Commit 04c7e28f authored by djm@openbsd.org's avatar djm@openbsd.org Committed by Damien Miller

upstream commit

pass negotiated signing algorithm though to
sshkey_verify() and check that the negotiated algorithm matches the type in
the signature (only matters for RSA SHA1/SHA2 sigs). ok markus@

OpenBSD-Commit-ID: 735fb15bf4adc060d3bee9d047a4bcaaa81b1af9
parent 931c78df
/* $OpenBSD: auth2-hostbased.c,v 1.31 2017/06/24 06:34:38 djm Exp $ */
/* $OpenBSD: auth2-hostbased.c,v 1.32 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
......@@ -144,7 +144,7 @@ userauth_hostbased(struct ssh *ssh)
authenticated = 0;
if (PRIVSEP(hostbased_key_allowed(authctxt->pw, cuser, chost, key)) &&
PRIVSEP(sshkey_verify(key, sig, slen,
sshbuf_ptr(b), sshbuf_len(b), ssh->compat)) == 0)
sshbuf_ptr(b), sshbuf_len(b), pkalg, ssh->compat)) == 0)
authenticated = 1;
auth2_record_key(authctxt, authenticated, key);
......
/* $OpenBSD: auth2-pubkey.c,v 1.71 2017/09/07 23:48:09 djm Exp $ */
/* $OpenBSD: auth2-pubkey.c,v 1.72 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000 Markus Friedl. All rights reserved.
*
......@@ -198,7 +198,7 @@ userauth_pubkey(struct ssh *ssh)
authenticated = 0;
if (PRIVSEP(user_key_allowed(authctxt->pw, key, 1)) &&
PRIVSEP(sshkey_verify(key, sig, slen, sshbuf_ptr(b),
sshbuf_len(b), ssh->compat)) == 0) {
sshbuf_len(b), pkalg, ssh->compat)) == 0) {
authenticated = 1;
}
sshbuf_free(b);
......
/* $OpenBSD: clientloop.c,v 1.307 2017/11/25 05:58:47 dtucker Exp $ */
/* $OpenBSD: clientloop.c,v 1.308 2017/12/18 02:25:15 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
......@@ -1934,7 +1934,8 @@ client_global_hostkeys_private_confirm(struct ssh *ssh, int type,
goto out;
}
if ((r = sshkey_verify(ctx->keys[i], sig, siglen,
sshbuf_ptr(signdata), sshbuf_len(signdata), 0)) != 0) {
sshbuf_ptr(signdata), sshbuf_len(signdata),
ssh->kex->hostkey_alg, 0)) != 0) {
error("%s: server gave bad signature for %s key %zu",
__func__, sshkey_type(ctx->keys[i]), i);
goto out;
......
/* $OpenBSD: hash.c,v 1.4 2017/12/14 21:07:39 naddy Exp $ */
#include "includes.h"
#include "crypto_api.h"
#include <stdarg.h>
......
/* $OpenBSD: kexc25519c.c,v 1.8 2017/05/31 04:17:12 djm Exp $ */
/* $OpenBSD: kexc25519c.c,v 1.9 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2010 Damien Miller. All rights reserved.
......@@ -141,7 +141,7 @@ input_kex_c25519_reply(int type, u_int32_t seq, struct ssh *ssh)
goto out;
if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
ssh->compat)) != 0)
kex->hostkey_alg, ssh->compat)) != 0)
goto out;
/* save session id */
......
/* $OpenBSD: kexdhc.c,v 1.20 2017/05/30 14:23:52 markus Exp $ */
/* $OpenBSD: kexdhc.c,v 1.21 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
*
......@@ -183,7 +183,7 @@ input_kex_dh(int type, u_int32_t seq, struct ssh *ssh)
goto out;
if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,
ssh->compat)) != 0)
kex->hostkey_alg, ssh->compat)) != 0)
goto out;
/* save session id */
......
/* $OpenBSD: kexecdhc.c,v 1.11 2017/05/30 14:23:52 markus Exp $ */
/* $OpenBSD: kexecdhc.c,v 1.12 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2010 Damien Miller. All rights reserved.
......@@ -188,7 +188,7 @@ input_kex_ecdh_reply(int type, u_int32_t seq, struct ssh *ssh)
goto out;
if ((r = sshkey_verify(server_host_key, signature, slen, hash,
hashlen, ssh->compat)) != 0)
hashlen, kex->hostkey_alg, ssh->compat)) != 0)
goto out;
/* save session id */
......
