external/openssh: update to 6.8p1.
In preparation for some updates to external/openssh to make it work with
BoringSSL, this change updates the code to a recent version. The current
version (5.9p1) is coming up on four years old now.
* Confirmed that f5c67b478bef9992de9e9ec91ce10af4f6205e0d matches
OpenSSH 5.9p1 exactly (save for the removal of the scard
subdirectory).
* Downloaded openssh-6.8p1.tar.gz (SHA256:
3ff64ce73ee124480b5bf767b9830d7d3c03bbcb6abe716b78f0192c37ce160e)
and verified with PGP signature. (I've verified Damien's key in
person previously.)
* Applied changes between f5c67b478bef9992de9e9ec91ce10af4f6205e0d and
OpenSSH 5.9p1 to 6.8p1 and updated the build as best I can. The
ugliest change is probably the duplication of umac.c to umac128.c
because Android conditionally compiles that file twice. See the
comment in those files.
Change-Id: I63cb07a8118afb5a377f116087a0882914cea486
diff --git a/kex.c b/kex.c
index c65e28f..2a00d28 100644
--- a/kex.c
+++ b/kex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.c,v 1.86 2010/09/22 05:01:29 djm Exp $ */
+/* $OpenBSD: kex.c,v 1.105 2015/01/30 00:22:25 djm Exp $ */
/*
* Copyright (c) 2000, 2001 Markus Friedl. All rights reserved.
*
@@ -25,7 +25,7 @@
#include "includes.h"
-#include <sys/param.h>
+#include <sys/param.h> /* MAX roundup */
#include <signal.h>
#include <stdarg.h>
@@ -33,23 +33,29 @@
#include <stdlib.h>
#include <string.h>
+#ifdef WITH_OPENSSL
#include <openssl/crypto.h>
+#include <openssl/dh.h>
+#endif
-#include "xmalloc.h"
#include "ssh2.h"
-#include "buffer.h"
#include "packet.h"
#include "compat.h"
#include "cipher.h"
-#include "key.h"
+#include "sshkey.h"
#include "kex.h"
#include "log.h"
#include "mac.h"
#include "match.h"
+#include "misc.h"
#include "dispatch.h"
#include "monitor.h"
#include "roaming.h"
+#include "ssherr.h"
+#include "sshbuf.h"
+#include "digest.h"
+
#if OPENSSL_VERSION_NUMBER >= 0x00907000L
# if defined(HAVE_EVP_SHA256)
# define evp_ssh_sha256 EVP_sha256
@@ -59,8 +65,73 @@
#endif
/* prototype */
-static void kex_kexinit_finish(Kex *);
-static void kex_choose_conf(Kex *);
+static int kex_choose_conf(struct ssh *);
+static int kex_input_newkeys(int, u_int32_t, void *);
+
+struct kexalg {
+ char *name;
+ u_int type;
+ int ec_nid;
+ int hash_alg;
+};
+static const struct kexalg kexalgs[] = {
+#ifdef WITH_OPENSSL
+ { KEX_DH1, KEX_DH_GRP1_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_DH14, KEX_DH_GRP14_SHA1, 0, SSH_DIGEST_SHA1 },
+ { KEX_DHGEX_SHA1, KEX_DH_GEX_SHA1, 0, SSH_DIGEST_SHA1 },
+#ifdef HAVE_EVP_SHA256
+ { KEX_DHGEX_SHA256, KEX_DH_GEX_SHA256, 0, SSH_DIGEST_SHA256 },
+#endif /* HAVE_EVP_SHA256 */
+#ifdef OPENSSL_HAS_ECC
+ { KEX_ECDH_SHA2_NISTP256, KEX_ECDH_SHA2,
+ NID_X9_62_prime256v1, SSH_DIGEST_SHA256 },
+ { KEX_ECDH_SHA2_NISTP384, KEX_ECDH_SHA2, NID_secp384r1,
+ SSH_DIGEST_SHA384 },
+# ifdef OPENSSL_HAS_NISTP521
+ { KEX_ECDH_SHA2_NISTP521, KEX_ECDH_SHA2, NID_secp521r1,
+ SSH_DIGEST_SHA512 },
+# endif /* OPENSSL_HAS_NISTP521 */
+#endif /* OPENSSL_HAS_ECC */
+#endif /* WITH_OPENSSL */
+#if defined(HAVE_EVP_SHA256) || !defined(WITH_OPENSSL)
+ { KEX_CURVE25519_SHA256, KEX_C25519_SHA256, 0, SSH_DIGEST_SHA256 },
+#endif /* HAVE_EVP_SHA256 || !WITH_OPENSSL */
+ { NULL, -1, -1, -1},
+};
+
+char *
+kex_alg_list(char sep)
+{
+ char *ret = NULL, *tmp;
+ size_t nlen, rlen = 0;
+ const struct kexalg *k;
+
+ for (k = kexalgs; k->name != NULL; k++) {
+ if (ret != NULL)
+ ret[rlen++] = sep;
+ nlen = strlen(k->name);
+ if ((tmp = realloc(ret, rlen + nlen + 2)) == NULL) {
+ free(ret);
+ return NULL;
+ }
+ ret = tmp;
+ memcpy(ret + rlen, k->name, nlen + 1);
+ rlen += nlen;
+ }
+ return ret;
+}
+
+static const struct kexalg *
+kex_alg_by_name(const char *name)
+{
+ const struct kexalg *k;
+
+ for (k = kexalgs; k->name != NULL; k++) {
+ if (strcmp(k->name, name) == 0)
