+The type of padding to be used. The interpretation of this value will depend
+on the algorithm in use. The default provider understands these RSA padding
+modes: 1 (RSA_PKCS1_PADDING), 2 (RSA_SSLV23_PADDING), 3 (RSA_NO_PADDING),
+4 (RSA_PKCS1_OAEP_PADDING), 5 (RSA_X931_PADDING), 6 (RSA_PKCS1_PSS_PADDING) and
+7 (RSA_PKCS1_WITH_TLS_PADDING). See L<EVP_PKEY_CTX_set_rsa_padding(3)> for
+further details.
+