Add support for TLS_FALLBACK_SCSV

Includes changes to openssl.config not present in the original
commit.

Bug: 17750026
(cherry-picked from commit 9a68a8fb86e7440763286e3ea8578099abd598e7)

Change-Id: I89ed89b87b4f4eeeddb6de0c6ad1d48cb6d0ee7b

2 files changed, 481 insertions, 0 deletions

diff --git a/patches/0018-tls_fallback_scsv.patch b/patches/0018-tls_fallback_scsv.patch
new file mode 100644
index 0000000..a61c894
--- /dev/null
+++ b/patches/0018-tls_fallback_scsv.patch
@@ -0,0 +1,476 @@
+From f7a067d743b7cc65979678ac15190b334352716a Mon Sep 17 00:00:00 2001
+From: Bodo Moeller <bmoeller@google.com>
+Date: Thu, 2 Oct 2014 15:47:44 +0100
+Subject: [PATCH] Add support for TLS_FALLBACK_SCSV.
+
+Change-Id: I56626b12407f19e7ed48a680b596e2b2c7b46de1
+---
+ apps/s_client.c         | 10 +++++++++
+ crypto/err/openssl.ec   |  1 +
+ include/openssl/dtls1.h |  3 ++-
+ include/openssl/ssl.h   | 10 +++++++++
+ include/openssl/ssl3.h  |  7 +++++-
+ include/openssl/tls1.h  | 15 ++++++++-----
+ ssl/d1_lib.c            | 10 +++++++++
+ ssl/dtls1.h             |  3 ++-
+ ssl/s23_clnt.c          |  3 +++
+ ssl/s23_srvr.c          |  3 +++
+ ssl/s2_lib.c            |  2 ++
+ ssl/s3_enc.c            |  2 +-
+ ssl/s3_lib.c            | 29 ++++++++++++++++++++++++-
+ ssl/ssl.h               | 10 +++++++++
+ ssl/ssl3.h              |  7 +++++-
+ ssl/ssl_err.c           |  2 ++
+ ssl/ssl_lib.c           | 58 +++++++++++++++++++++++++++++++++++++------------
+ ssl/t1_enc.c            |  1 +
+ ssl/tls1.h              | 15 ++++++++-----
+ 19 files changed, 159 insertions(+), 32 deletions(-)
+
+diff --git a/apps/s_client.c b/apps/s_client.c
+index 0c70580..299facd 100644
+--- a/apps/s_client.c
++++ b/apps/s_client.c
+@@ -335,6 +335,7 @@ static void sc_usage(void)
+ 	BIO_printf(bio_err," -tls1_1       - just use TLSv1.1\n");
+ 	BIO_printf(bio_err," -tls1         - just use TLSv1\n");
+ 	BIO_printf(bio_err," -dtls1        - just use DTLSv1\n");    
++	BIO_printf(bio_err," -fallback_scsv - send TLS_FALLBACK_SCSV\n");
+ 	BIO_printf(bio_err," -mtu          - set the link layer MTU\n");
+ 	BIO_printf(bio_err," -no_tls1_2/-no_tls1_1/-no_tls1/-no_ssl3/-no_ssl2 - turn off that protocol\n");
+ 	BIO_printf(bio_err," -bugs         - Switch on all SSL implementation bug workarounds\n");
+@@ -621,6 +622,7 @@ int MAIN(int argc, char **argv)
+ 	char *sess_out = NULL;
+ 	struct sockaddr peer;
+ 	int peerlen = sizeof(peer);
++	int fallback_scsv = 0;
