copyright (C) 2002-2004 Fhg Fokus
 * Copyright (C) 2004-2005 Nils Ohlmeier
 *
 * This file belongs to sipsak, a free sip testing tool.
 *
 * sipsak 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 2 of the License, or
 * (at your option) any later version.
 *
 * sipsak 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.
 */
#include "sipsak.h"
#include "auth.h"
#include "exit_code.h"
#include "helper.h"
#include "md5.h"

#ifdef HAVE_OPENSSL_SHA1
# include <openssl/sha.h>
#endif

#define SIPSAK_ALGO_MD5 1
#define SIPSAK_ALGO_SHA1 2
#define SIPSAK_ALGO_SHA256 3

/* converts a hash into hex output
   taken from the RFC 2617 */
void cvt_hex(unsigned char *_b, unsigned char *_h, int length)
{
        unsigned short i;
        unsigned char j;

        for (i = 0; i < length; i++) {
                j = (_b[i] >> 4) & 0xf;
                if (j <= (unsigned char)9) {
                        _h[i * 2] = (j + (unsigned char)'0');
                } else {
                        _h[i * 2] = (unsigned char)(j + (unsigned char)'a' - (unsigned char)10);
                }
                j = _b[i] & 0xf;
                if (j <= (unsigned char)9) {
                        _h[i * 2 + 1] = (j + (unsigned char)'0');
                } else {
                        _h[i * 2 + 1] = (unsigned char)(j + (unsigned char)'a' - (unsigned char)10);
                }
        };
        _h[2*length] = '\0';
}

/* check for, create and insert a auth header into the message */
void insert_auth(char *message, char *authreq)
{
	char *auth, *begin, *end, *insert, *backup, *realm, *usern, *nonce;
	char *method, *uri;
	char *qop_tmp = NULL;
	unsigned char ha1[SIPSAK_HASHLEN], ha2[SIPSAK_HASHLEN], resp[SIPSAK_HASHLEN];
	unsigned char ha1_hex[SIPSAK_HASHHEXLEN+1], ha2_hex[SIPSAK_HASHHEXLEN+1], resp_hex[SIPSAK_HASHHEXLEN+1];
	int qop_auth=0, proxy_auth=0, algo=0;
	unsigned int cnonce;
	MD5_CTX Md5Ctx;
#ifdef HAVE_OPENSSL_SHA1
	SHA_CTX Sha1Ctx;
	SHA256_CTX Sha256Ctx;
#endif

	auth=begin=end=insert=backup=realm=usern=nonce=method=uri = NULL;

	memset(&ha1[0], '\0', SIPSAK_HASHLEN);
	memset(&ha2[0], '\0', SIPSAK_HASHLEN);
	memset(&resp[0], '\0', SIPSAK_HASHLEN);
	memset(&ha1_hex[0], '\0', SIPSAK_HASHHEXLEN+1);
	memset(&ha2_hex[0], '\0', SIPSAK_HASHHEXLEN+1);
	memset(&resp_hex[0], '\0', SIPSAK_HASHHEXLEN+1);

	/* prevent double auth insertion */
	if ((begin=STRCASESTR(message, AUTH_STR))!=NULL ||
			(begin=STRCASESTR(message, PROXYAUZ_STR))!=NULL) {
		fprintf(stderr, "request:\n%s\nresponse:\n%s\nerror: authorization failed\n  "
			"     request already contains (Proxy-) Authorization, but "
			"received 40[1|7], see above\n", message, authreq);
		exit_code(2, __PRETTY_FUNCTION__, "failed to add auth header, because request contained already one");
	}
	/* make a backup of all except the request line because for
	   simplicity we insert the auth header direct behind the request line */
	insert=strchr(message, '\n');
	if (!insert) {
		printf("failed to find newline\n");
		return;
	}
	insert++;
	backup=str_alloc(strlen(insert)+1);
	strncpy(backup, insert, strlen(insert));

