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author	Damien Miller <djm@cvs.openbsd.org>	2019-01-21 10:28:03 +0000
committer	Damien Miller <djm@cvs.openbsd.org>	2019-01-21 10:28:03 +0000
commit	cb48bf977a475468637078c2e9ac1f91bf4826f3 (patch)
tree	6e5d820632af6095ee637fc459905b99459bae5b /usr.bin
parent	397ed748f82b9b2a91eed79b7dcd928bf86c5ec5 (diff)

use KEM API for vanilla DH KEX

from markus@ ok djm@

Diffstat (limited to 'usr.bin')

-rw-r--r--

usr.bin/ssh/Makefile.inc

-rw-r--r--

usr.bin/ssh/kex.h

-rw-r--r--

usr.bin/ssh/kexdh.c

139

-rw-r--r--

usr.bin/ssh/kexdhc.c

143

-rw-r--r--

usr.bin/ssh/kexdhs.c

134

-rw-r--r--

usr.bin/ssh/kexkemc.c

-rw-r--r--

usr.bin/ssh/kexkems.c

-rw-r--r--

usr.bin/ssh/monitor.c

-rw-r--r--

usr.bin/ssh/ssh-keyscan.c

-rw-r--r--

usr.bin/ssh/ssh_api.c

-rw-r--r--

usr.bin/ssh/sshconnect2.c

-rw-r--r--

usr.bin/ssh/sshd.c

12 files changed, 155 insertions, 371 deletions

diff --git a/usr.bin/ssh/Makefile.inc b/usr.bin/ssh/Makefile.inc
index 52c769712aa..60360a200b7 100644
--- a/usr.bin/ssh/Makefile.inc
+++ b/usr.bin/ssh/Makefile.inc

@@ -1,4 +1,4 @@

-# $OpenBSD: Makefile.inc,v 1.63 2019/01/21 10:24:09 djm Exp $

+# $OpenBSD: Makefile.inc,v 1.64 2019/01/21 10:28:01 djm Exp $

.include <bsd.own.mk>

@@ -49,10 +49,8 @@ SRCS_KEX+= dh.c

SRCS_KEX+= kexdh.c

SRCS_KEX+= kexecdh.c

SRCS_KEX+= kexgex.c

-SRCS_KEXC+= kexdhc.c

SRCS_KEXC+= kexecdhc.c

SRCS_KEXC+= kexgexc.c

-SRCS_KEXS+= kexdhs.c

SRCS_KEXS+= kexecdhs.c

SRCS_KEXS+= kexgexs.c

.endif

diff --git a/usr.bin/ssh/kex.h b/usr.bin/ssh/kex.h
index 57f78a27af9..eef75db497a 100644
--- a/usr.bin/ssh/kex.h
+++ b/usr.bin/ssh/kex.h

@@ -1,4 +1,4 @@

-/* $OpenBSD: kex.h,v 1.100 2019/01/21 10:24:09 djm Exp $ */

+/* $OpenBSD: kex.h,v 1.101 2019/01/21 10:28:01 djm Exp $ */

@@ -195,6 +195,11 @@ int kexc25519_server(struct ssh *);

int kex_kem_client(struct ssh *);

int kex_kem_server(struct ssh *);

+int kex_dh_keypair(struct kex *);

+int kex_dh_enc(struct kex *, const u_char *, size_t, struct sshbuf **,

+ struct sshbuf **);

+int kex_dh_dec(struct kex *, const u_char *, size_t, struct sshbuf **);

int kex_c25519_keypair(struct kex *);

int kex_c25519_enc(struct kex *, const u_char *, size_t, struct sshbuf **,

struct sshbuf **);

@@ -208,9 +213,6 @@ int kex_kem_sntrup4591761x25519_dec(struct kex *, const u_char *, size_t,

int kex_dh_keygen(struct kex *);

int kex_dh_compute_key(struct kex *, BIGNUM *, struct sshbuf *);

