res_sendsigned.c

   1 #ifndef __APPLE__
   2 #include "port_before.h"
   3 #include "fd_setsize.h"
   4 #endif
   5
   6 #include <sys/types.h>
   7 #include <sys/param.h>
   8
   9 #include <netinet/in.h>
  10 #include <arpa/nameser.h>
  11 #include <arpa/inet.h>
  12
  13 #include <errno.h>
  14 #include <netdb.h>
  15 #include <resolv.h>
  16 #include <stdio.h>
  17 #include <stdlib.h>
  18 #include <string.h>
  19 #include <unistd.h>
  20
  21 #ifndef __APPLE__
  22 #include <isc/dst.h>
  23 #include "port_after.h"
  24 #else
  25 #include "dst.h"
  26 #endif
  27
  28 #include "res_private.h"
  29
  30 // #define DEBUG
  31 #include "res_debug.h"
  32
  33
  34 /* res_nsendsigned */
  35 int
  36 res_nsendsigned(res_state statp, const u_char *msg, int msglen,
  37                 ns_tsig_key *key, u_char *answer, int anslen)
  38 {
  39         res_state nstatp;
  40         DST_KEY *dstkey;
  41         int usingTCP = 0;
  42         u_char *newmsg;
  43         int newmsglen, bufsize, siglen;
  44         u_char sig[64];
  45         HEADER *hp;
  46         time_t tsig_time;
  47         int ret;
  48
  49         dst_init();
  50
  51         nstatp = (res_state) malloc(sizeof(*statp));
  52         if (nstatp == NULL) {
  53                 errno = ENOMEM;
  54                 return (-1);
  55         }
  56         memcpy(nstatp, statp, sizeof(*statp));
  57         nstatp->_pad = 9;
  58
  59         bufsize = msglen + 1024;
  60         newmsg = (u_char *) malloc(bufsize);
  61         if (newmsg == NULL) {
  62                 errno = ENOMEM;
  63                 return (-1);
  64         }
  65         memcpy(newmsg, msg, msglen);
  66         newmsglen = msglen;
  67
  68         if (ns_samename(key->alg, NS_TSIG_ALG_HMAC_MD5) != 1)
  69                 dstkey = NULL;
  70         else
  71                 dstkey = dst_buffer_to_key(key->name, KEY_HMAC_MD5,
  72                                            NS_KEY_TYPE_AUTH_ONLY,
  73                                            NS_KEY_PROT_ANY,
  74                                            key->data, key->len);
  75         if (dstkey == NULL) {
  76                 errno = EINVAL;
  77                 free(nstatp);
  78                 free(newmsg);
  79                 return (-1);
  80         }
  81
  82         nstatp->nscount = 1;
  83         siglen = sizeof(sig);
  84         ret = ns_sign(newmsg, &newmsglen, bufsize, ns_r_noerror, dstkey, NULL, 0,
  85                       sig, &siglen, 0);
  86         if (ret < 0) {
  87                 free (nstatp);
  88                 free (newmsg);
  89                 dst_free_key(dstkey);
  90                 if (ret == NS_TSIG_ERROR_NO_SPACE)
  91                         errno  = EMSGSIZE;
  92                 else if (ret == -1)
  93                         errno  = EINVAL;
  94                 return (ret);
  95         }
  96
  97         if (newmsglen > NS_PACKETSZ || (nstatp->options & RES_IGNTC))
  98                 usingTCP = 1;
  99         if (usingTCP == 0)
 100                 nstatp->options |= RES_IGNTC;
 101         else
 102                 nstatp->options |= RES_USEVC;
 103
 104 retry:
 105
 106         ret = res_nsend(nstatp, newmsg, newmsglen, answer, anslen);
 107         if (ret < 0) {
 108                 free (nstatp);
 109                 free (newmsg);
 110                 dst_free_key(dstkey);
 111                 return (ret);
 112         }
 113
 114         anslen = ret;
 115         ret = ns_verify(answer, &anslen, dstkey, sig, siglen,
 116                         NULL, NULL, &tsig_time, nstatp->options & RES_KEEPTSIG);
 117         if (ret != 0) {
 118                 Dprint(nstatp->pfcode & RES_PRF_REPLY,
 119                        (stdout, ";; TSIG invalid (%s)\n", p_rcode(ret)));
 120                 free (nstatp);
 121                 free (newmsg);
 122                 dst_free_key(dstkey);
 123                 if (ret == -1)
 124                         errno = EINVAL;
 125                 else
 126                         errno = ENOTTY;
 127                 return (-1);
 128         }
 129         Dprint(nstatp->pfcode & RES_PRF_REPLY, (stdout, ";; TSIG ok\n"));
 130
 131         hp = (HEADER *) answer;
 132         if (hp->tc && usingTCP == 0) {
 133                 nstatp->options &= ~RES_IGNTC;
 134                 usingTCP = 1;
 135                 goto retry;
 136         }
 137
 138         free (nstatp);
 139         free (newmsg);
 140         dst_free_key(dstkey);
 141         return (anslen);
 142 }