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/*
* 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 2 of the License, or
* (at your option) any later version.
*
* 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; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*
* Author : F. Tarek Rogers - 01 Sept 2004
*/
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <ctype.h>
#include <openssl/md5.h>
#define MAX_HEADER_LEN 1025
#define MD5_HASH_SIZE 16
#define HASH_HEX_SIZE 2*MD5_HASH_SIZE
/* This function is from RFC 2617 Section 5 */
void hashToHex (unsigned char *_b, unsigned char *_h)
{
unsigned short i;
unsigned char j;
for (i = 0; i < MD5_HASH_SIZE; i++) {
j = (_b[i] >> 4) & 0xf;
if (j <= 9) {
_h[i * 2] = (j + '0');
} else {
_h[i * 2] = (j + 'a' - 10);
}
j = _b[i] & 0xf;
if (j <= 9) {
_h[i * 2 + 1] = (j + '0');
} else {
_h[i * 2 + 1] = (j + 'a' - 10);
}
};
_h[HASH_HEX_SIZE] = '\0';
}
char *stristr (const char *s1, const char *s2) {
char *cp = (char*) s1;
char *p1, *p2, *endp;
char l, r;
endp = (char*)s1 + (strlen(s1) - strlen(s2)) ;
while (*cp && (cp <= endp)) {
p1 = cp;
p2 = (char*)s2;
while (*p1 && *p2) {
l = toupper(*p1);
r = toupper(*p2);
if (l != r) {
break;
}
p1++;
p2++;
}
if (*p2 == 0) {
return cp;
}
cp++;
}
return 0;
}
int createAuthHeader(char * user, char * password, char * method,
char * uri, char * msgbody, char * auth, char * result) {
unsigned char ha1[MD5_HASH_SIZE], ha2[MD5_HASH_SIZE];
unsigned char resp[MD5_HASH_SIZE], body[MD5_HASH_SIZE];
unsigned char ha1_hex[HASH_HEX_SIZE+1], ha2_hex[HASH_HEX_SIZE+1];
unsigned char resp_hex[HASH_HEX_SIZE+1], body_hex[HASH_HEX_SIZE+1];
char tmp[MAX_HEADER_LEN], authtype[16], cnonce[32], nc[32], algo[32], opaque[64];
char *start, *end;
static unsigned int mync = 1;
int has_opaque = 0;
MD5_CTX Md5Ctx;
if ((start = stristr(auth, "Digest")) == NULL) {
sprintf(result, "createAuthHeader: authentication must be digest");
return 0;
}
// extract the algo. If it is not "MD5", exit with an error
if ((start = stristr(auth, "algorithm=")) != NULL) {
start = start + strlen("algorithm=");
if (*start == '"') { start++; }
end = start + strcspn(start, " ,\"\r\n");
strncpy(algo, start, end - start);
algo[end - start] ='\0';
if (strncasecmp(algo, "MD5", 3)) {
sprintf(result, "createAuthHeader: authentication must use MD5");
return 0;
}
}
// Extract the Auth Type - If not present, using 'none'
cnonce[0] = '\0';
if ((start = stristr(auth, "qop=")) != NULL) {
start = start + strlen("qop=");
if (*start == '"') { start++; }
end = start + strcspn(start, " ,\"\r\n");
strncpy(authtype, start, end - start);
authtype[end - start] ='\0';
sprintf(cnonce, "%x", rand());
sprintf(nc, "%08x", mync++);
}
// Extract the Opaque value - if present
opaque[0] = '\0';
if ((start = stristr(auth, "opaque=")) != NULL) {
start = start + strlen("opaque=");
if (*start == '"') { start++; }
end = start + strcspn(start, " ,\"\r\n");
strncpy(opaque, start, end - start);
opaque[end - start] ='\0';
has_opaque = 1;
}
// Extract the Realm
if ((start = stristr(auth, "realm=")) == NULL) {
sprintf(result, "createAuthHeader: couldn't parse realm");
return 0;
}
start = start + strlen("realm=");
if (*start == '"') { start++; }
end = start + strcspn(start, " ,\"\r\n");
strncpy(tmp, start, end - start);
tmp[end - start] ='\0';
// Load in A1
MD5_Init(&Md5Ctx);
MD5_Update(&Md5Ctx, user, strlen(user));
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, tmp, strlen(tmp));
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, password, strlen(password));
MD5_Final(ha1, &Md5Ctx);
hashToHex(&ha1[0], &ha1_hex[0]);
sprintf(result, "Digest username=\"%s\",realm=\"%s\"",user,tmp);
if (cnonce[0] != '\0') {
sprintf(result, "%s,cnonce=\"%s\",nc=%s,qop=\"%s\"",result,cnonce,nc,authtype);
}
// Construct the URI
sprintf(tmp, "sip:%s", uri);
// If using Auth-Int make a hash of the body - which is NULL for REG
if (stristr(authtype, "auth-int") != NULL) {
MD5_Init(&Md5Ctx);
MD5_Update(&Md5Ctx, msgbody, strlen(msgbody));
MD5_Final(body, &Md5Ctx);
hashToHex(&body[0], &body_hex[0]);
}
// Load in A2
MD5_Init(&Md5Ctx);
MD5_Update(&Md5Ctx, method, strlen(method));
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, tmp, strlen(tmp));
if (stristr(authtype, "auth-int") != NULL) {
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, &body_hex, HASH_HEX_SIZE);
}
MD5_Final(ha2, &Md5Ctx);
hashToHex(&ha2[0], &ha2_hex[0]);
sprintf(result, "%s,uri=\"%s\"",result,tmp);
// Extract the Nonce
if ((start = stristr(auth, "nonce=")) == NULL) {
sprintf(result, "createAuthHeader: couldn't parse nonce");
return 0;
}
start = start + strlen("nonce=");
if (*start == '"') { start++; }
end = start + strcspn(start, " ,\"\r\n");
strncpy(tmp, start, end - start);
tmp[end - start] ='\0';
MD5_Init(&Md5Ctx);
MD5_Update(&Md5Ctx, &ha1_hex, HASH_HEX_SIZE);
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, tmp, strlen(tmp));
if (cnonce[0] != '\0') {
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, nc, strlen(nc));
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, cnonce, strlen(cnonce));
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, authtype, strlen(authtype));
}
MD5_Update(&Md5Ctx, ":", 1);
MD5_Update(&Md5Ctx, &ha2_hex, HASH_HEX_SIZE);
MD5_Final(resp, &Md5Ctx);
hashToHex(&resp[0], &resp_hex[0]);
sprintf(result, "%s,nonce=\"%s\",response=\"%s\",algorithm=md5",result,tmp,resp_hex);
if (has_opaque) {
sprintf(result, "%s,opaque=\"%s\"",result,opaque);
}
return 1;
}
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