	begin=STRCASESTR(authreq, WWWAUTH_STR);
	if (begin==NULL) {
		begin=STRCASESTR(authreq, PROXYAUTH_STR);
		proxy_auth = 1;
	}
	if (begin) {
		/* make a copy of the auth header to prevent that our searches
		   hit content of other header fields */
		end=strchr(begin, '\n');
		auth=str_alloc((size_t)(end-begin+1));
		strncpy(auth, begin, (size_t)(end-begin));
		/* we support Digest with MD5 or SHA1 */
		if ((begin=STRCASESTR(auth, "Basic"))!=NULL) {
			fprintf(stderr, "%s\nerror: authentication method Basic is deprecated since"
				" RFC 3261 and not supported by sipsak\n", authreq);
			exit_code(3, __PRETTY_FUNCTION__, "authentication method 'Basic' is deprecated");
		}
		if ((begin=STRCASESTR(auth, "Digest"))==NULL) {
			fprintf(stderr, "%s\nerror: couldn't find authentication method Digest in "
				"the 40[1|7] response above\n", authreq);
			exit_code(3, __PRETTY_FUNCTION__, "missing authentication method 'Digest' in reply");
		}
		if ((begin=STRCASESTR(auth, "algorithm="))!=NULL) {
			begin+=10;
			if ((STRNCASECMP(begin, "MD5", 3))==0 || (STRNCASECMP(begin, "\"MD5\"", 5))==0) {
				algo = SIPSAK_ALGO_MD5;
			}
#ifdef HAVE_OPENSSL_SHA1
			else if ((STRNCASECMP(begin, "SHA1", 4))==0 || (STRNCASECMP(begin, "\"SHA1\"", 6))==0) {
				algo = SIPSAK_ALGO_SHA1;
			}
			else if ((STRNCASECMP(begin, "SHA-256", 7))==0 || (STRNCASECMP(begin, "\"SHA-256\"", 9))==0) {
				algo = SIPSAK_ALGO_SHA256;
			}
#endif
			else {
				fprintf(stderr, "\n%s\nerror: unsupported authentication algorithm\n", authreq);
				exit_code(2, __PRETTY_FUNCTION__, "unsupported authentication algorithm");
			}
		}
		else {
			algo = SIPSAK_ALGO_MD5;
		}
		/* we need the username at some points */
		if (auth_username != NULL) {
			usern = auth_username;
		}
		else {
			usern=str_alloc(strlen(username)+11);
			if (nameend>0)
				snprintf(usern, strlen(username)+10, "%s%i", username, namebeg);
			else
				snprintf(usern, strlen(username)+10, "%s", username);
		}
		/* extract the method from the original request */
		end=strchr(message, ' ');
		method=str_alloc((size_t)(end-message+1));
		strncpy(method, message, (size_t)(end-message));
		/* extract the uri also */
		begin=end++;
		begin++;
		end=strchr(end, ' ');
		uri=str_alloc((size_t)(end-begin+1));
		strncpy(uri, begin, (size_t)(end-begin));

		/* lets start with some basic stuff... username, uri and algorithm */
		if (proxy_auth == 1) {
			snprintf(insert, PROXYAUZ_STR_LEN+1, PROXYAUZ_STR);
			insert+=PROXYAUZ_STR_LEN;
		}
		else {
			snprintf(insert, AUTH_STR_LEN+1, AUTH_STR);
			insert+=AUTH_STR_LEN;
		}
		snprintf(insert, strlen(usern)+14, "username=\"%s\", ", usern);
		insert+=strlen(insert);
		snprintf(insert, strlen(uri)+9, "uri=\"%s\", ", uri);
		insert+=strlen(insert);
		snprintf(insert, ALGO_STR_LEN+1, ALGO_STR);
		insert+=ALGO_STR_LEN;
		if (algo == SIPSAK_ALGO_MD5) {
			snprintf(insert, MD5_STR_LEN+1, MD5_STR);
			insert+=MD5_STR_LEN;
		}
#ifdef HAVE_OPENSSL_SHA1
		else if (algo == SIPSAK_ALGO_SHA1) {
			snprintf(insert, SHA1_STR_LEN+1, SHA1_STR);
			insert+=SHA1_STR_LEN;
		}
		else if (algo == SIPSAK_ALGO_SHA256) {
			snprintf(insert, SHA256_STR_LEN+1, SHA256_STR);
			insert+=SHA256_STR_LEN;
		}
#endif
		/* search for the realm, copy it to request and extract it for hash*/
		if ((begin=STRCASESTR(auth, REALM_STR))!=NULL) {
			end=strchr(begin, ',');
			if (!end)
				end=strchr(begin, '\r');
			strncpy(insert, begin, (size_t)(end-begin+1));
			insert=insert+(end-begin+1);
			if (*(insert-1) == '\r')
				*(insert-1)=',';
			snprintf(insert, 2, " ");
			insert++;
			begin+=REALM_STR_LEN+1;
			end--;
			realm=str_alloc((size_t)(end-begin+1));
			strncpy(realm, begin, (size_t)(end-begin));
		}
		else {
			fprintf(stderr, "%s\nerror: realm not found in 401 above\n", authreq);
			exit_code(3, __PRETTY_FUNCTION__, "realm not found in reply");
		}
		/* copy opaque if needed */
		if ((begin=STRCASESTR(auth, OPAQUE_STR))!=NULL) {
			end=strchr(begin, ',');
			if (!end) {
				end=strchr(begin, '\r');
			}
			strncpy(insert, begin, (size_t)(end-begin+1));
			insert=insert+(end-begin+1);
			if (*(insert-1) == '\r')
				*(insert-1)=',';
			snprintf(insert, 2, " ");
			insert++;
		}
		/* lets see if qop=auth is uspported */
		if ((begin=STRCASESTR(auth, QOP_STR))!=NULL) {
			if (STRCASESTR(begin, QOPAUTH_STR)==NULL) {
				fprintf(stderr, "response\n%s\nerror: qop \"auth\" not supported by"
					" server\n", authreq);
				exit_code(3, __PRETTY_FUNCTION__, "qop 'auth' is not supported by server");
			}
			qop_auth=1;
		}
		/* search, copy and extract the nonce */
		if ((begin=STRCASESTR(auth, NONCE_STR))!=NULL) {
			end=strchr(begin, ',');
			if (!end)
				end=strchr(begin, '\r');
			strncpy(insert, begin, (size_t)(end-begin+1));
			insert=insert+(end-begin+1);
			if (*(insert-1) == '\r')
				*(insert-1)=',';
			snprintf(insert, 2, " ");
			insert++;
			begin+=NONCE_STR_LEN+1;
			end--;
			nonce=str_alloc((size_t)(end-begin+1));
			strncpy(nonce, begin, (size_t)(end-begin));
		}
		else {
			fprintf(stderr, "%s\nerror: nonce not found in 401 above\n", authreq);
			exit_code(3, __PRETTY_FUNCTION__, "missing nonce in reply");
		}
		/* if qop is supported we need som additional header */
		if (qop_auth == 1) {
			snprintf(insert, QOP_STR_LEN+QOPAUTH_STR_LEN+3, "%s%s, ", QOP_STR, QOPAUTH_STR);
			insert+=strlen(insert);
			nonce_count++;
			snprintf(insert, NC_STR_LEN+11, "%s%08x, ", NC_STR, nonce_count);
			insert+=strlen(insert);
			cnonce=(unsigned int)rand();
			snprintf(insert, 12+8, "cnonce=\"%x\", ", cnonce);
			insert+=strlen(insert);
			/* hopefully 100 is enough */
			qop_tmp=str_alloc(100);
			snprintf(qop_tmp, 8+8+8, "%08x:%x:auth:", nonce_count, cnonce);
		}
		/* if no password is given we try it with empty password */
		if (!password)
			password = EMPTY_STR;

