def crypto_secretbox_open(ciphertext, nonce, key):
"""
Decrypt and returns the encrypted message ``ciphertext`` with the secret
``key`` and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise exc.ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise exc.ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox_open(plaintext, padded, len(padded), nonce, key)
ensure(res == 0,
"Decryption failed. Ciphertext failed verification",
raising=exc.CryptoError)
plaintext = ffi.buffer(plaintext, len(padded))
return plaintext[crypto_secretbox_ZEROBYTES:]
def crypto_secretbox_open(ciphertext, nonce, key):
"""
Decrypt and returns the encrypted message ``ciphertext`` with the secret
``key`` and the nonce ``nonce``.
:param ciphertext: bytes
:param nonce: bytes
:param key: bytes
:rtype: bytes
"""
if len(key) != crypto_secretbox_KEYBYTES:
raise exc.ValueError("Invalid key")
if len(nonce) != crypto_secretbox_NONCEBYTES:
raise exc.ValueError("Invalid nonce")
padded = b"\x00" * crypto_secretbox_BOXZEROBYTES + ciphertext
plaintext = ffi.new("unsigned char[]", len(padded))
res = lib.crypto_secretbox_open(
plaintext, padded, len(padded), nonce, key)
ensure(res == 0, "Decryption failed. Ciphertext failed verification",
raising=exc.CryptoError)
plaintext = ffi.buffer(plaintext, len(padded))
return plaintext[crypto_secretbox_ZEROBYTES:]