Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/pypdf/_crypt_providers/_pycryptodome.py: 66%

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3# 

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9# this list of conditions and the following disclaimer. 

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11# this list of conditions and the following disclaimer in the documentation 

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14# derived from this software without specific prior written permission. 

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27 

28import secrets 

29 

30from Crypto import __version__ 

31from Crypto.Cipher import AES, ARC4 

32from Crypto.Util.Padding import pad 

33 

34from pypdf._crypt_providers._base import CryptBase 

35 

36crypt_provider = ("pycryptodome", __version__) 

37 

38 

39class CryptRC4(CryptBase): 

40 def __init__(self, key: bytes) -> None: 

41 self.key = key 

42 

43 def encrypt(self, data: bytes) -> bytes: 

44 return ARC4.ARC4Cipher(self.key).encrypt(data) 

45 

46 def decrypt(self, data: bytes) -> bytes: 

47 return ARC4.ARC4Cipher(self.key).decrypt(data) 

48 

49 

50class CryptAES(CryptBase): 

51 def __init__(self, key: bytes) -> None: 

52 self.key = key 

53 

54 def encrypt(self, data: bytes) -> bytes: 

55 iv = secrets.token_bytes(16) 

56 data = pad(data, 16) 

57 aes = AES.new(self.key, AES.MODE_CBC, iv) 

58 return iv + aes.encrypt(data) 

59 

60 def decrypt(self, data: bytes) -> bytes: 

61 iv = data[:16] 

62 data = data[16:] 

63 # for empty encrypted data 

64 if not data: 

65 return data 

66 

67 # just for robustness, it does not happen under normal circumstances 

68 if len(data) % 16 != 0: 

69 data = pad(data, 16) 

70 

71 aes = AES.new(self.key, AES.MODE_CBC, iv) 

72 d = aes.decrypt(data) 

73 return d[: -d[-1]] 

74 

75 

76def rc4_encrypt(key: bytes, data: bytes) -> bytes: 

77 return ARC4.ARC4Cipher(key).encrypt(data) 

78 

79 

80def rc4_decrypt(key: bytes, data: bytes) -> bytes: 

81 return ARC4.ARC4Cipher(key).decrypt(data) 

82 

83 

84def aes_ecb_encrypt(key: bytes, data: bytes) -> bytes: 

85 return AES.new(key, AES.MODE_ECB).encrypt(data) 

86 

87 

88def aes_ecb_decrypt(key: bytes, data: bytes) -> bytes: 

89 return AES.new(key, AES.MODE_ECB).decrypt(data) 

90 

91 

92def aes_cbc_encrypt(key: bytes, iv: bytes, data: bytes) -> bytes: 

93 return AES.new(key, AES.MODE_CBC, iv).encrypt(data) 

94 

95 

96def aes_cbc_decrypt(key: bytes, iv: bytes, data: bytes) -> bytes: 

97 return AES.new(key, AES.MODE_CBC, iv).decrypt(data)