-int kex_dh_hash(int, const struct sshbuf *, const struct sshbuf *,

- const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,

- const BIGNUM *, const BIGNUM *, const u_char *, size_t, u_char *, size_t *);

int kexgex_hash(int, const struct sshbuf *, const struct sshbuf *,

const u_char *, size_t, const u_char *, size_t, const u_char *, size_t,

diff --git a/usr.bin/ssh/kexdh.c b/usr.bin/ssh/kexdh.c
index 6f35e57c368..a59dd21036f 100644
--- a/usr.bin/ssh/kexdh.c
+++ b/usr.bin/ssh/kexdh.c

@@ -1,6 +1,6 @@

-/* $OpenBSD: kexdh.c,v 1.29 2019/01/21 10:03:37 djm Exp $ */

+/* $OpenBSD: kexdh.c,v 1.30 2019/01/21 10:28:01 djm Exp $ */

* Redistribution and use in source and binary forms, with or without

* modification, are permitted provided that the following conditions

@@ -25,18 +25,15 @@

#include <sys/types.h>

+#include <stdio.h>

+#include <string.h>

#include <signal.h>

-#include <openssl/evp.h>

-#include "ssh2.h"

#include "sshkey.h"

-#include "cipher.h"

#include "kex.h"

-#include "dh.h"

-#include "ssherr.h"

#include "sshbuf.h"

#include "digest.h"

+#include "ssherr.h"

#include "dh.h"

int

@@ -107,52 +104,94 @@ kex_dh_compute_key(struct kex *kex, BIGNUM *dh_pub, struct sshbuf *out)

}

int

-kex_dh_hash(

- int hash_alg,

- const struct sshbuf *client_version,

- const struct sshbuf *server_version,

- const u_char *ckexinit, size_t ckexinitlen,

- const u_char *skexinit, size_t skexinitlen,

- const u_char *serverhostkeyblob, size_t sbloblen,

- const BIGNUM *client_dh_pub,

- const BIGNUM *server_dh_pub,

- const u_char *shared_secret, size_t secretlen,

- u_char *hash, size_t *hashlen)

+kex_dh_keypair(struct kex *kex)

{

- struct sshbuf *b;

+ const BIGNUM *pub_key;

+ struct sshbuf *buf = NULL;

int r;

- if (*hashlen < ssh_digest_bytes(hash_alg))

- return SSH_ERR_INVALID_ARGUMENT;

- if ((b = sshbuf_new()) == NULL)

- return SSH_ERR_ALLOC_FAIL;

- if ((r = sshbuf_put_stringb(b, client_version)) < 0 ||

- (r = sshbuf_put_stringb(b, server_version)) < 0 ||

- /* kexinit messages: fake header: len+SSH2_MSG_KEXINIT */

- (r = sshbuf_put_u32(b, ckexinitlen+1)) != 0 ||

- (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||

- (r = sshbuf_put(b, ckexinit, ckexinitlen)) != 0 ||

- (r = sshbuf_put_u32(b, skexinitlen+1)) != 0 ||

- (r = sshbuf_put_u8(b, SSH2_MSG_KEXINIT)) != 0 ||

- (r = sshbuf_put(b, skexinit, skexinitlen)) != 0 ||

- (r = sshbuf_put_string(b, serverhostkeyblob, sbloblen)) != 0 ||

- (r = sshbuf_put_bignum2(b, client_dh_pub)) != 0 ||

- (r = sshbuf_put_bignum2(b, server_dh_pub)) != 0 ||

- (r = sshbuf_put(b, shared_secret, secretlen)) != 0) {

- sshbuf_free(b);

+ if ((r = kex_dh_keygen(kex)) != 0)

return r;

- }

-#ifdef DEBUG_KEX

- sshbuf_dump(b, stderr);

+ DH_get0_key(kex->dh, &pub_key, NULL);

+ if ((buf = sshbuf_new()) == NULL)

+ return SSH_ERR_ALLOC_FAIL;

+ if ((r = sshbuf_put_bignum2(buf, pub_key)) != 0 ||

+ (r = sshbuf_get_u32(buf, NULL)) != 0)

+ goto out;

+#ifdef DEBUG_KEXDH

+ DHparams_print_fp(stderr, kex->dh);

+ fprintf(stderr, "pub= ");

+ BN_print_fp(stderr, pub_key);

+ fprintf(stderr, "\n");

