upstream: pass most arguments to the KEX hash functions as sshbuf

rather than pointer+length; ok markus@

OpenBSD-Commit-ID: ef0c89c52ccc89817a13a5205725148a28492bf7

5 files changed, 80 insertions, 63 deletions

diff --git a/kex.h b/kex.h
index 44e6d197..6d446d1c 100644
--- a/kex.h
+++ b/kex.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: kex.h,v 1.106 2019/01/21 10:40:11 djm Exp $ */
+/* $OpenBSD: kex.h,v 1.107 2019/01/23 00:30:41 djm Exp $ */
 
 /*
  * Copyright (c) 2000, 2001 Markus Friedl.  All rights reserved.
@@ -229,7 +229,7 @@ int	 kex_dh_keygen(struct kex *);
 int	 kex_dh_compute_key(struct kex *, BIGNUM *, struct sshbuf *);
 
 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,
+    const struct sshbuf *, const struct sshbuf *, const struct sshbuf *,
     int, int, int,
     const BIGNUM *, const BIGNUM *, const BIGNUM *,
     const BIGNUM *, const u_char *, size_t,
diff --git a/kexgen.c b/kexgen.c
index 91c960fe..bb0cb5c1 100644
--- a/kexgen.c
+++ b/kexgen.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgen.c,v 1.1 2019/01/21 11:22:00 djm Exp $ */
+/* $OpenBSD: kexgen.c,v 1.2 2019/01/23 00:30:41 djm Exp $ */
 /*
  * Copyright (c) 2019 Markus Friedl.  All rights reserved.
  *
@@ -48,9 +48,9 @@ kex_gen_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 struct sshbuf *client_kexinit,
+    const struct sshbuf *server_kexinit,
+    const struct sshbuf *server_host_key_blob,
     const struct sshbuf *client_pub,
     const struct sshbuf *server_pub,
     const struct sshbuf *shared_secret,
@@ -66,13 +66,13 @@ kex_gen_hash(
 	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_u32(b, sshbuf_len(client_kexinit) + 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_putb(b, client_kexinit)) != 0 ||
+	    (r = sshbuf_put_u32(b, sshbuf_len(server_kexinit) + 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_putb(b, server_kexinit)) != 0 ||
+	    (r = sshbuf_put_stringb(b, server_host_key_blob)) != 0 ||
 	    (r = sshbuf_put_stringb(b, client_pub)) != 0 ||
 	    (r = sshbuf_put_stringb(b, server_pub)) != 0 ||
 	    (r = sshbuf_putb(b, shared_secret)) != 0) {
@@ -139,16 +139,21 @@ input_kex_gen_reply(int type, u_int32_t seq, struct ssh *ssh)
 	struct sshkey *server_host_key = NULL;
 	struct sshbuf *shared_secret = NULL;
 	struct sshbuf *server_blob = NULL;
-	u_char *server_host_key_blob = NULL, *signature = NULL;
+	struct sshbuf *tmp = NULL, *server_host_key_blob = NULL;
+	u_char *signature = NULL;
 	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t slen, sbloblen, hashlen;
+	size_t slen, hashlen;
 	int r;
 
 	/* hostkey */
-	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)
+	if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
+		goto out;
+	/* sshkey_fromb() consumes its buffer, so make a copy */
+	if ((tmp = sshbuf_fromb(server_host_key_blob)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_fromb(tmp, &server_host_key)) != 0)
 		goto out;
 	if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)
 		goto out;
@@ -192,9 +197,9 @@ input_kex_gen_reply(int type, u_int32_t seq, struct ssh *ssh)
 	    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,
+	    kex->my,
+	    kex->peer,
+	    server_host_key_blob,
 	    kex->client_pub,
 	    server_blob,
 	    shared_secret,
@@ -212,8 +217,9 @@ out:
 	explicit_bzero(kex->c25519_client_key, sizeof(kex->c25519_client_key));
 	explicit_bzero(kex->sntrup4591761_client_key,
 	    sizeof(kex->sntrup4591761_client_key));
-	free(server_host_key_blob);
+	sshbuf_free(server_host_key_blob);
 	free(signature);
+	sshbuf_free(tmp);
 	sshkey_free(server_host_key);
 	sshbuf_free(server_blob);
 	sshbuf_free(shared_secret);
@@ -238,9 +244,9 @@ input_kex_gen_init(int type, u_int32_t seq, struct ssh *ssh)
 	struct sshbuf *shared_secret = NULL;
 	struct sshbuf *server_pubkey = NULL;
 	struct sshbuf *client_pubkey = NULL;
-	u_char *server_host_key_blob = NULL, *signature = NULL;
-	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t slen, sbloblen, hashlen;
+	struct sshbuf *server_host_key_blob = NULL;
+	u_char *signature = NULL, hash[SSH_DIGEST_MAX_LENGTH];
+	size_t slen, hashlen;
 	int r;
 
 	if ((r = kex_load_hostkey(ssh, &server_host_private,
@@ -281,17 +287,20 @@ input_kex_gen_init(int type, u_int32_t seq, struct ssh *ssh)
 		goto out;
 
