Module auth 

PostgreSQL client-side authentication helpers.

Covers the two mechanisms we need today:

• MD5 (AuthenticationMD5Password, request code 5). Legacy but still widely deployed. Payload is "md5" + hex(md5(hex(md5(password + username)) + salt)).
• SCRAM-SHA-256 (AuthenticationSASL, mechanism SCRAM-SHA-256, request code 10). The current PG default.

Both implementations verify the server’s end of the handshake where the protocol allows it — MD5 has no server-side verifier, SCRAM does (the server-final message includes v=<server-signature>).

Structs

Scram

SCRAM client state machine. Create with Scram::client_first, feed the server-first into client_final, and feed the server-final into verify_server.

ScramMessage

Result of one SCRAM step: the opaque bytes to send to the server.

Functions

md5_password_response

Compute the response payload for AuthenticationMD5Password.