Radiator Server Documentation — v10.34.1
Table of Contents

chap

Validates passwords using the Challenge-Handshake Authentication Protocol (CHAP). CHAP uses a challenge-response mechanism that avoids transmitting the password in cleartext.

Basic Syntax

@execute {
    backend {
        name "USERS";
        query "FIND_USER";
    }

    chap;
}

Result

The chap action produces the following pipeline results:

  • Accept: The challenge-response verification succeeds. Execution continues to the next action.
  • Reject: Authentication failed. This occurs when:
    • The user was not found (reason: "No such user"). Ensure the preceding backend action populates the user context.
    • The response does not match (reason: "Incorrect password").
  • Ignore: The request does not contain CHAP credentials. This allows combining chap with other authentication actions such as pap or mschapv2 in the same pipeline - the non-matching action is skipped.