+ 	int enable_timeouts = 0 ;
+ 	long socket_mtu = 0;
+ #ifndef OPENSSL_NO_JPAKE
+@@ -827,6 +829,10 @@ int MAIN(int argc, char **argv)
+ 			meth=DTLSv1_client_method();
+ 			socket_type=SOCK_DGRAM;
+ 			}
++		else if (strcmp(*argv,"-fallback_scsv") == 0)
++			{
++			fallback_scsv = 1;
++			}
+ 		else if (strcmp(*argv,"-timeout") == 0)
+ 			enable_timeouts=1;
+ 		else if (strcmp(*argv,"-mtu") == 0)
+@@ -1273,6 +1279,10 @@ bad:
+ 		SSL_set_session(con, sess);
+ 		SSL_SESSION_free(sess);
+ 		}
++
++	if (fallback_scsv)
++		SSL_set_mode(con, SSL_MODE_SEND_FALLBACK_SCSV);
++
+ #ifndef OPENSSL_NO_TLSEXT
+ 	if (servername != NULL)
+ 		{
+diff --git a/crypto/err/openssl.ec b/crypto/err/openssl.ec
+index e0554b4..34754e5 100644
+--- a/crypto/err/openssl.ec
++++ b/crypto/err/openssl.ec
+@@ -71,6 +71,7 @@ R SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION		1060
+ R SSL_R_TLSV1_ALERT_PROTOCOL_VERSION		1070
+ R SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY	1071
+ R SSL_R_TLSV1_ALERT_INTERNAL_ERROR		1080
++R SSL_R_SSLV3_ALERT_INAPPROPRIATE_FALLBACK	1086
+ R SSL_R_TLSV1_ALERT_USER_CANCELLED		1090
+ R SSL_R_TLSV1_ALERT_NO_RENEGOTIATION		1100
+ R SSL_R_TLSV1_UNSUPPORTED_EXTENSION		1110
+diff --git a/ssl/d1_lib.c b/ssl/d1_lib.c
+index 6bde16f..82ca653 100644
+--- a/ssl/d1_lib.c
++++ b/ssl/d1_lib.c
+@@ -266,6 +266,16 @@ long dtls1_ctrl(SSL *s, int cmd, long larg, void *parg)
+ 	case DTLS_CTRL_LISTEN:
+ 		ret = dtls1_listen(s, parg);
+ 		break;
++	case SSL_CTRL_CHECK_PROTO_VERSION:
++		/* For library-internal use; checks that the current protocol
++		 * is the highest enabled version (according to s->ctx->method,
++		 * as version negotiation may have changed s->method). */
++#if DTLS_MAX_VERSION != DTLS1_VERSION
++#  error Code needs update for DTLS_method() support beyond DTLS1_VERSION.
++#endif
++		/* Just one protocol version is supported so far;
++		 * fail closed if the version is not as expected. */
++		return s->version == DTLS_MAX_VERSION;
+ 
+ 	default:
+ 		ret = ssl3_ctrl(s, cmd, larg, parg);
+diff --git a/ssl/dtls1.h b/ssl/dtls1.h
+index e65d501..192c5de 100644
+--- a/ssl/dtls1.h
++++ b/ssl/dtls1.h
+@@ -84,6 +84,8 @@ extern "C" {
+ #endif
+ 
+ #define DTLS1_VERSION			0xFEFF
++#define DTLS_MAX_VERSION		DTLS1_VERSION
++
+ #define DTLS1_BAD_VER			0x0100
+ 
+ #if 0
+@@ -284,4 +286,3 @@ typedef struct dtls1_record_data_st
+ }
+ #endif
+ #endif
+-
+diff --git a/ssl/s23_clnt.c b/ssl/s23_clnt.c
+index 2bc9214..467adfe 100644
