Coverage for /pythoncovmergedfiles/medio/medio/usr/local/lib/python3.11/site-packages/starkbank_ecdsa-2.3.1-py3.11.egg/ellipticcurve/signature.py: 82%

1from .utils.compatibility import * 

2from .utils.der import parse, encodeConstructed, encodePrimitive, DerFieldType 

3from .utils.binary import hexFromByteString, byteStringFromHex, base64FromByteString, byteStringFromBase64 

4 

5 

6class Signature: 

7 

8 def __init__(self, r, s, recoveryId=None): 

9 self.r = r 

10 self.s = s 

11 self.recoveryId = recoveryId 

12 

13 def toDer(self, withRecoveryId=False): 

14 hexadecimal = self._toString() 

15 encodedSequence = byteStringFromHex(hexadecimal) 

16 if not withRecoveryId: 

17 return encodedSequence 

18 return toBytes(chr(27 + self.recoveryId)) + encodedSequence 

19 

20 def toBase64(self, withRecoveryId=False): 

21 return base64FromByteString(self.toDer(withRecoveryId)) 

22 

23 @classmethod 

24 def fromDer(cls, string, recoveryByte=False): 

25 recoveryId = None 

26 if recoveryByte: 

27 rawByte = string[0] if isinstance(string[0], intTypes) else ord(string[0]) 

28 if not 27 <= rawByte <= 30: 

29 raise Exception("Recovery byte must be in [27, 30], got {b}".format(b=rawByte)) 

30 recoveryId = rawByte - 27 

31 string = string[1:] 

32 

33 hexadecimal = hexFromByteString(string) 

34 signature = cls._fromString(string=hexadecimal, recoveryId=recoveryId) 

35 if byteStringFromHex(signature._toString()) != string: 

36 raise Exception("Signature is not in canonical DER form") 

37 return signature 

38 

39 @classmethod 

40 def fromBase64(cls, string, recoveryByte=False): 

41 der = byteStringFromBase64(string) 

42 return cls.fromDer(der, recoveryByte) 

43 

44 def _toString(self): 

45 return encodeConstructed( 

46 encodePrimitive(DerFieldType.integer, self.r), 

47 encodePrimitive(DerFieldType.integer, self.s), 

48 ) 

49 

50 @classmethod 

51 def _fromString(cls, string, recoveryId=None): 

52 r, s = parse(string)[0] 

53 return Signature(r=r, s=s, recoveryId=recoveryId)