diff --git a/ChangeLog b/ChangeLog
index 6d8a5bc..00b19ec 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,12 +1,27 @@
 mbed TLS ChangeLog (Sorted per branch, date)
 
-= mbed TLS 2.x branch
+= mbed TLS 2.2.1 released 2015-12-xx
+
+Security
+   * Fix potential double free when mbedtls_asn1_store_named_data() fails to
+     allocate memory. Only used for certificate generation, not triggerable
+     remotely in SSL/TLS. Found by Rafał Przywara. #367
+   * Disable MD5 handshake signatures in TLS 1.2 by default
 
 Bugfix
+   * Fix over-restrictive length limit in GCM. Found by Andreas-N. #362
    * Fix bug in certificate validation that caused valid chains to be rejected
      when the first intermediate certificate has pathLenConstraint=0. Found by
      Nicholas Wilson. Introduced in mbed TLS 2.2.0. #280
 
+Changes
+   * To avoid dropping an entire DTLS datagram if a single record in a datagram
+     is invalid, we now only drop the record and look at subsequent records (if
+     any are presemt) in the same datagram to avoid interoperability issues.
+     Previously the library was dropping the entire datagram. Where a record is
+     unexpected, the function mbedtls_ssl_read_record() will now return
+     MBEDTLS_ERR_SSL_UNEXPECTED_RECORD.
+
 = mbed TLS 2.2.0 released 2015-11-04
 
 Security
diff --git a/include/mbedtls/error.h b/include/mbedtls/error.h
index a182713..5e549f6 100644
--- a/include/mbedtls/error.h
+++ b/include/mbedtls/error.h
@@ -79,7 +79,7 @@
  * ECP       4   8 (Started from top)
  * MD        5   4
  * CIPHER    6   6
- * SSL       6   16 (Started from top)
+ * SSL       6   17 (Started from top)
  * SSL       7   31
  *
  * Module dependent error code (5 bits 0x.00.-0x.F8.)
diff --git a/include/mbedtls/ssl.h b/include/mbedtls/ssl.h
index 810409c..ff5f389 100644
--- a/include/mbedtls/ssl.h
+++ b/include/mbedtls/ssl.h
@@ -106,6 +106,7 @@
 #define MBEDTLS_ERR_SSL_WANT_WRITE                        -0x6880  /**< Connection requires a write call. */
 #define MBEDTLS_ERR_SSL_TIMEOUT                           -0x6800  /**< The operation timed out. */
 #define MBEDTLS_ERR_SSL_CLIENT_RECONNECT                  -0x6780  /**< The client initiated a reconnect from the same port. */
+#define MBEDTLS_ERR_SSL_UNEXPECTED_RECORD                 -0x6700  /**< Record header looks valid but is not expected. */
 
