Function ed25519_password

pymysql/_auth.py:76–111

Sign a random scramble with elliptic curve Ed25519. Secret and public key are derived from password.

(password, scramble)

def ed25519_password(password, scramble):
    """Sign a random scramble with elliptic curve Ed25519.

    Secret and public key are derived from password.
    """
    # variable names based on rfc8032 section-5.1.6
    #
    if not _nacl_bindings:
        _init_nacl()

    # h = SHA512(password)
    h = hashlib.sha512(password).digest()

    # s = prune(first_half(h))
    s = _scalar_clamp(h[:32])

    # r = SHA512(second_half(h) || M)
    r = hashlib.sha512(h[32:] + scramble).digest()

    # R = encoded point [r]B
    r = _nacl_bindings.crypto_core_ed25519_scalar_reduce(r)
    R = _nacl_bindings.crypto_scalarmult_ed25519_base_noclamp(r)

    # A = encoded point [s]B
    A = _nacl_bindings.crypto_scalarmult_ed25519_base_noclamp(s)

    # k = SHA512(R || A || M)
    k = hashlib.sha512(R + A + scramble).digest()

    # S = (k * s + r) mod L
    k = _nacl_bindings.crypto_core_ed25519_scalar_reduce(k)
    ks = _nacl_bindings.crypto_core_ed25519_scalar_mul(k, s)
    S = _nacl_bindings.crypto_core_ed25519_scalar_add(ks, r)

    # signature = R || S
    return R + S


# sha256_password