From 8f870b047c3544f6c6f15bd09cc18739e8284e95 Mon Sep 17 00:00:00 2001
From: Paul Bakker <p.j.bakker@polarssl.org>
Date: Fri, 20 Jun 2014 13:32:38 +0200
Subject: [PATCH] Add dhm_init()

---
 include/polarssl/dhm.h | 11 ++++++++++-
 library/dhm.c          | 15 ++++++++++-----
 library/ssl_tls.c      |  3 +++
 3 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/include/polarssl/dhm.h b/include/polarssl/dhm.h
index 322a78860..064472f35 100644
--- a/include/polarssl/dhm.h
+++ b/include/polarssl/dhm.h
@@ -169,6 +169,13 @@ typedef struct
 }
 dhm_context;
 
+/**
+ * \brief          Initialize DHM context
+ *
+ * \param ctx      DHM context to be initialized
+ */
+void dhm_init( dhm_context *ctx );
+
 /**
  * \brief          Parse the ServerKeyExchange parameters
  *
@@ -256,7 +263,9 @@ int dhm_calc_secret( dhm_context *ctx,
                      void *p_rng );
 
 /**
- * \brief          Free the components of a DHM key
+ * \brief          Free and clear the components of a DHM key
+ *
+ * \param ctx      DHM context to free and clear
  */
 void dhm_free( dhm_context *ctx );
 
diff --git a/library/dhm.c b/library/dhm.c
index 5a87e3ca7..1b1d6d65c 100644
--- a/library/dhm.c
+++ b/library/dhm.c
@@ -116,6 +116,11 @@ cleanup:
     return( ret );
 }
 
+void dhm_init( dhm_context *ctx )
+{
+    memset( ctx, 0, sizeof( dhm_context ) );
+}
+
 /*
  * Parse the ServerKeyExchange parameters
  */
@@ -125,8 +130,6 @@ int dhm_read_params( dhm_context *ctx,
 {
     int ret;
 
-    dhm_free( ctx );
-
     if( ( ret = dhm_read_bignum( &ctx->P,  p, end ) ) != 0 ||
         ( ret = dhm_read_bignum( &ctx->G,  p, end ) ) != 0 ||
         ( ret = dhm_read_bignum( &ctx->GY, p, end ) ) != 0 )
@@ -417,7 +420,6 @@ int dhm_parse_dhm( dhm_context *dhm, const unsigned char *dhmin,
     pem_context pem;
 
     pem_init( &pem );
-    memset( dhm, 0, sizeof( dhm_context ) );
 
     ret = pem_read_buffer( &pem,
                            "-----BEGIN DH PARAMETERS-----",
@@ -561,6 +563,8 @@ int dhm_self_test( int verbose )
     int ret;
     dhm_context dhm;
 
+    dhm_init( &dhm );
+
     if( verbose != 0 )
         polarssl_printf( "  DHM parameter load: " );
 
@@ -570,15 +574,16 @@ int dhm_self_test( int verbose )
         if( verbose != 0 )
             polarssl_printf( "failed\n" );
 
-        return( ret );
+        goto exit;
     }
 
     if( verbose != 0 )
         polarssl_printf( "passed\n\n" );
 
+exit:
     dhm_free( &dhm );
 
-    return( 0 );
+    return( ret );
 #else
     if( verbose != 0 )
         polarssl_printf( "  DHM parameter load: skipped\n" );
diff --git a/library/ssl_tls.c b/library/ssl_tls.c
index 963f02b71..a6761adce 100644
--- a/library/ssl_tls.c
+++ b/library/ssl_tls.c
@@ -3334,6 +3334,9 @@ static int ssl_handshake_init( ssl_context *ssl )
     ssl->handshake->update_checksum = ssl_update_checksum_start;
     ssl->handshake->sig_alg = SSL_HASH_SHA1;
 
+#if defined(POLARSSL_DHM_C)
+    dhm_init( &ssl->handshake->dhm_ctx );
+#endif
 #if defined(POLARSSL_ECDH_C)
     ecdh_init( &ssl->handshake->ecdh_ctx );
 #endif