 /*
  * Various constants
@@ -1610,7 +1611,7 @@
 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
 /**
  * \brief          Set the allowed hashes for signatures during the handshake.
- *                 (Default: all available hashes.)
+ *                 (Default: all available hashes except MD5.)
  *
  * \note           This only affects which hashes are offered and can be used
  *                 for signatures during the handshake. Hashes for message
@@ -2167,7 +2168,8 @@
  * \note           If this function returns something other than 0 or
  *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
  *                 becomes unusable, and you should either free it or call
- *                 \c mbedtls_ssl_session_reset() on it before re-using it.
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
  *
  * \note           If DTLS is in use, then you may choose to handle
  *                 MBEDTLS_ERR_SSL_HELLO_VERIFY_REQUIRED specially for logging
@@ -2183,6 +2185,12 @@
  *                 the following state after execution of this function.
  *                 Do not call this function if state is MBEDTLS_SSL_HANDSHAKE_OVER.
  *
+ * \note           If this function returns something other than 0 or
+ *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
+ *
  * \param ssl      SSL context
  *
  * \return         0 if successful, or
@@ -2201,6 +2209,12 @@
  * \param ssl      SSL context
  *
  * \return         0 if successful, or any mbedtls_ssl_handshake() return value.
+ *
+ * \note           If this function returns something other than 0 or
+ *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
  */
 int mbedtls_ssl_renegotiate( mbedtls_ssl_context *ssl );
 #endif /* MBEDTLS_SSL_RENEGOTIATION */
@@ -2218,6 +2232,13 @@
  *                 MBEDTLS_ERR_SSL_CLIENT_RECONNECT (see below), or
  *                 another negative error code.
  *
+ * \note           If this function returns something other than a positive
+ *                 value or MBEDTLS_ERR_SSL_WANT_READ/WRITE or
+ *                 MBEDTLS_ERR_SSL_CLIENT_RECONNECT, then the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
+ *
  * \note           When this function return MBEDTLS_ERR_SSL_CLIENT_RECONNECT
  *                 (which can only happen server-side), it means that a client
  *                 is initiating a new connection using the same source port.
@@ -2251,6 +2272,12 @@
  *                 or MBEDTLS_ERR_SSL_WANT_WRITE of MBEDTLS_ERR_SSL_WANT_READ,
  *                 or another negative error code.
  *
+ * \note           If this function returns something other than a positive
+ *                 value or MBEDTLS_ERR_SSL_WANT_READ/WRITE, the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
+ *
  * \note           When this function returns MBEDTLS_ERR_SSL_WANT_WRITE/READ,
  *                 it must be called later with the *same* arguments,
  *                 until it returns a positive value.
@@ -2274,6 +2301,12 @@
  * \param message   The alert message (SSL_ALERT_MSG_*)
  *
  * \return          0 if successful, or a specific SSL error code.
+ *
+ * \note           If this function returns something other than 0 or
+ *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
  */
 int mbedtls_ssl_send_alert_message( mbedtls_ssl_context *ssl,
                             unsigned char level,
@@ -2282,6 +2315,14 @@
  * \brief          Notify the peer that the connection is being closed
  *
  * \param ssl      SSL context
+ *
+ * \return          0 if successful, or a specific SSL error code.
+ *
+ * \note           If this function returns something other than 0 or
+ *                 MBEDTLS_ERR_SSL_WANT_READ/WRITE, then the ssl context
+ *                 becomes unusable, and you should either free it or call
+ *                 \c mbedtls_ssl_session_reset() on it before re-using it for
+ *                 a new connection; the current connection must be closed.
  */
 int mbedtls_ssl_close_notify( mbedtls_ssl_context *ssl );
 
diff --git a/library/asn1write.c b/library/asn1write.c
index 456660d..00ed73c 100644
--- a/library/asn1write.c
+++ b/library/asn1write.c
@@ -339,19 +339,18 @@
     }
     else if( cur->val.len < val_len )
     {
-        // Enlarge existing value buffer if needed
-        //
-        mbedtls_free( cur->val.p );
-        cur->val.p = NULL;
-
-        cur->val.len = val_len;
-        cur->val.p = mbedtls_calloc( 1, val_len );
-        if( cur->val.p == NULL )
-        {
-            mbedtls_free( cur->oid.p );
-            mbedtls_free( cur );
+        /*
+         * Enlarge existing value buffer if needed
+         * Preserve old data until the allocation succeeded, to leave list in
+         * a consistent state in case allocation fails.
+         */
+        void *p = mbedtls_calloc( 1, val_len );
+        if( p == NULL )
             return( NULL );
-        }
+
+        mbedtls_free( cur->val.p );
+        cur->val.p = p;
+        cur->val.len = val_len;
     }
 
