Module join_token 

HMAC-SHA256 join-token issuance and constant-time verification.

Token format (opaque to callers, transmitted as hex):

[for_node: u64 LE | expiry_unix_secs: u64 LE | mac: 32 bytes]

The MAC is HMAC-SHA256 over for_node || expiry_unix_secs keyed by the cluster’s cluster_secret. Verification is constant-time via hmac::Mac::verify_slice (which uses the subtle crate internally).

The nodedb crate’s ctl::join_token module is a thin CLI wrapper that delegates issuance to issue_token here. Verification is consumed by the bootstrap-listener handler in nodedb/src/control/cluster/bootstrap_listener.rs.

Enums

TokenError

Error returned by token operations.

Constants

TOKEN_BYTE_LEN

Total token byte length before hex encoding.

TOKEN_HEADER_LEN

Number of bytes in the token header (for_node + expiry).

TOKEN_HEX_LEN

Expected hex string length of a token.

TOKEN_MAC_LEN

Number of bytes in the HMAC-SHA256 tag.

Functions

issue_token

Convenience: issue a token and return it as a lowercase hex string.

issue_token_bytes

Issue a new HMAC-SHA256 join token for for_node that expires at expiry_unix_secs. Returns the raw token bytes (hex-encode for printing or transmission).

token_hash

Compute SHA-256 of the token bytes. Used as the stable identity for state-machine tracking (never stores the raw token).

token_to_hex

Encode raw token bytes as a lowercase hex string.

verify_token

Verify a hex-encoded token against secret. Returns the bound (for_node, expiry_unix_secs) on success.