blob: 94dd00d8dbfd3e18ff2d8b6fbbfb93303422aafe [file] [log] [blame]
# Authors:
# Trevor Perrin
# Google - parsing subject field
# See the LICENSE file for legal information regarding use of this file.
"""Class representing an X.509 certificate."""
from .utils.asn1parser import ASN1Parser
from .utils.cryptomath import *
from .utils.keyfactory import _createPublicRSAKey
from .utils.pem import *
class X509(object):
"""This class represents an X.509 certificate.
@type bytes: L{bytearray} of unsigned bytes
@ivar bytes: The DER-encoded ASN.1 certificate
@type publicKey: L{tlslite.utils.rsakey.RSAKey}
@ivar publicKey: The subject public key from the certificate.
@type subject: L{bytearray} of unsigned bytes
@ivar subject: The DER-encoded ASN.1 subject distinguished name.
def __init__(self):
self.bytes = bytearray(0)
self.publicKey = None
self.subject = None
def parse(self, s):
"""Parse a PEM-encoded X.509 certificate.
@type s: str
@param s: A PEM-encoded X.509 certificate (i.e. a base64-encoded
certificate wrapped with "-----BEGIN CERTIFICATE-----" and
"-----END CERTIFICATE-----" tags).
bytes = dePem(s, "CERTIFICATE")
return self
def parseBinary(self, bytes):
"""Parse a DER-encoded X.509 certificate.
@type bytes: str or L{bytearray} of unsigned bytes
@param bytes: A DER-encoded X.509 certificate.
self.bytes = bytearray(bytes)
p = ASN1Parser(bytes)
#Get the tbsCertificate
tbsCertificateP = p.getChild(0)
#Is the optional version field present?
#This determines which index the key is at.
if tbsCertificateP.value[0]==0xA0:
subjectPublicKeyInfoIndex = 6
subjectPublicKeyInfoIndex = 5
#Get the subject
self.subject = tbsCertificateP.getChildBytes(\
subjectPublicKeyInfoIndex - 1)
#Get the subjectPublicKeyInfo
subjectPublicKeyInfoP = tbsCertificateP.getChild(\
#Get the algorithm
algorithmP = subjectPublicKeyInfoP.getChild(0)
rsaOID = algorithmP.value
if list(rsaOID) != [6, 9, 42, 134, 72, 134, 247, 13, 1, 1, 1, 5, 0]:
raise SyntaxError("Unrecognized AlgorithmIdentifier")
#Get the subjectPublicKey
subjectPublicKeyP = subjectPublicKeyInfoP.getChild(1)
#Adjust for BIT STRING encapsulation
if (subjectPublicKeyP.value[0] !=0):
raise SyntaxError()
subjectPublicKeyP = ASN1Parser(subjectPublicKeyP.value[1:])
#Get the modulus and exponent
modulusP = subjectPublicKeyP.getChild(0)
publicExponentP = subjectPublicKeyP.getChild(1)
#Decode them into numbers
n = bytesToNumber(modulusP.value)
e = bytesToNumber(publicExponentP.value)
#Create a public key instance
self.publicKey = _createPublicRSAKey(n, e)
def getFingerprint(self):
"""Get the hex-encoded fingerprint of this certificate.
@rtype: str
@return: A hex-encoded fingerprint.
return b2a_hex(SHA1(self.bytes))
def writeBytes(self):
return self.bytes