diff --git a/ChangeLog b/ChangeLog
index 8f7843d..1b01eb6 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,10 +1,20 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
-= mbed TLS 2.1.x released xxxx-xx-xx
+
+= mbed TLS 2.1.10 branch released 2017-xx-xx
 
 Bugfix
    * Fix ssl_parse_record_header() to silently discard invalid DTLS records
      as recommended in RFC 6347 Section 4.1.2.7.
+   * Fix memory leak in mbedtls_ssl_set_hostname() when called multiple times.
+     Found by projectgus and jethrogb, #836.
+   * Fix usage help in ssl_server2 example. Found and fixed by Bei Lin.
+   * Parse signature algorithm extension when renegotiating. Previously,
+     renegotiated handshakes would only accept signatures using SHA-1
+     regardless of the peer's preferences, or fail if SHA-1 was disabled.
+   * Fix leap year calculation in x509_date_is_valid() to ensure that invalid
+     dates on leap years with 100 and 400 intervals are handled correctly. Found
+     by Nicholas Wilson. #694
 
 = mbed TLS 2.1.9 branch released 2017-08-10
 
diff --git a/configs/README.txt b/configs/README.txt
index e9867bc..933fa7f 100644
--- a/configs/README.txt
+++ b/configs/README.txt
@@ -8,7 +8,7 @@
 them, you can pick one of the following methods:
 
 1. Replace the default file include/mbedtls/config.h with the chosen one.
-   (Depending on your compiler, you may need to ajust the line with
+   (Depending on your compiler, you may need to adjust the line with
    #include "mbedtls/check_config.h" then.)
 
 2. Define MBEDTLS_CONFIG_FILE and adjust the include path accordingly.
diff --git a/include/mbedtls/asn1.h b/include/mbedtls/asn1.h
index 082832c..e159e57 100644
--- a/include/mbedtls/asn1.h
+++ b/include/mbedtls/asn1.h
@@ -59,7 +59,7 @@
 
 /**
  * \name DER constants
- * These constants comply with DER encoded the ANS1 type tags.
+ * These constants comply with the DER encoded ASN.1 type tags.
  * DER encoding uses hexadecimal representation.
  * An example DER sequence is:\n
  * - 0x02 -- tag indicating INTEGER
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 60f59a9..12a98eb 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -1579,14 +1579,23 @@
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 /**
- * \brief          Set hostname for ServerName TLS extension
- *                 (client-side only)
+ * \brief          Set or reset the hostname to check against the received 
+ *                 server certificate. It sets the ServerName TLS extension, 
+ *                 too, if that extension is enabled. (client-side only)
  *
  *
  * \param ssl      SSL context
- * \param hostname the server hostname
+ * \param hostname the server hostname, may be NULL to clear hostname
+ 
+ * \note           Maximum hostname length MBEDTLS_SSL_MAX_HOST_NAME_LEN.
  *
- * \return         0 if successful or MBEDTLS_ERR_SSL_ALLOC_FAILED
+ * \return         0 if successful, MBEDTLS_ERR_SSL_ALLOC_FAILED on 
+ *                 allocation failure, MBEDTLS_ERR_SSL_BAD_INPUT_DATA on 
+ *                 too long input hostname.
+ *
+ *                 Hostname set to the one provided on success (cleared
+ *                 when NULL). On allocation failure hostname is cleared. 
+ *                 On too long input failure, old hostname is unchanged.
  */
 int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname );
 #endif /* MBEDTLS_X509_CRT_PARSE_C */
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 31eb203..94c521d 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -80,6 +80,13 @@
     }
 
     /*
+     * Sect. 3, RFC 6066 (TLS Extensions Definitions)
+     *
+     * In order to provide any of the server names, clients MAY include an
+     * extension of type "server_name" in the (extended) client hello. The
+     * "extension_data" field of this extension SHALL contain
+     * "ServerNameList" where:
+     *
      * struct {
      *     NameType name_type;
      *     select (name_type) {
@@ -96,6 +103,7 @@
      * struct {
      *     ServerName server_name_list<1..2^16-1>
      * } ServerNameList;
+     *
      */
     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME      ) & 0xFF );
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 01b4ada..1002adf 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -1603,11 +1603,8 @@
 #if defined(MBEDTLS_SSL_PROTO_TLS1_2) && \
     defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
             case MBEDTLS_TLS_EXT_SIG_ALG:
-                    MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
-#if defined(MBEDTLS_SSL_RENEGOTIATION)
-                if( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS )
-                    break;
-#endif
+                MBEDTLS_SSL_DEBUG_MSG( 3, ( "found signature_algorithms extension" ) );
+
                 ret = ssl_parse_signature_algorithms_ext( ssl, ext + 4, ext_size );
                 if( ret != 0 )
                     return( ret );
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index ba586a0..8088e88 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5980,7 +5980,7 @@
 {
     conf->sig_hashes = hashes;
 }
-#endif
+#endif /* MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED */
 
