Add client side of supported versions and keyshare extensions with basic regress

ok jsing@

5 files changed, 454 insertions, 5 deletions

diff --git a/src/lib/libssl/s3_lib.c b/src/lib/libssl/s3_lib.c
index 091713d12a..0761c5b5ce 100644
--- a/src/lib/libssl/s3_lib.c
+++ b/src/lib/libssl/s3_lib.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: s3_lib.c,v 1.176 2018/11/08 22:28:52 jsing Exp $ */
+/* $OpenBSD: s3_lib.c,v 1.177 2019/01/18 12:09:52 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -1627,6 +1627,11 @@ ssl3_clear(SSL *s)
 
         s->internal->packet_length = 0;
         s->version = TLS1_VERSION;
+
+        tls13_secrets_destroy(S3I(s)->hs_tls13.secrets);
+        freezero(S3I(s)->hs_tls13.x25519_private, X25519_KEY_LENGTH);
+        freezero(S3I(s)->hs_tls13.x25519_public, X25519_KEY_LENGTH);
+        freezero(S3I(s)->hs_tls13.x25519_peer_public, X25519_KEY_LENGTH);
 }
 
 static long
diff --git a/src/lib/libssl/ssl_locl.h b/src/lib/libssl/ssl_locl.h
index 94bb76eca3..1653b2ab96 100644
--- a/src/lib/libssl/ssl_locl.h
+++ b/src/lib/libssl/ssl_locl.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_locl.h,v 1.225 2018/11/21 15:13:29 jsing Exp $ */
+/* $OpenBSD: ssl_locl.h,v 1.226 2019/01/18 12:09:52 beck Exp $ */
 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
  * All rights reserved.
  *
@@ -162,6 +162,7 @@
 
 #include "bytestring.h"
 #include "ssl_sigalgs.h"
+#include "tls13_internal.h"
 
 __BEGIN_HIDDEN_DECLS
 
@@ -430,6 +431,22 @@ typedef struct ssl_handshake_st {
         unsigned char *key_block;
 } SSL_HANDSHAKE;
 
+typedef struct ssl_handshake_tls13_st {
+        uint16_t min_version;
+        uint16_t max_version;
+        uint16_t version;
+
+        /* Version proposed by peer server. */
+        uint16_t server_version;
+
+        /* X25519 key share. */
+        uint8_t *x25519_public;
+        uint8_t *x25519_private;
+        uint8_t *x25519_peer_public;
+
+        struct tls13_secrets *secrets;
+} SSL_HANDSHAKE_TLS13;
+
 typedef struct ssl_ctx_internal_st {
         uint16_t min_version;
         uint16_t max_version;
@@ -803,6 +820,7 @@ typedef struct ssl3_state_internal_st {
         int in_read_app_data;
 
         SSL_HANDSHAKE hs;
+        SSL_HANDSHAKE_TLS13 hs_tls13;
 
         struct  {
                 int new_mac_secret_size;
diff --git a/src/lib/libssl/ssl_tlsext.c b/src/lib/libssl/ssl_tlsext.c
index da34a79f7d..91b3b7d958 100644
--- a/src/lib/libssl/ssl_tlsext.c
+++ b/src/lib/libssl/ssl_tlsext.c
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.c,v 1.28 2019/01/18 03:39:27 beck Exp $ */
+/* $OpenBSD: ssl_tlsext.c,v 1.29 2019/01/18 12:09:52 beck Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -16,6 +16,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#include <openssl/curve25519.h>
 #include <openssl/ocsp.h>
 
 #include "ssl_locl.h"
@@ -1193,6 +1194,196 @@ tlsext_srtp_client_parse(SSL *s, CBS *cbs, int *alert)
 