     if( val != NULL )
diff --git a/library/bignum.c b/library/bignum.c
index 58a4cd2..21069d8 100644
--- a/library/bignum.c
+++ b/library/bignum.c
@@ -18,12 +18,21 @@
  *
  *  This file is part of mbed TLS (https://tls.mbed.org)
  */
+
 /*
- *  This MPI implementation is based on:
+ *  The following sources were referenced in the design of this Multi-precision
+ *  Integer library:
  *
- *  http://www.cacr.math.uwaterloo.ca/hac/about/chap14.pdf
- *  http://www.stillhq.com/extracted/gnupg-api/mpi/
- *  http://math.libtomcrypt.com/files/tommath.pdf
+ *  [1] Handbook of Applied Cryptography - 1997
+ *      Menezes, van Oorschot and Vanstone
+ *
+ *  [2] Multi-Precision Math
+ *      Tom St Denis
+ *      https://github.com/libtom/libtommath/blob/develop/tommath.pdf
+ *
+ *  [3] GNU Multi-Precision Arithmetic Library
+ *      https://gmplib.org/manual/index.html
+ *
  */
 
 #if !defined(MBEDTLS_CONFIG_FILE)
@@ -348,6 +357,24 @@
 }
 
 /*
+ * Count leading zero bits in a given integer
+ */
+static size_t mbedtls_clz( const mbedtls_mpi_uint x )
+{
+    size_t j;
+    mbedtls_mpi_uint mask = (mbedtls_mpi_uint) 1 << (biL - 1);
+
+    for( j = 0; j < biL; j++ )
+    {
+        if( x & mask ) break;
+
+        mask >>= 1;
+    }
+
+    return j;
+}
+
+/*
  * Return the number of bits
  */
 size_t mbedtls_mpi_bitlen( const mbedtls_mpi *X )
@@ -361,9 +388,7 @@
         if( X->p[i] != 0 )
             break;
 
-    for( j = biL; j > 0; j-- )
-        if( ( ( X->p[i] >> ( j - 1 ) ) & 1 ) != 0 )
-            break;
+    j = biL - mbedtls_clz( X->p[i] );
 