+ return k;
+ }
+ return NULL;
+}
/* Validate KEX method name list */
int
@@ -70,258 +141,374 @@
if (names == NULL || strcmp(names, "") == 0)
return 0;
- s = cp = xstrdup(names);
+ if ((s = cp = strdup(names)) == NULL)
+ return 0;
for ((p = strsep(&cp, ",")); p && *p != '\0';
(p = strsep(&cp, ","))) {
- if (strcmp(p, KEX_DHGEX_SHA256) != 0 &&
- strcmp(p, KEX_DHGEX_SHA1) != 0 &&
- strcmp(p, KEX_DH14) != 0 &&
- strcmp(p, KEX_DH1) != 0 &&
- (strncmp(p, KEX_ECDH_SHA2_STEM,
- sizeof(KEX_ECDH_SHA2_STEM) - 1) != 0 ||
- kex_ecdh_name_to_nid(p) == -1)) {
+ if (kex_alg_by_name(p) == NULL) {
error("Unsupported KEX algorithm \"%.100s\"", p);
- xfree(s);
+ free(s);
return 0;
}
}
debug3("kex names ok: [%s]", names);
- xfree(s);
+ free(s);
return 1;
}
/* put algorithm proposal into buffer */
-static void
-kex_prop2buf(Buffer *b, char *proposal[PROPOSAL_MAX])
+int
+kex_prop2buf(struct sshbuf *b, char *proposal[PROPOSAL_MAX])
{
u_int i;
+ int r;
- buffer_clear(b);
+ sshbuf_reset(b);
+
/*
* add a dummy cookie, the cookie will be overwritten by
* kex_send_kexinit(), each time a kexinit is set
*/
- for (i = 0; i < KEX_COOKIE_LEN; i++)
- buffer_put_char(b, 0);
- for (i = 0; i < PROPOSAL_MAX; i++)
- buffer_put_cstring(b, proposal[i]);
- buffer_put_char(b, 0); /* first_kex_packet_follows */
- buffer_put_int(b, 0); /* uint32 reserved */
+ for (i = 0; i < KEX_COOKIE_LEN; i++) {
+ if ((r = sshbuf_put_u8(b, 0)) != 0)
+ return r;
+ }
+ for (i = 0; i < PROPOSAL_MAX; i++) {
+ if ((r = sshbuf_put_cstring(b, proposal[i])) != 0)
+ return r;
+ }
+ if ((r = sshbuf_put_u8(b, 0)) != 0 || /* first_kex_packet_follows */
+ (r = sshbuf_put_u32(b, 0)) != 0) /* uint32 reserved */
+ return r;
+ return 0;
}
/* parse buffer and return algorithm proposal */
-static char **
-kex_buf2prop(Buffer *raw, int *first_kex_follows)
+int
+kex_buf2prop(struct sshbuf *raw, int *first_kex_follows, char ***propp)
{
- Buffer b;
+ struct sshbuf *b = NULL;
+ u_char v;
u_int i;
- char **proposal;
+ char **proposal = NULL;
+ int r;
- proposal = xcalloc(PROPOSAL_MAX, sizeof(char *));
-
- buffer_init(&b);
- buffer_append(&b, buffer_ptr(raw), buffer_len(raw));
- /* skip cookie */
- for (i = 0; i < KEX_COOKIE_LEN; i++)
- buffer_get_char(&b);
+ *propp = NULL;
+ if ((proposal = calloc(PROPOSAL_MAX, sizeof(char *))) == NULL)
+ return SSH_ERR_ALLOC_FAIL;
+ if ((b = sshbuf_fromb(raw)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = sshbuf_consume(b, KEX_COOKIE_LEN)) != 0) /* skip cookie */
+ goto out;
/* extract kex init proposal strings */
for (i = 0; i < PROPOSAL_MAX; i++) {
- proposal[i] = buffer_get_cstring(&b,NULL);
+ if ((r = sshbuf_get_cstring(b, &(proposal[i]), NULL)) != 0)
+ goto out;
debug2("kex_parse_kexinit: %s", proposal[i]);
}
/* first kex follows / reserved */
- i = buffer_get_char(&b);
+ if ((r = sshbuf_get_u8(b, &v)) != 0 ||
+ (r = sshbuf_get_u32(b, &i)) != 0)
+ goto out;
if (first_kex_follows != NULL)
*first_kex_follows = i;
- debug2("kex_parse_kexinit: first_kex_follows %d ", i);
- i = buffer_get_int(&b);
+ debug2("kex_parse_kexinit: first_kex_follows %d ", v);
debug2("kex_parse_kexinit: reserved %u ", i);
- buffer_free(&b);
- return proposal;
+ r = 0;
+ *propp = proposal;
+ out:
+ if (r != 0 && proposal != NULL)
+ kex_prop_free(proposal);
+ sshbuf_free(b);
+ return r;
}
-static void
+void
kex_prop_free(char **proposal)
{
u_int i;
for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(proposal[i]);
- xfree(proposal);
+ free(proposal[i]);
+ free(proposal);
}
/* ARGSUSED */
-static void
+static int
kex_protocol_error(int type, u_int32_t seq, void *ctxt)
{
error("Hm, kex protocol error: type %d seq %u", type, seq);
+ return 0;
}
static void
-kex_reset_dispatch(void)
+kex_reset_dispatch(struct ssh *ssh)
{
- dispatch_range(SSH2_MSG_TRANSPORT_MIN,
+ ssh_dispatch_range(ssh, SSH2_MSG_TRANSPORT_MIN,
