- djm@cvs.openbsd.org 2012/05/23 03:28:28

[dns.c dns.h key.c key.h ssh-keygen.c]
     add support for RFC6594 SSHFP DNS records for ECDSA key types.
     patch from bugzilla-m67 AT nulld.me in bz#1978; ok + tweak markus@
This commit is contained in:
Damien Miller 2012-06-20 21:51:11 +10:00
parent ac58ce86e6
commit 3bde12aeef
6 changed files with 92 additions and 44 deletions

View File

@ -16,6 +16,10 @@
[mux.c]
fix double-free in new session handler
NB. Id sync only
- djm@cvs.openbsd.org 2012/05/23 03:28:28
[dns.c dns.h key.c key.h ssh-keygen.c]
add support for RFC6594 SSHFP DNS records for ECDSA key types.
patch from bugzilla-m67 AT nulld.me in bz#1978; ok + tweak markus@
20120519
- (dtucker) [configure.ac] bz#2010: fix non-portable shell construct. Patch

103
dns.c
View File

@ -1,4 +1,4 @@
/* $OpenBSD: dns.c,v 1.27 2010/08/31 11:54:45 djm Exp $ */
/* $OpenBSD: dns.c,v 1.28 2012/05/23 03:28:28 djm Exp $ */
/*
* Copyright (c) 2003 Wesley Griffin. All rights reserved.
@ -78,27 +78,46 @@ dns_read_key(u_int8_t *algorithm, u_int8_t *digest_type,
u_char **digest, u_int *digest_len, Key *key)
{
int success = 0;
enum fp_type fp_type = 0;
switch (key->type) {
case KEY_RSA:
*algorithm = SSHFP_KEY_RSA;
if (!*digest_type)
*digest_type = SSHFP_HASH_SHA1;
break;
case KEY_DSA:
*algorithm = SSHFP_KEY_DSA;
if (!*digest_type)
*digest_type = SSHFP_HASH_SHA1;
break;
case KEY_ECDSA:
*algorithm = SSHFP_KEY_ECDSA;
if (!*digest_type)
*digest_type = SSHFP_HASH_SHA256;
break;
/* XXX KEY_ECDSA */
default:
*algorithm = SSHFP_KEY_RESERVED; /* 0 */
*digest_type = SSHFP_HASH_RESERVED; /* 0 */
}
if (*algorithm) {
*digest_type = SSHFP_HASH_SHA1;
*digest = key_fingerprint_raw(key, SSH_FP_SHA1, digest_len);
switch (*digest_type) {
case SSHFP_HASH_SHA1:
fp_type = SSH_FP_SHA1;
break;
case SSHFP_HASH_SHA256:
fp_type = SSH_FP_SHA256;
break;
default:
*digest_type = SSHFP_HASH_RESERVED; /* 0 */
}
if (*algorithm && *digest_type) {
*digest = key_fingerprint_raw(key, fp_type, digest_len);
if (*digest == NULL)
fatal("dns_read_key: null from key_fingerprint_raw()");
success = 1;
} else {
*digest_type = SSHFP_HASH_RESERVED;
*digest = NULL;
*digest_len = 0;
success = 0;
@ -180,7 +199,7 @@ verify_host_key_dns(const char *hostname, struct sockaddr *address,
struct rrsetinfo *fingerprints = NULL;
u_int8_t hostkey_algorithm;
u_int8_t hostkey_digest_type;
u_int8_t hostkey_digest_type = SSHFP_HASH_RESERVED;
u_char *hostkey_digest;
u_int hostkey_digest_len;
@ -216,7 +235,7 @@ verify_host_key_dns(const char *hostname, struct sockaddr *address,
fingerprints->rri_nrdatas);
}
/* Initialize host key parameters */
/* Initialize default host key parameters */
if (!dns_read_key(&hostkey_algorithm, &hostkey_digest_type,
&hostkey_digest, &hostkey_digest_len, hostkey)) {
error("Error calculating host key fingerprint.");
@ -240,16 +259,27 @@ verify_host_key_dns(const char *hostname, struct sockaddr *address,
continue;
}
if (hostkey_digest_type != dnskey_digest_type) {
hostkey_digest_type = dnskey_digest_type;
xfree(hostkey_digest);
/* Initialize host key parameters */
if (!dns_read_key(&hostkey_algorithm,
&hostkey_digest_type, &hostkey_digest,
&hostkey_digest_len, hostkey)) {
error("Error calculating key fingerprint.");
freerrset(fingerprints);
return -1;
}
}
/* Check if the current key is the same as the given key */
if (hostkey_algorithm == dnskey_algorithm &&
hostkey_digest_type == dnskey_digest_type) {
if (hostkey_digest_len == dnskey_digest_len &&
memcmp(hostkey_digest, dnskey_digest,
hostkey_digest_len) == 0) {
timingsafe_bcmp(hostkey_digest, dnskey_digest,
hostkey_digest_len) == 0)
*flags |= DNS_VERIFY_MATCH;
}
}
xfree(dnskey_digest);
}
@ -275,31 +305,36 @@ int
export_dns_rr(const char *hostname, Key *key, FILE *f, int generic)
{
u_int8_t rdata_pubkey_algorithm = 0;
u_int8_t rdata_digest_type = SSHFP_HASH_SHA1;
u_int8_t rdata_digest_type = SSHFP_HASH_RESERVED;
u_int8_t dtype;
u_char *rdata_digest;
u_int rdata_digest_len;
u_int i;
u_int i, rdata_digest_len;
int success = 0;
if (dns_read_key(&rdata_pubkey_algorithm, &rdata_digest_type,
&rdata_digest, &rdata_digest_len, key)) {
for (dtype = SSHFP_HASH_SHA1; dtype < SSHFP_HASH_MAX; dtype++) {
rdata_digest_type = dtype;
if (dns_read_key(&rdata_pubkey_algorithm, &rdata_digest_type,
&rdata_digest, &rdata_digest_len, key)) {
if (generic) {
fprintf(f, "%s IN TYPE%d \\# %d %02x %02x ",
hostname, DNS_RDATATYPE_SSHFP,
2 + rdata_digest_len,
rdata_pubkey_algorithm, rdata_digest_type);
} else {
fprintf(f, "%s IN SSHFP %d %d ", hostname,
rdata_pubkey_algorithm, rdata_digest_type);
}
for (i = 0; i < rdata_digest_len; i++)
fprintf(f, "%02x", rdata_digest[i]);
fprintf(f, "\n");
xfree(rdata_digest); /* from key_fingerprint_raw() */
success = 1;
}
}
if (generic)
fprintf(f, "%s IN TYPE%d \\# %d %02x %02x ", hostname,
DNS_RDATATYPE_SSHFP, 2 + rdata_digest_len,
rdata_pubkey_algorithm, rdata_digest_type);
else
fprintf(f, "%s IN SSHFP %d %d ", hostname,
rdata_pubkey_algorithm, rdata_digest_type);
for (i = 0; i < rdata_digest_len; i++)
fprintf(f, "%02x", rdata_digest[i]);
fprintf(f, "\n");
xfree(rdata_digest); /* from key_fingerprint_raw() */
success = 1;
} else {
error("export_dns_rr: unsupported algorithm");
/* No SSHFP record was generated at all */
if (success == 0) {
error("%s: unsupported algorithm and/or digest_type", __func__);
}
return success;

