/**
* \brief Make signature, including padding if relevant.
*
- * \param ctx PK context to use
+ * \param ctx PK context to use - must hold a private key
* \param md_alg Hash algorithm used (see notes)
* \param hash Hash of the message to sign
* \param hash_len Hash length or 0 (see notes)
/**
* \brief Decrypt message (including padding if relevant).
*
- * \param ctx PK context to use
+ * \param ctx PK context to use - must hold a private key
* \param input Input to decrypt
* \param ilen Input size
* \param output Decrypted output