 #endif /* OPENSSL_NO_SRTP */
 
+/*
+ * TLSv1.3 Key Share - RFC 8446 section 4.2.8.
+ */
+int
+tlsext_keyshare_client_needs(SSL *s)
+{
+        /* XXX once this gets initialized when we get tls13_client.c */
+        if (S3I(s)->hs_tls13.max_version == 0)
+                return 0;
+        return (!SSL_IS_DTLS(s) && S3I(s)->hs_tls13.max_version >=
+            TLS1_3_VERSION);
+}
+
+int
+tlsext_keyshare_client_build(SSL *s, CBB *cbb)
+{
+        uint8_t *public_key = NULL, *private_key = NULL;
+        CBB client_shares, key_exchange;
+
+        /* Generate and provide key shares. */
+        if (!CBB_add_u16_length_prefixed(cbb, &client_shares))
+                return 0;
+
+        /* XXX - other groups. */
+
+        /* Generate X25519 key pair. */
+        if ((public_key = malloc(X25519_KEY_LENGTH)) == NULL)
+                goto err;
+        if ((private_key = malloc(X25519_KEY_LENGTH)) == NULL)
+                goto err;
+        X25519_keypair(public_key, private_key);
+
+        /* Add the group and serialize the public key. */
+        if (!CBB_add_u16(&client_shares, tls1_ec_nid2curve_id(NID_X25519)))
+                goto err;
+        if (!CBB_add_u16_length_prefixed(&client_shares, &key_exchange))
+                goto err;
+        if (!CBB_add_bytes(&key_exchange, public_key, X25519_KEY_LENGTH))
+                goto err;
+
+        if (!CBB_flush(cbb))
+                goto err;
+
+        S3I(s)->hs_tls13.x25519_public = public_key;
+        S3I(s)->hs_tls13.x25519_private = private_key;
+
+        return 1;
+
+err:
+        freezero(public_key, X25519_KEY_LENGTH);
+        freezero(private_key, X25519_KEY_LENGTH);
+
+        return 0;
+}
+
+int
+tlsext_keyshare_server_parse(SSL *s, CBS *cbs, int *alert)
+{
+        /* XXX we accept this but currently ignore it */
+        if (!CBS_skip(cbs, CBS_len(cbs))) {
+                *alert = TLS1_AD_INTERNAL_ERROR;
+                return 0;
+        }
+
+        return 1;
+}
+
+int
+tlsext_keyshare_server_needs(SSL *s)
+{
+        return (!SSL_IS_DTLS(s) && s->version >= TLS1_3_VERSION);
+}
+
+int
+tlsext_keyshare_server_build(SSL *s, CBB *cbb)
+{
+        return 0;
+}
+
+int
+tlsext_keyshare_client_parse(SSL *s, CBS *cbs, int *alert)
+{
+        CBS key_exchange;
+        uint16_t group;
+        size_t out_len;
+
+        /* Unpack server share. */
+        if (!CBS_get_u16(cbs, &group))
+                goto err;
+
+        /* Handle other groups and verify that they're valid. */
+        if (group != tls1_ec_nid2curve_id(NID_X25519))
+                goto err;
+
+        if (!CBS_get_u16_length_prefixed(cbs, &key_exchange))
+                goto err;
+        if (CBS_len(&key_exchange) != X25519_KEY_LENGTH)
+                goto err;
+        if (!CBS_stow(&key_exchange, &S3I(s)->hs_tls13.x25519_peer_public,
+                &out_len))
+                goto err;
+
+        return 1;
+
+ err:
+        *alert = SSL_AD_DECODE_ERROR;
+        return 0;
+}
+
+/*
+ * Supported Versions - RFC 8446 section 4.2.1.
+ */
+int
+tlsext_versions_client_needs(SSL *s)
+{
+        /* XXX once this gets initialized when we get tls13_client.c */
+        if (S3I(s)->hs_tls13.max_version == 0)
+                return 0;
+        return (!SSL_IS_DTLS(s) && S3I(s)->hs_tls13.max_version >=
+            TLS1_3_VERSION);
+}
+
+int
+tlsext_versions_client_build(SSL *s, CBB *cbb)
+{
+        uint16_t version;
+        CBB versions;
+        uint16_t max, min;
+
+        max = S3I(s)->hs_tls13.max_version;
+        min = S3I(s)->hs_tls13.min_version;
+
+        if (min < TLS1_VERSION)
+                return 0;
+
+        if (!CBB_add_u8_length_prefixed(cbb, &versions))
+                return 0;
+
+        /* XXX - fix, but contiguous for now... */
+        for (version = max; version >= min; version--) {
+                if (!CBB_add_u16(&versions, version))
+                        return 0;
+        }
+
+        if (!CBB_flush(cbb))
+                return 0;
+
+        return 1;
+}
+
+int
+tlsext_versions_server_parse(SSL *s, CBS *cbs, int *alert)
+{
+        /* XXX we accept this but currently ignore it */
+        if (!CBS_skip(cbs, CBS_len(cbs))) {
+                *alert = TLS1_AD_INTERNAL_ERROR;
+                return 0;
+        }
+
+        return 1;
+}
+
+int
+tlsext_versions_server_needs(SSL *s)
+{
+        return (!SSL_IS_DTLS(s) && s->version >= TLS1_3_VERSION);
+}
+
+int
+tlsext_versions_server_build(SSL *s, CBB *cbb)
+{
+        return 0;
+}
+
+int
+tlsext_versions_client_parse(SSL *s, CBS *cbs, int *alert)
+{
+        uint16_t selected_version;
+
+        if (!CBS_get_u16(cbs, &selected_version)) {
+                *alert = SSL_AD_DECODE_ERROR;
+                return 0;
+        }
+
+        /* XXX test between min and max once initialization code goes in */
+        S3I(s)->hs_tls13.server_version = selected_version;
+
+        return 1;
+}
+
 struct tls_extension_funcs {
         int (*needs)(SSL *s);
         int (*build)(SSL *s, CBB *cbb);
@@ -1208,6 +1399,36 @@ struct tls_extension {
 
