Fix RSASSA-PSS example programs
diff --git a/include/polarssl/rsa.h b/include/polarssl/rsa.h
index 504dde2..d8c8341 100644
--- a/include/polarssl/rsa.h
+++ b/include/polarssl/rsa.h
@@ -128,6 +128,21 @@
                int hash_id);
 
 /**
+ * \brief          Set padding for an already initialized RSA context
+ *
+ *                 Note: Set padding to RSA_PKCS_V21 for the RSAES-OAEP
+ *                 encryption scheme and the RSASSA-PSS signature scheme.
+ *
+ * \param ctx      RSA context to be set
+ * \param padding  RSA_PKCS_V15 or RSA_PKCS_V21
+ * \param hash_id  RSA_PKCS_V21 hash identifier
+ *
+ * \note           The hash_id parameter is actually ignored
+ *                 when using RSA_PKCS_V15 padding.
+ */
+void rsa_set_padding( rsa_context *ctx, int padding, int hash_id);
+
+/**
  * \brief          Generate an RSA keypair
  *
  * \param ctx      RSA context that will hold the key