diff --git a/include/polarssl/config.h b/include/polarssl/config.h
index ff0ccec..9ca39e7 100644
--- a/include/polarssl/config.h
+++ b/include/polarssl/config.h
@@ -811,6 +811,20 @@
  */
 //#define POLARSSL_SSL_DEBUG_ALL
 
+/** \def POLARSSL_SSL_EXTENDED_MASTER_SECRET
+ *
+ * Enable support for Extended Master Secret, aka Session Hash
+ * (draft-ietf-tls-session-hash-02).
+ *
+ * This was introduced as "the proper fix" to the Triple Handshake familiy of
+ * attacks, but it is recommended to always use it (even if you disable
+ * renegotiation), since it actually fixes a more fundamental issue in the
+ * original SSL/TLS design, and has implications beyond Triple Handshake.
+ *
+ * Comment this macro to disable support for Extended Master Secret.
+ */
+#define POLARSSL_SSL_EXTENDED_MASTER_SECRET
+
 /**
  * \def POLARSSL_SSL_FALLBACK_SCSV
  *
diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 875709c..7b5ec8e 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -209,6 +209,9 @@
 #define SSL_IS_NOT_FALLBACK             0
 #define SSL_IS_FALLBACK                 1
 
+#define SSL_EXTENDED_MS_DISABLED        0
+#define SSL_EXTENDED_MS_ENABLED         1
+
 #define SSL_COMPRESS_NULL               0
 #define SSL_COMPRESS_DEFLATE            1
 
@@ -406,6 +409,8 @@
 
 #define TLS_EXT_ALPN                        16
 
+#define TLS_EXT_EXTENDED_MASTER_SECRET  0x0017 /* 23 */
+
 #define TLS_EXT_SESSION_TICKET              35
 
 #define TLS_EXT_RENEGOTIATION_INFO      0xFF01
@@ -657,6 +662,9 @@
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
     int new_session_ticket;             /*!< use NewSessionTicket?    */
 #endif /* POLARSSL_SSL_SESSION_TICKETS */
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    int extended_ms;                    /*!< use Extended Master Secret? */
+#endif
 };
 
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
@@ -705,6 +713,9 @@
 #if defined(POLARSSL_SSL_FALLBACK_SCSV) && defined(POLARSSL_SSL_CLI_C)
     char fallback;              /*!< flag for fallback connections    */
 #endif
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    char extended_ms;           /*!< flag for extended master secret  */
+#endif
 