SSH2_MSG_TRANSPORT_MAX, &kex_protocol_error);
- dispatch_set(SSH2_MSG_KEXINIT, &kex_input_kexinit);
+ ssh_dispatch_set(ssh, SSH2_MSG_KEXINIT, &kex_input_kexinit);
}
-void
-kex_finish(Kex *kex)
+int
+kex_send_newkeys(struct ssh *ssh)
{
- kex_reset_dispatch();
+ int r;
- packet_start(SSH2_MSG_NEWKEYS);
- packet_send();
- /* packet_write_wait(); */
+ kex_reset_dispatch(ssh);
+ if ((r = sshpkt_start(ssh, SSH2_MSG_NEWKEYS)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ return r;
debug("SSH2_MSG_NEWKEYS sent");
-
debug("expecting SSH2_MSG_NEWKEYS");
- packet_read_expect(SSH2_MSG_NEWKEYS);
- packet_check_eom();
- debug("SSH2_MSG_NEWKEYS received");
-
- kex->done = 1;
- buffer_clear(&kex->peer);
- /* buffer_clear(&kex->my); */
- kex->flags &= ~KEX_INIT_SENT;
- xfree(kex->name);
- kex->name = NULL;
+ ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_input_newkeys);
+ return 0;
}
-void
-kex_send_kexinit(Kex *kex)
+static int
+kex_input_newkeys(int type, u_int32_t seq, void *ctxt)
{
- u_int32_t rnd = 0;
- u_char *cookie;
- u_int i;
+ struct ssh *ssh = ctxt;
+ struct kex *kex = ssh->kex;
+ int r;
- if (kex == NULL) {
- error("kex_send_kexinit: no kex, cannot rekey");
- return;
- }
- if (kex->flags & KEX_INIT_SENT) {
- debug("KEX_INIT_SENT");
- return;
- }
+ debug("SSH2_MSG_NEWKEYS received");
+ ssh_dispatch_set(ssh, SSH2_MSG_NEWKEYS, &kex_protocol_error);
+ if ((r = sshpkt_get_end(ssh)) != 0)
+ return r;
+ kex->done = 1;
+ sshbuf_reset(kex->peer);
+ /* sshbuf_reset(kex->my); */
+ kex->flags &= ~KEX_INIT_SENT;
+ free(kex->name);
+ kex->name = NULL;
+ return 0;
+}
+
+int
+kex_send_kexinit(struct ssh *ssh)
+{
+ u_char *cookie;
+ struct kex *kex = ssh->kex;
+ int r;
+
+ if (kex == NULL)
+ return SSH_ERR_INTERNAL_ERROR;
+ if (kex->flags & KEX_INIT_SENT)
+ return 0;
kex->done = 0;
/* generate a random cookie */
- if (buffer_len(&kex->my) < KEX_COOKIE_LEN)
- fatal("kex_send_kexinit: kex proposal too short");
- cookie = buffer_ptr(&kex->my);
- for (i = 0; i < KEX_COOKIE_LEN; i++) {
- if (i % 4 == 0)
- rnd = arc4random();
- cookie[i] = rnd;
- rnd >>= 8;
- }
- packet_start(SSH2_MSG_KEXINIT);
- packet_put_raw(buffer_ptr(&kex->my), buffer_len(&kex->my));
- packet_send();
+ if (sshbuf_len(kex->my) < KEX_COOKIE_LEN)
+ return SSH_ERR_INVALID_FORMAT;
+ if ((cookie = sshbuf_mutable_ptr(kex->my)) == NULL)
+ return SSH_ERR_INTERNAL_ERROR;
+ arc4random_buf(cookie, KEX_COOKIE_LEN);
+
+ if ((r = sshpkt_start(ssh, SSH2_MSG_KEXINIT)) != 0 ||
+ (r = sshpkt_putb(ssh, kex->my)) != 0 ||
+ (r = sshpkt_send(ssh)) != 0)
+ return r;
debug("SSH2_MSG_KEXINIT sent");
kex->flags |= KEX_INIT_SENT;
+ return 0;
}
/* ARGSUSED */
-void
+int
kex_input_kexinit(int type, u_int32_t seq, void *ctxt)
{
- char *ptr;
- u_int i, dlen;
- Kex *kex = (Kex *)ctxt;
+ struct ssh *ssh = ctxt;
+ struct kex *kex = ssh->kex;
+ const u_char *ptr;
+ u_int i;
+ size_t dlen;
+ int r;
debug("SSH2_MSG_KEXINIT received");
if (kex == NULL)
- fatal("kex_input_kexinit: no kex, cannot rekey");
+ return SSH_ERR_INVALID_ARGUMENT;
- ptr = packet_get_raw(&dlen);
- buffer_append(&kex->peer, ptr, dlen);
+ ptr = sshpkt_ptr(ssh, &dlen);
+ if ((r = sshbuf_put(kex->peer, ptr, dlen)) != 0)
+ return r;
/* discard packet */
for (i = 0; i < KEX_COOKIE_LEN; i++)
- packet_get_char();
+ if ((r = sshpkt_get_u8(ssh, NULL)) != 0)
+ return r;
for (i = 0; i < PROPOSAL_MAX; i++)
- xfree(packet_get_string(NULL));
- (void) packet_get_char();
- (void) packet_get_int();
- packet_check_eom();
+ if ((r = sshpkt_get_string(ssh, NULL, NULL)) != 0)
+ return r;
+ /*
+ * XXX RFC4253 sec 7: "each side MAY guess" - currently no supported
+ * KEX method has the server move first, but a server might be using
+ * a custom method or one that we otherwise don't support. We should
+ * be prepared to remember first_kex_follows here so we can eat a
+ * packet later.
