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#!/usr/bin/env python
#
# This Source Code Form is subject to the terms of the Mozilla Public
# License, v. 2.0. If a copy of the MPL was not distributed with this
"""
Reads a certificate specification from stdin or a file and outputs a
signed x509 certificate with the desired properties.
The input format is as follows:
issuer:<issuer distinguished name specification>
subject:<subject distinguished name specification>
[version:{1,2,3,4}]
[validity:<YYYYMMDD-YYYYMMDD|duration in days>]
[issuerKey:<key specification>]
[subjectKey:<key specification>]
[signature:{sha256WithRSAEncryption,sha1WithRSAEncryption,
md5WithRSAEncryption,ecdsaWithSHA256,ecdsaWithSHA384,
ecdsaWithSHA512}]
[serialNumber:<integer in the interval [1, 127]>]
[extension:<extension name:<extension-specific data>>]
[...]
Known extensions are:
basicConstraints:[cA],[pathLenConstraint]
keyUsage:[digitalSignature,nonRepudiation,keyEncipherment,
dataEncipherment,keyAgreement,keyCertSign,cRLSign]
extKeyUsage:[serverAuth,clientAuth,codeSigning,emailProtection
nsSGC, # Netscape Server Gated Crypto
OCSPSigning,timeStamping]
subjectAlternativeName:[<dNSName|directoryName|"ip4:"iPV4Address>,...]
authorityInformationAccess:<OCSP URI>
certificatePolicies:[<policy OID>,...]
nameConstraints:{permitted,excluded}:[<dNSName|directoryName>,...]
nsCertType:sslServer
TLSFeature:[<TLSFeature>,...]
embeddedSCTList:[<key specification>:<YYYYMMDD>,...]
delegationUsage:
Where:
[] indicates an optional field or component of a field
<> indicates a required component of a field
{} indicates a choice of exactly one value among a set of values
[a,b,c] indicates a list of potential values, of which zero or more
may be used
For instance, the version field is optional. However, if it is
specified, it must have exactly one value from the set {1,2,3,4}.
Most fields have reasonable default values. By default one shared RSA
key is used for all signatures and subject public key information
fields. Using "issuerKey:<key specification>" or
"subjectKey:<key specification>" causes a different key be used for
signing or as the subject public key information field, respectively.
See pykey.py for the list of available specifications.
The signature algorithm is sha256WithRSAEncryption by default.
The validity period may be specified as either concrete notBefore and
notAfter values or as a validity period centered around 'now'. For the
latter, this will result in a notBefore of 'now' - duration/2 and a
notAfter of 'now' + duration/2.
Issuer and subject distinguished name specifications are of the form
'[stringEncoding]/C=XX/O=Example/CN=example.com'. C (country name), ST
(state or province name), L (locality name), O (organization name), OU
(organizational unit name), CN (common name) and emailAddress (email
address) are currently supported. The optional stringEncoding field may
be 'utf8String' or 'printableString'. If the given string does not
contain a '/', it is assumed to represent a common name. If an empty
string is provided, then an empty distinguished name is returned.
DirectoryNames also use this format. When specifying a directoryName in
a nameConstraints extension, the implicit form may not be used.
If an extension name has '[critical]' after it, it will be marked as
critical. Otherwise (by default), it will not be marked as critical.
TLSFeature values can either consist of a named value (currently only
'OCSPMustStaple' which corresponds to status_request) or a numeric TLS
feature value (see rfc7633 for more information).
If a serial number is not explicitly specified, it is automatically
generated based on the contents of the certificate.
"""
import base64
import datetime
import hashlib
import re
import socket
import sys
from struct import pack
import pyct
import pykey
import six
from pyasn1.codec.der import decoder, encoder
from pyasn1.type import constraint, tag, univ, useful
from pyasn1_modules import rfc2459
class Error(Exception):
"""Base class for exceptions in this module."""
pass
class UnknownBaseError(Error):
"""Base class for handling unexpected input in this module."""
