* Run "gpg" to see if the payload matches the detached signature.
- * gpg_output_to tells where the output from "gpg" should go:
- * = 0: standard error of the calling process
- * > 0: the specified file descriptor
+ * gpg_output, when set, receives the diagnostic output from GPG.
int verify_signed_buffer(const char *payload, size_t payload_size,
const char *signature, size_t signature_size,