+ * XXX2 - RFC4253 is kind of ambiguous on what first_kex_follows means
+ * for cases where the server *doesn't* go first. I guess we should
+ * ignore it when it is set for these cases, which is what we do now.
+ */
+ if ((r = sshpkt_get_u8(ssh, NULL)) != 0 || /* first_kex_follows */
+ (r = sshpkt_get_u32(ssh, NULL)) != 0 || /* reserved */
+ (r = sshpkt_get_end(ssh)) != 0)
+ return r;
- kex_kexinit_finish(kex);
-}
-
-Kex *
-kex_setup(char *proposal[PROPOSAL_MAX])
-{
- Kex *kex;
-
- kex = xcalloc(1, sizeof(*kex));
- buffer_init(&kex->peer);
- buffer_init(&kex->my);
- kex_prop2buf(&kex->my, proposal);
- kex->done = 0;
-
- kex_send_kexinit(kex); /* we start */
- kex_reset_dispatch();
-
- return kex;
-}
-
-static void
-kex_kexinit_finish(Kex *kex)
-{
if (!(kex->flags & KEX_INIT_SENT))
- kex_send_kexinit(kex);
+ if ((r = kex_send_kexinit(ssh)) != 0)
+ return r;
+ if ((r = kex_choose_conf(ssh)) != 0)
+ return r;
- kex_choose_conf(kex);
+ if (kex->kex_type < KEX_MAX && kex->kex[kex->kex_type] != NULL)
+ return (kex->kex[kex->kex_type])(ssh);
- if (kex->kex_type >= 0 && kex->kex_type < KEX_MAX &&
- kex->kex[kex->kex_type] != NULL) {
- (kex->kex[kex->kex_type])(kex);
- } else {
- fatal("Unsupported key exchange %d", kex->kex_type);
- }
+ return SSH_ERR_INTERNAL_ERROR;
}
-static void
-choose_enc(Enc *enc, char *client, char *server)
+int
+kex_new(struct ssh *ssh, char *proposal[PROPOSAL_MAX], struct kex **kexp)
+{
+ struct kex *kex;
+ int r;
+
+ *kexp = NULL;
+ if ((kex = calloc(1, sizeof(*kex))) == NULL)
+ return SSH_ERR_ALLOC_FAIL;
+ if ((kex->peer = sshbuf_new()) == NULL ||
+ (kex->my = sshbuf_new()) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if ((r = kex_prop2buf(kex->my, proposal)) != 0)
+ goto out;
+ kex->done = 0;
+ kex_reset_dispatch(ssh);
+ r = 0;
+ *kexp = kex;
+ out:
+ if (r != 0)
+ kex_free(kex);
+ return r;
+}
+
+void
+kex_free_newkeys(struct newkeys *newkeys)
+{
+ if (newkeys == NULL)
+ return;
+ if (newkeys->enc.key) {
+ explicit_bzero(newkeys->enc.key, newkeys->enc.key_len);
+ free(newkeys->enc.key);
+ newkeys->enc.key = NULL;
+ }
+ if (newkeys->enc.iv) {
+ explicit_bzero(newkeys->enc.iv, newkeys->enc.block_size);
+ free(newkeys->enc.iv);
+ newkeys->enc.iv = NULL;
+ }
+ free(newkeys->enc.name);
+ explicit_bzero(&newkeys->enc, sizeof(newkeys->enc));
+ free(newkeys->comp.name);
+ explicit_bzero(&newkeys->comp, sizeof(newkeys->comp));
+ mac_clear(&newkeys->mac);
+ if (newkeys->mac.key) {
+ explicit_bzero(newkeys->mac.key, newkeys->mac.key_len);
+ free(newkeys->mac.key);
+ newkeys->mac.key = NULL;
+ }
+ free(newkeys->mac.name);
+ explicit_bzero(&newkeys->mac, sizeof(newkeys->mac));
+ explicit_bzero(newkeys, sizeof(*newkeys));
+ free(newkeys);
+}
+
+void
+kex_free(struct kex *kex)
+{
+ u_int mode;
+
+#ifdef WITH_OPENSSL
+ if (kex->dh)
+ DH_free(kex->dh);
+#ifdef OPENSSL_HAS_ECC
+ if (kex->ec_client_key)
+ EC_KEY_free(kex->ec_client_key);
+#endif /* OPENSSL_HAS_ECC */
+#endif /* WITH_OPENSSL */
+ for (mode = 0; mode < MODE_MAX; mode++) {
+ kex_free_newkeys(kex->newkeys[mode]);
+ kex->newkeys[mode] = NULL;
+ }
+ sshbuf_free(kex->peer);
+ sshbuf_free(kex->my);
+ free(kex->session_id);
+ free(kex->client_version_string);
+ free(kex->server_version_string);
+ free(kex);
+}
+
+int
+kex_setup(struct ssh *ssh, char *proposal[PROPOSAL_MAX])
+{
+ int r;
+
+ if ((r = kex_new(ssh, proposal, &ssh->kex)) != 0)
+ return r;
+ if ((r = kex_send_kexinit(ssh)) != 0) { /* we start */
+ kex_free(ssh->kex);
+ ssh->kex = NULL;
+ return r;
+ }
+ return 0;
+}
+
+static int