def __init__(self, value):
super(UnknownBaseError, self).__init__()
self.value = value
self.category = "input"
def __str__(self):
return 'Unknown %s type "%s"' % (self.category, repr(self.value))
class UnknownAlgorithmTypeError(UnknownBaseError):
"""Helper exception type to handle unknown algorithm types."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "algorithm"
class UnknownParameterTypeError(UnknownBaseError):
"""Helper exception type to handle unknown input parameters."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "parameter"
class UnknownExtensionTypeError(UnknownBaseError):
"""Helper exception type to handle unknown input extensions."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "extension"
class UnknownKeyPurposeTypeError(UnknownBaseError):
"""Helper exception type to handle unknown key purposes."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "keyPurpose"
class UnknownKeyTargetError(UnknownBaseError):
"""Helper exception type to handle unknown key targets."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "key target"
class UnknownVersionError(UnknownBaseError):
"""Helper exception type to handle unknown specified versions."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "version"
class UnknownNameConstraintsSpecificationError(UnknownBaseError):
"""Helper exception type to handle unknown specified
nameConstraints."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "nameConstraints specification"
class UnknownDNTypeError(UnknownBaseError):
"""Helper exception type to handle unknown DN types."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "DN"
class UnknownNSCertTypeError(UnknownBaseError):
"""Helper exception type to handle unknown nsCertType types."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "nsCertType"
class UnknownTLSFeature(UnknownBaseError):
"""Helper exception type to handle unknown TLS Features."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "TLSFeature"
class UnknownDelegatedCredentialError(UnknownBaseError):
"""Helper exception type to handle unknown Delegated Credential args."""
def __init__(self, value):
UnknownBaseError.__init__(self, value)
self.category = "delegatedCredential"
class InvalidSCTSpecification(Error):
"""Helper exception type to handle invalid SCT specifications."""
def __init__(self, value):
super(InvalidSCTSpecification, self).__init__()
self.value = value
def __str__(self):
return repr('invalid SCT specification "{}"' % self.value)
class InvalidSerialNumber(Error):
"""Exception type to handle invalid serial numbers."""
def __init__(self, value):
super(InvalidSerialNumber, self).__init__()
self.value = value
def __str__(self):
return repr(self.value)
def getASN1Tag(asn1Type):
"""Helper function for returning the base tag value of a given
type from the pyasn1 package"""
return asn1Type.tagSet.baseTag.tagId
def stringToAccessDescription(string):
"""Helper function that takes a string representing a URI
presumably identifying an OCSP authority information access
location. Returns an AccessDescription usable by pyasn1."""
accessMethod = rfc2459.id_ad_ocsp
accessLocation = rfc2459.GeneralName()
accessLocation["uniformResourceIdentifier"] = string
sequence = univ.Sequence()
sequence.setComponentByPosition(0, accessMethod)
sequence.setComponentByPosition(1, accessLocation)
return sequence
def stringToDN(string, tag=None):
"""Takes a string representing a distinguished name or directory
name and returns a Name for use by pyasn1. See the documentation
for the issuer and subject fields for more details. Takes an
optional implicit tag in cases where the Name needs to be tagged
differently."""
if string and "/" not in string:
string = "/CN=%s" % string
rdns = rfc2459.RDNSequence()
pattern = "/(C|ST|L|O|OU|CN|emailAddress)="
split = re.split(pattern, string)
# split should now be [[encoding], <type>, <value>, <type>, <value>, ...]
if split[0]:
encoding = split[0]
else:
encoding = "utf8String"
for pos, (nameType, value) in enumerate(zip(split[1::2], split[2::2])):
ava = rfc2459.AttributeTypeAndValue()
if nameType == "C":
ava["type"] = rfc2459.id_at_countryName
nameComponent = rfc2459.X520countryName(value)
elif nameType == "ST":
ava["type"] = rfc2459.id_at_stateOrProvinceName
nameComponent = rfc2459.X520StateOrProvinceName()
elif nameType == "L":
ava["type"] = rfc2459.id_at_localityName
nameComponent = rfc2459.X520LocalityName()
elif nameType == "O":
ava["type"] = rfc2459.id_at_organizationName
nameComponent = rfc2459.X520OrganizationName()
elif nameType == "OU":
ava["type"] = rfc2459.id_at_organizationalUnitName
nameComponent = rfc2459.X520OrganizationalUnitName()
elif nameType == "CN":
ava["type"] = rfc2459.id_at_commonName
nameComponent = rfc2459.X520CommonName()
elif nameType == "emailAddress":
ava["type"] = rfc2459.emailAddress
nameComponent = rfc2459.Pkcs9email(value)
else:
raise UnknownDNTypeError(nameType)
if not nameType == "C" and not nameType == "emailAddress":
