# Read ASN.1/PEM X.509 certificates on stdin, parse each into plain text,
# then build substrate from it
import sys, string, base64
from pyasn1.type import tag,namedtype,namedval,univ,constraint,char,useful
from pyasn1.codec.der import decoder,encoder
from pyasn1 import error
# Would be autogenerated from ASN.1 source by a ASN.1 parser
# X.509 spec (rfc2459)
MAX = 64 # XXX ?
class DirectoryString(univ.Choice):
componentType = namedtype.NamedTypes(
namedtype.NamedType('teletexString', char.TeletexString().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))),
namedtype.NamedType('printableString', char.PrintableString().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))),
namedtype.NamedType('universalString', char.UniversalString().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))),
namedtype.NamedType('utf8String', char.UTF8String().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))),
namedtype.NamedType('bmpString', char.BMPString().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))),
namedtype.NamedType('ia5String', char.IA5String().subtype(subtypeSpec=constraint.ValueSizeConstraint(1, MAX))) # hm, this should not be here!? XXX
)
class AttributeValue(DirectoryString): pass
class AttributeType(univ.ObjectIdentifier): pass
class AttributeTypeAndValue(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('type', AttributeType()),
namedtype.NamedType('value', AttributeValue())
)
class RelativeDistinguishedName(univ.SetOf):
componentType = AttributeTypeAndValue()
class RDNSequence(univ.SequenceOf):
componentType = RelativeDistinguishedName()
class Name(univ.Choice):
componentType = namedtype.NamedTypes(
namedtype.NamedType('', RDNSequence())
)
class AlgorithmIdentifier(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('algorithm', univ.ObjectIdentifier()),
namedtype.OptionalNamedType('parameters', univ.Null())
# XXX syntax screwed?
# namedtype.OptionalNamedType('parameters', univ.ObjectIdentifier())
)
class Extension(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('extnID', univ.ObjectIdentifier()),
namedtype.DefaultedNamedType('critical', univ.Boolean('False')),
namedtype.NamedType('extnValue', univ.OctetString())
)
class Extensions(univ.SequenceOf):
componentType = Extension()
sizeSpec = univ.SequenceOf.sizeSpec + constraint.ValueSizeConstraint(1, MAX)
class SubjectPublicKeyInfo(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('algorithm', AlgorithmIdentifier()),
namedtype.NamedType('subjectPublicKey', univ.BitString())
)
class UniqueIdentifier(univ.BitString): pass
class Time(univ.Choice):
componentType = namedtype.NamedTypes(
namedtype.NamedType('utcTime', useful.UTCTime()),
namedtype.NamedType('generalTime', useful.GeneralizedTime())
)
class Validity(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('notBefore', Time()),
namedtype.NamedType('notAfter', Time())
)
class CertificateSerialNumber(univ.Integer): pass
class Version(univ.Integer):
namedValues = namedval.NamedValues(
('v1', 0), ('v2', 1), ('v3', 2)
)
class TBSCertificate(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.DefaultedNamedType('version', Version('v1', tagSet=Version.tagSet.tagExplicitly(tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0)))),
namedtype.NamedType('serialNumber', CertificateSerialNumber()),
namedtype.NamedType('signature', AlgorithmIdentifier()),
namedtype.NamedType('issuer', Name()),
namedtype.NamedType('validity', Validity()),
namedtype.NamedType('subject', Name()),
namedtype.NamedType('subjectPublicKeyInfo', SubjectPublicKeyInfo()),
namedtype.OptionalNamedType('issuerUniqueID', UniqueIdentifier().subtype(implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 1))),
namedtype.OptionalNamedType('subjectUniqueID', UniqueIdentifier().subtype(implicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 2))),
namedtype.OptionalNamedType('extensions', Extensions().subtype(explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 3)))
)
class Certificate(univ.Sequence):
componentType = namedtype.NamedTypes(
namedtype.NamedType('tbsCertificate', TBSCertificate()),
namedtype.NamedType('signatureAlgorithm', AlgorithmIdentifier()),
namedtype.NamedType('signatureValue', univ.BitString())
)
# end of ASN.1 data structures
certType = Certificate()
# Read PEM certs from stdin and print them out in plain text
stSpam, stHam, stDump = 0, 1, 2
state = stSpam
certCnt = 0
for certLine in sys.stdin.readlines():
certLine = string.strip(certLine)
if state == stSpam:
if state == stSpam:
if certLine == '-----BEGIN CERTIFICATE-----':
certLines = []
state = stHam
continue
if state == stHam:
if certLine == '-----END CERTIFICATE-----':
state = stDump
else:
certLines.append(certLine)
if state == stDump:
substrate = ''
for certLine in certLines:
substrate = substrate + base64.b64decode(certLine)
cert = decoder.decode(substrate, asn1Spec=certType)[0]
print cert.prettyPrint()
assert encoder.encode(cert) == substrate, 'cert recode fails'
certCnt = certCnt + 1
state = stSpam
print '*** %s PEM cert(s) de/serialized' % certCnt
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