Add pk_rsa_set_padding() and rsa_set_padding()
diff --git a/library/pk.c b/library/pk.c
index 80eccc9..d1bd215 100644
--- a/library/pk.c
+++ b/library/pk.c
@@ -109,6 +109,20 @@
 }
 
 /*
+ * Set RSA padding
+ */
+int pk_rsa_set_padding( pk_context *ctx, int padding, int hash_id )
+{
+    if( ctx == NULL || ctx->pk_info == NULL ||
+        ctx->pk_info->type != POLARSSL_PK_RSA )
+        return( POLARSSL_ERR_PK_BAD_INPUT_DATA );
+
+    rsa_set_padding( pk_rsa( *ctx ), padding, hash_id );
+
+    return( 0 );
+}
+
+/*
  * Initialize an RSA-alt context
  */
 int pk_init_ctx_rsa_alt( pk_context *ctx, void * key,