# The value may have things like '\0' (i.e. a slash followed by
# the number zero) that have to be decoded into the resulting
# '\x00' (i.e. a byte with value zero).
nameComponent[encoding] = six.ensure_binary(value).decode(
encoding="unicode_escape"
)
ava["value"] = nameComponent
rdn = rfc2459.RelativeDistinguishedName()
rdn.setComponentByPosition(0, ava)
rdns.setComponentByPosition(pos, rdn)
if tag:
name = rfc2459.Name().subtype(implicitTag=tag)
else:
name = rfc2459.Name()
name.setComponentByPosition(0, rdns)
return name
def stringToAlgorithmIdentifiers(string):
"""Helper function that converts a description of an algorithm
to a representation usable by the pyasn1 package and a hash
algorithm constant for use by pykey."""
algorithmIdentifier = rfc2459.AlgorithmIdentifier()
algorithmType = None
algorithm = None
# We add Null parameters for RSA only
addParameters = False
if string == "sha1WithRSAEncryption":
algorithmType = pykey.HASH_SHA1
algorithm = rfc2459.sha1WithRSAEncryption
addParameters = True
elif string == "sha256WithRSAEncryption":
algorithmType = pykey.HASH_SHA256
algorithm = univ.ObjectIdentifier("1.2.840.113549.1.1.11")
addParameters = True
elif string == "md5WithRSAEncryption":
algorithmType = pykey.HASH_MD5
algorithm = rfc2459.md5WithRSAEncryption
addParameters = True
elif string == "ecdsaWithSHA256":
algorithmType = pykey.HASH_SHA256
algorithm = univ.ObjectIdentifier("1.2.840.10045.4.3.2")
elif string == "ecdsaWithSHA384":
algorithmType = pykey.HASH_SHA384
algorithm = univ.ObjectIdentifier("1.2.840.10045.4.3.3")
elif string == "ecdsaWithSHA512":
algorithmType = pykey.HASH_SHA512
algorithm = univ.ObjectIdentifier("1.2.840.10045.4.3.4")
else:
raise UnknownAlgorithmTypeError(string)
algorithmIdentifier["algorithm"] = algorithm
if addParameters:
# Directly setting parameters to univ.Null doesn't currently work.
nullEncapsulated = encoder.encode(univ.Null())
algorithmIdentifier["parameters"] = univ.Any(nullEncapsulated)
return (algorithmIdentifier, algorithmType)
def datetimeToTime(dt):
"""Takes a datetime object and returns an rfc2459.Time object with
that time as its value as a GeneralizedTime"""
time = rfc2459.Time()
time["generalTime"] = useful.GeneralizedTime(dt.strftime("%Y%m%d%H%M%SZ"))
return time
def serialBytesToString(serialBytes):
"""Takes a list of integers in the interval [0, 255] and returns
the corresponding serial number string."""
serialBytesLen = len(serialBytes)
if serialBytesLen > 127:
raise InvalidSerialNumber("{} bytes is too long".format(serialBytesLen))
# Prepend the ASN.1 INTEGER tag and length bytes.
stringBytes = [getASN1Tag(univ.Integer), serialBytesLen] + serialBytes
return bytes(stringBytes)
class Certificate(object):
"""Utility class for reading a certificate specification and
generating a signed x509 certificate"""
def __init__(self, paramStream):
self.versionValue = 2 # a value of 2 is X509v3
self.signature = "sha256WithRSAEncryption"
self.issuer = "Default Issuer"
actualNow = datetime.datetime.utcnow()
self.now = datetime.datetime.strptime(str(actualNow.year), "%Y")
aYearAndAWhile = datetime.timedelta(days=400)
self.notBefore = self.now - aYearAndAWhile
self.notAfter = self.now + aYearAndAWhile
self.subject = "Default Subject"
self.extensions = None
# The serial number can be automatically generated from the
# certificate specification. We need this value to depend in
# part of what extensions are present. self.extensions are
# pyasn1 objects. Depending on the string representation of
# these objects can cause the resulting serial number to change
# unexpectedly, so instead we depend on the original string
# representation of the extensions as specified.
self.extensionLines = None
self.savedEmbeddedSCTListData = None
self.subjectKey = pykey.keyFromSpecification("default")
self.issuerKey = pykey.keyFromSpecification("default")
self.serialNumber = None
self.decodeParams(paramStream)
# If a serial number wasn't specified, generate one based on
# the certificate contents.
if not self.serialNumber:
self.serialNumber = self.generateSerialNumber()
# This has to be last because the SCT signature depends on the
# contents of the certificate.
if self.savedEmbeddedSCTListData:
self.addEmbeddedSCTListData()
def generateSerialNumber(self):
"""Generates a serial number for this certificate based on its
contents. Intended to be reproducible for compatibility with
the build system on OS X (see the comment above main, later in
this file)."""