+--- a/ssl/s23_clnt.c
++++ b/ssl/s23_clnt.c
+@@ -736,6 +736,9 @@ static int ssl23_get_server_hello(SSL *s)
+ 			goto err;
+ 			}
+ 
++		/* ensure that TLS_MAX_VERSION is up-to-date */
++		OPENSSL_assert(s->version <= TLS_MAX_VERSION);
++
+ 		if (p[0] == SSL3_RT_ALERT && p[5] != SSL3_AL_WARNING)
+ 			{
+ 			/* fatal alert */
+diff --git a/ssl/s23_srvr.c b/ssl/s23_srvr.c
+index 4877849..82d6867 100644
+--- a/ssl/s23_srvr.c
++++ b/ssl/s23_srvr.c
+@@ -425,6 +425,9 @@ int ssl23_get_client_hello(SSL *s)
+ 			}
+ 		}
+ 
++	/* ensure that TLS_MAX_VERSION is up-to-date */
++	OPENSSL_assert(s->version <= TLS_MAX_VERSION);
++
+ #ifdef OPENSSL_FIPS
+ 	if (FIPS_mode() && (s->version < TLS1_VERSION))
+ 		{
+diff --git a/ssl/s2_lib.c b/ssl/s2_lib.c
+index 9914604..b9624b9 100644
+--- a/ssl/s2_lib.c
++++ b/ssl/s2_lib.c
+@@ -391,6 +391,8 @@ long ssl2_ctrl(SSL *s, int cmd, long larg, void *parg)
+ 	case SSL_CTRL_GET_SESSION_REUSED:
+ 		ret=s->hit;
+ 		break;
++	case SSL_CTRL_CHECK_PROTO_VERSION:
++		return ssl3_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, larg, parg);
+ 	default:
+ 		break;
+ 		}
+diff --git a/ssl/s3_enc.c b/ssl/s3_enc.c
+index 53b94b7..3595cff 100644
+--- a/ssl/s3_enc.c
++++ b/ssl/s3_enc.c
+@@ -891,7 +891,7 @@ int ssl3_alert_code(int code)
+ 	case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE: return(SSL3_AD_HANDSHAKE_FAILURE);
+ 	case SSL_AD_BAD_CERTIFICATE_HASH_VALUE: return(SSL3_AD_HANDSHAKE_FAILURE);
+ 	case SSL_AD_UNKNOWN_PSK_IDENTITY:return(TLS1_AD_UNKNOWN_PSK_IDENTITY);
++	case SSL_AD_INAPPROPRIATE_FALLBACK:return(TLS1_AD_INAPPROPRIATE_FALLBACK);
+ 	default:			return(-1);
+ 		}
+ 	}
+-
+diff --git a/ssl/s3_lib.c b/ssl/s3_lib.c
+index 896d1e1..914e108 100644
+--- a/ssl/s3_lib.c
++++ b/ssl/s3_lib.c
+@@ -3439,6 +3439,33 @@ long sl3_ctrl(SSL *s, int cmd, long larg, void *parg)
+ 		return 64;
+ 
+ #endif /* !OPENSSL_NO_TLSEXT */
++
++	case SSL_CTRL_CHECK_PROTO_VERSION:
++		/* For library-internal use; checks that the current protocol
++		 * is the highest enabled version (according to s->ctx->method,
++		 * as version negotiation may have changed s->method). */
++		if (s->version == s->ctx->method->version)
++			return 1;
++		/* Apparently we're using a version-flexible SSL_METHOD
++		 * (not at its highest protocol version). */
++		if (s->ctx->method->version == SSLv23_method()->version)
++			{
++#if TLS_MAX_VERSION != TLS1_2_VERSION
++#  error Code needs update for SSLv23_method() support beyond TLS1_2_VERSION.
