I<ctx> must be created with EVP_MD_CTX_new() before calling this function. If
I<pctx> is not NULL, the EVP_PKEY_CTX of the signing operation will be written
I<ctx> must be created with EVP_MD_CTX_new() before calling this function. If
I<pctx> is not NULL, the EVP_PKEY_CTX of the signing operation will be written