Botan::SPAKE2p Namespace Reference

Classes
class	ProverContext
class	ProverSecret
class	RegistrationRecord
class	SystemParameters
class	VerifierContext

Detailed Description

SPAKE2+ (RFC 9383) password authenticated key exchange

SPAKE2+ is an augmented PAKE; the two sides are asymmetric. The prover knows the password itself, while the verifier stores only a registration record derived from the password. An attacker who steals the registration record cannot impersonate the prover without first performing a dictionary attack on the record.

The expected message flow is

• The prover calls ProverContext::generate_message and sends the result (shareP) to the verifier.
• The verifier calls VerifierContext::process_message and sends the result (shareV followed by confirmV) to the prover.
• The prover calls ProverContext::process_message, which checks the verifier's key confirmation, and sends the result (confirmP) to the verifier.
• The verifier calls VerifierContext::verify_confirmation

After the final confirmation step both sides can call shared_secret to obtain the session key (K_shared in RFC 9383)

Protocols which embed SPAKE2+ and perform the prover's key confirmation themselves (such as the proposed TLS PAKE extension) may instead call VerifierContext::skip_confirmation in place of the final step.