 	/* calc H */
-	if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
-	    &sbloblen)) != 0)
+	if ((server_host_key_blob = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_putb(server_host_public, server_host_key_blob)) != 0)
 		goto out;
 	hashlen = sizeof(hash);
 	if ((r = kex_gen_hash(
 	    kex->hash_alg,
 	    kex->client_version,
 	    kex->server_version,
-	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
-	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
-	    server_host_key_blob, sbloblen,
+	    kex->peer,
+	    kex->my,
+	    server_host_key_blob,
 	    client_pubkey,
 	    server_pubkey,
 	    shared_secret,
@@ -305,7 +314,7 @@ input_kex_gen_init(int type, u_int32_t seq, struct ssh *ssh)
 
 	/* send server hostkey, ECDH pubkey 'Q_S' and signed H */
 	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_ECDH_REPLY)) != 0 ||
-	    (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 ||
+	    (r = sshpkt_put_stringb(ssh, server_host_key_blob)) != 0 ||
 	    (r = sshpkt_put_stringb(ssh, server_pubkey)) != 0 ||
 	    (r = sshpkt_put_string(ssh, signature, slen)) != 0 ||
 	    (r = sshpkt_send(ssh)) != 0)
@@ -315,7 +324,7 @@ input_kex_gen_init(int type, u_int32_t seq, struct ssh *ssh)
 		r = kex_send_newkeys(ssh);
 out:
 	explicit_bzero(hash, sizeof(hash));
-	free(server_host_key_blob);
+	sshbuf_free(server_host_key_blob);
 	free(signature);
 	sshbuf_free(shared_secret);
 	sshbuf_free(client_pubkey);
diff --git a/kexgex.c b/kexgex.c
index f828f2b2..8040a132 100644
--- a/kexgex.c
+++ b/kexgex.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgex.c,v 1.31 2019/01/21 10:03:37 djm Exp $ */
+/* $OpenBSD: kexgex.c,v 1.32 2019/01/23 00:30:41 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -48,9 +48,9 @@ kexgex_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 struct sshbuf *client_kexinit,
+    const struct sshbuf *server_kexinit,
+    const struct sshbuf *server_host_key_blob,
     int min, int wantbits, int max,
     const BIGNUM *prime,
     const BIGNUM *gen,
@@ -69,13 +69,13 @@ kexgex_hash(
 	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_u32(b, sshbuf_len(client_kexinit) + 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_putb(b, client_kexinit)) != 0 ||
+	    (r = sshbuf_put_u32(b, sshbuf_len(server_kexinit) + 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_putb(b, server_kexinit)) != 0 ||
+	    (r = sshbuf_put_stringb(b, server_host_key_blob)) != 0 ||
 	    (min != -1 && (r = sshbuf_put_u32(b, min)) != 0) ||
 	    (r = sshbuf_put_u32(b, wantbits)) != 0 ||
 	    (max != -1 && (r = sshbuf_put_u32(b, max)) != 0) ||
diff --git a/kexgexc.c b/kexgexc.c
index ac42127a..1c65b8a1 100644
--- a/kexgexc.c
+++ b/kexgexc.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexc.c,v 1.33 2019/01/21 10:07:22 djm Exp $ */
+/* $OpenBSD: kexgexc.c,v 1.34 2019/01/23 00:30:41 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -146,20 +146,24 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
 	BIGNUM *dh_server_pub = NULL;
 	const BIGNUM *pub_key, *dh_p, *dh_g;
 	struct sshbuf *shared_secret = NULL;
+	struct sshbuf *tmp = NULL, *server_host_key_blob = NULL;
 	struct sshkey *server_host_key = NULL;
-	u_char *signature = NULL, *server_host_key_blob = NULL;
+	u_char *signature = NULL;
 	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t slen, sbloblen, hashlen;
+	size_t slen, hashlen;
 	int r;
 