+choose_enc(struct sshenc *enc, char *client, char *server)
{
char *name = match_list(client, server, NULL);
+
if (name == NULL)
- fatal("no matching cipher found: client %s server %s",
- client, server);
+ return SSH_ERR_NO_CIPHER_ALG_MATCH;
if ((enc->cipher = cipher_by_name(name)) == NULL)
- fatal("matching cipher is not supported: %s", name);
+ return SSH_ERR_INTERNAL_ERROR;
enc->name = name;
enc->enabled = 0;
enc->iv = NULL;
+ enc->iv_len = cipher_ivlen(enc->cipher);
enc->key = NULL;
enc->key_len = cipher_keylen(enc->cipher);
enc->block_size = cipher_blocksize(enc->cipher);
+ return 0;
}
-static void
-choose_mac(Mac *mac, char *client, char *server)
+static int
+choose_mac(struct ssh *ssh, struct sshmac *mac, char *client, char *server)
{
char *name = match_list(client, server, NULL);
+
if (name == NULL)
- fatal("no matching mac found: client %s server %s",
- client, server);
+ return SSH_ERR_NO_MAC_ALG_MATCH;
if (mac_setup(mac, name) < 0)
- fatal("unsupported mac %s", name);
+ return SSH_ERR_INTERNAL_ERROR;
/* truncate the key */
- if (datafellows & SSH_BUG_HMAC)
+ if (ssh->compat & SSH_BUG_HMAC)
mac->key_len = 16;
mac->name = name;
mac->key = NULL;
mac->enabled = 0;
+ return 0;
}
-static void
-choose_comp(Comp *comp, char *client, char *server)
+static int
+choose_comp(struct sshcomp *comp, char *client, char *server)
{
char *name = match_list(client, server, NULL);
+
if (name == NULL)
- fatal("no matching comp found: client %s server %s", client, server);
+ return SSH_ERR_NO_COMPRESS_ALG_MATCH;
if (strcmp(name, "zlib@openssh.com") == 0) {
comp->type = COMP_DELAYED;
} else if (strcmp(name, "zlib") == 0) {
@@ -329,49 +516,42 @@
} else if (strcmp(name, "none") == 0) {
comp->type = COMP_NONE;
} else {
- fatal("unsupported comp %s", name);
+ return SSH_ERR_INTERNAL_ERROR;
}
comp->name = name;
+ return 0;
}
-static void
-choose_kex(Kex *k, char *client, char *server)
+static int
+choose_kex(struct kex *k, char *client, char *server)
{
+ const struct kexalg *kexalg;
+
k->name = match_list(client, server, NULL);
+
if (k->name == NULL)
- fatal("Unable to negotiate a key exchange method");
- if (strcmp(k->name, KEX_DH1) == 0) {
- k->kex_type = KEX_DH_GRP1_SHA1;
- k->evp_md = EVP_sha1();
- } else if (strcmp(k->name, KEX_DH14) == 0) {
- k->kex_type = KEX_DH_GRP14_SHA1;
- k->evp_md = EVP_sha1();
- } else if (strcmp(k->name, KEX_DHGEX_SHA1) == 0) {
- k->kex_type = KEX_DH_GEX_SHA1;
- k->evp_md = EVP_sha1();
-#if OPENSSL_VERSION_NUMBER >= 0x00907000L
- } else if (strcmp(k->name, KEX_DHGEX_SHA256) == 0) {
- k->kex_type = KEX_DH_GEX_SHA256;
- k->evp_md = evp_ssh_sha256();
- } else if (strncmp(k->name, KEX_ECDH_SHA2_STEM,
- sizeof(KEX_ECDH_SHA2_STEM) - 1) == 0) {
- k->kex_type = KEX_ECDH_SHA2;
- k->evp_md = kex_ecdh_name_to_evpmd(k->name);
-#endif
- } else
- fatal("bad kex alg %s", k->name);
+ return SSH_ERR_NO_KEX_ALG_MATCH;
+ if ((kexalg = kex_alg_by_name(k->name)) == NULL)
+ return SSH_ERR_INTERNAL_ERROR;
+ k->kex_type = kexalg->type;
+ k->hash_alg = kexalg->hash_alg;
+ k->ec_nid = kexalg->ec_nid;
+ return 0;
}
-static void
-choose_hostkeyalg(Kex *k, char *client, char *server)
+static int
+choose_hostkeyalg(struct kex *k, char *client, char *server)
{
char *hostkeyalg = match_list(client, server, NULL);
+
if (hostkeyalg == NULL)
- fatal("no hostkey alg");
- k->hostkey_type = key_type_from_name(hostkeyalg);
+ return SSH_ERR_NO_HOSTKEY_ALG_MATCH;
+ k->hostkey_type = sshkey_type_from_name(hostkeyalg);
if (k->hostkey_type == KEY_UNSPEC)
- fatal("bad hostkey alg '%s'", hostkeyalg);