     return( ( i * biL ) + j );
 }
@@ -1187,6 +1212,101 @@
 }
 
 /*
+ * Unsigned integer divide - double mbedtls_mpi_uint dividend, u1/u0, and
+ * mbedtls_mpi_uint divisor, d
+ */
+static mbedtls_mpi_uint mbedtls_int_div_int( mbedtls_mpi_uint u1,
+            mbedtls_mpi_uint u0, mbedtls_mpi_uint d, mbedtls_mpi_uint *r )
+{
+#if defined(MBEDTLS_HAVE_UDBL)
+    mbedtls_t_udbl dividend, quotient;
+#else
+    const mbedtls_mpi_uint radix = 1 << biH;
+    mbedtls_mpi_uint d0, d1, q0, q1, rAX, r0, quotient;
+    mbedtls_mpi_uint u0_msw, u0_lsw;
+    int s;
+#endif
+
+    /*
+     * Check for overflow
+     */
+    if( 0 == d || u1 >= d )
+    {
+        if (r != NULL) *r = ~0;
+
+        return ( ~0 );
+    }
+
+#if defined(MBEDTLS_HAVE_UDBL)
+    dividend  = (mbedtls_t_udbl) u1 << biL;
+    dividend |= (mbedtls_t_udbl) u0;
+    quotient = dividend / d;
+    if( quotient > ( (mbedtls_t_udbl) 1 << biL ) - 1 )
+        quotient = ( (mbedtls_t_udbl) 1 << biL ) - 1;
+
+    if( r != NULL )
+        *r = dividend - (quotient * d);
+
+    return (mbedtls_mpi_uint) quotient;
+#else
+
+    /*
+     * Algorithm D, Section 4.3.1 - The Art of Computer Programming
+     *   Vol. 2 - Seminumerical Algorithms, Knuth
+     */
+
+    /*
+     * Normalize the divisor, d, and dividend, u0, u1
+     */
+    s = mbedtls_clz( d );
+    d = d << s;
+
+    u1 = u1 << s;
+    u1 |= ( u0 >> ( 32 - s ) ) & ( -s >> 31 );
+    u0 =  u0 << s;
+
+    d1 = d >> biH;
+    d0 = d & 0xffff;
+
+    u0_msw = u0 >> biH;
+    u0_lsw = u0 & 0xffff;
+
+    /*
+     * Find the first quotient and remainder
+     */
+    q1 = u1 / d1;
+    r0 = u1 - d1 * q1;
+
+    while( q1 >= radix || ( q1 * d0 > radix * r0 + u0_msw ) )
+    {
+        q1 -= 1;
+        r0 += d1;
+
+        if ( r0 >= radix ) break;
+    }
+
+    rAX = ( u1 * radix ) + ( u0_msw - q1 * d );
+    q0 = rAX / d1;
+    r0 = rAX - q0 * d1;
+
+    while( q0 >= radix || ( q0 * d0 > radix * r0 + u0_lsw ) )
+    {
+        q0 -= 1;
+        r0 += d1;
+
+        if ( r0 >= radix ) break;
+    }
+
+    if (r != NULL)
+        *r = ( rAX * radix + u0_lsw - q0 * d ) >> s;
+
+    quotient = q1 * radix + q0;
+
+    return quotient;
+#endif
+}
+
+/*
  * Division by mbedtls_mpi: A = Q * B + R  (HAC 14.20)
  */
 int mbedtls_mpi_div_mpi( mbedtls_mpi *Q, mbedtls_mpi *R, const mbedtls_mpi *A, const mbedtls_mpi *B )
@@ -1243,57 +1363,8 @@
             Z.p[i - t - 1] = ~0;
         else
         {
-#if defined(MBEDTLS_HAVE_UDBL)
-            mbedtls_t_udbl r;
-
-            r  = (mbedtls_t_udbl) X.p[i] << biL;
-            r |= (mbedtls_t_udbl) X.p[i - 1];
-            r /= Y.p[t];
-            if( r > ( (mbedtls_t_udbl) 1 << biL ) - 1 )
-                r = ( (mbedtls_t_udbl) 1 << biL ) - 1;
-
-            Z.p[i - t - 1] = (mbedtls_mpi_uint) r;
-#else
-            /*
-             * __udiv_qrnnd_c, from gmp/longlong.h
-             */
-            mbedtls_mpi_uint q0, q1, r0, r1;
-            mbedtls_mpi_uint d0, d1, d, m;
-
-            d  = Y.p[t];
-            d0 = ( d << biH ) >> biH;
-            d1 = ( d >> biH );
-
-            q1 = X.p[i] / d1;
-            r1 = X.p[i] - d1 * q1;
-            r1 <<= biH;
-            r1 |= ( X.p[i - 1] >> biH );
-
-            m = q1 * d0;
-            if( r1 < m )
-            {
-                q1--, r1 += d;
-                while( r1 >= d && r1 < m )
-                    q1--, r1 += d;
-            }
-            r1 -= m;
-
-            q0 = r1 / d1;
-            r0 = r1 - d1 * q0;
-            r0 <<= biH;
-            r0 |= ( X.p[i - 1] << biH ) >> biH;
-
-            m = q0 * d0;
-            if( r0 < m )
-            {
-                q0--, r0 += d;
-                while( r0 >= d && r0 < m )
-                    q0--, r0 += d;
-            }
-            r0 -= m;
-
-            Z.p[i - t - 1] = ( q1 << biH ) | q0;
-#endif /* MBEDTLS_HAVE_UDBL && !64-bit Apple with Clang 5.0 */
+            Z.p[i - t - 1] = mbedtls_int_div_int( X.p[i], X.p[i - 1],
+                                                            Y.p[t], NULL);
         }
 
         Z.p[i - t - 1]++;
diff --git a/library/error.c b/library/error.c
index a1cf83a..debda1d 100644
--- a/library/error.c
+++ b/library/error.c
@@ -430,6 +430,8 @@
             mbedtls_snprintf( buf, buflen, "SSL - The operation timed out" );
         if( use_ret == -(MBEDTLS_ERR_SSL_CLIENT_RECONNECT) )
             mbedtls_snprintf( buf, buflen, "SSL - The client initiated a reconnect from the same port" );
+        if( use_ret == -(MBEDTLS_ERR_SSL_UNEXPECTED_RECORD) )
+            mbedtls_snprintf( buf, buflen, "SSL - Record header looks valid but is not expected" );
 #endif /* MBEDTLS_SSL_TLS_C */
 