     /*
      * Callbacks (RNG, debug, I/O, verification)
@@ -1414,6 +1425,21 @@
 void ssl_set_fallback( ssl_context *ssl, char fallback );
 #endif /* POLARSSL_SSL_FALLBACK_SCSV && POLARSSL_SSL_CLI_C */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+/**
+ * \brief           Enable or disable Extended Master Secret negotiation.
+ *                  (Default: SSL_EXTENDED_MS_ENABLED)
+ *
+ * \note            This should always be enabled, it is a security fix to the
+ *                  protocol, and should not cause any interoperability issue
+ *                  (used only if the peer supports it too).
+ *
+ * \param ssl       SSL context
+ * \param ems       SSL_EXTENDED_MS_ENABLED or SSL_EXTENDED_MS_DISABLED
+ */
+void ssl_set_extended_master_secret( ssl_context *ssl, char ems );
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
 /**
  * \brief          Set the maximum fragment length to emit and/or negotiate
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 50ab05f..065f3a8 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -359,6 +359,31 @@
 }
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static void ssl_write_extended_ms_ext( ssl_context *ssl,
+                                       unsigned char *buf, size_t *olen )
+{
+    unsigned char *p = buf;
+
+    if( ssl->extended_ms == SSL_EXTENDED_MS_DISABLED )
+    {
+        *olen = 0;
+        return;
+    }
+
+    SSL_DEBUG_MSG( 3, ( "client hello, adding extended_master_secret "
+                        "extension" ) );
+
+    *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
+    *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET      ) & 0xFF );
+
+    *p++ = 0x00;
+    *p++ = 0x00;
+
+    *olen = 4;
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
 static void ssl_write_session_ticket_ext( ssl_context *ssl,
                                           unsigned char *buf, size_t *olen )
@@ -662,6 +687,11 @@
     ext_len += olen;
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
+    ext_len += olen;
+#endif
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
     ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
     ext_len += olen;
@@ -780,6 +810,25 @@
 }
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static int ssl_parse_extended_ms_ext( ssl_context *ssl,
+                                         const unsigned char *buf,
+                                         size_t len )
+{
+    if( ssl->extended_ms == SSL_EXTENDED_MS_DISABLED ||
+        len != 0 )
+    {
+        return( POLARSSL_ERR_SSL_BAD_HS_SERVER_HELLO );
+    }
+
+    ((void) buf);
+
+    ssl->handshake->extended_ms = SSL_EXTENDED_MS_ENABLED;
+
+    return( 0 );
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
 static int ssl_parse_session_ticket_ext( ssl_context *ssl,
                                          const unsigned char *buf,
@@ -1152,6 +1201,19 @@
             break;
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+        case TLS_EXT_EXTENDED_MASTER_SECRET:
+            SSL_DEBUG_MSG( 3, ( "found extended_master_secret extension" ) );
+
+            if( ( ret = ssl_parse_extended_ms_ext( ssl,
+                            ext + 4, ext_size ) ) != 0 )
+            {
+                return( ret );
+            }
+
+            break;
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
         case TLS_EXT_SESSION_TICKET:
             SSL_DEBUG_MSG( 3, ( "found session_ticket extension" ) );
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 57b0ecf..f65338e 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -635,6 +635,26 @@
 }
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static int ssl_parse_extended_ms_ext( ssl_context *ssl,
+                                      const unsigned char *buf,
+                                      size_t len )
+{
+    if( len != 0 )
+    {
+        SSL_DEBUG_MSG( 1, ( "bad client hello message" ) );
+        return( POLARSSL_ERR_SSL_BAD_HS_CLIENT_HELLO );
+    }
+
+    ((void) buf);
+
+    if( ssl->extended_ms == SSL_EXTENDED_MS_ENABLED )
+        ssl->handshake->extended_ms = SSL_EXTENDED_MS_ENABLED;
+
+    return( 0 );
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
 static int ssl_parse_session_ticket_ext( ssl_context *ssl,
                                          unsigned char *buf,
@@ -1500,6 +1520,16 @@
             break;
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+        case TLS_EXT_EXTENDED_MASTER_SECRET:
+            SSL_DEBUG_MSG( 3, ( "found extended master secret extension" ) );
+
+            ret = ssl_parse_extended_ms_ext( ssl, ext + 4, ext_size );
+            if( ret != 0 )
+                return( ret );
+            break;
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
         case TLS_EXT_SESSION_TICKET:
             SSL_DEBUG_MSG( 3, ( "found session ticket extension" ) );
@@ -1649,6 +1679,32 @@
 }
 #endif /* POLARSSL_SSL_TRUNCATED_HMAC */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+static void ssl_write_extended_ms_ext( ssl_context *ssl,
+                                       unsigned char *buf,
+                                       size_t *olen )
+{
+    unsigned char *p = buf;
+
+    if( ssl->handshake->extended_ms == SSL_EXTENDED_MS_DISABLED )
+    {
+        *olen = 0;
+        return;
+    }
+
+    SSL_DEBUG_MSG( 3, ( "server hello, adding extended master secret "
+                        "extension" ) );
+
+    *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET >> 8 ) & 0xFF );
+    *p++ = (unsigned char)( ( TLS_EXT_EXTENDED_MASTER_SECRET      ) & 0xFF );
+
+    *p++ = 0x00;
+    *p++ = 0x00;
+
+    *olen = 4;
+}
+#endif /* POLARSSL_SSL_EXTENDED_MASTER_SECRET */
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
 static void ssl_write_session_ticket_ext( ssl_context *ssl,
                                           unsigned char *buf,
@@ -1952,6 +2008,11 @@
     ext_len += olen;
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    ssl_write_extended_ms_ext( ssl, p + 2 + ext_len, &olen );
+    ext_len += olen;
+#endif
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
     ssl_write_session_ticket_ext( ssl, p + 2 + ext_len, &olen );
     ext_len += olen;
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index bd4494f..1fe3a95 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -470,6 +470,11 @@
         SSL_DEBUG_BUF( 3, "premaster secret", handshake->premaster,
                        handshake->pmslen );
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+        if( ssl->handshake->extended_ms == SSL_EXTENDED_MS_ENABLED )
+            SSL_DEBUG_MSG( 3, ( "using extended master secret" ) );
+        // XXX to be continued, WIP
+#endif
         handshake->tls_prf( handshake->premaster, handshake->pmslen,
                             "master secret",
                             handshake->randbytes, 64, session->master, 48 );
@@ -3437,6 +3442,10 @@
     memset( ssl-> in_ctr, 0, SSL_BUFFER_LEN );
     memset( ssl->out_ctr, 0, SSL_BUFFER_LEN );
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    ssl->extended_ms = SSL_EXTENDED_MS_ENABLED;
+#endif
+
 #if defined(POLARSSL_SSL_SESSION_TICKETS)
     ssl->ticket_lifetime = SSL_DEFAULT_TICKET_LIFETIME;
 #endif
@@ -3984,6 +3993,13 @@
 }
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+void ssl_set_extended_master_secret( ssl_context *ssl, char ems )
+{
+    ssl->extended_ms = ems;
+}
+#endif
+
 #if defined(POLARSSL_SSL_MAX_FRAGMENT_LENGTH)
 int ssl_set_max_frag_len( ssl_context *ssl, unsigned char mfl_code )
 {
diff --git a/programs/ssl/ssl_client2.c b/programs/ssl/ssl_client2.c
index 8ca83eb..d4cde0f 100644
--- a/programs/ssl/ssl_client2.c
+++ b/programs/ssl/ssl_client2.c
@@ -96,6 +96,7 @@
 #define DFL_TICKETS             SSL_SESSION_TICKETS_ENABLED
 #define DFL_ALPN_STRING         NULL
 #define DFL_FALLBACK            -1
+#define DFL_EXTENDED_MS         -1
 
