U Š¾úg•ã@s>dZdgZddlmZddlmZGdd„deƒZdd„ZdS) z OpenPGP mode. Ú OpenPgpModeé)Ú _copy_bytes)Úget_random_bytesc@s(eZdZdZdd„Zdd„Zdd„ZdS) razOpenPGP mode. This mode is a variant of CFB, and it is only used in PGP and OpenPGP_ applications. If in doubt, use another mode. An Initialization Vector (*IV*) is required. Unlike CFB, the *encrypted* IV (not the IV itself) is transmitted to the receiver. The IV is a random data block. For legacy reasons, two of its bytes are duplicated to act as a checksum for the correctness of the key, which is now known to be insecure and is ignored. The encrypted IV is therefore 2 bytes longer than the clean IV. .. _OpenPGP: http://tools.ietf.org/html/rfc4880 :undocumented: __init__ cCsð|j|_d|_|j||jfd|j|jddœ|—Ž}tdd|ƒ}t|ƒ|jkrj| ||dd…¡|_nDt|ƒ|jdkr–||_| |¡dd…}nt d|j|jdfƒ‚||_ |_ |j||jf|j|j d…|jddœ|—Ž|_ dS)NFóé)ÚIVZ segment_sizeéþÿÿÿéz4Length of IV must be %d or %d bytes for MODE_OPENPGP) Ú block_sizeÚ_done_first_blockÚnewZMODE_CFBrÚlenÚencryptÚ _encrypted_IVÚdecryptÚ ValueErrorÚivrÚ_cipher)ÚselfÚfactoryÚkeyrZ cipher_paramsZ IV_cipher©rúC/tmp/pip-unpacked-wheel-_q8s9isk/Cryptodome/Cipher/_mode_openpgp.pyÚ__init__=s<þüû þ þüûzOpenPgpMode.__init__cCs&|j |¡}|js"|j|}d|_|S)a›Encrypt data with the key and the parameters set at initialization. A cipher object is stateful: once you have encrypted a message you cannot encrypt (or decrypt) another message using the same object. The data to encrypt can be broken up in two or more pieces and `encrypt` can be called multiple times. That is, the statement: >>> c.encrypt(a) + c.encrypt(b) is equivalent to: >>> c.encrypt(a+b) This function does not add any padding to the plaintext. :Parameters: plaintext : bytes/bytearray/memoryview The piece of data to encrypt. :Return: the encrypted data, as a byte string. It is as long as *plaintext* with one exception: when encrypting the first message chunk, the encypted IV is prepended to the returned ciphertext. T)rrr r)rÚ plaintextÚresrrrrgs   zOpenPgpMode.encryptcCs |j |¡S)aÙDecrypt data with the key and the parameters set at initialization. A cipher object is stateful: once you have decrypted a message you cannot decrypt (or encrypt) another message with the same object. The data to decrypt can be broken up in two or more pieces and `decrypt` can be called multiple times. That is, the statement: >>> c.decrypt(a) + c.decrypt(b) is equivalent to: >>> c.decrypt(a+b) This function does not remove any padding from the plaintext. :Parameters: ciphertext : bytes/bytearray/memoryview The piece of data to decrypt. :Return: the decrypted data (byte string). )rr)rZ ciphertextrrrrŒszOpenPgpMode.decryptN)Ú__name__Ú __module__Ú __qualname__Ú__doc__rrrrrrrr(s*%c Ksœ| dd¡}| dd¡}d||fkr.t|jƒ}|dk rH|dk rLtdƒ‚n|}z| d¡}Wn2tk rŒ}ztdt|ƒƒ‚W5d}~XYnXt||||ƒS)a#Create a new block cipher, configured in OpenPGP mode. :Parameters: factory : module The module. :Keywords: key : bytes/bytearray/memoryview The secret key to use in the symmetric cipher. IV : bytes/bytearray/memoryview The initialization vector to use for encryption or decryption. For encryption, the IV must be as long as the cipher block size. For decryption, it must be 2 bytes longer (it is actually the *encrypted* IV which was prefixed to the ciphertext). rNr)NNz*You must either use 'iv' or 'IV', not bothrzMissing component: )Úpoprr Ú TypeErrorÚKeyErrorÚstrr)rÚkwargsrrrÚerrrÚ_create_openpgp_cipherªs     "r&N) rÚ__all__ZCryptodome.Util.py3compatrZCryptodome.RandomrÚobjectrr&rrrrÚs