++#endif
++			if (!(s->options & SSL_OP_NO_TLSv1_2))
++				return s->version == TLS1_2_VERSION;
++			if (!(s->options & SSL_OP_NO_TLSv1_1))
++				return s->version == TLS1_1_VERSION;
++			if (!(s->options & SSL_OP_NO_TLSv1))
++				return s->version == TLS1_VERSION;
++			if (!(s->options & SSL_OP_NO_SSLv3))
++				return s->version == SSL3_VERSION;
++			if (!(s->options & SSL_OP_NO_SSLv2))
++				return s->version == SSL2_VERSION;
++			}
++		return 0; /* Unexpected state; fail closed. */
++
+ 	default:
+ 		break;
+ 		}
+@@ -3816,6 +3843,7 @@ long ssl3_ctx_callback_ctrl(SSL_CTX *ctx, int cmd, void (*fp)(void))
+ 		break;
+ #endif
+ #endif
++
+ 	default:
+ 		return(0);
+ 		}
+@@ -4406,4 +4434,3 @@ long ssl_get_algorithm2(SSL *s)
+ 		return SSL_HANDSHAKE_MAC_SHA256 | TLS1_PRF_SHA256;
+ 	return alg2;
+ 	}
+-		
+diff --git a/ssl/ssl.h b/ssl/ssl.h
+index 7566f2d..4607401 100644
+--- a/ssl/ssl.h
++++ b/ssl/ssl.h
+@@ -676,6 +676,11 @@ struct ssl_session_st
+  * attacks. */
+ #define SSL_MODE_CBC_RECORD_SPLITTING 0x00000100L
+ 
++/* Send TLS_FALLBACK_SCSV in the ClientHello.
++ * To be set by applications that reconnect with a downgraded protocol
++ * version; see draft-ietf-tls-downgrade-scsv-00 for details. */
++#define SSL_MODE_SEND_FALLBACK_SCSV 0x00000200L
++
+ /* Note: SSL[_CTX]_set_{options,mode} use |= op on the previous value,
+  * they cannot be used to clear bits. */
+ 
+@@ -1615,6 +1620,7 @@ DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
+ #define SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE
+ #define SSL_AD_BAD_CERTIFICATE_HASH_VALUE TLS1_AD_BAD_CERTIFICATE_HASH_VALUE
+ #define SSL_AD_UNKNOWN_PSK_IDENTITY     TLS1_AD_UNKNOWN_PSK_IDENTITY /* fatal */
++#define SSL_AD_INAPPROPRIATE_FALLBACK	TLS1_AD_INAPPROPRIATE_FALLBACK /* fatal */
+ 
+ #define SSL_ERROR_NONE			0
+ #define SSL_ERROR_SSL			1
+@@ -1729,6 +1735,8 @@ DECLARE_PEM_rw(SSL_SESSION, SSL_SESSION)
+ #define SSL_CTRL_GET_EXTRA_CHAIN_CERTS		82
+ #define SSL_CTRL_CLEAR_EXTRA_CHAIN_CERTS	83
+ 
++#define SSL_CTRL_CHECK_PROTO_VERSION		119
++
+ #define DTLSv1_get_timeout(ssl, arg) \
+ 	SSL_ctrl(ssl,DTLS_CTRL_GET_TIMEOUT,0, (void *)arg)
+ #define DTLSv1_handle_timeout(ssl) \
+@@ -2519,6 +2527,7 @@ void ERR_load_SSL_strings(void);
+ #define SSL_R_HTTPS_PROXY_REQUEST			 155
+ #define SSL_R_HTTP_REQUEST				 156
+ #define SSL_R_ILLEGAL_PADDING				 283
++#define SSL_R_INAPPROPRIATE_FALLBACK			 380
+ #define SSL_R_INCONSISTENT_COMPRESSION			 340
+ #define SSL_R_INVALID_CHALLENGE_LENGTH			 158
+ #define SSL_R_INVALID_COMMAND				 280
+@@ -2668,6 +2677,7 @@ void ERR_load_SSL_strings(void);
+ #define SSL_R_TLSV1_ALERT_DECRYPTION_FAILED		 1021
+ #define SSL_R_TLSV1_ALERT_DECRYPT_ERROR			 1051
+ #define SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION		 1060
++#define SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK	 1086
+ #define SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY		 1071
