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author | peter <peter@FreeBSD.org> | 2008-07-12 05:00:28 +0000 |
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committer | peter <peter@FreeBSD.org> | 2008-07-12 05:00:28 +0000 |
commit | ba8f85b49c38af7bc2a9acdef5dcde2de008d25e (patch) | |
tree | ceac31a567976fd5866cb5791b059781f6e045de /lib/bind/nameser/ns_verify.c | |
parent | 0f328cea2580ffb8f9e363be671a517787111472 (diff) | |
download | FreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.zip FreeBSD-src-ba8f85b49c38af7bc2a9acdef5dcde2de008d25e.tar.gz |
Flatten bind9 vendor work area
Diffstat (limited to 'lib/bind/nameser/ns_verify.c')
-rw-r--r-- | lib/bind/nameser/ns_verify.c | 484 |
1 files changed, 484 insertions, 0 deletions
diff --git a/lib/bind/nameser/ns_verify.c b/lib/bind/nameser/ns_verify.c new file mode 100644 index 0000000..b80b588 --- /dev/null +++ b/lib/bind/nameser/ns_verify.c @@ -0,0 +1,484 @@ +/* + * Copyright (c) 2004 by Internet Systems Consortium, Inc. ("ISC") + * Copyright (c) 1999 by Internet Software Consortium, Inc. + * + * Permission to use, copy, modify, and distribute this software for any + * purpose with or without fee is hereby granted, provided that the above + * copyright notice and this permission notice appear in all copies. + * + * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES + * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF + * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR + * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES + * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN + * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT + * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. + */ + +#ifndef lint +static const char rcsid[] = "$Id: ns_verify.c,v 1.2.18.3 2006/03/10 00:20:08 marka Exp $"; +#endif + +/* Import. */ + +#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 <errno.h> +#include <netdb.h> +#include <resolv.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> +#include <unistd.h> + +#include <isc/dst.h> + +#include "port_after.h" + +/* Private. */ + +#define BOUNDS_CHECK(ptr, count) \ + do { \ + if ((ptr) + (count) > eom) { \ + return (NS_TSIG_ERROR_FORMERR); \ + } \ + } while (0) + +/* Public. */ + +u_char * +ns_find_tsig(u_char *msg, u_char *eom) { + HEADER *hp = (HEADER *)msg; + int n, type; + u_char *cp = msg, *start; + + if (msg == NULL || eom == NULL || msg > eom) + return (NULL); + + if (cp + HFIXEDSZ >= eom) + return (NULL); + + if (hp->arcount == 0) + return (NULL); + + cp += HFIXEDSZ; + + n = ns_skiprr(cp, eom, ns_s_qd, ntohs(hp->qdcount)); + if (n < 0) + return (NULL); + cp += n; + + n = ns_skiprr(cp, eom, ns_s_an, ntohs(hp->ancount)); + if (n < 0) + return (NULL); + cp += n; + + n = ns_skiprr(cp, eom, ns_s_ns, ntohs(hp->nscount)); + if (n < 0) + return (NULL); + cp += n; + + n = ns_skiprr(cp, eom, ns_s_ar, ntohs(hp->arcount) - 1); + if (n < 0) + return (NULL); + cp += n; + + start = cp; + n = dn_skipname(cp, eom); + if (n < 0) + return (NULL); + cp += n; + if (cp + INT16SZ >= eom) + return (NULL); + + GETSHORT(type, cp); + if (type != ns_t_tsig) + return (NULL); + return (start); +} + +/* ns_verify + * + * Parameters: + *\li statp res stuff + *\li msg received message + *\li msglen length