/* $OpenBSD: kexgexc.c,v 1.25 2017/05/30 14:23:52 markus Exp $ */
/* $OpenBSD: kexgexc.c,v 1.26 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000 Niels Provos. All rights reserved.
* Copyright (c) 2001 Markus Friedl. All rights reserved.
......@@ -230,7 +230,7 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
goto out;
if ((r = sshkey_verify(server_host_key, signature, slen, hash,
hashlen, ssh->compat)) != 0)
hashlen, kex->hostkey_alg, ssh->compat)) != 0)
goto out;
/* save session id */
......
/* $OpenBSD: key.c,v 1.131 2017/05/30 14:16:41 markus Exp $ */
/* $OpenBSD: key.c,v 1.132 2017/12/18 02:25:15 djm Exp $ */
/*
* placed in the public domain
*/
......@@ -95,21 +95,6 @@ key_sign(const Key *key, u_char **sigp, u_int *lenp,
return 0;
}
int
key_verify(const Key *key, const u_char *signature, u_int signaturelen,
const u_char *data, u_int datalen)
{
int r;
if ((r = sshkey_verify(key, signature, signaturelen,
data, datalen, datafellows)) != 0) {
fatal_on_fatal_errors(r, __func__, 0);
error("%s: %s", __func__, ssh_err(r));
return r == SSH_ERR_SIGNATURE_INVALID ? 0 : -1;
}
return 1;
}
Key *
key_demote(const Key *k)
{
......
/* $OpenBSD: key.h,v 1.51 2017/05/30 14:16:41 markus Exp $ */
/* $OpenBSD: key.h,v 1.52 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
......@@ -58,7 +58,6 @@ int key_to_blob(const Key *, u_char **, u_int *);
int key_sign(const Key *, u_char **, u_int *, const u_char *, u_int,
const char *);
int key_verify(const Key *, const u_char *, u_int, const u_char *, u_int);
/* authfile.c */
Key *key_load_cert(const char *);
......
......@@ -14,7 +14,7 @@
* OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
/* $OpenBSD: krl.c,v 1.40 2017/05/31 09:15:42 deraadt Exp $ */
/* $OpenBSD: krl.c,v 1.41 2017/12/18 02:25:15 djm Exp $ */
#include "includes.h"
......@@ -1014,7 +1014,7 @@ ssh_krl_from_blob(struct sshbuf *buf, struct ssh_krl **krlp,
}
/* Check signature over entire KRL up to this point */
if ((r = sshkey_verify(key, blob, blen,
sshbuf_ptr(buf), sig_off, 0)) != 0)
sshbuf_ptr(buf), sig_off, NULL, 0)) != 0)
goto out;
/* Check if this key has already signed this KRL */
for (i = 0; i < nca_used; i++) {
......
/* $OpenBSD: monitor.c,v 1.175 2017/10/05 15:52:03 djm Exp $ */
/* $OpenBSD: monitor.c,v 1.176 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* Copyright 2002 Markus Friedl <markus@openbsd.org>
......@@ -1339,12 +1339,14 @@ mm_answer_keyverify(int sock, struct sshbuf *m)
{
struct sshkey *key;
u_char *signature, *data, *blob;
char *sigalg;
size_t signaturelen, datalen, bloblen;
int r, ret, valid_data = 0, encoded_ret;
if ((r = sshbuf_get_string(m, &blob, &bloblen)) != 0 ||
(r = sshbuf_get_string(m, &signature, &signaturelen)) != 0 ||
(r = sshbuf_get_string(m, &data, &datalen)) != 0)
(r = sshbuf_get_string(m, &data, &datalen)) != 0 ||
(r = sshbuf_get_cstring(m, &sigalg, NULL)) != 0)
fatal("%s: buffer error: %s", __func__, ssh_err(r));
if (hostbased_cuser == NULL || hostbased_chost == NULL ||
......@@ -1373,7 +1375,7 @@ mm_answer_keyverify(int sock, struct sshbuf *m)
fatal("%s: bad signature data blob", __func__);
ret = sshkey_verify(key, signature, signaturelen, data, datalen,
active_state->compat);
sigalg, active_state->compat);
debug3("%s: %s %p signature %s", __func__, auth_method, key,
(ret == 0) ? "verified" : "unverified");
auth2_record_key(authctxt, ret == 0, key);
......