+ #define SSL_R_TLSV1_ALERT_INTERNAL_ERROR		 1080
+ #define SSL_R_TLSV1_ALERT_NO_RENEGOTIATION		 1100
+diff --git a/ssl/ssl3.h b/ssl/ssl3.h
+index 83d59bf..cba9434 100644
+--- a/ssl/ssl3.h
++++ b/ssl/ssl3.h
+@@ -128,9 +128,14 @@
+ extern "C" {
+ #endif
+ 
+-/* Signalling cipher suite value: from draft-ietf-tls-renegotiation-03.txt */
++/* Signalling cipher suite value from RFC 5746
++ * (TLS_EMPTY_RENEGOTIATION_INFO_SCSV) */
+ #define SSL3_CK_SCSV				0x030000FF
+ 
++/* Signalling cipher suite value from draft-ietf-tls-downgrade-scsv-00
++ * (TLS_FALLBACK_SCSV) */
++#define SSL3_CK_FALLBACK_SCSV			0x03005600
++
+ #define SSL3_CK_RSA_NULL_MD5			0x03000001
+ #define SSL3_CK_RSA_NULL_SHA			0x03000002
+ #define SSL3_CK_RSA_RC4_40_MD5 			0x03000003
+diff --git a/ssl/ssl_err.c b/ssl/ssl_err.c
+index ac0aad9..816f6ee 100644
+--- a/ssl/ssl_err.c
++++ b/ssl/ssl_err.c
+@@ -391,6 +391,7 @@ static ERR_STRING_DATA SSL_str_reasons[]=
+ {ERR_REASON(SSL_R_HTTPS_PROXY_REQUEST)   ,"https proxy request"},
+ {ERR_REASON(SSL_R_HTTP_REQUEST)          ,"http request"},
+ {ERR_REASON(SSL_R_ILLEGAL_PADDING)       ,"illegal padding"},
++{ERR_REASON(SSL_R_INAPPROPRIATE_FALLBACK),"inappropriate fallback"},
+ {ERR_REASON(SSL_R_INCONSISTENT_COMPRESSION),"inconsistent compression"},
+ {ERR_REASON(SSL_R_INVALID_CHALLENGE_LENGTH),"invalid challenge length"},
+ {ERR_REASON(SSL_R_INVALID_COMMAND)       ,"invalid command"},
+@@ -540,6 +541,7 @@ static ERR_STRING_DATA SSL_str_reasons[]=
+ {ERR_REASON(SSL_R_TLSV1_ALERT_DECRYPTION_FAILED),"tlsv1 alert decryption failed"},
+ {ERR_REASON(SSL_R_TLSV1_ALERT_DECRYPT_ERROR),"tlsv1 alert decrypt error"},
+ {ERR_REASON(SSL_R_TLSV1_ALERT_EXPORT_RESTRICTION),"tlsv1 alert export restriction"},
++{ERR_REASON(SSL_R_TLSV1_ALERT_INAPPROPRIATE_FALLBACK),"tlsv1 alert inappropriate fallback"},
+ {ERR_REASON(SSL_R_TLSV1_ALERT_INSUFFICIENT_SECURITY),"tlsv1 alert insufficient security"},
+ {ERR_REASON(SSL_R_TLSV1_ALERT_INTERNAL_ERROR),"tlsv1 alert internal error"},
+ {ERR_REASON(SSL_R_TLSV1_ALERT_NO_RENEGOTIATION),"tlsv1 alert no renegotiation"},
+diff --git a/ssl/ssl_lib.c b/ssl/ssl_lib.c
+index 3de68a7..ec0ec2e 100644
+--- a/ssl/ssl_lib.c
++++ b/ssl/ssl_lib.c
+@@ -1441,6 +1441,8 @@ int ssl_cipher_list_to_bytes(SSL *s,STACK_OF(SSL_CIPHER) *sk,unsigned char *p,
+ 
+ 	if (sk == NULL) return(0);
+ 	q=p;
++	if (put_cb == NULL)
++		put_cb = s->method->put_cipher_by_char;
+ 
+ 	for (i=0; i<sk_SSL_CIPHER_num(sk); i++)
+ 		{
+@@ -1460,25 +1462,36 @@ int ssl_cipher_list_to_bytes(SSL *s,STACK_OF(SSL_CIPHER) *sk,unsigned char *p,
+ 		    s->psk_client_callback == NULL)
+ 			continue;
+ #endif /* OPENSSL_NO_PSK */
+-		j = put_cb ? put_cb(c,p) : ssl_put_cipher_by_char(s,c,p);
++		j = put_cb(c,p);
+ 		p+=j;
+ 		}
+-	/* If p == q, no ciphers and caller indicates an error. Otherwise
+-	 * add SCSV if not renegotiating.
