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bovine.crypto.signature

Signature dataclass

Helper class to parse HTTP Signatures

Source code in bovine/bovine/crypto/signature.py 
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@dataclass
class Signature:
    """Helper class to parse HTTP Signatures"""

    key_id: str
    algorithm: str
    headers: str
    signature: str

    def __post_init__(self):
        if self.algorithm not in ["rsa-sha256", "hs2019"]:
            logger.error(f"Unsupported algorithm {self.algorithm}")
            logger.error(self.signature)
            logger.error(self.headers)
            logger.error(self.key_id)

            raise ValueError("Unsupported algorithm", self.algorithm)

    @property
    def fields(self) -> List[str]:
        """Returns the fields that are used when building the signature"""
        return self.headers.split(" ")

    @staticmethod
    def from_signature_header(header):
        """Takes the signature header and turns into Signature object

        The header is assumed of the for key=value,... The keys keyId,
        algorithm, headers, and signature are parsed. If algorithm
        is absent it is assumed to be rsa-sha256. The other keys are required.
        """
        headers = header.split(",")
        headers = [x.split('="', 1) for x in headers]
        parsed = {x[0]: x[1].replace('"', "") for x in headers}

        return Signature(
            parsed["keyId"],
            parsed.get("algorithm", "rsa-sha256"),
            parsed["headers"],
            parsed["signature"],
        )

fields: List[str] property

Returns the fields that are used when building the signature

from_signature_header(header) staticmethod

Takes the signature header and turns into Signature object

The header is assumed of the for key=value,… The keys keyId, algorithm, headers, and signature are parsed. If algorithm is absent it is assumed to be rsa-sha256. The other keys are required.

Source code in bovine/bovine/crypto/signature.py 
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@staticmethod
def from_signature_header(header):
    """Takes the signature header and turns into Signature object

    The header is assumed of the for key=value,... The keys keyId,
    algorithm, headers, and signature are parsed. If algorithm
    is absent it is assumed to be rsa-sha256. The other keys are required.
    """
    headers = header.split(",")
    headers = [x.split('="', 1) for x in headers]
    parsed = {x[0]: x[1].replace('"', "") for x in headers}

    return Signature(
        parsed["keyId"],
        parsed.get("algorithm", "rsa-sha256"),
        parsed["headers"],
        parsed["signature"],
    )