 #if defined(MBEDTLS_X509_USE_C) || defined(MBEDTLS_X509_CREATE_C)
diff --git a/library/gcm.c b/library/gcm.c
index 4298254..aaacf97 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -362,7 +362,7 @@
     /* Total length is restricted to 2^39 - 256 bits, ie 2^36 - 2^5 bytes
      * Also check for possible overflow */
     if( ctx->len + length < ctx->len ||
-        (uint64_t) ctx->len + length > 0x03FFFFE0ull )
+        (uint64_t) ctx->len + length > 0xFFFFFFFE0ull )
     {
         return( MBEDTLS_ERR_GCM_BAD_INPUT );
     }
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index 9663fae..4452169 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -2096,7 +2096,7 @@
      */
     if( ( *md_alg = mbedtls_ssl_md_alg_from_hash( (*p)[0] ) ) == MBEDTLS_MD_NONE )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "Server used unsupported "
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "Server used unsupported "
                             "HashAlgorithm %d", *(p)[0] ) );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
     }
@@ -2106,7 +2106,7 @@
      */
     if( ( *pk_alg = mbedtls_ssl_pk_alg_from_sig( (*p)[1] ) ) == MBEDTLS_PK_NONE )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "server used unsupported "
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used unsupported "
                             "SignatureAlgorithm %d", (*p)[1] ) );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
     }
@@ -2116,7 +2116,7 @@
      */
     if( mbedtls_ssl_check_sig_hash( ssl, *md_alg ) != 0 )
     {
-        MBEDTLS_SSL_DEBUG_MSG( 2, ( "server used HashAlgorithm "
+        MBEDTLS_SSL_DEBUG_MSG( 1, ( "server used HashAlgorithm "
                                     "that was not offered" ) );
         return( MBEDTLS_ERR_SSL_BAD_HS_SERVER_KEY_EXCHANGE );
     }
diff --git a/library/ssl_srv.c b/library/ssl_srv.c
index 9afd399..6b5b461 100644
--- a/library/ssl_srv.c
+++ b/library/ssl_srv.c
@@ -2584,7 +2584,9 @@
     {
         dn_size = crt->subject_raw.len;
 
-        if( end < p || (size_t)( end - p ) < 2 + dn_size )
+        if( end < p ||
+            (size_t)( end - p ) < dn_size ||
+            (size_t)( end - p ) < 2 + dn_size )
         {
             MBEDTLS_SSL_DEBUG_MSG( 1, ( "skipping CAs: buffer too short" ) );
             break;
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index c18a3b4..4424f56 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3465,6 +3465,18 @@
  * uint16 epoch;            // DTLS only
  * uint48 sequence_number;  // DTLS only
  * uint16 length;
+ *
+ * Return 0 if header looks sane (and, for DTLS, the record is expected)
+ * MBEDTLS_ERR_SSL_INVALID_RECORD if the header looks bad,
+ * MBEDTLS_ERR_SSL_UNEXPECTED_RECORD (DTLS only) if sane but unexpected.
+ *
+ * With DTLS, mbedtls_ssl_read_record() will:
+ * 1. proceed with the record if this function returns 0
+ * 2. drop only the current record if this function returns UNEXPECTED_RECORD
+ * 3. return CLIENT_RECONNECT if this function return that value
+ * 4. drop the whole datagram if this function returns anything else.
+ * Point 2 is needed when the peer is resending, and we have already received
+ * the first record from a datagram but are still waiting for the others.
  */
 static int ssl_parse_record_header( mbedtls_ssl_context *ssl )
 {
@@ -3500,34 +3512,6 @@
         return( MBEDTLS_ERR_SSL_INVALID_RECORD );
     }
 