 #if defined(MBEDTLS_ECP_C)
 /*
@@ -5991,36 +5991,55 @@
 {
     conf->curve_list = curve_list;
 }
-#endif
+#endif /* MBEDTLS_ECP_C */
 
 #if defined(MBEDTLS_X509_CRT_PARSE_C)
 int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname )
 {
-    size_t hostname_len;
+    /* Initialize to suppress unnecessary compiler warning */
+    size_t hostname_len = 0;
+
+    /* Check if new hostname is valid before
+     * making any change to current one */
+
+    if( hostname != NULL )
+    {
+        hostname_len = strlen( hostname );
+
+        if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN )
+            return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+    }
+
+    /* Now it's clear that we will overwrite the old hostname,
+     * so we can free it safely */
+
+    if( ssl->hostname != NULL )
+    {
+        mbedtls_zeroize( ssl->hostname, strlen( ssl->hostname ) );
+        mbedtls_free( ssl->hostname );
+    }
+
+    /* Passing NULL as hostname shall clear the old one */
 
     if( hostname == NULL )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+    {
+        ssl->hostname = NULL;
+    }
+    else
+    {
+        ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 );
 
-    hostname_len = strlen( hostname );
+        if( ssl->hostname == NULL )
+            return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
 
-    if( hostname_len + 1 == 0 )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
+        memcpy( ssl->hostname, hostname, hostname_len );
 
-    if( hostname_len > MBEDTLS_SSL_MAX_HOST_NAME_LEN )
-        return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
-
-    ssl->hostname = mbedtls_calloc( 1, hostname_len + 1 );
-
-    if( ssl->hostname == NULL )
-        return( MBEDTLS_ERR_SSL_ALLOC_FAILED );
-
-    memcpy( ssl->hostname, hostname, hostname_len );
-
-    ssl->hostname[hostname_len] = '\0';
+        ssl->hostname[hostname_len] = '\0';
+    }
 
     return( 0 );
 }
-#endif
+#endif /* MBEDTLS_X509_CRT_PARSE_C */
 
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
 void mbedtls_ssl_conf_sni( mbedtls_ssl_config *conf,
diff --git a/library/x509.c b/library/x509.c
index e87ba69..3cfa1d1 100644
--- a/library/x509.c
+++ b/library/x509.c
@@ -491,9 +491,10 @@
     return( 0 );
 }
 
-static int x509_date_is_valid(const mbedtls_x509_time *t)
+static int x509_date_is_valid(const mbedtls_x509_time *t )
 {
     int ret = MBEDTLS_ERR_X509_INVALID_DATE;
+    int month_len;
 
     CHECK_RANGE( 0, 9999, t->year );
     CHECK_RANGE( 0, 23,   t->hour );
@@ -503,17 +504,22 @@
     switch( t->mon )
     {
         case 1: case 3: case 5: case 7: case 8: case 10: case 12:
-            CHECK_RANGE( 1, 31, t->day );
+            month_len = 31;
             break;
         case 4: case 6: case 9: case 11:
-            CHECK_RANGE( 1, 30, t->day );
+            month_len = 30;
             break;
         case 2:
-            CHECK_RANGE( 1, 28 + (t->year % 4 == 0), t->day );
+            if( ( !( t->year % 4 ) && t->year % 100 ) ||
+                !( t->year % 400 ) )
+                month_len = 29;
+            else
+                month_len = 28;
             break;
         default:
             return( ret );
     }
+    CHECK_RANGE( 1, month_len, t->day );
 
     return( 0 );
 }
diff --git a/programs/ssl/ssl_server2.c b/programs/ssl/ssl_server2.c
index 728b9ba..0271a8f 100644
--- a/programs/ssl/ssl_server2.c
+++ b/programs/ssl/ssl_server2.c
@@ -314,7 +314,7 @@
 #define USAGE \
     "\n usage: ssl_server2 param=<>...\n"                   \
     "\n acceptable parameters:\n"                           \
-    "    server_addr=%%d      default: (all interfaces)\n"  \
+    "    server_addr=%%s      default: (all interfaces)\n"  \
     "    server_port=%%d      default: 4433\n"              \
     "    debug_level=%%d      default: 0 (disabled)\n"      \
     "    nbio=%%d             default: 0 (blocking I/O)\n"  \
diff --git a/tests/ssl-opt.sh b/tests/ssl-opt.sh
index 9c9cf46..d8f0fd7 100755
--- a/tests/ssl-opt.sh
+++ b/tests/ssl-opt.sh
@@ -1340,6 +1340,40 @@
             -s "=> renegotiate" \
             -s "write hello request"
 