of message + *\li key tsig key used for verifying. + *\li querysig (response), the signature in the query + *\li querysiglen (response), the length of the signature in the query + *\li sig (query), a buffer to hold the signature + *\li siglen (query), input - length of signature buffer + * output - length of signature + * + * Errors: + *\li - bad input (-1) + *\li - invalid dns message (NS_TSIG_ERROR_FORMERR) + *\li - TSIG is not present (NS_TSIG_ERROR_NO_TSIG) + *\li - key doesn't match (-ns_r_badkey) + *\li - TSIG verification fails with BADKEY (-ns_r_badkey) + *\li - TSIG verification fails with BADSIG (-ns_r_badsig) + *\li - TSIG verification fails with BADTIME (-ns_r_badtime) + *\li - TSIG verification succeeds, error set to BAKEY (ns_r_badkey) + *\li - TSIG verification succeeds, error set to BADSIG (ns_r_badsig) + *\li - TSIG verification succeeds, error set to BADTIME (ns_r_badtime) + */ +int +ns_verify(u_char *msg, int *msglen, void *k, + const u_char *querysig, int querysiglen, u_char *sig, int *siglen, + time_t *timesigned, int nostrip) +{ + HEADER *hp = (HEADER *)msg; + DST_KEY *key = (DST_KEY *)k; + u_char *cp = msg, *eom; + char name[MAXDNAME], alg[MAXDNAME]; + u_char *recstart, *rdatastart; + u_char *sigstart, *otherstart; + int n; + int error; + u_int16_t type, length; + u_int16_t fudge, sigfieldlen, otherfieldlen; + + dst_init(); + if (msg == NULL || msglen == NULL || *msglen < 0) + return (-1); + + eom = msg + *msglen; + + recstart = ns_find_tsig(msg, eom); + if (recstart == NULL) + return (NS_TSIG_ERROR_NO_TSIG); + + cp = recstart; + + /* Read the key name. */ + n = dn_expand(msg, eom, cp, name, MAXDNAME); + if (n < 0) + return (NS_TSIG_ERROR_FORMERR); + cp += n; + + /* Read the type. */ + BOUNDS_CHECK(cp, 2*INT16SZ + INT32SZ + INT16SZ); + GETSHORT(type, cp); + if (type != ns_t_tsig) + return (NS_TSIG_ERROR_NO_TSIG); + + /* Skip the class and TTL, save the length. */ + cp += INT16SZ + INT32SZ; + GETSHORT(length, cp); + if (eom - cp != length) + return (NS_TSIG_ERROR_FORMERR); + + /* Read the algorithm name. */ + rdatastart = cp; + n = dn_expand(msg, eom, cp, alg, MAXDNAME); + if (n < 0) + return (NS_TSIG_ERROR_FORMERR); + if (ns_samename(alg, NS_TSIG_ALG_HMAC_MD5) != 1) + return (-ns_r_badkey); + cp += n; + + /* Read the time signed and fudge. */ + BOUNDS_CHECK(cp, INT16SZ + INT32SZ + INT16SZ); + cp += INT16SZ; + GETLONG((*timesigned), cp); + GETSHORT(fudge, cp); + + /* Read the signature. */ + BOUNDS_CHECK(cp, INT16SZ); + GETSHORT(sigfieldlen, cp); + BOUNDS_CHECK(cp, sigfieldlen); + sigstart = cp; + cp += sigfieldlen; + + /* Skip id and read error. */ + BOUNDS_CHECK(cp, 2*INT16SZ); + cp += INT16SZ; + GETSHORT(error, cp); + + /* Parse the other data. */ + BOUNDS_CHECK(cp, INT16SZ); + GETSHORT(otherfieldlen, cp); + BOUNDS_CHECK(cp, otherfieldlen); + otherstart = cp; + cp += otherfieldlen; + + if (cp != eom) + return (NS_TSIG_ERROR_FORMERR); + + /* Verify that the key used is OK. */ + if (key != NULL) { + if (key->dk_alg != KEY_HMAC_MD5) + return (-ns_r_badkey); + if (error != ns_r_badsig && error != ns_r_badkey) { + if (ns_samename(key->dk_key_name, name) != 1) + return (-ns_r_badkey); + } + } + + hp->arcount = htons(ntohs(hp->arcount) - 1); + + /* + * Do the verification. + */ + + if (key != NULL && error != ns_r_badsig && error != ns_r_badkey) { + void *ctx; + u_char buf[MAXDNAME]; + u_char buf2[MAXDNAME]; + + /* Digest the query signature, if this is a response. */ + dst_verify_data(SIG_MODE_INIT, key, &ctx, NULL, 0, NULL, 0); + if (querysiglen > 0 && querysig != NULL) { + u_int16_t len_n = htons(querysiglen); + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, + (u_char *)&len_n, INT16SZ, NULL, 0); + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, + querysig, querysiglen, NULL, 0); + } + + /* Digest the message. */ + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, msg, recstart - msg, + NULL, 0); + + /* Digest the key name. */ + n = ns_name_pton(name, buf2, sizeof(buf2)); + if (n < 0) + return (-1); + n = ns_name_ntol(buf2, buf, sizeof(buf)); + if (n < 0) + return (-1); + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, buf, n, NULL, 0); + + /* Digest the class and TTL. */ + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, + recstart + dn_skipname(recstart, eom) + INT16SZ, + INT16SZ + INT32SZ, NULL, 0); + + /* Digest the algorithm. */ + n = ns_name_pton(alg, buf2, sizeof(buf2)); + if (n < 0) + return (-1); + n = ns_name_ntol(buf2, buf, sizeof(buf)); + if (n < 0) + return (-1); + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, buf, n, NULL, 0); + + /* Digest the time signed and fudge. */ + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, + rdatastart + dn_skipname(rdatastart, eom), + INT16SZ + INT32SZ + INT16SZ, NULL, 0); + + /* Digest the error and other data. */ + dst_verify_data(SIG_MODE_UPDATE, key, &ctx, + otherstart - INT16SZ - INT16SZ, + otherfieldlen + INT16SZ + INT16SZ, NULL, 0); + + n = dst_verify_data(SIG_MODE_FINAL, key, &ctx, NULL, 0, + sigstart, sigfieldlen); + + if (n < 0) + return (-ns_r_badsig); + + if (sig != NULL && siglen != NULL) { + if (*siglen < sigfieldlen) + return (NS_TSIG_ERROR_NO_SPACE); + memcpy(sig, sigstart, sigfieldlen); + *siglen = sigfieldlen; + } + } else { + if (sigfieldlen > 0) + return (NS_TSIG_ERROR_FORMERR); + if (sig != NULL && siglen != NULL) + *siglen = 0; + } + + /* Reset the counter, since we still need to check for badtime. */ + hp->arcount = htons(ntohs(hp->arcount) + 1); + + /* Verify the time. */ + if (abs((*timesigned) - time(NULL)) > fudge) + return (-ns_r_badtime); + + if (nostrip == 0) { + *msglen = recstart - msg; + hp->arcount = htons(ntohs(hp->arcount) - 1); + } + + if (error != NOERROR) + return (error); + + return (0); +} + +int +ns_verify_tcp_init(void *k, const u_char *querysig, int querysiglen, + ns_tcp_tsig_state *state) +{ + dst_init(); + if (state == NULL || k == NULL || querysig == NULL || querysiglen < 0) + return (-1); + state->counter = -1; + state->key = k; + if (state->key->dk_alg != KEY_HMAC_MD5) + return (-ns_r_badkey); + if (querysiglen > (int)sizeof(state->sig)) + return (-1); + memcpy(state->sig, querysig, querysiglen); + state->siglen = querysiglen; + return (0); +} + +int +ns_verify_tcp(u_char *msg, int *msglen, ns_tcp_tsig_state *state, + int required) +{ + HEADER *hp = (HEADER *)msg; + u_char *recstart, *sigstart; + unsigned int sigfieldlen, otherfieldlen; + u_char *cp, *eom, *cp2; + char name[MAXDNAME], alg[MAXDNAME]; + u_char buf[MAXDNAME]; + int n, type, length, fudge, error; + time_t