- xfree(hostkeyalg);
+ return SSH_ERR_INTERNAL_ERROR;
+ k->hostkey_nid = sshkey_ecdsa_nid_from_name(hostkeyalg);
+ free(hostkeyalg);
+ return 0;
}
static int
@@ -398,18 +578,20 @@
return (1);
}
-static void
-kex_choose_conf(Kex *kex)
+static int
+kex_choose_conf(struct ssh *ssh)
{
- Newkeys *newkeys;
- char **my, **peer;
+ struct kex *kex = ssh->kex;
+ struct newkeys *newkeys;
+ char **my = NULL, **peer = NULL;
char **cprop, **sprop;
int nenc, nmac, ncomp;
- u_int mode, ctos, need;
- int first_kex_follows, type;
+ u_int mode, ctos, need, dh_need, authlen;
+ int r, first_kex_follows;
- my = kex_buf2prop(&kex->my, NULL);
- peer = kex_buf2prop(&kex->peer, &first_kex_follows);
+ if ((r = kex_buf2prop(kex->my, NULL, &my)) != 0 ||
+ (r = kex_buf2prop(kex->peer, &first_kex_follows, &peer)) != 0)
+ goto out;
if (kex->server) {
cprop=peer;
@@ -421,85 +603,109 @@
/* Check whether server offers roaming */
if (!kex->server) {
- char *roaming;
- roaming = match_list(KEX_RESUME, peer[PROPOSAL_KEX_ALGS], NULL);
+ char *roaming = match_list(KEX_RESUME,
+ peer[PROPOSAL_KEX_ALGS], NULL);
+
if (roaming) {
kex->roaming = 1;
- xfree(roaming);
+ free(roaming);
}
}
/* Algorithm Negotiation */
for (mode = 0; mode < MODE_MAX; mode++) {
- newkeys = xcalloc(1, sizeof(*newkeys));
+ if ((newkeys = calloc(1, sizeof(*newkeys))) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
kex->newkeys[mode] = newkeys;
ctos = (!kex->server && mode == MODE_OUT) ||
(kex->server && mode == MODE_IN);
nenc = ctos ? PROPOSAL_ENC_ALGS_CTOS : PROPOSAL_ENC_ALGS_STOC;
nmac = ctos ? PROPOSAL_MAC_ALGS_CTOS : PROPOSAL_MAC_ALGS_STOC;
ncomp = ctos ? PROPOSAL_COMP_ALGS_CTOS : PROPOSAL_COMP_ALGS_STOC;
- choose_enc (&newkeys->enc, cprop[nenc], sprop[nenc]);
- choose_mac (&newkeys->mac, cprop[nmac], sprop[nmac]);
- choose_comp(&newkeys->comp, cprop[ncomp], sprop[ncomp]);
+ if ((r = choose_enc(&newkeys->enc, cprop[nenc],
+ sprop[nenc])) != 0)
+ goto out;
+ authlen = cipher_authlen(newkeys->enc.cipher);
+ /* ignore mac for authenticated encryption */
+ if (authlen == 0 &&
+ (r = choose_mac(ssh, &newkeys->mac, cprop[nmac],
+ sprop[nmac])) != 0)
+ goto out;
+ if ((r = choose_comp(&newkeys->comp, cprop[ncomp],
+ sprop[ncomp])) != 0)
+ goto out;
debug("kex: %s %s %s %s",
ctos ? "client->server" : "server->client",
newkeys->enc.name,
- newkeys->mac.name,
+ authlen == 0 ? newkeys->mac.name : "<implicit>",
newkeys->comp.name);
}
- choose_kex(kex, cprop[PROPOSAL_KEX_ALGS], sprop[PROPOSAL_KEX_ALGS]);
- choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
- sprop[PROPOSAL_SERVER_HOST_KEY_ALGS]);
- need = 0;
+ if ((r = choose_kex(kex, cprop[PROPOSAL_KEX_ALGS],
+ sprop[PROPOSAL_KEX_ALGS])) != 0 ||
+ (r = choose_hostkeyalg(kex, cprop[PROPOSAL_SERVER_HOST_KEY_ALGS],
+ sprop[PROPOSAL_SERVER_HOST_KEY_ALGS])) != 0)
+ goto out;
+ need = dh_need = 0;
for (mode = 0; mode < MODE_MAX; mode++) {
newkeys = kex->newkeys[mode];
- if (need < newkeys->enc.key_len)
- need = newkeys->enc.key_len;
- if (need < newkeys->enc.block_size)
- need = newkeys->enc.block_size;
- if (need < newkeys->mac.key_len)
- need = newkeys->mac.key_len;
+ need = MAX(need, newkeys->enc.key_len);
+ need = MAX(need, newkeys->enc.block_size);
+ need = MAX(need, newkeys->enc.iv_len);
+ need = MAX(need, newkeys->mac.key_len);
+ dh_need = MAX(dh_need, cipher_seclen(newkeys->enc.cipher));
+ dh_need = MAX(dh_need, newkeys->enc.block_size);
+ dh_need = MAX(dh_need, newkeys->enc.iv_len);
+ dh_need = MAX(dh_need, newkeys->mac.key_len);
}
/* XXX need runden? */
kex->we_need = need;
+ kex->dh_need = dh_need;