 #define GET_REQUEST "GET %s HTTP/1.0\r\nExtra-header: "
 #define GET_REQUEST_END "\r\n\r\n"
@@ -134,6 +135,7 @@
     int tickets;                /* enable / disable session tickets         */
     const char *alpn_string;    /* ALPN supported protocols                 */
     int fallback;               /* is this a fallback connection?           */
+    char extended_ms;           /* negotiate extended master secret?        */
 } opt;
 
 static void my_debug( void *ctx, int level, const char *str )
@@ -293,6 +295,13 @@
 #define USAGE_FALLBACK ""
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+#define USAGE_EMS \
+    "    extended_ms=0/1     default: (library default: on)\n"
+#else
+#define USAGE_EMS ""
+#endif
+
 #define USAGE \
     "\n usage: ssl_client2 param=<>...\n"                   \
     "\n acceptable parameters:\n"                           \
@@ -323,6 +332,7 @@
     USAGE_TRUNC_HMAC                                        \
     USAGE_ALPN                                              \
     USAGE_FALLBACK                                          \
+    USAGE_EMS                                               \
     "\n"                                                    \
     "    min_version=%%s      default: \"\" (ssl3)\n"       \
     "    max_version=%%s      default: \"\" (tls1_2)\n"     \
@@ -424,6 +434,7 @@
     opt.tickets             = DFL_TICKETS;
     opt.alpn_string         = DFL_ALPN_STRING;
     opt.fallback            = DFL_FALLBACK;
+    opt.extended_ms         = DFL_EXTENDED_MS;
 
     for( i = 1; i < argc; i++ )
     {
@@ -539,6 +550,15 @@
                 default: goto usage;
             }
         }
+        else if( strcmp( p, "extended_ms" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.extended_ms = SSL_EXTENDED_MS_DISABLED; break;
+                case 1: opt.extended_ms = SSL_EXTENDED_MS_ENABLED; break;
+                default: goto usage;
+            }
+        }
         else if( strcmp( p, "min_version" ) == 0 )
         {
             if( strcmp( q, "ssl3" ) == 0 )
@@ -902,6 +922,11 @@
         }
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    if( opt.extended_ms != DFL_EXTENDED_MS )
+        ssl_set_extended_master_secret( &ssl, opt.extended_ms );
+#endif
+
 #if defined(POLARSSL_SSL_ALPN)
     if( opt.alpn_string != NULL )
         if( ( ret = ssl_set_alpn_protocols( &ssl, alpn_list ) ) != 0 )
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 721dab4..35a156b 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -116,6 +116,7 @@
 #define DFL_SNI                 NULL
 #define DFL_ALPN_STRING         NULL
 #define DFL_DHM_FILE            NULL
+#define DFL_EXTENDED_MS         -1
 