hasher = hashlib.sha256()
hasher.update(six.ensure_binary(str(self.versionValue)))
hasher.update(six.ensure_binary(self.signature))
hasher.update(six.ensure_binary(self.issuer))
hasher.update(six.ensure_binary(str(self.notBefore)))
hasher.update(six.ensure_binary(str(self.notAfter)))
hasher.update(six.ensure_binary(self.subject))
if self.extensionLines:
for extensionLine in self.extensionLines:
hasher.update(six.ensure_binary(extensionLine))
if self.savedEmbeddedSCTListData:
# savedEmbeddedSCTListData is
# (embeddedSCTListSpecification, critical), where |critical|
# may be None
hasher.update(six.ensure_binary(self.savedEmbeddedSCTListData[0]))
if self.savedEmbeddedSCTListData[1]:
hasher.update(six.ensure_binary(self.savedEmbeddedSCTListData[1]))
serialBytes = [c for c in hasher.digest()[:20]]
# Ensure that the most significant bit isn't set (which would
# indicate a negative number, which isn't valid for serial
# numbers).
serialBytes[0] &= 0x7F
# Also ensure that the least significant bit on the most
# significant byte is set (to prevent a leading zero byte,
# which also wouldn't be valid).
serialBytes[0] |= 0x01
return serialBytesToString(serialBytes)
def decodeParams(self, paramStream):
for line in paramStream.readlines():
self.decodeParam(line.strip())
def decodeParam(self, line):
param = line.split(":")[0]
value = ":".join(line.split(":")[1:])
if param == "version":
self.setVersion(value)
elif param == "subject":
self.subject = value
elif param == "issuer":
self.issuer = value
elif param == "validity":
self.decodeValidity(value)
elif param == "extension":
self.decodeExtension(value)
elif param == "issuerKey":
self.setupKey("issuer", value)
elif param == "subjectKey":
self.setupKey("subject", value)
elif param == "signature":
self.signature = value
elif param == "serialNumber":
serialNumber = int(value)
# Ensure only serial numbers that conform to the rules listed in
# generateSerialNumber() are permitted.
if serialNumber < 1 or serialNumber > 127:
raise InvalidSerialNumber(value)
self.serialNumber = serialBytesToString([serialNumber])
else:
raise UnknownParameterTypeError(param)
def setVersion(self, version):
intVersion = int(version)
if intVersion >= 1 and intVersion <= 4:
self.versionValue = intVersion - 1
else:
raise UnknownVersionError(version)
def decodeValidity(self, duration):
match = re.search("([0-9]{8})-([0-9]{8})", duration)
if match:
self.notBefore = datetime.datetime.strptime(match.group(1), "%Y%m%d")
self.notAfter = datetime.datetime.strptime(match.group(2), "%Y%m%d")
else:
delta = datetime.timedelta(days=(int(duration) / 2))
self.notBefore = self.now - delta
self.notAfter = self.now + delta
def decodeExtension(self, extension):
match = re.search(r"([a-zA-Z]+)(\[critical\])?:(.*)", extension)
if not match:
raise UnknownExtensionTypeError(extension)
extensionType = match.group(1)
critical = match.group(2)
value = match.group(3)
if extensionType == "basicConstraints":
self.addBasicConstraints(value, critical)
elif extensionType == "keyUsage":
self.addKeyUsage(value, critical)
elif extensionType == "extKeyUsage":
self.addExtKeyUsage(value, critical)
elif extensionType == "subjectAlternativeName":
self.addSubjectAlternativeName(value, critical)
elif extensionType == "authorityInformationAccess":
self.addAuthorityInformationAccess(value, critical)
elif extensionType == "certificatePolicies":
self.addCertificatePolicies(value, critical)
elif extensionType == "nameConstraints":
self.addNameConstraints(value, critical)
elif extensionType == "nsCertType":
self.addNSCertType(value, critical)
elif extensionType == "TLSFeature":
self.addTLSFeature(value, critical)
elif extensionType == "embeddedSCTList":
self.savedEmbeddedSCTListData = (value, critical)
elif extensionType == "delegationUsage":
self.addDelegationUsage(critical)
else:
raise UnknownExtensionTypeError(extensionType)
if extensionType != "embeddedSCTList":
if not self.extensionLines:
self.extensionLines = []
self.extensionLines.append(extension)
def setupKey(self, subjectOrIssuer, value):
if subjectOrIssuer == "subject":
self.subjectKey = pykey.keyFromSpecification(value)
elif subjectOrIssuer == "issuer":
self.issuerKey = pykey.keyFromSpecification(value)
else:
raise UnknownKeyTargetError(subjectOrIssuer)
def addExtension(self, extensionType, extensionValue, critical):
if not self.extensions:
self.extensions = []
encapsulated = univ.OctetString(encoder.encode(extensionValue))
extension = rfc2459.Extension()