		if (algo == SIPSAK_ALGO_MD5) {
			if (authhash) {
				strncpy((char*)&ha1_hex[0], authhash, SIPSAK_HASHHEXLEN_MD5);
			}
			else {
				MD5Init(&Md5Ctx);
				MD5Update(&Md5Ctx, usern, (unsigned int)strlen(usern));
				MD5Update(&Md5Ctx, ":", 1);
				MD5Update(&Md5Ctx, realm, (unsigned int)strlen(realm));
				MD5Update(&Md5Ctx, ":", 1);
				MD5Update(&Md5Ctx, password, (unsigned int)strlen(password));
				MD5Final(&ha1[0], &Md5Ctx);
				cvt_hex(&ha1[0], &ha1_hex[0], SIPSAK_HASHLEN_MD5);
			}

			MD5Init(&Md5Ctx);
			MD5Update(&Md5Ctx, method, (unsigned int)strlen(method));
			MD5Update(&Md5Ctx, ":", 1);
			MD5Update(&Md5Ctx, uri, (unsigned int)strlen(uri));
			MD5Final(&ha2[0], &Md5Ctx);
			cvt_hex(&ha2[0], &ha2_hex[0], SIPSAK_HASHLEN_MD5);

			MD5Init(&Md5Ctx);
			MD5Update(&Md5Ctx, &ha1_hex, SIPSAK_HASHHEXLEN_MD5);
			MD5Update(&Md5Ctx, ":", 1);
			MD5Update(&Md5Ctx, nonce, (unsigned int)strlen(nonce));
			MD5Update(&Md5Ctx, ":", 1);
			if (qop_auth == 1) {
				MD5Update(&Md5Ctx, qop_tmp, (unsigned int)strlen(qop_tmp));
			}
			MD5Update(&Md5Ctx, &ha2_hex, SIPSAK_HASHHEXLEN_MD5);
			MD5Final(&resp[0], &Md5Ctx);
			cvt_hex(&resp[0], &resp_hex[0], SIPSAK_HASHLEN_MD5);
		}
#ifdef HAVE_OPENSSL_SHA1
		else if (algo == SIPSAK_ALGO_SHA1) {
			if (authhash) {
				strncpy((char*)&ha1_hex[0], authhash, SIPSAK_HASHHEXLEN_SHA1);
			}
			else {
				SHA1_Init(&Sha1Ctx);
				SHA1_Update(&Sha1Ctx, usern, (unsigned int)strlen(usern));
				SHA1_Update(&Sha1Ctx, ":", 1);
				SHA1_Update(&Sha1Ctx, realm, (unsigned int)strlen(realm));
				SHA1_Update(&Sha1Ctx, ":", 1);
				SHA1_Update(&Sha1Ctx, password, (unsigned int)strlen(password));
				SHA1_Final(&ha1[0], &Sha1Ctx);
				cvt_hex(&ha1[0], &ha1_hex[0], SIPSAK_HASHLEN_SHA1);
			}