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
-    {
-        /* Drop unexpected ChangeCipherSpec messages */
-        if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
-            ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
-            ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ChangeCipherSpec" ) );
-            return( MBEDTLS_ERR_SSL_INVALID_RECORD );
-        }
-
-        /* Drop unexpected ApplicationData records,
-         * except at the beginning of renegotiations */
-        if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
-            ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
-#if defined(MBEDTLS_SSL_RENEGOTIATION)
-            && ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
-                   ssl->state == MBEDTLS_SSL_SERVER_HELLO )
-#endif
-            )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
-            return( MBEDTLS_ERR_SSL_INVALID_RECORD );
-        }
-    }
-#endif
-
     /* Check version */
     if( major_ver != ssl->major_ver )
     {
@@ -3541,53 +3525,6 @@
         return( MBEDTLS_ERR_SSL_INVALID_RECORD );
     }
 
-    /* Check epoch (and sequence number) with DTLS */
-#if defined(MBEDTLS_SSL_PROTO_DTLS)
-    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
-    {
-        unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1];
-
-        if( rec_epoch != ssl->in_epoch )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: "
-                                        "expected %d, received %d",
-                                        ssl->in_epoch, rec_epoch ) );
-
-#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
-            /*
-             * Check for an epoch 0 ClientHello. We can't use in_msg here to
-             * access the first byte of record content (handshake type), as we
-             * have an active transform (possibly iv_len != 0), so use the
-             * fact that the record header len is 13 instead.
-             */
-            if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
-                ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
-                rec_epoch == 0 &&
-                ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
-                ssl->in_left > 13 &&
-                ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO )
-            {
-                MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect "
-                                            "from the same port" ) );
-                return( ssl_handle_possible_reconnect( ssl ) );
-            }
-            else
-#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
-                return( MBEDTLS_ERR_SSL_INVALID_RECORD );
-        }
-
-#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
-        /* Replay detection only works for the current epoch */
-        if( rec_epoch == ssl->in_epoch &&
-            mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
-        {
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) );
-            return( MBEDTLS_ERR_SSL_INVALID_RECORD );
-        }
-#endif
-    }
-#endif /* MBEDTLS_SSL_PROTO_DTLS */
-
     /* Check length against the size of our buffer */
     if( ssl->in_msglen > MBEDTLS_SSL_BUFFER_LEN
                          - (size_t)( ssl->in_msg - ssl->in_buf ) )
@@ -3637,6 +3574,82 @@
 #endif
     }
 