+# Checks that no Signature Algorithm with SHA-1 gets negotiated. Negotiating SHA-1 would mean that
+# the server did not parse the Signature Algorithm extension. This test is valid only if an MD
+# algorithm stronger than SHA-1 is enabled in config.h
+run_test    "Renegotiation: Signature Algorithms parsing, client-initiated" \
+            "$P_SRV debug_level=3 exchanges=2 renegotiation=1 auth_mode=optional" \
+            "$P_CLI debug_level=3 exchanges=2 renegotiation=1 renegotiate=1" \
+            0 \
+            -c "client hello, adding renegotiation extension" \
+            -s "received TLS_EMPTY_RENEGOTIATION_INFO" \
+            -s "found renegotiation extension" \
+            -s "server hello, secure renegotiation extension" \
+            -c "found renegotiation extension" \
+            -c "=> renegotiate" \
+            -s "=> renegotiate" \
+            -S "write hello request" \
+            -S "client hello v3, signature_algorithm ext: 2" # Is SHA-1 negotiated?
+
+# Checks that no Signature Algorithm with SHA-1 gets negotiated. Negotiating SHA-1 would mean that
+# the server did not parse the Signature Algorithm extension. This test is valid only if an MD
+# algorithm stronger than SHA-1 is enabled in config.h
+run_test    "Renegotiation: Signature Algorithms parsing, server-initiated" \
+            "$P_SRV debug_level=3 exchanges=2 renegotiation=1 auth_mode=optional renegotiate=1" \
+            "$P_CLI debug_level=3 exchanges=2 renegotiation=1" \
+            0 \
+            -c "client hello, adding renegotiation extension" \
+            -s "received TLS_EMPTY_RENEGOTIATION_INFO" \
+            -s "found renegotiation extension" \
+            -s "server hello, secure renegotiation extension" \
+            -c "found renegotiation extension" \
+            -c "=> renegotiate" \
+            -s "=> renegotiate" \
+            -s "write hello request" \
+            -S "client hello v3, signature_algorithm ext: 2" # Is SHA-1 negotiated?
+
 run_test    "Renegotiation: double" \
             "$P_SRV debug_level=3 exchanges=2 renegotiation=1 auth_mode=optional renegotiate=1" \
             "$P_CLI debug_level=3 exchanges=2 renegotiation=1 renegotiate=1" \
diff --git a/tests/suites/test_suite_ssl.data b/tests/suites/test_suite_ssl.data
index a39f6f0..b92c1fe 100644
--- a/tests/suites/test_suite_ssl.data
+++ b/tests/suites/test_suite_ssl.data
@@ -54,3 +54,6 @@
 
 SSL DTLS replay: big jump then just delayed
 ssl_dtls_replay:"abcd12340000,abcd12340100":"abcd123400ff":0
+
+SSL SET_HOSTNAME memory leak: call ssl_set_hostname twice
+ssl_set_hostname_twice:"server0":"server1"
diff --git a/tests/suites/test_suite_ssl.function b/tests/suites/test_suite_ssl.function
index 8d3448c..60683af 100644
--- a/tests/suites/test_suite_ssl.function
+++ b/tests/suites/test_suite_ssl.function
@@ -40,3 +40,16 @@
     mbedtls_ssl_config_free( &conf );
 }
 /* END_CASE */
+
+/* BEGIN_CASE depends_on:MBEDTLS_X509_CRT_PARSE_C */
+void ssl_set_hostname_twice( char *hostname0, char *hostname1 )
+{
+    mbedtls_ssl_context ssl;
+    mbedtls_ssl_init( &ssl );
+
+    TEST_ASSERT( mbedtls_ssl_set_hostname( &ssl, hostname0 ) == 0 );
+    TEST_ASSERT( mbedtls_ssl_set_hostname( &ssl, hostname1 ) == 0 );
+
+    mbedtls_ssl_free( &ssl );
+}
+/* END_CASE */
\ No newline at end of file
diff --git a/tests/suites/test_suite_x509parse.data b/tests/suites/test_suite_x509parse.data
index e337ed7..5731677 100644
--- a/tests/suites/test_suite_x509parse.data
+++ b/tests/suites/test_suite_x509parse.data
@@ -1620,3 +1620,18 @@
 depends_on:MBEDTLS_X509_USE_C
 x509_get_time:MBEDTLS_ASN1_UTC_TIME:"0011302359n0Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
 
+X509 Get time (Generalized Time, year multiple of 100 but not 400 is not a leap year)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_GENERALIZED_TIME:"19000229000000Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0
+
+X509 Get time (Generalized Time, year multiple of 4 but not 100 is a leap year)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_GENERALIZED_TIME:"19920229000000Z":0:1992:2:29:0:0:0
+
+X509 Get time (Generalized Time, year multiple of 400 is a leap year)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_GENERALIZED_TIME:"20000229000000Z":0:2000:2:29:0:0:0
+
+X509 Get time (Generalized Time invalid leap year not multiple of 4, 100 or 400)
+depends_on:MBEDTLS_X509_USE_C
+x509_get_time:MBEDTLS_ASN1_GENERALIZED_TIME:"19910229000000Z":MBEDTLS_ERR_X509_INVALID_DATE:0:0:0:0:0:0