/* $OpenBSD: monitor_wrap.c,v 1.95 2017/10/05 15:52:03 djm Exp $ */
/* $OpenBSD: monitor_wrap.c,v 1.96 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
* Copyright 2002 Markus Friedl <markus@openbsd.org>
......@@ -441,7 +441,7 @@ mm_key_allowed(enum mm_keytype type, const char *user, const char *host,
int
mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
const u_char *data, size_t datalen, u_int compat)
const u_char *data, size_t datalen, const char *sigalg, u_int compat)
{
Buffer m;
u_char *blob;
......@@ -458,6 +458,7 @@ mm_sshkey_verify(const struct sshkey *key, const u_char *sig, size_t siglen,
buffer_put_string(&m, blob, len);
buffer_put_string(&m, sig, siglen);
buffer_put_string(&m, data, datalen);
buffer_put_cstring(&m, sigalg);
free(blob);
mm_request_send(pmonitor->m_recvfd, MONITOR_REQ_KEYVERIFY, &m);
......
/* $OpenBSD: monitor_wrap.h,v 1.35 2017/05/31 08:09:45 markus Exp $ */
/* $OpenBSD: monitor_wrap.h,v 1.36 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright 2002 Niels Provos <provos@citi.umich.edu>
......@@ -51,7 +51,7 @@ int mm_user_key_allowed(struct passwd *, struct sshkey *, int);
int mm_hostbased_key_allowed(struct passwd *, const char *,
const char *, struct sshkey *);
int mm_sshkey_verify(const struct sshkey *, const u_char *, size_t,
const u_char *, size_t, u_int);
const u_char *, size_t, const char *, u_int);
#ifdef GSSAPI
OM_uint32 mm_ssh_gssapi_server_ctx(Gssctxt **, gss_OID);
......
/* $OpenBSD: serverloop.c,v 1.200 2017/12/10 05:55:29 dtucker Exp $ */
/* $OpenBSD: serverloop.c,v 1.201 2017/12/18 02:25:15 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1995 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
......@@ -715,7 +715,8 @@ server_input_hostkeys_prove(struct ssh *ssh, struct sshbuf **respp)
ssh->kex->session_id, ssh->kex->session_id_len)) != 0 ||
(r = sshkey_puts(key, sigbuf)) != 0 ||
(r = ssh->kex->sign(key_prv, key_pub, &sig, &slen,
sshbuf_ptr(sigbuf), sshbuf_len(sigbuf), NULL, 0)) != 0 ||
sshbuf_ptr(sigbuf), sshbuf_len(sigbuf),
ssh->kex->hostkey_alg, 0)) != 0 ||
(r = sshbuf_put_string(resp, sig, slen)) != 0) {
error("%s: couldn't prepare signature: %s",
__func__, ssh_err(r));
......
/* $OpenBSD: ssh-keygen.c,v 1.308 2017/11/03 05:14:04 djm Exp $ */
/* $OpenBSD: ssh-keygen.c,v 1.309 2017/12/18 02:25:15 djm Exp $ */
/*
* Author: Tatu Ylonen <ylo@cs.hut.fi>
* Copyright (c) 1994 Tatu Ylonen <ylo@cs.hut.fi>, Espoo, Finland
......@@ -539,7 +539,7 @@ do_convert_private_ssh2_from_blob(u_char *blob, u_int blen)
/* try the key */
if (sshkey_sign(key, &sig, &slen, data, sizeof(data), NULL, 0) != 0 ||
sshkey_verify(key, sig, slen, data, sizeof(data), 0) != 0) {
sshkey_verify(key, sig, slen, data, sizeof(data), NULL, 0) != 0) {
sshkey_free(key);
free(sig);
return NULL;
......
