Address issues find by manual coverity scan.
diff --git a/programs/aes/crypt_and_hash.c b/programs/aes/crypt_and_hash.c
index 102144e..4af39a5 100644
--- a/programs/aes/crypt_and_hash.c
+++ b/programs/aes/crypt_and_hash.c
@@ -184,7 +184,12 @@
         mbedtls_fprintf( stderr, "Message Digest '%s' not found\n", argv[5] );
         goto exit;
     }
-    mbedtls_md_setup( &md_ctx, md_info, 1 );
+
+    if( mbedtls_md_setup( &md_ctx, md_info, 1 ) != 0 )
+    {
+        mbedtls_fprintf( stderr, "mbedtls_md_setup unsuccessful: This shouldn't happen.\n" );
+        goto exit;
+    }
 
     /*
      * Read the secret key and clean the command line.
@@ -399,6 +404,18 @@
             goto exit;
         }
 
+        /*
+         * Make coverity happy.
+         */
+        if( mbedtls_cipher_get_block_size( &cipher_ctx ) == 0 )
+        {
+            mbedtls_fprintf( stderr, "mbedtls_cipher_get_block_size returned with 0. This shouldn't happen.\n" );
+            goto exit;
+        }
+
+        /*
+         * Check the file size.
+         */
         if( ( ( filesize - mbedtls_md_get_size( md_info ) ) %
                 mbedtls_cipher_get_block_size( &cipher_ctx ) ) != 0 )
         {