15
dns.h
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@ -1,4 +1,4 @@
/* $OpenBSD: dns.h,v 1.11 2010/02/26 20:29:54 djm Exp $ */
/* $OpenBSD: dns.h,v 1.12 2012/05/23 03:28:28 djm Exp $ */
/*
* Copyright (c) 2003 Wesley Griffin. All rights reserved.
@ -29,14 +29,17 @@
#define DNS_H
enum sshfp_types {
SSHFP_KEY_RESERVED,
SSHFP_KEY_RSA,
SSHFP_KEY_DSA
SSHFP_KEY_RESERVED = 0,
SSHFP_KEY_RSA = 1,
SSHFP_KEY_DSA = 2,
SSHFP_KEY_ECDSA = 3
};
enum sshfp_hashes {
SSHFP_HASH_RESERVED,
SSHFP_HASH_SHA1
SSHFP_HASH_RESERVED = 0,
SSHFP_HASH_SHA1 = 1,
SSHFP_HASH_SHA256 = 2,
SSHFP_HASH_MAX = 3
};
#define DNS_RDATACLASS_IN 1

5
key.c
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@ -1,4 +1,4 @@
/* $OpenBSD: key.c,v 1.98 2011/10/18 04:58:26 djm Exp $ */
/* $OpenBSD: key.c,v 1.99 2012/05/23 03:28:28 djm Exp $ */
/*
* read_bignum():
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -342,6 +342,9 @@ key_fingerprint_raw(Key *k, enum fp_type dgst_type, u_int *dgst_raw_length)
case SSH_FP_SHA1:
md = EVP_sha1();
break;
case SSH_FP_SHA256:
md = EVP_sha256();
break;
default:
fatal("key_fingerprint_raw: bad digest type %d",
dgst_type);

5
key.h
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@ -1,4 +1,4 @@
/* $OpenBSD: key.h,v 1.33 2010/10/28 11:22:09 djm Exp $ */
/* $OpenBSD: key.h,v 1.34 2012/05/23 03:28:28 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
@ -48,7 +48,8 @@ enum types {
};
enum fp_type {
SSH_FP_SHA1,
SSH_FP_MD5
SSH_FP_MD5,
SSH_FP_SHA256
};
enum fp_rep {
SSH_FP_HEX,

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@ -1,4 +1,4 @@
/* $OpenBSD: ssh-keygen.c,v 1.213 2012/02/29 11:21:26 djm Exp $ */
/* $OpenBSD: ssh-keygen.c,v 1.214 2012/05/23 03:28:28 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
@ -2194,6 +2194,8 @@ main(int argc, char **argv)
_PATH_HOST_RSA_KEY_FILE, rr_hostname);
n += do_print_resource_record(pw,
_PATH_HOST_DSA_KEY_FILE, rr_hostname);
n += do_print_resource_record(pw,
_PATH_HOST_ECDSA_KEY_FILE, rr_hostname);
if (n == 0)
fatal("no keys found.");