+-	 */
+-	if (p != q && !s->renegotiate)
++	/* If p == q, no ciphers; caller indicates an error.
++	 * Otherwise, add applicable SCSVs. */
++	if (p != q)
+ 		{
+-		static SSL_CIPHER scsv =
++		if (!s->renegotiate)
+ 			{
+-			0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
+-			};
+-		j = put_cb ? put_cb(&scsv,p) : ssl_put_cipher_by_char(s,&scsv,p);
+-		p+=j;
++			static SSL_CIPHER scsv =
++				{
++				0, NULL, SSL3_CK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
++				};
++			j = put_cb(&scsv,p);
++			p+=j;
+ #ifdef OPENSSL_RI_DEBUG
+-		fprintf(stderr, "SCSV sent by client\n");
++			fprintf(stderr, "TLS_EMPTY_RENEGOTIATION_INFO_SCSV sent by client\n");
+ #endif
+-		}
++			}
+ 
++		if (s->mode & SSL_MODE_SEND_FALLBACK_SCSV)
++			{
++			static SSL_CIPHER scsv =
++				{
++				0, NULL, SSL3_CK_FALLBACK_SCSV, 0, 0, 0, 0, 0, 0, 0, 0, 0
++				};
++			j = put_cb(&scsv,p);
++			p+=j;
++			}
++ 		}
+ 	return(p-q);
+ 	}
+ 
+@@ -1488,11 +1501,12 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num,
+ 	const SSL_CIPHER *c;
+ 	STACK_OF(SSL_CIPHER) *sk;
+ 	int i,n;
++
+ 	if (s->s3)
+ 		s->s3->send_connection_binding = 0;
+ 
+ 	n=ssl_put_cipher_by_char(s,NULL,NULL);
+-	if ((num%n) != 0)
++	if (n == 0 || (num%n) != 0)
+ 		{
+ 		SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,SSL_R_ERROR_IN_RECEIVED_CIPHER_LIST);
+ 		return(NULL);
+@@ -1507,7 +1521,7 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num,
+ 
+ 	for (i=0; i<num; i+=n)
+ 		{
+-		/* Check for SCSV */
++		/* Check for TLS_EMPTY_RENEGOTIATION_INFO_SCSV */
+ 		if (s->s3 && (n != 3 || !p[0]) &&
+ 			(p[n-2] == ((SSL3_CK_SCSV >> 8) & 0xff)) &&
+ 			(p[n-1] == (SSL3_CK_SCSV & 0xff)))
+@@ -1527,6 +1541,22 @@ STACK_OF(SSL_CIPHER) *ssl_bytes_to_cipher_list(SSL *s,unsigned char *p,int num,
+ 			continue;
+ 			}
+ 
++		/* Check for TLS_FALLBACK_SCSV */
++		if (s->s3 && (n != 3 || !p[0]) &&
++			(p[n-2] == ((SSL3_CK_FALLBACK_SCSV >> 8) & 0xff)) &&
++			(p[n-1] == (SSL3_CK_FALLBACK_SCSV & 0xff)))
++			{
++			/* The SCSV indicates that the client previously tried a higher version.