 static struct tls_extension tls_extensions[] = {
         {
+                .type = TLSEXT_TYPE_supported_versions,
+                .messages = SSL_TLSEXT_MSG_CH | SSL_TLSEXT_MSG_SH |
+                    SSL_TLSEXT_MSG_HRR,
+                .client = {
+                        .needs = tlsext_versions_client_needs,
+                        .build = tlsext_versions_client_build,
+                        .parse = tlsext_versions_server_parse,
+                },
+                .server = {
+                        .needs = tlsext_versions_server_needs,
+                        .build = tlsext_versions_server_build,
+                        .parse = tlsext_versions_client_parse,
+                },
+        },
+        {
+                .type = TLSEXT_TYPE_key_share,
+                .messages = SSL_TLSEXT_MSG_CH | SSL_TLSEXT_MSG_SH |
+                    SSL_TLSEXT_MSG_HRR,
+                .client = {
+                        .needs = tlsext_keyshare_client_needs,
+                        .build = tlsext_keyshare_client_build,
+                        .parse = tlsext_keyshare_server_parse,
+                },
+                .server = {
+                        .needs = tlsext_keyshare_server_needs,
+                        .build = tlsext_keyshare_server_build,
+                        .parse = tlsext_keyshare_client_parse,
+                },
+        },
+        {
                 .type = TLSEXT_TYPE_server_name,
                 .messages = SSL_TLSEXT_MSG_CH | SSL_TLSEXT_MSG_EE,
                 .client = {
diff --git a/src/lib/libssl/ssl_tlsext.h b/src/lib/libssl/ssl_tlsext.h
index e5c1628c98..8f5aaa89dc 100644
--- a/src/lib/libssl/ssl_tlsext.h
+++ b/src/lib/libssl/ssl_tlsext.h
@@ -1,4 +1,4 @@
-/* $OpenBSD: ssl_tlsext.h,v 1.15 2019/01/18 00:54:42 jsing Exp $ */
+/* $OpenBSD: ssl_tlsext.h,v 1.16 2019/01/18 12:09:52 beck Exp $ */
 /*
  * Copyright (c) 2016, 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
@@ -86,6 +86,20 @@ int tlsext_sessionticket_server_needs(SSL *s);
 int tlsext_sessionticket_server_build(SSL *s, CBB *cbb);
 int tlsext_sessionticket_server_parse(SSL *s, CBS *cbs, int *alert);
 