/* ignore the next message if the proposals do not match */
if (first_kex_follows && !proposals_match(my, peer) &&
- !(datafellows & SSH_BUG_FIRSTKEX)) {
- type = packet_read();
- debug2("skipping next packet (type %u)", type);
- }
-
+ !(ssh->compat & SSH_BUG_FIRSTKEX))
+ ssh->dispatch_skip_packets = 1;
+ r = 0;
+ out:
kex_prop_free(my);
kex_prop_free(peer);
+ return r;
}
-static u_char *
-derive_key(Kex *kex, int id, u_int need, u_char *hash, u_int hashlen,
- BIGNUM *shared_secret)
+static int
+derive_key(struct ssh *ssh, int id, u_int need, u_char *hash, u_int hashlen,
+ const struct sshbuf *shared_secret, u_char **keyp)
{
- Buffer b;
- EVP_MD_CTX md;
+ struct kex *kex = ssh->kex;
+ struct ssh_digest_ctx *hashctx = NULL;
char c = id;
u_int have;
- int mdsz;
+ size_t mdsz;
u_char *digest;
+ int r;
- if ((mdsz = EVP_MD_size(kex->evp_md)) <= 0)
- fatal("bad kex md size %d", mdsz);
- digest = xmalloc(roundup(need, mdsz));
-
- buffer_init(&b);
- buffer_put_bignum2(&b, shared_secret);
+ if ((mdsz = ssh_digest_bytes(kex->hash_alg)) == 0)
+ return SSH_ERR_INVALID_ARGUMENT;
+ if ((digest = calloc(1, roundup(need, mdsz))) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
/* K1 = HASH(K || H || "A" || session_id) */
- EVP_DigestInit(&md, kex->evp_md);
- if (!(datafellows & SSH_BUG_DERIVEKEY))
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, hashlen);
- EVP_DigestUpdate(&md, &c, 1);
- EVP_DigestUpdate(&md, kex->session_id, kex->session_id_len);
- EVP_DigestFinal(&md, digest, NULL);
+ if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL ||
+ ssh_digest_update_buffer(hashctx, shared_secret) != 0 ||
+ ssh_digest_update(hashctx, hash, hashlen) != 0 ||
+ ssh_digest_update(hashctx, &c, 1) != 0 ||
+ ssh_digest_update(hashctx, kex->session_id,
+ kex->session_id_len) != 0 ||
+ ssh_digest_final(hashctx, digest, mdsz) != 0) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ ssh_digest_free(hashctx);
+ hashctx = NULL;
/*
* expand key:
@@ -507,104 +713,123 @@
* Key = K1 || K2 || ... || Kn
*/
for (have = mdsz; need > have; have += mdsz) {
- EVP_DigestInit(&md, kex->evp_md);
- if (!(datafellows & SSH_BUG_DERIVEKEY))
- EVP_DigestUpdate(&md, buffer_ptr(&b), buffer_len(&b));
- EVP_DigestUpdate(&md, hash, hashlen);
- EVP_DigestUpdate(&md, digest, have);
- EVP_DigestFinal(&md, digest + have, NULL);
+ if ((hashctx = ssh_digest_start(kex->hash_alg)) == NULL ||
+ ssh_digest_update_buffer(hashctx, shared_secret) != 0 ||
+ ssh_digest_update(hashctx, hash, hashlen) != 0 ||
+ ssh_digest_update(hashctx, digest, have) != 0 ||
+ ssh_digest_final(hashctx, digest + have, mdsz) != 0) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ ssh_digest_free(hashctx);
+ hashctx = NULL;
}
- buffer_free(&b);
#ifdef DEBUG_KEX
fprintf(stderr, "key '%c'== ", c);
dump_digest("key", digest, need);
#endif
- return digest;
+ *keyp = digest;
+ digest = NULL;
+ r = 0;
+ out:
+ if (digest)
+ free(digest);
+ ssh_digest_free(hashctx);
+ return r;
}
-Newkeys *current_keys[MODE_MAX];
-
#define NKEYS 6
-void
-kex_derive_keys(Kex *kex, u_char *hash, u_int hashlen, BIGNUM *shared_secret)
+int
+kex_derive_keys(struct ssh *ssh, u_char *hash, u_int hashlen,
+ const struct sshbuf *shared_secret)
{
+ struct kex *kex = ssh->kex;
u_char *keys[NKEYS];
- u_int i, mode, ctos;
+ u_int i, j, mode, ctos;
+ int r;
for (i = 0; i < NKEYS; i++) {
- keys[i] = derive_key(kex, 'A'+i, kex->we_need, hash, hashlen,
- shared_secret);
+ if ((r = derive_key(ssh, 'A'+i, kex->we_need, hash, hashlen,
+ shared_secret, &keys[i])) != 0) {