extension["extnID"] = extensionType
# critical is either the string '[critical]' or None.
# We only care whether or not it is truthy.
if critical:
extension["critical"] = True
extension["extnValue"] = encapsulated
self.extensions.append(extension)
def addBasicConstraints(self, basicConstraints, critical):
cA = basicConstraints.split(",")[0]
pathLenConstraint = basicConstraints.split(",")[1]
basicConstraintsExtension = rfc2459.BasicConstraints()
basicConstraintsExtension["cA"] = cA == "cA"
if pathLenConstraint:
pathLenConstraintValue = univ.Integer(int(pathLenConstraint)).subtype(
subtypeSpec=constraint.ValueRangeConstraint(0, float("inf"))
)
basicConstraintsExtension["pathLenConstraint"] = pathLenConstraintValue
self.addExtension(
rfc2459.id_ce_basicConstraints, basicConstraintsExtension, critical
)
def addKeyUsage(self, keyUsage, critical):
keyUsageExtension = rfc2459.KeyUsage(keyUsage)
self.addExtension(rfc2459.id_ce_keyUsage, keyUsageExtension, critical)
def keyPurposeToOID(self, keyPurpose):
if keyPurpose == "serverAuth":
return rfc2459.id_kp_serverAuth
if keyPurpose == "clientAuth":
return rfc2459.id_kp_clientAuth
if keyPurpose == "codeSigning":
return rfc2459.id_kp_codeSigning
if keyPurpose == "emailProtection":
return rfc2459.id_kp_emailProtection
if keyPurpose == "nsSGC":
return univ.ObjectIdentifier("2.16.840.1.113730.4.1")
if keyPurpose == "OCSPSigning":
return univ.ObjectIdentifier("1.3.6.1.5.5.7.3.9")
if keyPurpose == "timeStamping":
return rfc2459.id_kp_timeStamping
raise UnknownKeyPurposeTypeError(keyPurpose)
def addExtKeyUsage(self, extKeyUsage, critical):
extKeyUsageExtension = rfc2459.ExtKeyUsageSyntax()
for count, keyPurpose in enumerate(extKeyUsage.split(",")):
extKeyUsageExtension.setComponentByPosition(
count, self.keyPurposeToOID(keyPurpose)
)
self.addExtension(rfc2459.id_ce_extKeyUsage, extKeyUsageExtension, critical)
def addSubjectAlternativeName(self, names, critical):
IPV4_PREFIX = "ip4:"
subjectAlternativeName = rfc2459.SubjectAltName()
for count, name in enumerate(names.split(",")):
generalName = rfc2459.GeneralName()
if "/" in name:
directoryName = stringToDN(
name, tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 4)
)
generalName["directoryName"] = directoryName
elif "@" in name:
generalName["rfc822Name"] = name
elif name.startswith(IPV4_PREFIX):
generalName["iPAddress"] = socket.inet_pton(
socket.AF_INET, name[len(IPV4_PREFIX) :]
)
else:
