def digest(self):
"""Return the digest of the strings passed to the update()
method so far."""
digest = ffi.new("unsigned char[]", self.hash_size // 8)
shc = ffi.new("SHA2_CTX *")
# Create a temporary ctx that copies self.ctx because SHA512_t_Final
# will zeroize the context passed in.
lib.memcpy(shc, self.ctx, ffi.sizeof("SHA2_CTX"))
lib.SHA2Final(digest, shc)
return b"".join(six.int2byte(i) for i in digest)
def __init__(self, message=None, t=256):
self.ctx = ffi.new("SHA2_CTX *")
if t == 256:
lib.SHA2Init(lib.SHA512_256, self.ctx)
elif t == 224:
lib.SHA2Init(lib.SHA512_224, self.ctx)
else:
raise ValueError("The module only supports "
"SHA512/256 or SHA512/224.")
self.hash_size = t
if message:
self.update(message)