+ for (j = 0; j < i; j++)
+ free(keys[j]);
+ return r;
+ }
}
-
- debug2("kex_derive_keys");
for (mode = 0; mode < MODE_MAX; mode++) {
- current_keys[mode] = kex->newkeys[mode];
- kex->newkeys[mode] = NULL;
ctos = (!kex->server && mode == MODE_OUT) ||
(kex->server && mode == MODE_IN);
- current_keys[mode]->enc.iv = keys[ctos ? 0 : 1];
- current_keys[mode]->enc.key = keys[ctos ? 2 : 3];
- current_keys[mode]->mac.key = keys[ctos ? 4 : 5];
+ kex->newkeys[mode]->enc.iv = keys[ctos ? 0 : 1];
+ kex->newkeys[mode]->enc.key = keys[ctos ? 2 : 3];
+ kex->newkeys[mode]->mac.key = keys[ctos ? 4 : 5];
}
+ return 0;
}
-Newkeys *
-kex_get_newkeys(int mode)
+#ifdef WITH_OPENSSL
+int
+kex_derive_keys_bn(struct ssh *ssh, u_char *hash, u_int hashlen,
+ const BIGNUM *secret)
{
- Newkeys *ret;
+ struct sshbuf *shared_secret;
+ int r;
- ret = current_keys[mode];
- current_keys[mode] = NULL;
- return ret;
+ if ((shared_secret = sshbuf_new()) == NULL)
+ return SSH_ERR_ALLOC_FAIL;
+ if ((r = sshbuf_put_bignum2(shared_secret, secret)) == 0)
+ r = kex_derive_keys(ssh, hash, hashlen, shared_secret);
+ sshbuf_free(shared_secret);
+ return r;
}
+#endif
-void
+#ifdef WITH_SSH1
+int
derive_ssh1_session_id(BIGNUM *host_modulus, BIGNUM *server_modulus,
u_int8_t cookie[8], u_int8_t id[16])
{
- const EVP_MD *evp_md = EVP_md5();
- EVP_MD_CTX md;
- u_int8_t nbuf[2048], obuf[EVP_MAX_MD_SIZE];
- int len;
+ u_int8_t hbuf[2048], sbuf[2048], obuf[SSH_DIGEST_MAX_LENGTH];
+ struct ssh_digest_ctx *hashctx = NULL;
+ size_t hlen, slen;
+ int r;
- EVP_DigestInit(&md, evp_md);
-
- len = BN_num_bytes(host_modulus);
- if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
- fatal("%s: bad host modulus (len %d)", __func__, len);
- BN_bn2bin(host_modulus, nbuf);
- EVP_DigestUpdate(&md, nbuf, len);
-
- len = BN_num_bytes(server_modulus);
- if (len < (512 / 8) || (u_int)len > sizeof(nbuf))
- fatal("%s: bad server modulus (len %d)", __func__, len);
- BN_bn2bin(server_modulus, nbuf);
- EVP_DigestUpdate(&md, nbuf, len);
-
- EVP_DigestUpdate(&md, cookie, 8);
-
- EVP_DigestFinal(&md, obuf, NULL);
- memcpy(id, obuf, 16);
-
- memset(nbuf, 0, sizeof(nbuf));
- memset(obuf, 0, sizeof(obuf));
- memset(&md, 0, sizeof(md));
+ hlen = BN_num_bytes(host_modulus);
+ slen = BN_num_bytes(server_modulus);
+ if (hlen < (512 / 8) || (u_int)hlen > sizeof(hbuf) ||
+ slen < (512 / 8) || (u_int)slen > sizeof(sbuf))
+ return SSH_ERR_KEY_BITS_MISMATCH;
+ if (BN_bn2bin(host_modulus, hbuf) <= 0 ||
+ BN_bn2bin(server_modulus, sbuf) <= 0) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ if ((hashctx = ssh_digest_start(SSH_DIGEST_MD5)) == NULL) {
+ r = SSH_ERR_ALLOC_FAIL;
+ goto out;
+ }
+ if (ssh_digest_update(hashctx, hbuf, hlen) != 0 ||
+ ssh_digest_update(hashctx, sbuf, slen) != 0 ||
+ ssh_digest_update(hashctx, cookie, 8) != 0 ||
+ ssh_digest_final(hashctx, obuf, sizeof(obuf)) != 0) {
+ r = SSH_ERR_LIBCRYPTO_ERROR;
+ goto out;
+ }
+ memcpy(id, obuf, ssh_digest_bytes(SSH_DIGEST_MD5));
+ r = 0;
+ out:
+ ssh_digest_free(hashctx);
+ explicit_bzero(hbuf, sizeof(hbuf));
+ explicit_bzero(sbuf, sizeof(sbuf));
+ explicit_bzero(obuf, sizeof(obuf));
+ return r;
}
+#endif
#if defined(DEBUG_KEX) || defined(DEBUG_KEXDH) || defined(DEBUG_KEXECDH)
void
dump_digest(char *msg, u_char *digest, int len)
{
- int i;
-
fprintf(stderr, "%s\n", msg);
- for (i = 0; i < len; i++) {
- fprintf(stderr, "%02x", digest[i]);
- if (i%32 == 31)
- fprintf(stderr, "\n");
- else if (i%8 == 7)
- fprintf(stderr, " ");
- }
- fprintf(stderr, "\n");
+ sshbuf_dump_data(digest, len, stderr);
}
#endif