 #define LONG_RESPONSE "<p>01-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n" \
     "02-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah-blah\r\n"  \
@@ -176,6 +177,7 @@
     char *sni;                  /* string describing sni information        */
     const char *alpn_string;    /* ALPN supported protocols                 */
     const char *dhm_file;       /* the file with the DH parameters          */
+    char extended_ms;           /* allow negotiation of extended MS?        */
 } opt;
 
 static void my_debug( void *ctx, int level, const char *str )
@@ -299,6 +301,13 @@
 #define USAGE_ALPN ""
 #endif /* POLARSSL_SSL_ALPN */
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+#define USAGE_EMS \
+    "    extended_ms=0/1     default: (library default: on)\n"
+#else
+#define USAGE_EMS ""
+#endif
+
 #define USAGE \
     "\n usage: ssl_server2 param=<>...\n"                   \
     "\n acceptable parameters:\n"                           \
@@ -324,6 +333,7 @@
     USAGE_CACHE                                             \
     USAGE_MAX_FRAG_LEN                                      \
     USAGE_ALPN                                              \
+    USAGE_EMS                                               \
     "\n"                                                    \
     "    min_version=%%s      default: \"ssl3\"\n"          \
     "    max_version=%%s      default: \"tls1_2\"\n"        \
@@ -713,6 +723,7 @@
     opt.sni                 = DFL_SNI;
     opt.alpn_string         = DFL_ALPN_STRING;
     opt.dhm_file            = DFL_DHM_FILE;
+    opt.extended_ms         = DFL_EXTENDED_MS;
 
     for( i = 1; i < argc; i++ )
     {
@@ -880,6 +891,15 @@
         {
             opt.alpn_string = q;
         }
+        else if( strcmp( p, "extended_ms" ) == 0 )
+        {
+            switch( atoi( q ) )
+            {
+                case 0: opt.extended_ms = SSL_EXTENDED_MS_DISABLED; break;
+                case 1: opt.extended_ms = SSL_EXTENDED_MS_ENABLED; break;
+                default: goto usage;
+            }
+        }
         else if( strcmp( p, "tickets" ) == 0 )
         {
             opt.tickets = atoi( q );
@@ -1257,6 +1277,11 @@
     };
 #endif
 
+#if defined(POLARSSL_SSL_EXTENDED_MASTER_SECRET)
+    if( opt.extended_ms != DFL_EXTENDED_MS )
+        ssl_set_extended_master_secret( &ssl, opt.extended_ms );
+#endif
+
 #if defined(POLARSSL_SSL_ALPN)
     if( opt.alpn_string != NULL )
         if( ( ret = ssl_set_alpn_protocols( &ssl, alpn_list ) ) != 0 )
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index b0dcad9..eeac11b 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -440,6 +440,41 @@
             0 \
             -s "dumping 'computed mac' (10 bytes)"
 
+# Tests for Extended Master Secret extension
+
+run_test    "Extended Master Secret: default" \
+            "$P_SRV debug_level=3" \
+            "$P_CLI debug_level=3" \
+            0 \
+            -c "client hello, adding extended_master_secret extension" \
+            -s "found extended master secret extension" \
+            -s "server hello, adding extended master secret extension" \
+            -c "found extended_master_secret extension" \
+            -c "using extended master secret" \
+            -s "using extended master secret"
+
+run_test    "Extended Master Secret: client enabled, server disabled" \
+            "$P_SRV debug_level=3 extended_ms=0" \
+            "$P_CLI debug_level=3 extended_ms=1" \
+            0 \
+            -c "client hello, adding extended_master_secret extension" \
+            -s "found extended master secret extension" \
+            -S "server hello, adding extended master secret extension" \
+            -C "found extended_master_secret extension" \
+            -C "using extended master secret" \
+            -S "using extended master secret"
+
+run_test    "Extended Master Secret: client disabled, server enabled" \
+            "$P_SRV debug_level=3 extended_ms=1" \
+            "$P_CLI debug_level=3 extended_ms=0" \
+            0 \
+            -C "client hello, adding extended_master_secret extension" \
+            -S "found extended master secret extension" \
+            -S "server hello, adding extended master secret extension" \
+            -C "found extended_master_secret extension" \
+            -C "using extended master secret" \
+            -S "using extended master secret"
+
 # Tests for FALLBACK_SCSV
 
 run_test    "Fallback SCSV: default" \