Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.8/site-packages/jwt/utils.py: 34%

1import base64 

2import binascii 

3import re 

4from typing import Union 

5 

6try: 

7 from cryptography.hazmat.primitives.asymmetric.ec import EllipticCurve 

8 from cryptography.hazmat.primitives.asymmetric.utils import ( 

9 decode_dss_signature, 

10 encode_dss_signature, 

11 ) 

12except ModuleNotFoundError: 

13 pass 

14 

15 

16def force_bytes(value: Union[bytes, str]) -> bytes: 

17 if isinstance(value, str): 

18 return value.encode("utf-8") 

19 elif isinstance(value, bytes): 

20 return value 

21 else: 

22 raise TypeError("Expected a string value") 

23 

24 

25def base64url_decode(input: Union[bytes, str]) -> bytes: 

26 input_bytes = force_bytes(input) 

27 

28 rem = len(input_bytes) % 4 

29 

30 if rem > 0: 

31 input_bytes += b"=" * (4 - rem) 

32 

33 return base64.urlsafe_b64decode(input_bytes) 

34 

35 

36def base64url_encode(input: bytes) -> bytes: 

37 return base64.urlsafe_b64encode(input).replace(b"=", b"") 

38 

39 

40def to_base64url_uint(val: int) -> bytes: 

41 if val < 0: 

42 raise ValueError("Must be a positive integer") 

43 

44 int_bytes = bytes_from_int(val) 

45 

46 if len(int_bytes) == 0: 

47 int_bytes = b"\x00" 

48 

49 return base64url_encode(int_bytes) 

50 

51 

52def from_base64url_uint(val: Union[bytes, str]) -> int: 

53 data = base64url_decode(force_bytes(val)) 

54 return int.from_bytes(data, byteorder="big") 

55 

56 

57def number_to_bytes(num: int, num_bytes: int) -> bytes: 

58 padded_hex = "%0*x" % (2 * num_bytes, num) 

59 return binascii.a2b_hex(padded_hex.encode("ascii")) 

60 

61 

62def bytes_to_number(string: bytes) -> int: 

63 return int(binascii.b2a_hex(string), 16) 

64 

65 

66def bytes_from_int(val: int) -> bytes: 

67 remaining = val 

68 byte_length = 0 

69 

70 while remaining != 0: 

71 remaining >>= 8 

72 byte_length += 1 

73 

74 return val.to_bytes(byte_length, "big", signed=False) 

75 

76 

77def der_to_raw_signature(der_sig: bytes, curve: "EllipticCurve") -> bytes: 

78 num_bits = curve.key_size 

79 num_bytes = (num_bits + 7) // 8 

80 

81 r, s = decode_dss_signature(der_sig) 

82 

83 return number_to_bytes(r, num_bytes) + number_to_bytes(s, num_bytes) 

84 

85 

86def raw_to_der_signature(raw_sig: bytes, curve: "EllipticCurve") -> bytes: 

87 num_bits = curve.key_size 

88 num_bytes = (num_bits + 7) // 8 

89 

90 if len(raw_sig) != 2 * num_bytes: 

91 raise ValueError("Invalid signature") 

92 

93 r = bytes_to_number(raw_sig[:num_bytes]) 

94 s = bytes_to_number(raw_sig[num_bytes:]) 

95 

96 return bytes(encode_dss_signature(r, s)) 

97 

98 

99# Based on https://github.com/hynek/pem/blob/7ad94db26b0bc21d10953f5dbad3acfdfacf57aa/src/pem/_core.py#L224-L252 

100_PEMS = { 

101 b"CERTIFICATE", 

102 b"TRUSTED CERTIFICATE", 

103 b"PRIVATE KEY", 

104 b"PUBLIC KEY", 

105 b"ENCRYPTED PRIVATE KEY", 

106 b"OPENSSH PRIVATE KEY", 

107 b"DSA PRIVATE KEY", 

108 b"RSA PRIVATE KEY", 

109 b"RSA PUBLIC KEY", 

110 b"EC PRIVATE KEY", 

111 b"DH PARAMETERS", 

112 b"NEW CERTIFICATE REQUEST", 

113 b"CERTIFICATE REQUEST", 

114 b"SSH2 PUBLIC KEY", 

115 b"SSH2 ENCRYPTED PRIVATE KEY", 

116 b"X509 CRL", 

117} 

118 

119_PEM_RE = re.compile( 

120 b"----[- ]BEGIN (" 

121 + b"|".join(_PEMS) 

122 + b""")[- ]----\r? 

123.+?\r? 

124----[- ]END \\1[- ]----\r?\n?""", 

125 re.DOTALL, 

126) 

127 

128 

129def is_pem_format(key: bytes) -> bool: 

130 return bool(_PEM_RE.search(key)) 

131 

132 

133# Based on https://github.com/pyca/cryptography/blob/bcb70852d577b3f490f015378c75cba74986297b/src/cryptography/hazmat/primitives/serialization/ssh.py#L40-L46 

134_SSH_KEY_FORMATS = ( 

135 b"ssh-ed25519", 

136 b"ssh-rsa", 

137 b"ssh-dss", 

138 b"ecdsa-sha2-nistp256", 

139 b"ecdsa-sha2-nistp384", 

140 b"ecdsa-sha2-nistp521", 

141) 

142 

143 

144def is_ssh_key(key: bytes) -> bool: 

145 return key.startswith(_SSH_KEY_FORMATS)