timesigned; + + if (msg == NULL || msglen == NULL || state == NULL) + return (-1); + + eom = msg + *msglen; + + state->counter++; + if (state->counter == 0) + return (ns_verify(msg, msglen, state->key, + state->sig, state->siglen, + state->sig, &state->siglen, ×igned, 0)); + + if (state->siglen > 0) { + u_int16_t siglen_n = htons(state->siglen); + + dst_verify_data(SIG_MODE_INIT, state->key, &state->ctx, + NULL, 0, NULL, 0); + dst_verify_data(SIG_MODE_UPDATE, state->key, &state->ctx, + (u_char *)&siglen_n, INT16SZ, NULL, 0); + dst_verify_data(SIG_MODE_UPDATE, state->key, &state->ctx, + state->sig, state->siglen, NULL, 0); + state->siglen = 0; + } + + cp = recstart = ns_find_tsig(msg, eom); + + if (recstart == NULL) { + if (required) + return (NS_TSIG_ERROR_NO_TSIG); + dst_verify_data(SIG_MODE_UPDATE, state->key, &state->ctx, + msg, *msglen, NULL, 0); + return (0); + } + + hp->arcount = htons(ntohs(hp->arcount) - 1); + dst_verify_data(SIG_MODE_UPDATE, state->key, &state->ctx, + msg, recstart - msg, NULL, 0); + + /* Read the key name. */ + n = dn_expand(msg, eom, cp, name, MAXDNAME); + if (n < 0) + return (NS_TSIG_ERROR_FORMERR); + cp += n; + + /* Read the type. */ + BOUNDS_CHECK(cp, 2*INT16SZ + INT32SZ + INT16SZ); + GETSHORT(type, cp); + if (type != ns_t_tsig) + return (NS_TSIG_ERROR_NO_TSIG); + + /* Skip the class and TTL, save the length. */ + cp += INT16SZ + INT32SZ; + GETSHORT(length, cp); + if (eom - cp != length) + return (NS_TSIG_ERROR_FORMERR); + + /* Read the algorithm name. */ + n = dn_expand(msg, eom, cp, alg, MAXDNAME); + if (n < 0) + return (NS_TSIG_ERROR_FORMERR); + if (ns_samename(alg, NS_TSIG_ALG_HMAC_MD5) != 1) + return (-ns_r_badkey); + cp += n; + + /* Verify that the key used is OK. */ + if ((ns_samename(state->key->dk_key_name, name) != 1 || + state->key->dk_alg != KEY_HMAC_MD5)) + return (-ns_r_badkey); + + /* Read the time signed and fudge. */ + BOUNDS_CHECK(cp, INT16SZ + INT32SZ + INT16SZ); + cp += INT16SZ; + GETLONG(timesigned, cp); + GETSHORT(fudge, cp); + + /* Read the signature. */ + BOUNDS_CHECK(cp, INT16SZ); + GETSHORT(sigfieldlen, cp); + BOUNDS_CHECK(cp, sigfieldlen); + sigstart = cp; + cp += sigfieldlen; + + /* Skip id and read error. */ + BOUNDS_CHECK(cp, 2*INT16SZ); + cp += INT16SZ; + GETSHORT(error, cp); + + /* Parse the other data. */ + BOUNDS_CHECK(cp, INT16SZ); + GETSHORT(otherfieldlen, cp); + BOUNDS_CHECK(cp, otherfieldlen); + cp += otherfieldlen; + + if (cp != eom) + return (NS_TSIG_ERROR_FORMERR); + + /* + * Do the verification. + */ + + /* Digest the time signed and fudge. */ + cp2 = buf; + PUTSHORT(0, cp2); /*%< Top 16 bits of time. */ + PUTLONG(timesigned, cp2); + PUTSHORT(NS_TSIG_FUDGE, cp2); + + dst_verify_data(SIG_MODE_UPDATE, state->key, &state->ctx, + buf, cp2 - buf, NULL, 0); + + n = dst_verify_data(SIG_MODE_FINAL, state->key, &state->ctx, NULL, 0, + sigstart, sigfieldlen); + if (n < 0) + return (-ns_r_badsig); + + if (sigfieldlen > sizeof(state->sig)) + return (NS_TSIG_ERROR_NO_SPACE); + + memcpy(state->sig, sigstart, sigfieldlen); + state->siglen = sigfieldlen; + + /* Verify the time. */ + if (abs(timesigned - time(NULL)) > fudge) + return (-ns_r_badtime); + + *msglen = recstart - msg; + + if (error != NOERROR) + return (error); + + return (0); +} + +/*! \file */ |