authsaslclientcram.c

   1 /* $Id: authsaslclientcram.c,v 1.5 2008/07/10 02:43:55 mrsam Exp $ */
   2
   3 /*
   4 ** Copyright 2000-2008 Double Precision, Inc.  See COPYING for
   5 ** distribution information.
   6 */
   7
   8 #include        "courier_auth_config.h"
   9 #include        "courierauthsasl.h"
  10 #include        "libhmac/hmac.h"
  11 #include        "authsaslclient.h"
  12 #include        <stdlib.h>
  13 #include        <stdio.h>
  14 #include        <ctype.h>
  15 #include        <string.h>
  16 #include        <errno.h>
  17
  18 int authsaslclient_cram(const struct authsaslclientinfo *info,
  19                         const char *challenge,
  20                         const struct hmac_hashinfo *hashinfo)
  21 {
  22 char    *base64buf=malloc(strlen(challenge)+1);
  23 unsigned char   *keybuf;
  24 char *p;
  25 const   char *userid=info->userid ? info->userid:"";
  26 const   char *password=info->password ? info->password:"";
  27 int     i;
  28
  29         if (!base64buf)
  30         {
  31                 perror("malloc");
  32                 return (AUTHSASL_ERROR);
  33         }
  34         strcpy(base64buf, challenge);
  35
  36         if ( (i=authsasl_frombase64(base64buf))<0 ||
  37              (keybuf=(unsigned char *)malloc(hashinfo->hh_L*3)) == 0)
  38         {
  39                 free(base64buf);
  40                 perror("malloc");
  41                 return (AUTHSASL_ERROR);
  42         }
  43
  44         hmac_hashkey( hashinfo, password, strlen(password),
  45                         keybuf, keybuf+hashinfo->hh_L );
  46
  47         hmac_hashtext( hashinfo, base64buf, i,
  48                 keybuf, keybuf+hashinfo->hh_L,
  49                 keybuf+hashinfo->hh_L*2);
  50
  51         free(base64buf);
  52         base64buf=malloc(strlen(userid)+2+hashinfo->hh_L*2);
  53         if (!base64buf)
  54         {
  55                 perror("malloc");
  56                 free(keybuf);
  57                 return (AUTHSASL_ERROR);
  58         }
  59         strcat(strcpy(base64buf, userid), " ");
  60         p=base64buf+strlen(base64buf);
  61         for (i=0; i<hashinfo->hh_L; i++)
  62         {
  63         static const char xdigit[]="0123456789abcdef";
  64         int     c=keybuf[hashinfo->hh_L*2+i];
  65
  66                 *p++ = xdigit[ (c >> 4) & 0x0F ];
  67                 *p++ = xdigit[c & 0x0F];
  68         }
  69         *p=0;
  70         free(keybuf);
  71         keybuf=(unsigned char *)authsasl_tobase64(base64buf, -1);
  72         free(base64buf);
  73
  74         if (!keybuf)
  75         {
  76                 perror("malloc");
  77                 free(keybuf);
  78                 return (AUTHSASL_ERROR);
  79         }
  80         i= (*info->final_conv_func)((char *)keybuf, info->conv_func_arg);
  81         free(keybuf);
  82         return (i);
  83 }