 	debug("got SSH2_MSG_KEX_DH_GEX_REPLY");
 	/* 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)
+	if ((r = sshpkt_getb_froms(ssh, &server_host_key_blob)) != 0)
 		goto out;
-	if ((r = kex_verify_host_key(ssh, server_host_key)) != 0)
+	/* sshkey_fromb() consumes its buffer, so make a copy */
+	if ((tmp = sshbuf_fromb(server_host_key_blob)) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_fromb(tmp, &server_host_key)) != 0 ||
+	    (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 ||
@@ -183,9 +187,9 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
 	    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,
+	    kex->my,
+	    kex->peer,
+	    server_host_key_blob,
 	    kex->min, kex->nbits, kex->max,
 	    dh_p, dh_g,
 	    pub_key,
@@ -207,7 +211,8 @@ input_kex_dh_gex_reply(int type, u_int32_t seq, struct ssh *ssh)
 	BN_clear_free(dh_server_pub);
 	sshbuf_free(shared_secret);
 	sshkey_free(server_host_key);
-	free(server_host_key_blob);
+	sshbuf_free(tmp);
+	sshbuf_free(server_host_key_blob);
 	free(signature);
 	return r;
 }
diff --git a/kexgexs.c b/kexgexs.c
index a617d445..8ee3aacc 100644
--- a/kexgexs.c
+++ b/kexgexs.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: kexgexs.c,v 1.41 2019/01/21 10:05:09 djm Exp $ */
+/* $OpenBSD: kexgexs.c,v 1.42 2019/01/23 00:30:41 djm Exp $ */
 /*
  * Copyright (c) 2000 Niels Provos.  All rights reserved.
  * Copyright (c) 2001 Markus Friedl.  All rights reserved.
@@ -129,11 +129,11 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
 	BIGNUM *dh_client_pub = NULL;
 	const BIGNUM *pub_key, *dh_p, *dh_g;
 	struct sshbuf *shared_secret = NULL;
+	struct sshbuf *server_host_key_blob = NULL;
 	struct sshkey *server_host_public, *server_host_private;
-	u_char *signature = NULL, *server_host_key_blob = NULL;
+	u_char *signature = NULL;
 	u_char hash[SSH_DIGEST_MAX_LENGTH];
-	size_t sbloblen, slen;
-	size_t hashlen;
+	size_t slen, hashlen;
 	int r;
 
 	if ((r = kex_load_hostkey(ssh, &server_host_private,
@@ -150,8 +150,11 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
 	}
 	if ((r = kex_dh_compute_key(kex, dh_client_pub, shared_secret)) != 0)
 		goto out;
-	if ((r = sshkey_to_blob(server_host_public, &server_host_key_blob,
-	    &sbloblen)) != 0)
+	if ((server_host_key_blob = sshbuf_new()) == NULL) {
+		r = SSH_ERR_ALLOC_FAIL;
+		goto out;
+	}
+	if ((r = sshkey_putb(server_host_public, server_host_key_blob)) != 0)
 		goto out;
 
 	/* calc H */
@@ -162,9 +165,9 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
 	    kex->hash_alg,
 	    kex->client_version,
 	    kex->server_version,
-	    sshbuf_ptr(kex->peer), sshbuf_len(kex->peer),
-	    sshbuf_ptr(kex->my), sshbuf_len(kex->my),
-	    server_host_key_blob, sbloblen,
+	    kex->peer,
+	    kex->my,
+	    server_host_key_blob,
 	    kex->min, kex->nbits, kex->max,
 	    dh_p, dh_g,
 	    dh_client_pub,
@@ -180,7 +183,7 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
 
 	/* send server hostkey, DH pubkey 'f' and signed H */
 	if ((r = sshpkt_start(ssh, SSH2_MSG_KEX_DH_GEX_REPLY)) != 0 ||
-	    (r = sshpkt_put_string(ssh, server_host_key_blob, sbloblen)) != 0 ||
+	    (r = sshpkt_put_stringb(ssh, server_host_key_blob)) != 0 ||
 	    (r = sshpkt_put_bignum2(ssh, pub_key)) != 0 ||     /* f */
 	    (r = sshpkt_put_string(ssh, signature, slen)) != 0 ||
 	    (r = sshpkt_send(ssh)) != 0)
@@ -194,7 +197,7 @@ input_kex_dh_gex_init(int type, u_int32_t seq, struct ssh *ssh)
 	kex->dh = NULL;
 	BN_clear_free(dh_client_pub);
 	sshbuf_free(shared_secret);
-	free(server_host_key_blob);
+	sshbuf_free(server_host_key_blob);
 	free(signature);
 	return r;
 }