rfc2617.c

Go to the documentation of this file.

/*
 * $Id: rfc2617.c 570 2008-06-25 13:21:32Z vingarzan $
 *
 * Digest response calculation as per RFC2617
 *
 * Copyright (C) 2001-2003 FhG Fokus
 *
 * This file is part of ser, a free SIP server.
 *
 * ser 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
 *
 * For a license to use the ser software under conditions
 * other than those described here, or to purchase support for this
 * software, please contact iptel.org by e-mail at the following addresses:
 *    info@iptel.org
 *
 * ser 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
 */


#include <sys/types.h>
#include <stdlib.h>
#include <string.h>
#include <stdio.h>

#include "rfc2617.h"
#include "../../md5global.h"
#include "../../md5.h"


static char hexa_chars[17]="0123456789abcdef";

inline void cvt_hex(HASH _b, HASHHEX _h)
{
    unsigned short i;   
    for (i = 0; i < HASHLEN; i++) {
        _h[i * 2] = hexa_chars[(_b[i] >> 4) & 0xf];
        _h[i * 2 + 1] =  hexa_chars[_b[i] & 0xf];
    };
    _h[HASHHEXLEN] = '\0';
}


/* 
 * calculate H(A1) as per spec 
 */
void calc_HA1(ha_alg_t _alg, str* _username, str* _realm, str* _password,
          str* _nonce, str* _cnonce, HASHHEX _sess_key)
{
    MD5_CTX Md5Ctx;
    HASH HA1;
    MD5Init(&Md5Ctx);
    MD5Update(&Md5Ctx, _username->s, _username->len);
    MD5Update(&Md5Ctx, ":", 1);
    MD5Update(&Md5Ctx, _realm->s, _realm->len);
    MD5Update(&Md5Ctx, ":", 1);
    MD5Update(&Md5Ctx, _password->s, _password->len);
    MD5Final(HA1, &Md5Ctx);

    if (_alg == HA_MD5_SESS) {
        MD5Init(&Md5Ctx);
        MD5Update(&Md5Ctx, HA1, HASHLEN);
        MD5Update(&Md5Ctx, ":", 1);
        MD5Update(&Md5Ctx, _nonce->s, _nonce->len);
        MD5Update(&Md5Ctx, ":", 1);
        MD5Update(&Md5Ctx, _cnonce->s, _cnonce->len);
        MD5Final(HA1, &Md5Ctx);
    };

    cvt_hex(HA1, _sess_key);
}

void calc_H(str *ent, HASHHEX hash)
{
    MD5_CTX Md5Ctx;
    HASH HA1;
    MD5Init(&Md5Ctx);
    MD5Update(&Md5Ctx, ent->s, ent->len);
    MD5Final(HA1, &Md5Ctx);
    cvt_hex(HA1, hash);
}

/* 
 * calculate request-digest/response-digest as per HTTP Digest spec 
 */
void calc_response(HASHHEX _ha1,      /* H(A1) */
           str* _nonce,       /* nonce from server */
           str* _nc,          /* 8 hex digits */
           str* _cnonce,      /* client nonce */
           str* _qop,         /* qop-value: "", "auth", "auth-int" */
           int _auth_int,     /* 1 if auth-int is used */
           str* _method,      /* method from the request */
           str* _uri,         /* requested URL */
           HASHHEX _hentity,  /* H(entity body) if qop="auth-int" */
           HASHHEX _response) /* request-digest or response-digest */
{
    MD5_CTX Md5Ctx;
    HASH HA2;
    HASH RespHash;
    HASHHEX HA2Hex;
    
         /* calculate H(A2) */
    MD5Init(&Md5Ctx);
    MD5Update(&Md5Ctx, _method->s, _method->len);
    MD5Update(&Md5Ctx, ":", 1);
    MD5Update(&Md5Ctx, _uri->s, _uri->len);

    if (_auth_int) {
        MD5Update(&Md5Ctx, ":", 1);
        MD5Update(&Md5Ctx, _hentity, HASHHEXLEN);
    };

    MD5Final(HA2, &Md5Ctx);
    cvt_hex(HA2, HA2Hex);
    
         /* calculate response */
    MD5Init(&Md5Ctx);
    MD5Update(&Md5Ctx, _ha1, HASHHEXLEN);
    MD5Update(&Md5Ctx, ":", 1);
    MD5Update(&Md5Ctx, _nonce->s, _nonce->len);
    MD5Update(&Md5Ctx, ":", 1);

    if (_qop->len) {
        MD5Update(&Md5Ctx, _nc->s, _nc->len);
        MD5Update(&Md5Ctx, ":", 1);
        MD5Update(&Md5Ctx, _cnonce->s, _cnonce->len);
        MD5Update(&Md5Ctx, ":", 1);
        MD5Update(&Md5Ctx, _qop->s, _qop->len);
        MD5Update(&Md5Ctx, ":", 1);
    };
    MD5Update(&Md5Ctx, HA2Hex, HASHHEXLEN);
    MD5Final(RespHash, &Md5Ctx);
    cvt_hex(RespHash, _response);
}

---