+int tlsext_versions_client_needs(SSL *s);
+int tlsext_versions_client_build(SSL *s, CBB *cbb);
+int tlsext_versions_client_parse(SSL *s, CBS *cbs, int *alert);
+int tlsext_versions_server_needs(SSL *s);
+int tlsext_versions_server_build(SSL *s, CBB *cbb);
+int tlsext_versions_server_parse(SSL *s, CBS *cbs, int *alert);
+
+int tlsext_keyshare_client_needs(SSL *s);
+int tlsext_keyshare_client_build(SSL *s, CBB *cbb);
+int tlsext_keyshare_client_parse(SSL *s, CBS *cbs, int *alert);
+int tlsext_keyshare_server_needs(SSL *s);
+int tlsext_keyshare_server_build(SSL *s, CBB *cbb);
+int tlsext_keyshare_server_parse(SSL *s, CBS *cbs, int *alert);
+
 #ifndef OPENSSL_NO_SRTP
 int tlsext_srtp_client_needs(SSL *s);
 int tlsext_srtp_client_build(SSL *s, CBB *cbb);
diff --git a/src/regress/lib/libssl/tlsext/tlsexttest.c b/src/regress/lib/libssl/tlsext/tlsexttest.c
index 04403118af..7a9f7d9be7 100644
--- a/src/regress/lib/libssl/tlsext/tlsexttest.c
+++ b/src/regress/lib/libssl/tlsext/tlsexttest.c
@@ -1,7 +1,8 @@
-/* $OpenBSD: tlsexttest.c,v 1.21 2019/01/18 00:55:15 jsing Exp $ */
+/* $OpenBSD: tlsexttest.c,v 1.22 2019/01/18 12:09:52 beck Exp $ */
 /*
  * Copyright (c) 2017 Joel Sing <jsing@openbsd.org>
  * Copyright (c) 2017 Doug Hogan <doug@openbsd.org>
+ * Copyright (c) 2019 Bob Beck <beck@openbsd.org>
  *
  * Permission to use, copy, modify, and distribute this software for any
  * purpose with or without fee is hereby granted, provided that the above
@@ -2934,6 +2935,192 @@ test_tlsext_serverhello_build(void)
         return (failure);
 }
 
