Change how hostname is stored internally
diff --git a/library/ssl_cli.c b/library/ssl_cli.c
index bbc8838..a6e0202 100644
--- a/library/ssl_cli.c
+++ b/library/ssl_cli.c
@@ -65,6 +65,7 @@
                                     size_t *olen )
 {
     unsigned char *p = buf;
+    size_t hostname_len;
 
     *olen = 0;
 
@@ -74,6 +75,8 @@
     MBEDTLS_SSL_DEBUG_MSG( 3, ( "client hello, adding server name extension: %s",
                    ssl->hostname ) );
 
+    hostname_len = strlen( ssl->hostname );
+
     /*
      * struct {
      *     NameType name_type;
@@ -95,19 +98,19 @@
     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME >> 8 ) & 0xFF );
     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME      ) & 0xFF );
 
-    *p++ = (unsigned char)( ( (ssl->hostname_len + 5) >> 8 ) & 0xFF );
-    *p++ = (unsigned char)( ( (ssl->hostname_len + 5)      ) & 0xFF );
+    *p++ = (unsigned char)( ( (hostname_len + 5) >> 8 ) & 0xFF );
+    *p++ = (unsigned char)( ( (hostname_len + 5)      ) & 0xFF );
 
-    *p++ = (unsigned char)( ( (ssl->hostname_len + 3) >> 8 ) & 0xFF );
-    *p++ = (unsigned char)( ( (ssl->hostname_len + 3)      ) & 0xFF );
+    *p++ = (unsigned char)( ( (hostname_len + 3) >> 8 ) & 0xFF );
+    *p++ = (unsigned char)( ( (hostname_len + 3)      ) & 0xFF );
 
     *p++ = (unsigned char)( ( MBEDTLS_TLS_EXT_SERVERNAME_HOSTNAME ) & 0xFF );
-    *p++ = (unsigned char)( ( ssl->hostname_len >> 8 ) & 0xFF );
-    *p++ = (unsigned char)( ( ssl->hostname_len      ) & 0xFF );
+    *p++ = (unsigned char)( ( hostname_len >> 8 ) & 0xFF );
+    *p++ = (unsigned char)( ( hostname_len      ) & 0xFF );
 
-    memcpy( p, ssl->hostname, ssl->hostname_len );
+    memcpy( p, ssl->hostname, hostname_len );
 
-    *olen = ssl->hostname_len + 9;
+    *olen = hostname_len + 9;
 }
 #endif /* MBEDTLS_SSL_SERVER_NAME_INDICATION */
 
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 276a0da..d417065 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -5453,23 +5453,24 @@
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
 int mbedtls_ssl_set_hostname( mbedtls_ssl_context *ssl, const char *hostname )
 {
+    size_t hostname_len;
+
     if( hostname == NULL )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
-    ssl->hostname_len = strlen( hostname );
+    hostname_len = strlen( hostname );
 
-    if( ssl->hostname_len + 1 == 0 )
+    if( hostname_len + 1 == 0 )
         return( MBEDTLS_ERR_SSL_BAD_INPUT_DATA );
 
-    ssl->hostname = mbedtls_malloc( ssl->hostname_len + 1 );
+    ssl->hostname = mbedtls_malloc( hostname_len + 1 );
 
     if( ssl->hostname == NULL )
         return( MBEDTLS_ERR_SSL_MALLOC_FAILED );
 
-    memcpy( ssl->hostname, (const unsigned char *) hostname,
-            ssl->hostname_len );
+    memcpy( ssl->hostname, hostname, hostname_len );
 
-    ssl->hostname[ssl->hostname_len] = '\0';
+    ssl->hostname[hostname_len] = '\0';
 
     return( 0 );
 }
@@ -6562,9 +6563,8 @@
 #if defined(MBEDTLS_SSL_SERVER_NAME_INDICATION)
     if( ssl->hostname != NULL )
     {
-        mbedtls_zeroize( ssl->hostname, ssl->hostname_len );
+        mbedtls_zeroize( ssl->hostname, strlen( ssl->hostname ) );
         mbedtls_free( ssl->hostname );
-        ssl->hostname_len = 0;
     }
 #endif