1 files changed, 471 insertions, 0 deletions
diff --git a/contrib/bind/lib/nameser/ns_verify.c b/contrib/bind/lib/nameser/ns_verify.c
new file mode 100644
index 000000000000..316da136f0cc
--- /dev/null
+++ b/contrib/bind/lib/nameser/ns_verify.c
@@ -0,0 +1,471 @@
+/*
+ * 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 INTERNET SOFTWARE CONSORTIUM DISCLAIMS
+ * ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL INTERNET SOFTWARE
+ * CONSORTIUM 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 8.11 1999/10/15 21:06:51 vixie 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 <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:
+ *	statp		res stuff
+ *	msg		received message
+ *	msglen		length of message
+ *	key		tsig key used for verifying.
+ *	querysig	(response), the signature in the query
+ *	querysiglen	(response), the length of the signature in the query
+ *	sig		(query), a buffer to hold the signature
+ *	siglen		(query), input - length of signature buffer
+ *				 output - length of signature
+ *
+ * Errors:
+ *	- bad input (-1)
+ *	- invalid dns message (NS_TSIG_ERROR_FORMERR)
+ *	- TSIG is not present (NS_TSIG_ERROR_NO_TSIG)
+ *	- key doesn't match (-ns_r_badkey)
+ *	- TSIG verification fails with BADKEY (-ns_r_badkey)
+ *	- TSIG verification fails with BADSIG (-ns_r_badsig)
+ *	- TSIG verification fails with BADTIME (-ns_r_badtime)
+ *	- TSIG verification succeeds, error set to BAKEY (ns_r_badkey)
+ *	- TSIG verification succeeds, error set to BADSIG (ns_r_badsig)
+ *	- 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, id, 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;
+
+	/* Read the original id and error. */
+	BOUNDS_CHECK(cp, 2*INT16SZ);
+	GETSHORT(id, cp);
+	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];
+
+		/* 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_ntol(recstart, buf, sizeof(buf));
+		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_ntol(rdatastart, buf, sizeof(buf));
+		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 > 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, *rdatastart, *sigstart;
+	int sigfieldlen, otherfieldlen;
+	u_char *cp, *eom = msg + *msglen, *cp2;
+	char name[MAXDNAME], alg[MAXDNAME];
+	u_char buf[MAXDNAME];
+	int n, type, length, fudge, id, error;
+	time_t timesigned;
+
+	if (msg == NULL || msglen == NULL || state == NULL)
+		return (-1);
+
+	state->counter++;
+	if (state->counter == 0)
+		return (ns_verify(msg, msglen, state->key,
+				  state->sig, state->siglen,
+				  state->sig, &state->siglen, &timesigned, 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. */
+	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;
+
+	/* 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;
+
+	/* Read the original id and error. */
+	BOUNDS_CHECK(cp, 2*INT16SZ);
+	GETSHORT(id, cp);
+	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_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);
+}