o Ìn~b³"ã@stddlmZddlZddlmZmZddlZddlmZm Z m Z ddl m Z ddlm Z Gdd„dƒZd d d „ZdS) é)ÚMGF1N)ÚbordÚ _copy_bytes)Úceil_divÚ bytes_to_longÚ long_to_bytes)Ústrxor)ÚRandomc@s8eZdZdZdd„Zdd„Zdd„Zdd „Zd d „Zd S) ÚPKCS1OAEP_CipherzXCipher object for PKCS#1 v1.5 OAEP. Do not create directly: use :func:`new` instead.csN|ˆ_|r |ˆ_ntjjˆ_|r|ˆ_n‡fdd„ˆ_tdd|ƒˆ_|ˆ_dS)a Initialize this PKCS#1 OAEP cipher object. :Parameters: key : an RSA key object If a private half is given, both encryption and decryption are possible. If a public half is given, only encryption is possible. hashAlgo : hash object The hash function to use. This can be a module under `Cryptodome.Hash` or an existing hash object created from any of such modules. If not specified, `Cryptodome.Hash.SHA1` is used. mgfunc : callable A mask generation function that accepts two parameters: a string to use as seed, and the lenth of the mask to generate, in bytes. If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice). label : bytes/bytearray/memoryview A label to apply to this particular encryption. If not specified, an empty string is used. Specifying a label does not improve security. randfunc : callable A function that returns random bytes. :attention: Modify the mask generation function only if you know what you are doing. Sender and receiver must use the same one. cst||ˆjƒS)N)rÚ_hashObj)ÚxÚy©Úself©úG/usr/local/lib/python3.10/dist-packages/Cryptodome/Cipher/PKCS1_OAEP.pyÚGsz+PKCS1OAEP_Cipher.__init__..N) Ú_keyr Ú CryptodomeZHashÚSHA1Ú_mgfrÚ_labelÚ _randfunc)rÚkeyÚhashAlgoÚmgfuncÚlabelÚrandfuncrrrÚ__init__$s  zPKCS1OAEP_Cipher.__init__cCó |j ¡S)zVLegacy function to check if you can call :meth:`encrypt`. .. deprecated:: 3.0)rÚ can_encryptrrrrr Ló zPKCS1OAEP_Cipher.can_encryptcCr)zVLegacy function to check if you can call :meth:`decrypt`. .. deprecated:: 3.0)rÚ can_decryptrrrrr"Rr!zPKCS1OAEP_Cipher.can_decryptcCsîtjj |jj¡}t|dƒ}|jj}t |ƒ}||d|d}|dkr(t dƒ‚|j  |j ¡  ¡}d|}||dtdd|ƒ} | |¡} | | ||d¡} t| | ƒ} | | |¡} t| | ƒ}d|| }t|ƒ}|j |¡}t||ƒ}|S) a\Encrypt a message with PKCS#1 OAEP. :param message: The message to encrypt, also known as plaintext. It can be of variable length, but not longer than the RSA modulus (in bytes) minus 2, minus twice the hash output size. For instance, if you use RSA 2048 and SHA-256, the longest message you can encrypt is 190 byte long. :type message: bytes/bytearray/memoryview :returns: The ciphertext, as large as the RSA modulus. :rtype: bytes :raises ValueError: if the message is too long. éérzPlaintext is too long.óóNé)rÚUtilÚnumberÚsizerÚnrr Ú digest_sizeÚlenÚ ValueErrorÚnewrÚdigestrrrrrZ_encryptr)rÚmessageÚmodBitsÚkÚhLenZmLenZps_lenÚlHashZpsÚdbZrosÚdbMaskÚmaskedDBÚseedMaskÚ maskedSeedÚemZem_intÚm_intÚcrrrÚencryptXs(        zPKCS1OAEP_Cipher.encryptcCsdtjj |jj¡}t|dƒ}|jj}t |ƒ|ks||dkr"t dƒ‚t |ƒ}|j  |¡}t ||ƒ}|j |j¡ ¡}|d} |d|d…} ||dd…} | | |¡} t| | ƒ} | | ||d¡}t| |ƒ}|||d… d¡}|d|…}t| ƒt||kƒB}t||ƒ}|D]}|t|ƒO}qŠ|||…D]}|t|ƒO}q™|dkrªt dƒ‚||dd…S) a5Decrypt a message with PKCS#1 OAEP. :param ciphertext: The encrypted message. :type ciphertext: bytes/bytearray/memoryview :returns: The original message (plaintext). :rtype: bytes :raises ValueError: if the ciphertext has the wrong length, or if decryption fails the integrity check (in which case, the decryption key is probably wrong). :raises TypeError: if the RSA key has no private half (i.e. you are trying to decrypt using a public key). r#r$z!Ciphertext with incorrect length.rr'Nr&zIncorrect decryption.)rr(r)r*rr+rr r,r-r.rZ_decryptrr/rr0rrÚfindrÚint)rZ ciphertextr2r3r4Zct_intr<r;r5r r:r8r9Úseedr7r6Zone_posZlHash1ÚinvalidZ hash_comparer rrrÚdecryptŽs6        zPKCS1OAEP_Cipher.decryptN) Ú__name__Ú __module__Ú __qualname__Ú__doc__rr r"r>rCrrrrr s( 6r ócCs|durtj}t|||||ƒS)a£Return a cipher object :class:`PKCS1OAEP_Cipher` that can be used to perform PKCS#1 OAEP encryption or decryption. :param key: The key object to use to encrypt or decrypt the message. Decryption is only possible with a private RSA key. :type key: RSA key object :param hashAlgo: The hash function to use. This can be a module under `Cryptodome.Hash` or an existing hash object created from any of such modules. If not specified, `Cryptodome.Hash.SHA1` is used. :type hashAlgo: hash object :param mgfunc: A mask generation function that accepts two parameters: a string to use as seed, and the lenth of the mask to generate, in bytes. If not specified, the standard MGF1 consistent with ``hashAlgo`` is used (a safe choice). :type mgfunc: callable :param label: A label to apply to this particular encryption. If not specified, an empty string is used. Specifying a label does not improve security. :type label: bytes/bytearray/memoryview :param randfunc: A function that returns random bytes. The default is `Random.get_random_bytes`. :type randfunc: callable N)r Zget_random_bytesr )rrrrrrrrr/Ìs r/)NNrHN)ZCryptodome.Signature.pssrZCryptodome.Hash.SHA1rZCryptodome.Util.py3compatrrZCryptodome.Util.numberrrrZCryptodome.Util.strxorrr r r/rrrrÚs   -