#endif

- if (ssh_digest_buffer(hash_alg, b, hash, *hashlen) != 0) {

- sshbuf_free(b);

- return SSH_ERR_LIBCRYPTO_ERROR;

+ kex->kem_client_pub = buf;

+ buf = NULL;

+ out:

+ sshbuf_free(buf);

+ return r;

+int

+kex_dh_enc(struct kex *kex, const u_char *pkblob, size_t pklen,

+ struct sshbuf **server_blobp, struct sshbuf **shared_secretp)

+ const BIGNUM *pub_key;

+ struct sshbuf *server_blob = NULL;

+ int r;

+ *server_blobp = NULL;

+ *shared_secretp = NULL;

+ if ((r = kex_dh_keygen(kex)) != 0)

+ goto out;

+ DH_get0_key(kex->dh, &pub_key, NULL);

+ if ((server_blob = sshbuf_new()) == NULL) {

+ r = SSH_ERR_ALLOC_FAIL;

+ goto out;

}

- sshbuf_free(b);

- *hashlen = ssh_digest_bytes(hash_alg);

-#ifdef DEBUG_KEX

- dump_digest("hash", hash, *hashlen);

-#endif

- return 0;

+ if ((r = sshbuf_put_bignum2(server_blob, pub_key)) != 0 ||

+ (r = sshbuf_get_u32(server_blob, NULL)) != 0)

+ goto out;

+ if ((r = kex_dh_dec(kex, pkblob, pklen, shared_secretp)) != 0)

+ goto out;

+ *server_blobp = server_blob;

+ server_blob = NULL;

+ out:

+ DH_free(kex->dh);

+ kex->dh = NULL;

+ sshbuf_free(server_blob);

+ return r;

+int

+kex_dh_dec(struct kex *kex, const u_char *pkblob, size_t pklen,

+ struct sshbuf **shared_secretp)

+ struct sshbuf *buf = NULL;

+ BIGNUM *dh_pub = NULL;

+ int r;

+ *shared_secretp = NULL;

+ if ((buf = sshbuf_new()) == NULL) {

+ r = SSH_ERR_ALLOC_FAIL;

+ goto out;

+ }

+ if ((r = sshbuf_put_u32(buf, pklen)) != 0 ||

+ (r = sshbuf_put(buf, pkblob, pklen)) != 0) {

+ goto out;

+ }

+ if ((r = sshbuf_get_bignum2(buf, &dh_pub)) != 0) {

+ goto out;

+ }

+ sshbuf_reset(buf);

+ if ((r = kex_dh_compute_key(kex, dh_pub, buf)) != 0)

+ goto out;

+ *shared_secretp = buf;

+ buf = NULL;

+ out:

+ DH_free(kex->dh);

+ kex->dh = NULL;

+ sshbuf_free(buf);

+ return r;

}

diff --git a/usr.bin/ssh/kexdhc.c b/usr.bin/ssh/kexdhc.c
deleted file mode 100644
index ca81b2d9e3d..00000000000
--- a/usr.bin/ssh/kexdhc.c
+++ /dev/null

@@ -1,143 +0,0 @@

-/* $OpenBSD: kexdhc.c,v 1.29 2019/01/21 10:07:22 djm Exp $ */

-/*

- *

- * Redistribution and use in source and binary forms, with or without

- * modification, are permitted provided that the following conditions

- * are met:

- * 1. Redistributions of source code must retain the above copyright

- * notice, this list of conditions and the following disclaimer.

- * 2. Redistributions in binary form must reproduce the above copyright

- * notice, this list of conditions and the following disclaimer in the

- * documentation and/or other materials provided with the distribution.

- *

- * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR

- * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES

- * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.

- * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,

- * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT

- * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,

- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY

- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

- * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

- */

-#include <sys/types.h>

-#include <openssl/dh.h>

-#include <stdio.h>

-#include <string.h>

-#include <signal.h>

-#include "sshkey.h"

-#include "cipher.h"

-#include "digest.h"

-#include "dh.h"

-#include "kex.h"

-#include "log.h"

-#include "packet.h"

-#include "ssh2.h"

-#include "dispatch.h"

-#include "compat.h"

-#include "ssherr.h"

-#include "sshbuf.h"

-static int input_kex_dh(int, u_int32_t, struct ssh *);

-int

-kexdh_client(struct ssh *ssh)

- struct kex *kex = ssh->kex;

- int r;

- const BIGNUM *pub_key;

- /* generate and send 'e', client DH public key */

- if ((r = kex_dh_keygen(kex)) != 0)

- goto out;

- debug("sending SSH2_MSG_KEXDH_INIT");

- DH_get0_key(kex->dh, &pub_key, NULL);

- if ((r = sshpkt_start(ssh, SSH2_MSG_KEXDH_INIT)) != 0 ||

- (r = sshpkt_put_bignum2(ssh, pub_key)) != 0 ||

- (r = sshpkt_send(ssh)) != 0)

- goto out;

-#ifdef DEBUG_KEXDH

- DHparams_print_fp(stderr, kex->dh);

- fprintf(stderr, "pub= ");

- BN_print_fp(stderr, pub_key);

- fprintf(stderr, "\n");

-#endif

- debug("expecting SSH2_MSG_KEXDH_REPLY");

- ssh_dispatch_set(ssh, SSH2_MSG_KEXDH_REPLY, &input_kex_dh);

- r = 0;

- out:

- return r;

-static int

-input_kex_dh(int type, u_int32_t seq, struct ssh *ssh)

- struct kex *kex = ssh->kex;

- BIGNUM *dh_server_pub = NULL;

- const BIGNUM *pub_key;

- struct sshkey *server_host_key = NULL;

- struct sshbuf *shared_secret = NULL;

- u_char *server_host_key_blob = NULL, *signature = NULL;

- u_char hash[SSH_DIGEST_MAX_LENGTH];

- size_t slen, sbloblen, hashlen;

- int r;

- /* key, cert */

- if ((r = sshpkt_get_string(ssh, &server_host_key_blob,

- &sbloblen)) != 0 ||

- (r = sshkey_from_blob(server_host_key_blob, sbloblen,

- &server_host_key)) != 0)

- goto out;

- if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)

- goto out;

- /* DH parameter f, server public DH key, signed H */

- if ((r = sshpkt_get_bignum2(ssh, &dh_server_pub)) != 0 ||

- (r = sshpkt_get_string(ssh, &signature, &slen)) != 0 ||

- (r = sshpkt_get_end(ssh)) != 0)

- goto out;

- if ((shared_secret = sshbuf_new()) == NULL) {

- r = SSH_ERR_ALLOC_FAIL;

- goto out;

- }

- if ((r = kex_dh_compute_key(kex, dh_server_pub, shared_secret)) != 0)

- goto out;

- /* calc and verify H */

- DH_get0_key(kex->dh, &pub_key, NULL);

- hashlen = sizeof(hash);

- if ((r = kex_dh_hash(

- kex->hash_alg,

- kex->client_version,

- kex->server_version,

- sshbuf_ptr(kex->my), sshbuf_len(kex->my),

- sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),

- server_host_key_blob, sbloblen,

- pub_key,

- dh_server_pub,

- sshbuf_ptr(shared_secret), sshbuf_len(shared_secret),

- hash, &hashlen)) != 0)

- goto out;

- if ((r = sshkey_verify(server_host_key, signature, slen, hash, hashlen,

- kex->hostkey_alg, ssh->compat)) != 0)

- goto out;

- if ((r = kex_derive_keys(ssh, hash, hashlen, shared_secret)) == 0)

- r = kex_send_newkeys(ssh);

- out:

- explicit_bzero(hash, sizeof(hash));

- DH_free(kex->dh);

- kex->dh = NULL;

- BN_clear_free(dh_server_pub);

- sshbuf_free(shared_secret);

- sshkey_free(server_host_key);

- free(server_host_key_blob);

- free(signature);

- return r;

diff --git a/usr.bin/ssh/kexdhs.c b/usr.bin/ssh/kexdhs.c
deleted file mode 100644
index f0cca9b5835..00000000000
--- a/usr.bin/ssh/kexdhs.c
+++ /dev/null

@@ -1,134 +0,0 @@

-/* $OpenBSD: kexdhs.c,v 1.35 2019/01/21 10:05:09 djm Exp $ */