+static unsigned char tlsext_versions_client[] = {
+        0x08, 0x03, 0x04, 0x03, 0x03, 0x03,
+        0x02, 0x03, 0x01,
+};
+
+static int
+test_tlsext_versions_client(void)
+{
+        unsigned char *data = NULL;
+        SSL_CTX *ssl_ctx = NULL;
+        SSL *ssl = NULL;
+        int failure = 0;
+        size_t dlen;
+        int alert;
+        CBB cbb;
+        CBS cbs;
+
+        CBB_init(&cbb, 0);
+
+        if ((ssl_ctx = SSL_CTX_new(TLS_client_method())) == NULL)
+                errx(1, "failed to create SSL_CTX");
+        if ((ssl = SSL_new(ssl_ctx)) == NULL)
+                errx(1, "failed to create SSL");
+
+        S3I(ssl)->hs_tls13.max_version = 0;
+
+        if (tlsext_versions_client_needs(ssl)) {
+                FAIL("client should not need versions\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_2_VERSION;
+
+        if (tlsext_versions_client_needs(ssl)) {
+                FAIL("client should not need versions\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_3_VERSION;
+
+        if (!tlsext_versions_client_needs(ssl)) {
+                FAIL("client should need versions\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_3_VERSION;
+        S3I(ssl)->hs_tls13.min_version = 0;
+        if (tlsext_versions_client_build(ssl, &cbb)) {
+                FAIL("client should not have built versions\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_3_VERSION;
+        S3I(ssl)->hs_tls13.min_version = TLS1_VERSION;
+        if (!tlsext_versions_client_build(ssl, &cbb)) {
+                FAIL("client should have built versions\n");
+                failure = 1;
+                goto done;
+        }
+
+        if (!CBB_finish(&cbb, &data, &dlen)) {
+                FAIL("failed to finish CBB");
+                failure = 1;
+                goto done;
+        }
+
+        if (dlen != sizeof(tlsext_versions_client)) {
+                FAIL("got versions with length %zu, "
+                    "want length %zu\n", dlen, (size_t) sizeof(tlsext_versions_client));
+                failure = 1;
+                goto done;
+        }
+
+        CBS_init(&cbs, tlsext_versions_client, sizeof(tlsext_versions_client));
+        if (!tlsext_versions_server_parse(ssl, &cbs, &alert)) {
+                FAIL("failed to parse client versions\n");
+                failure = 1;
+                goto done;
+        }
+        if (CBS_len(&cbs) != 0) {
+                FAIL("extension data remaining");
+                failure = 1;
+                goto done;
+        }
+ done:
+        CBB_cleanup(&cbb);
+        SSL_CTX_free(ssl_ctx);
+        SSL_free(ssl);
+        free(data);
+
+        return (failure);
+}
+
+static unsigned char tlsext_keyshare_client[] = {
+        0x00, 0x24, 0x00, 0x1d, 0x00, 0x20, 0xba, 0x83,
+        0x2e, 0x4a, 0x18, 0xbe, 0x96, 0xd2, 0x71, 0x70,
+        0x18, 0x04, 0xf9, 0x9d, 0x76, 0x98, 0xef, 0xe8,
+        0x4f, 0x8b, 0x85, 0x41, 0xa4, 0xd9, 0x61, 0x57,
+        0xad, 0x5b, 0xa4, 0xe9, 0x8b, 0x6b,
+};
+
+static int
+test_tlsext_keyshare_client(void)
+{
+        unsigned char *data = NULL;
+        SSL_CTX *ssl_ctx = NULL;
+        SSL *ssl = NULL;
+        int failure = 0;
+        size_t dlen;
+        int alert;
+        CBB cbb;
+        CBS cbs;
+
+        CBB_init(&cbb, 0);
+
+        if ((ssl_ctx = SSL_CTX_new(TLS_client_method())) == NULL)
+                errx(1, "failed to create SSL_CTX");
+        if ((ssl = SSL_new(ssl_ctx)) == NULL)
+                errx(1, "failed to create SSL");
+
+        S3I(ssl)->hs_tls13.max_version = 0;
+
+        if (tlsext_keyshare_client_needs(ssl)) {
+                FAIL("client should not need keyshare\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_2_VERSION;
+        if (tlsext_keyshare_client_needs(ssl)) {
+                FAIL("client should not need keyshare\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_3_VERSION;
+        if (!tlsext_keyshare_client_needs(ssl)) {
+                FAIL("client should need keyshare\n");
+                failure = 1;
+                goto done;
+        }
+
+        S3I(ssl)->hs_tls13.max_version = TLS1_3_VERSION;
+        if (!tlsext_keyshare_client_build(ssl, &cbb)) {
+                FAIL("client should have built keyshare\n");
+                failure = 1;
+                goto done;
+        }
+
+        if (!CBB_finish(&cbb, &data, &dlen)) {
+                FAIL("failed to finish CBB");
+                failure = 1;
+                goto done;
+        }
+
+        if (dlen != sizeof(tlsext_keyshare_client)) {
+                FAIL("got client sigalgs with length %zu, "
+                    "want length %zu\n", dlen, (size_t) sizeof(tlsext_keyshare_client));
+                failure = 1;
+                goto done;
+        }
+
+        CBS_init(&cbs, tlsext_keyshare_client, sizeof(tlsext_keyshare_client));
+        if (!tlsext_keyshare_server_parse(ssl, &cbs, &alert)) {
+                FAIL("failed to parse client keyshare\n");
+                failure = 1;
+                goto done;
+        }
+        if (CBS_len(&cbs) != 0) {
+                FAIL("extension data remaining");
+                failure = 1;
+                goto done;
+        }
+ done:
+        CBB_cleanup(&cbb);
+        SSL_CTX_free(ssl_ctx);
+        SSL_free(ssl);
+        free(data);
+
+        return (failure);
+}
+
 int
 main(int argc, char **argv)
 {
@@ -2966,6 +3153,10 @@ main(int argc, char **argv)
         failed |= test_tlsext_sessionticket_client();
         failed |= test_tlsext_sessionticket_server();
 
+        failed |= test_tlsext_versions_client();
+
+        failed |= test_tlsext_keyshare_client();
+
 #ifndef OPENSSL_NO_SRTP
         failed |= test_tlsext_srtp_client();
         failed |= test_tlsext_srtp_server();