common/resolv/res_sendsigned.c

	res_sendsigned.c revision 7c478bd95313f5f23a4c958a745db2134aa03244
/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 *
 * No ISC copyright for this file.
 */

#pragma ident   "%Z%%M% %I% %E% SMI"

#include "port_before.h"
#include "fd_setsize.h"

#include <sys/types.h>
#include <sys/param.h>

#include <netinet/in.h>
#include <arpa/nameser.h>
#include <arpa/inet.h>

#include <isc/dst.h>

#include <errno.h>
#include <netdb.h>
#include <resolv.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

#include "port_after.h"

#define DEBUG
#include "res_debug.h"


/* res_nsendsigned */
int
res_nsendsigned(res_state statp, const u_char *msg, int msglen,
        ns_tsig_key *key, u_char *answer, int anslen)
{
    res_state nstatp;
    DST_KEY *dstkey;
    int usingTCP = 0;
    u_char *newmsg;
    int newmsglen, bufsize, siglen;
    u_char sig[64];
    HEADER *hp;
    time_t tsig_time;
    int ret;

    dst_init();

    nstatp = (res_state) malloc(sizeof(*statp));
    if (nstatp == NULL) {
        errno = ENOMEM;
        return (-1);
    }
    memcpy(nstatp, statp, sizeof(*statp));

    bufsize = msglen + 1024;
    newmsg = (u_char *) malloc(bufsize);
    if (newmsg == NULL) {
        errno = ENOMEM;
        return (-1);
    }
    memcpy(newmsg, msg, msglen);
    newmsglen = msglen;

    if (ns_samename(key->alg, NS_TSIG_ALG_HMAC_MD5) != 1)
        dstkey = NULL;
    else
        dstkey = dst_buffer_to_key(key->name, KEY_HMAC_MD5,
                       NS_KEY_TYPE_AUTH_ONLY,
                       NS_KEY_PROT_ANY,
                       key->data, key->len);
    if (dstkey == NULL) {
        errno = EINVAL;
        free(nstatp);
        free(newmsg);
        return (-1);
    }

    nstatp->nscount = 1;
    siglen = sizeof(sig);
    ret = ns_sign(newmsg, &newmsglen, bufsize, NOERROR, dstkey, NULL, 0,
              sig, &siglen, 0);
    if (ret < 0) {
        free (nstatp);
        free (newmsg);
        dst_free_key(dstkey);
        if (ret == NS_TSIG_ERROR_NO_SPACE)
            errno  = EMSGSIZE;
        else if (ret == -1)
            errno  = EINVAL;
        return (ret);
    }

    if (newmsglen > PACKETSZ || (nstatp->options & RES_IGNTC))
        usingTCP = 1;
    if (usingTCP == 0)
        nstatp->options |= RES_IGNTC;
    else
        nstatp->options |= RES_USEVC;

retry:

    ret = res_nsend(nstatp, newmsg, newmsglen, answer, anslen);
    if (ret < 0) {
        free (nstatp);
        free (newmsg);
        dst_free_key(dstkey);
        return (ret);
    }

    anslen = ret;
    ret = ns_verify(answer, &anslen, dstkey, sig, siglen,
            NULL, NULL, &tsig_time, nstatp->options & RES_KEEPTSIG);
    if (ret != 0) {
#ifdef  ORIGINAL_ISC_CODE
        Dprint(nstatp->pfcode & RES_PRF_REPLY,
               (stdout, ";; TSIG invalid (%s)\n", p_rcode(ret)));
#else
        Dprint(nstatp->pfcode & RES_PRF_REPLY,
               (stdout, ";; TSIG invalid (%s)\n", p_rcode(-ret)));
#endif
        free (nstatp);
        free (newmsg);
        dst_free_key(dstkey);
        if (ret == -1)
            errno = EINVAL;
        else
            errno = ENOTTY;
        return (-1);
    }
    Dprint(nstatp->pfcode & RES_PRF_REPLY, (stdout, ";; TSIG ok\n"));

    hp = (HEADER *) answer;
    if (hp->tc && usingTCP == 0) {
        nstatp->options &= ~RES_IGNTC;
        usingTCP = 1;
        goto retry;
    }

    free (nstatp);
    free (newmsg);
    dst_free_key(dstkey);
    return (anslen);
}