PK: add nice interface functions
Also fix a const-corectness issue.
diff --git a/include/polarssl/ssl.h b/include/polarssl/ssl.h
index 7a468c4..d5a2fc0 100644
--- a/include/polarssl/ssl.h
+++ b/include/polarssl/ssl.h
@@ -110,7 +110,7 @@
#define POLARSSL_ERR_SSL_BAD_HS_PROTOCOL_VERSION -0x6E80 /**< Handshake protocol not within min/max boundaries */
#define POLARSSL_ERR_SSL_BAD_HS_NEW_SESSION_TICKET -0x6E00 /**< Processing of the NewSessionTicket handshake message failed. */
#define POLARSSL_ERR_SSL_SESSION_TICKET_EXPIRED -0x6D80 /**< Session ticket has expired. */
-
+#define POLARSSL_ERR_SSL_PK_TYPE_MISMATCH -0x6D00 /**< Public key type mismatch (eg, asked for RSA key exchange and presented EC key) */
/*
* Various constants