			SHA1_Init(&Sha1Ctx);
			SHA1_Update(&Sha1Ctx, method, (unsigned int)strlen(method));
			SHA1_Update(&Sha1Ctx, ":", 1);
			SHA1_Update(&Sha1Ctx, uri, (unsigned int)strlen(uri));
			SHA1_Final(&ha2[0], &Sha1Ctx);
			cvt_hex(&ha2[0], &ha2_hex[0], SIPSAK_HASHLEN_SHA1);

			SHA1_Init(&Sha1Ctx);
			SHA1_Update(&Sha1Ctx, &ha1_hex, SIPSAK_HASHHEXLEN_SHA1);
			SHA1_Update(&Sha1Ctx, ":", 1);
			SHA1_Update(&Sha1Ctx, nonce, (unsigned int)strlen(nonce));
			SHA1_Update(&Sha1Ctx, ":", 1);
			if (qop_auth == 1) {
				SHA1_Update(&Sha1Ctx, qop_tmp, (unsigned int)strlen(qop_tmp));
			}
			SHA1_Update(&Sha1Ctx, &ha2_hex, SIPSAK_HASHHEXLEN_SHA1);
			SHA1_Final(&resp[0], &Sha1Ctx);
			cvt_hex(&resp[0], &resp_hex[0], SIPSAK_HASHLEN_SHA1);
		}
		else if (algo == SIPSAK_ALGO_SHA256) {
			if (authhash) {
				strncpy((char*)&ha1_hex[0], authhash, SIPSAK_HASHHEXLEN_SHA256);
			}
			else {
				SHA256_Init(&Sha256Ctx);
				SHA256_Update(&Sha256Ctx, usern, (unsigned int)strlen(usern));
				SHA256_Update(&Sha256Ctx, ":", 1);
				SHA256_Update(&Sha256Ctx, realm, (unsigned int)strlen(realm));
				SHA256_Update(&Sha256Ctx, ":", 1);
				SHA256_Update(&Sha256Ctx, password, (unsigned int)strlen(password));
				SHA256_Final(&ha1[0], &Sha256Ctx);
				cvt_hex(&ha1[0], &ha1_hex[0], SIPSAK_HASHLEN_SHA256);
			}

			SHA256_Init(&Sha256Ctx);
			SHA256_Update(&Sha256Ctx, method, (unsigned int)strlen(method));
			SHA256_Update(&Sha256Ctx, ":", 1);
			SHA256_Update(&Sha256Ctx, uri, (unsigned int)strlen(uri));
			SHA256_Final(&ha2[0], &Sha256Ctx);
			cvt_hex(&ha2[0], &ha2_hex[0], SIPSAK_HASHLEN_SHA256);

			SHA256_Init(&Sha256Ctx);
			SHA256_Update(&Sha256Ctx, &ha1_hex, SIPSAK_HASHHEXLEN_SHA256);
			SHA256_Update(&Sha256Ctx, ":", 1);
			SHA256_Update(&Sha256Ctx, nonce, (unsigned int)strlen(nonce));
			SHA256_Update(&Sha256Ctx, ":", 1);
			if (qop_auth == 1) {
				SHA256_Update(&Sha256Ctx, qop_tmp, (unsigned int)strlen(qop_tmp));
			}
			SHA256_Update(&Sha256Ctx, &ha2_hex, SIPSAK_HASHHEXLEN_SHA256);
			SHA256_Final(&resp[0], &Sha256Ctx);
			cvt_hex(&resp[0], &resp_hex[0], SIPSAK_HASHLEN_SHA256);
		}
#endif

		snprintf(insert, RESPONSE_STR_LEN+1, RESPONSE_STR);
		insert+=RESPONSE_STR_LEN;
		snprintf(insert, sizeof(resp_hex) + 8,"\"%s\"\r\n", &resp_hex[0]);
		insert+=strlen(insert);
		/* the auth header is complete, reinsert the rest of the request */
		strncpy(insert, backup, strlen(backup));
	}
	else {
		fprintf(stderr, "%s\nerror: couldn't find Proxy- or WWW-Authentication header"
			" in the 401 response above\n",	authreq);
		exit_code(3, __PRETTY_FUNCTION__, "missing authentication header in reply");
	}
	if (verbose>1)
		printf("authorizing\n");
	/* hopefully we free all here */
	free(backup);
	free(auth);
	free(method);
	free(uri);
	free(realm);
	free(nonce);
	if (auth_username == NULL) free(usern);
	if (qop_auth == 1) free(qop_tmp);
}