+    /*
+     * DTLS-related tests done last, because most of them may result in
+     * silently dropping the record (but not the whole datagram), and we only
+     * want to consider that after ensuring that the "basic" fields (type,
+     * version, length) are sane.
+     */
+#if defined(MBEDTLS_SSL_PROTO_DTLS)
+    if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM )
+    {
+        unsigned int rec_epoch = ( ssl->in_ctr[0] << 8 ) | ssl->in_ctr[1];
+
+        /* Drop unexpected ChangeCipherSpec messages */
+        if( ssl->in_msgtype == MBEDTLS_SSL_MSG_CHANGE_CIPHER_SPEC &&
+            ssl->state != MBEDTLS_SSL_CLIENT_CHANGE_CIPHER_SPEC &&
+            ssl->state != MBEDTLS_SSL_SERVER_CHANGE_CIPHER_SPEC )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ChangeCipherSpec" ) );
+            return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+        }
+
+        /* Drop unexpected ApplicationData records,
+         * except at the beginning of renegotiations */
+        if( ssl->in_msgtype == MBEDTLS_SSL_MSG_APPLICATION_DATA &&
+            ssl->state != MBEDTLS_SSL_HANDSHAKE_OVER
+#if defined(MBEDTLS_SSL_RENEGOTIATION)
+            && ! ( ssl->renego_status == MBEDTLS_SSL_RENEGOTIATION_IN_PROGRESS &&
+                   ssl->state == MBEDTLS_SSL_SERVER_HELLO )
+#endif
+            )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "dropping unexpected ApplicationData" ) );
+            return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+        }
+
+        /* Check epoch (and sequence number) with DTLS */
+        if( rec_epoch != ssl->in_epoch )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "record from another epoch: "
+                                        "expected %d, received %d",
+                                        ssl->in_epoch, rec_epoch ) );
+
+#if defined(MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE) && defined(MBEDTLS_SSL_SRV_C)
+            /*
+             * Check for an epoch 0 ClientHello. We can't use in_msg here to
+             * access the first byte of record content (handshake type), as we
+             * have an active transform (possibly iv_len != 0), so use the
+             * fact that the record header len is 13 instead.
+             */
+            if( ssl->conf->endpoint == MBEDTLS_SSL_IS_SERVER &&
+                ssl->state == MBEDTLS_SSL_HANDSHAKE_OVER &&
+                rec_epoch == 0 &&
+                ssl->in_msgtype == MBEDTLS_SSL_MSG_HANDSHAKE &&
+                ssl->in_left > 13 &&
+                ssl->in_buf[13] == MBEDTLS_SSL_HS_CLIENT_HELLO )
+            {
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "possible client reconnect "
+                                            "from the same port" ) );
+                return( ssl_handle_possible_reconnect( ssl ) );
+            }
+            else
+#endif /* MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE && MBEDTLS_SSL_SRV_C */
+                return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+        }
+
+#if defined(MBEDTLS_SSL_DTLS_ANTI_REPLAY)
+        /* Replay detection only works for the current epoch */
+        if( rec_epoch == ssl->in_epoch &&
+            mbedtls_ssl_dtls_replay_check( ssl ) != 0 )
+        {
+            MBEDTLS_SSL_DEBUG_MSG( 1, ( "replayed record" ) );
+            return( MBEDTLS_ERR_SSL_UNEXPECTED_RECORD );
+        }
+#endif
+    }
+#endif /* MBEDTLS_SSL_PROTO_DTLS */
+
     return( 0 );
 }
 
@@ -3762,13 +3775,26 @@
         if( ssl->conf->transport == MBEDTLS_SSL_TRANSPORT_DATAGRAM &&
             ret != MBEDTLS_ERR_SSL_CLIENT_RECONNECT )
         {
-            /* Ignore bad record and get next one; drop the whole datagram
-             * since current header cannot be trusted to find the next record
-             * in current datagram */
-            ssl->next_record_offset = 0;
-            ssl->in_left = 0;
+            if( ret == MBEDTLS_ERR_SSL_UNEXPECTED_RECORD )
+            {
+                /* Skip unexpected record (but not whole datagram) */
+                ssl->next_record_offset = ssl->in_msglen
+                                        + mbedtls_ssl_hdr_len( ssl );
 
-            MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record (header)" ) );
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding unexpected record "
+                                            "(header)" ) );
+            }
+            else
+            {
+                /* Skip invalid record and the rest of the datagram */
+                ssl->next_record_offset = 0;
+                ssl->in_left = 0;
+
+                MBEDTLS_SSL_DEBUG_MSG( 1, ( "discarding invalid record "
+                                            "(header)" ) );
+            }
+
+            /* Get next record */
             goto read_record_header;
         }
 #endif
@@ -7071,6 +7097,23 @@
     memset( conf, 0, sizeof( mbedtls_ssl_config ) );
 }
 
+#if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
+static int ssl_preset_default_hashes[] = {
+#if defined(MBEDTLS_SHA512_C)
+    MBEDTLS_MD_SHA512,
+    MBEDTLS_MD_SHA384,
+#endif
+#if defined(MBEDTLS_SHA256_C)
+    MBEDTLS_MD_SHA256,
+    MBEDTLS_MD_SHA224,
+#endif
+#if defined(MBEDTLS_SHA1_C)
+    MBEDTLS_MD_SHA1,
+#endif
+    MBEDTLS_MD_NONE
+};
+#endif
+
 static int ssl_preset_suiteb_ciphersuites[] = {
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
     MBEDTLS_TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,
@@ -7227,7 +7270,7 @@
 #endif
 
 #if defined(MBEDTLS_KEY_EXCHANGE__WITH_CERT__ENABLED)
-            conf->sig_hashes = mbedtls_md_list();
+            conf->sig_hashes = ssl_preset_default_hashes;
 #endif
 
