o ¼Ç h ã@sxdZddlmZmZmZdd„Zdd„Zdd„Zd d „Zd d „Z d d„Z e dkr:ddl Z ddl Z e  e  ¡j¡dSdS)a` PostScript Type 1 fonts make use of two types of encryption: charstring encryption and ``eexec`` encryption. Charstring encryption is used for the charstrings themselves, while ``eexec`` is used to encrypt larger sections of the font program, such as the ``Private`` and ``CharStrings`` dictionaries. Despite the different names, the algorithm is the same, although ``eexec`` encryption uses a fixed initial key R=55665. The algorithm uses cipher feedback, meaning that the ciphertext is used to modify the key. Because of this, the routines in this module return the new key at the end of the operation. é)ÚbytechrÚ bytesjoinÚbyteordcCs8t|ƒ}||d?Ad@}||ddd@}t|ƒ|fS©NééÿimÎi¿Xiÿÿ©rr)ÚcipherÚRÚplain©r úh/var/www/html/construction_image-detection-poc/venv/lib/python3.10/site-packages/fontTools/misc/eexec.pyÚ _decryptCharó rcCs8t|ƒ}||d?Ad@}||ddd@}t|ƒ|fSrr)r r r r r r Ú _encryptCharrrcCó:g}|D]}t||ƒ\}}| |¡qt|ƒ}|t|ƒfS)a Decrypts a string using the Type 1 encryption algorithm. Args: cipherstring: String of ciphertext. R: Initial key. Returns: decryptedStr: Plaintext string. R: Output key for subsequent decryptions. Examples:: >>> testStr = b"\0\0asdadads asds\265" >>> decryptedStr, R = decrypt(testStr, 12321) >>> decryptedStr == b'0d\nh\x15\xe8\xc4\xb2\x15\x1d\x108\x1a<6\xa1' True >>> R == 36142 True )rÚappendrÚint)Ú cipherstringr Ú plainListr r Ú plainstringr r r Údecrypt s   rcCr)aé Encrypts a string using the Type 1 encryption algorithm. Note that the algorithm as described in the Type 1 specification requires the plaintext to be prefixed with a number of random bytes. (For ``eexec`` the number of random bytes is set to 4.) This routine does *not* add the random prefix to its input. Args: plainstring: String of plaintext. R: Initial key. Returns: cipherstring: Ciphertext string. R: Output key for subsequent encryptions. Examples:: >>> testStr = b"\0\0asdadads asds\265" >>> decryptedStr, R = decrypt(testStr, 12321) >>> decryptedStr == b'0d\nh\x15\xe8\xc4\xb2\x15\x1d\x108\x1a<6\xa1' True >>> R == 36142 True >>> testStr = b'0d\nh\x15\xe8\xc4\xb2\x15\x1d\x108\x1a<6\xa1' >>> encryptedStr, R = encrypt(testStr, 12321) >>> encryptedStr == b"\0\0asdadads asds\265" True >>> R == 36142 True )rrrr)rr Ú cipherListr r rr r r Úencrypt=s !  rcCsddl}| |¡S©Nr)ÚbinasciiÚhexlify)Úsrr r r Ú hexStringfs rcCsddl}t| ¡ƒ}| |¡Sr)rrÚsplitÚ unhexlify)Úhrr r r Ú deHexStringls  r"Ú__main__N)Ú__doc__ÚfontTools.misc.textToolsrrrrrrrrr"Ú__name__ÚsysÚdoctestÚexitÚtestmodÚfailedr r r r Ús)ü