/* $OpenBSD: ssh-rsa.c,v 1.62 2017/07/01 13:50:45 djm Exp $ */
/* $OpenBSD: ssh-rsa.c,v 1.63 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000, 2003 Markus Friedl <markus@openbsd.org>
*
......@@ -198,9 +198,10 @@ ssh_rsa_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
int
ssh_rsa_verify(const struct sshkey *key,
const u_char *sig, size_t siglen, const u_char *data, size_t datalen)
const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
const char *alg)
{
char *ktype = NULL;
char *sigtype = NULL;
int hash_alg, ret = SSH_ERR_INTERNAL_ERROR;
size_t len, diff, modlen, dlen;
struct sshbuf *b = NULL;
......@@ -215,11 +216,17 @@ ssh_rsa_verify(const struct sshkey *key,
if ((b = sshbuf_from(sig, siglen)) == NULL)
return SSH_ERR_ALLOC_FAIL;
if (sshbuf_get_cstring(b, &ktype, NULL) != 0) {
if (sshbuf_get_cstring(b, &sigtype, NULL) != 0) {
ret = SSH_ERR_INVALID_FORMAT;
goto out;
}
if ((hash_alg = rsa_hash_alg_from_ident(ktype)) == -1) {
/* XXX djm: need cert types that reliably yield SHA-2 signatures */
if (alg != NULL && strcmp(alg, sigtype) != 0 &&
strcmp(alg, "ssh-rsa-cert-v01@openssh.com") != 0) {
ret = SSH_ERR_SIGNATURE_INVALID;
goto out;
}
if ((hash_alg = rsa_hash_alg_from_ident(sigtype)) == -1) {
ret = SSH_ERR_KEY_TYPE_MISMATCH;
goto out;
}
......@@ -263,7 +270,7 @@ ssh_rsa_verify(const struct sshkey *key,
explicit_bzero(sigblob, len);
free(sigblob);
}
free(ktype);
free(sigtype);
sshbuf_free(b);
explicit_bzero(digest, sizeof(digest));
return ret;
......
/* $OpenBSD: sshkey.c,v 1.58 2017/12/18 02:22:29 djm Exp $ */
/* $OpenBSD: sshkey.c,v 1.59 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
* Copyright (c) 2008 Alexander von Gernler. All rights reserved.
......@@ -1814,7 +1814,7 @@ cert_parse(struct sshbuf *b, struct sshkey *key, struct sshbuf *certbuf)
goto out;
}
if ((ret = sshkey_verify(key->cert->signature_key, sig, slen,
sshbuf_ptr(key->cert->certblob), signed_len, 0)) != 0)
sshbuf_ptr(key->cert->certblob), signed_len, NULL, 0)) != 0)
goto out;
/* Success */
......@@ -2109,11 +2109,12 @@ sshkey_sign(const struct sshkey *key,
/*
* ssh_key_verify returns 0 for a correct signature and < 0 on error.
* If "alg" specified, then the signature must use that algorithm.
*/
int
sshkey_verify(const struct sshkey *key,
const u_char *sig, size_t siglen,
const u_char *data, size_t dlen, u_int compat)
const u_char *data, size_t dlen, const char *alg, u_int compat)
{
if (siglen == 0 || dlen > SSH_KEY_MAX_SIGN_DATA_SIZE)
return SSH_ERR_INVALID_ARGUMENT;
......@@ -2129,7 +2130,7 @@ sshkey_verify(const struct sshkey *key,
# endif /* OPENSSL_HAS_ECC */
case KEY_RSA_CERT:
case KEY_RSA:
return ssh_rsa_verify(key, sig, siglen, data, dlen);
return ssh_rsa_verify(key, sig, siglen, data, dlen, alg);
#endif /* WITH_OPENSSL */
case KEY_ED25519:
case KEY_ED25519_CERT:
......
/* $OpenBSD: sshkey.h,v 1.22 2017/12/18 02:22:29 djm Exp $ */
/* $OpenBSD: sshkey.h,v 1.23 2017/12/18 02:25:15 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
......@@ -178,7 +178,7 @@ int sshkey_sigtype(const u_char *, size_t, char **);
int sshkey_sign(const struct sshkey *, u_char **, size_t *,
const u_char *, size_t, const char *, u_int);
int sshkey_verify(const struct sshkey *, const u_char *, size_t,
const u_char *, size_t, u_int);
const u_char *, size_t, const char *, u_int);
/* for debug */
void sshkey_dump_ec_point(const EC_GROUP *, const EC_POINT *);
......@@ -205,7 +205,8 @@ int ssh_rsa_sign(const struct sshkey *key,
u_char **sigp, size_t *lenp, const u_char *data, size_t datalen,
const char *ident);
int ssh_rsa_verify(const struct sshkey *key,
const u_char *sig, size_t siglen, const u_char *data, size_t datalen);
const u_char *sig, size_t siglen, const u_char *data, size_t datalen,
const char *alg);
int ssh_dss_sign(const struct sshkey *key, u_char **sigp, size_t *lenp,
const u_char *data, size_t datalen, u_int compat);
int ssh_dss_verify(const struct sshkey *key,
......
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