++			 * Fail if the current version is an unexpected downgrade. */
++			if (!SSL_ctrl(s, SSL_CTRL_CHECK_PROTO_VERSION, 0, NULL))
++				{
++				SSLerr(SSL_F_SSL_BYTES_TO_CIPHER_LIST,SSL_R_INAPPROPRIATE_FALLBACK);
++				ssl3_send_alert(s,SSL3_AL_FATAL,SSL_AD_INAPPROPRIATE_FALLBACK);
++				goto err;
++				}
++			continue;
++			}
++
+ 		c=ssl_get_cipher_by_char(s,p);
+ 		p+=n;
+ 		if (c != NULL)
+diff --git a/ssl/t1_enc.c b/ssl/t1_enc.c
+index 22dd3ca..b8d497e 100644
+--- a/ssl/t1_enc.c
++++ b/ssl/t1_enc.c
+@@ -1266,6 +1266,7 @@ int tls1_alert_code(int code)
+ 	case SSL_AD_BAD_CERTIFICATE_STATUS_RESPONSE: return(TLS1_AD_BAD_CERTIFICATE_STATUS_RESPONSE);
+ 	case SSL_AD_BAD_CERTIFICATE_HASH_VALUE: return(TLS1_AD_BAD_CERTIFICATE_HASH_VALUE);
+ 	case SSL_AD_UNKNOWN_PSK_IDENTITY:return(TLS1_AD_UNKNOWN_PSK_IDENTITY);
++	case SSL_AD_INAPPROPRIATE_FALLBACK:return(TLS1_AD_INAPPROPRIATE_FALLBACK);
+ #if 0 /* not appropriate for TLS, not used for DTLS */
+ 	case DTLS1_AD_MISSING_HANDSHAKE_MESSAGE: return 
+ 					  (DTLS1_AD_MISSING_HANDSHAKE_MESSAGE);
+diff --git a/ssl/tls1.h b/ssl/tls1.h
+index b9a0899..dc36f79 100644
+--- a/ssl/tls1.h
++++ b/ssl/tls1.h
+@@ -159,17 +159,19 @@ extern "C" {
+ 
+ #define TLS1_ALLOW_EXPERIMENTAL_CIPHERSUITES	0
+ 
++#define TLS1_VERSION			0x0301
++#define TLS1_1_VERSION			0x0302
+ #define TLS1_2_VERSION			0x0303
+-#define TLS1_2_VERSION_MAJOR		0x03
+-#define TLS1_2_VERSION_MINOR		0x03
++#define TLS_MAX_VERSION			TLS1_2_VERSION
++
++#define TLS1_VERSION_MAJOR		0x03
++#define TLS1_VERSION_MINOR		0x01
+ 
+-#define TLS1_1_VERSION			0x0302
+ #define TLS1_1_VERSION_MAJOR		0x03
+ #define TLS1_1_VERSION_MINOR		0x02
+ 
+-#define TLS1_VERSION			0x0301
+-#define TLS1_VERSION_MAJOR		0x03
+-#define TLS1_VERSION_MINOR		0x01
++#define TLS1_2_VERSION_MAJOR		0x03
++#define TLS1_2_VERSION_MINOR		0x03
+ 
+ #define TLS1_get_version(s) \
+ 		((s->version >> 8) == TLS1_VERSION_MAJOR ? s->version : 0)
+@@ -187,6 +189,7 @@ extern "C" {
+ #define TLS1_AD_PROTOCOL_VERSION	70	/* fatal */
+ #define TLS1_AD_INSUFFICIENT_SECURITY	71	/* fatal */
+ #define TLS1_AD_INTERNAL_ERROR		80	/* fatal */
++#define TLS1_AD_INAPPROPRIATE_FALLBACK	86	/* fatal */
+ #define TLS1_AD_USER_CANCELLED		90
+ #define TLS1_AD_NO_RENEGOTIATION	100
+ /* codes 110-114 are from RFC3546 */
+-- 
+2.1.0.rc2.206.gedb03e5
+
diff --git a/patches/README b/patches/README
index 0859abe..2506ff8 100644
--- a/patches/README
+++ b/patches/README
@@ -37,3 +37,8 @@ alpn.patch
 This change adds support for ALPN in OpenSSL. ALPN is the IETF
 blessed version of NPN and we'll be supporting both ALPN and NPN for
 some time yet.
+
+tls_fallback_scsv.patch
+
+Adds the signalling cipher suite value (SCSV) from
+https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00