 #if defined(MBEDTLS_ECP_C)
diff --git a/scripts/footprint.sh b/scripts/footprint.sh
index a11844f..87d62df 100755
--- a/scripts/footprint.sh
+++ b/scripts/footprint.sh
@@ -6,6 +6,8 @@
 
 if [ -r $CONFIG_H ]; then :; else
     echo "$CONFIG_H not found" >&2
+    echo "This script needs to be run from the root of" >&2
+    echo "a git checkout or uncompressed tarball" >&2
     exit 1
 fi
 
@@ -14,15 +16,33 @@
     exit 1
 fi
 
+if which arm-none-eabi-gcc >/dev/null 2>&1; then :; else
+    echo "You need the ARM-GCC toolchain in your path" >&2
+    echo "See https://launchpad.net/gcc-arm-embedded/" >&2
+    exit 1
+fi
+
+ARMGCC_FLAGS='-Os -march=armv7-m -mthumb'
+OUTFILE='00-footprint-summary.txt'
+
+log()
+{
+    echo "$@"
+    echo "$@" >> "$OUTFILE"
+}
+
 doit()
 {
     NAME="$1"
     FILE="$2"
 
-    echo "$NAME:"
+    log ""
+    log "$NAME ($FILE):"
 
     cp $CONFIG_H ${CONFIG_H}.bak
-    cp "$FILE" include/mbedtls/config.h
+    if [ "$FILE" != $CONFIG_H ]; then
+        cp "$FILE"  $CONFIG_H
+    fi
 
     {
         scripts/config.pl unset MBEDTLS_NET_C || true
@@ -31,22 +51,44 @@
     } >/dev/null 2>&1
 
     CC=arm-none-eabi-gcc AR=arm-none-eabi-ar LD=arm-none-eabi-ld \
-        CFLAGS='-Wa,--noexecstack -Os -march=armv7-m -mthumb' \
-        make clean lib >/dev/null
+        CFLAGS="$ARMGCC_FLAGS" make clean lib >/dev/null
 
     OUT="size-${NAME}.txt"
     arm-none-eabi-size -t library/libmbed*.a > "$OUT"
-    head -n1 "$OUT"
-    tail -n1 "$OUT"
+    log "$( head -n1 "$OUT" )"
+    log "$( tail -n1 "$OUT" )"
 
     cp ${CONFIG_H}.bak $CONFIG_H
 }
 
+# truncate the file just this time
+echo "(generated by $0)" > "$OUTFILE"
+echo "" >> "$OUTFILE"
+
+log "Footprint of standard configurations (minus net.c, timing.c, fs_io)"
+log "for bare-metal ARM Cortex-M3/M4 microcontrollers."
+
+VERSION_H="include/mbedtls/version.h"
+MBEDTLS_VERSION=$( sed -n 's/.*VERSION_STRING *"\(.*\)"/\1/p' $VERSION_H )
+if git rev-parse HEAD >/dev/null; then
+    GIT_HEAD=$( git rev-parse HEAD | head -c 10 )
+    GIT_VERSION=" (git head: $GIT_HEAD)"
+else
+    GIT_VERSION=""
+fi
+
+log ""
+log "mbed TLS $MBEDTLS_VERSION$GIT_VERSION"
+log "$( arm-none-eabi-gcc --version | head -n1 )"
+log "CFLAGS=$ARMGCC_FLAGS"
+
 # creates the yotta config
 yotta/create-module.sh >/dev/null
 
-doit default    include/mbedtls/config.h.bak
+doit default    include/mbedtls/config.h
 doit yotta      yotta/module/mbedtls/config.h
 doit thread     configs/config-thread.h
-doit ecc        configs/config-suite-b.h
+doit suite-b    configs/config-suite-b.h
 doit psk        configs/config-ccm-psk-tls1_2.h
+
+zip mbedtls-footprint.zip "$OUTFILE" size-*.txt >/dev/null