ssl_hash() needs the StringInfo.data it is passed to be word aligned and it appears that it is (it is ep_malloc'd in ssl_save_session()). Add an intermediate cast to tell the compiler the alignment is okay and comments explaining the cast and warning anyone who might change how it is allocated to keep it aligned.

svn path=/trunk/; revision=25755

1 files changed, 17 insertions, 7 deletions

diff --git a/epan/dissectors/packet-ssl-utils.c b/epan/dissectors/packet-ssl-utils.c
index c08829865b..333a7ce950 100644
--- a/epan/dissectors/packet-ssl-utils.c
+++ b/epan/dissectors/packet-ssl-utils.c
@@ -955,7 +955,7 @@ static SslCipherSuite cipher_suites[]={
     {26,KEX_DH,SIG_NONE,ENC_DES,8,64,64,DIG_MD5,16,0, SSL_CIPHER_MODE_CBC},
     {27,KEX_DH,SIG_NONE,ENC_3DES,8,192,192,DIG_MD5,16,0, SSL_CIPHER_MODE_CBC},
     {47,KEX_RSA,SIG_RSA,ENC_AES,16,128,128,DIG_SHA,20,0, SSL_CIPHER_MODE_CBC},
-    {51,KEX_DH, SIG_RSA,ENC_AES,16,128,128,DIG_SHA,20,0, SSL_CIPHER_MODE_CBC}, 
+    {51,KEX_DH, SIG_RSA,ENC_AES,16,128,128,DIG_SHA,20,0, SSL_CIPHER_MODE_CBC},
     {53,KEX_RSA,SIG_RSA,ENC_AES256,16,256,256,DIG_SHA,20,0, SSL_CIPHER_MODE_CBC},
     {96,KEX_RSA,SIG_RSA,ENC_RC4,1,128,56,DIG_MD5,16,1, SSL_CIPHER_MODE_STREAM},
     {97,KEX_RSA,SIG_RSA,ENC_RC2,1,128,56,DIG_MD5,16,1, SSL_CIPHER_MODE_STREAM},
@@ -986,8 +986,7 @@ ssl_find_cipher(int num,SslCipherSuite* cs)
 }
 
 static gint
-tls_hash(StringInfo* secret,
-        StringInfo* seed, gint md, StringInfo* out)
+tls_hash(StringInfo* secret, StringInfo* seed, gint md, StringInfo* out)
 {
     guint8 *ptr;
     guint left;
@@ -1050,7 +1049,7 @@ tls_prf(StringInfo* secret, const gchar *usage,
         goto free_sha;
     }
     if (ssl_data_alloc(&seed, usage_len+rnd1->data_len+rnd2->data_len) < 0) {
-        ssl_debug_printf("tls_prf: can't allocate rnd %d\n", 
+        ssl_debug_printf("tls_prf: can't allocate rnd %d\n",
                          usage_len+rnd1->data_len+rnd2->data_len);
         goto free_md5;
     }
@@ -1289,7 +1288,7 @@ ssl_generate_keyring_material(SslDecryptSession*ssl_session)
     guint need_any = SSL_MASTER_SECRET | SSL_PRE_MASTER_SECRET;
     if (((ssl_session->state & need_all) != need_all) || ((ssl_session->state & need_any) == 0)) {
         ssl_debug_printf("ssl_generate_keyring_material not enough data to generate key "
-                         "(0x%02X required 0x%02X or 0x%02X)\n", ssl_session->state, 
+                         "(0x%02X required 0x%02X or 0x%02X)\n", ssl_session->state,
                          need_all|SSL_MASTER_SECRET, need_all|SSL_PRE_MASTER_SECRET);
         return -1;
     }
@@ -2325,9 +2324,16 @@ ssl_hash  (gconstpointer v)
   const guint* cur;
   hash = 0;
   id = (const StringInfo*) v;
-  cur = (const guint*) id->data;
 
-  for (l=4; (l<id->data_len); l+=4, cur++)
+  /*  id and id->data are mallocated in ssl_save_session().  As such 'data'
+   *  should be aligned for any kind of access (for example as a guint as
+   *  is done below).  The intermediate void* cast is to prevent "cast
+   *  increases required alignment of target type" warnings on CPUs (such
+   *  as SPARCs) that do not allow misaligned memory accesses.
+   */
+  cur = (const guint*)(void*) id->data;
+
+  for (l=4; (l < id->data_len); l+=4, cur++)
     hash = hash ^ (*cur);
 
   return hash;
@@ -2729,6 +2735,10 @@ ssl_save_session(SslDecryptSession* ssl, GHashTable *session_hash)
   master_secret = se_alloc0(48 + sizeof(StringInfo));
 
   master_secret->data = ((guchar*)master_secret+sizeof(StringInfo));
+
+  /*  ssl_hash() depends on session_id->data being aligned for guint access
+   *  so be careful in changing how it is allocated.
+   */
   session_id->data = ((guchar*)session_id+sizeof(StringInfo));
 
   ssl_data_set(session_id, ssl->session_id.data, ssl->session_id.data_len);