# The string may have things like '\0' (i.e. a slash
# followed by the number zero) that have to be decoded into
# the resulting '\x00' (i.e. a byte with value zero).
generalName["dNSName"] = six.ensure_binary(name).decode(
"unicode_escape"
)
subjectAlternativeName.setComponentByPosition(count, generalName)
self.addExtension(
rfc2459.id_ce_subjectAltName, subjectAlternativeName, critical
)
def addAuthorityInformationAccess(self, ocspURI, critical):
sequence = univ.Sequence()
accessDescription = stringToAccessDescription(ocspURI)
sequence.setComponentByPosition(0, accessDescription)
self.addExtension(rfc2459.id_pe_authorityInfoAccess, sequence, critical)
def addCertificatePolicies(self, policyOIDs, critical):
policies = rfc2459.CertificatePolicies()
for pos, policyOID in enumerate(policyOIDs.split(",")):
if policyOID == "any":
policyOID = "2.5.29.32.0"
policy = rfc2459.PolicyInformation()
policyIdentifier = rfc2459.CertPolicyId(policyOID)
policy["policyIdentifier"] = policyIdentifier
policies.setComponentByPosition(pos, policy)
self.addExtension(rfc2459.id_ce_certificatePolicies, policies, critical)
def addNameConstraints(self, constraints, critical):
nameConstraints = rfc2459.NameConstraints()
if constraints.startswith("permitted:"):
(subtreesType, subtreesTag) = ("permittedSubtrees", 0)
elif constraints.startswith("excluded:"):
(subtreesType, subtreesTag) = ("excludedSubtrees", 1)
else:
raise UnknownNameConstraintsSpecificationError(constraints)
generalSubtrees = rfc2459.GeneralSubtrees().subtype(
implicitTag=tag.Tag(
tag.tagClassContext, tag.tagFormatConstructed, subtreesTag
)
)
subtrees = constraints[(constraints.find(":") + 1) :]
for pos, name in enumerate(subtrees.split(",")):
generalName = rfc2459.GeneralName()
if "/" in name:
directoryName = stringToDN(
name, tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 4)
)
generalName["directoryName"] = directoryName
else:
generalName["dNSName"] = name
generalSubtree = rfc2459.GeneralSubtree()
generalSubtree["base"] = generalName
generalSubtrees.setComponentByPosition(pos, generalSubtree)
nameConstraints[subtreesType] = generalSubtrees
self.addExtension(rfc2459.id_ce_nameConstraints, nameConstraints, critical)
def addNSCertType(self, certType, critical):
if certType != "sslServer":
raise UnknownNSCertTypeError(certType)
self.addExtension(
univ.ObjectIdentifier("2.16.840.1.113730.1.1"),
univ.BitString("'01'B"),
critical,
)
def addDelegationUsage(self, critical):
if critical:
raise UnknownDelegatedCredentialError(critical)
self.addExtension(
univ.ObjectIdentifier("1.3.6.1.4.1.44363.44"), univ.Null(), critical
)
def addTLSFeature(self, features, critical):
namedFeatures = {"OCSPMustStaple": 5}
featureList = [f.strip() for f in features.split(",")]
sequence = univ.Sequence()
for pos, feature in enumerate(featureList):
featureValue = 0
try:
featureValue = int(feature)
except ValueError:
try:
featureValue = namedFeatures[feature]
except Exception:
raise UnknownTLSFeature(feature)
sequence.setComponentByPosition(pos, univ.Integer(featureValue))
self.addExtension(
univ.ObjectIdentifier("1.3.6.1.5.5.7.1.24"), sequence, critical
)
def addEmbeddedSCTListData(self):
(scts, critical) = self.savedEmbeddedSCTListData
encodedSCTs = []
for sctSpec in scts.split(","):
match = re.search(r"(\w+):(\d{8})", sctSpec)
if not match:
raise InvalidSCTSpecification(sctSpec)
keySpec = match.group(1)
key = pykey.keyFromSpecification(keySpec)
time = datetime.datetime.strptime(match.group(2), "%Y%m%d")
tbsCertificate = self.getTBSCertificate()
tbsDER = encoder.encode(tbsCertificate)
sct = pyct.SCT(key, time, tbsDER, self.issuerKey)
signed = sct.signAndEncode()
lengthPrefix = pack("!H", len(signed))
encodedSCTs.append(lengthPrefix + signed)
encodedSCTBytes = b"".join(encodedSCTs)
lengthPrefix = pack("!H", len(encodedSCTBytes))
extensionBytes = lengthPrefix + encodedSCTBytes
self.addExtension(
univ.ObjectIdentifier("1.3.6.1.4.1.11129.2.4.2"),
univ.OctetString(extensionBytes),
critical,
)
def getVersion(self):
return rfc2459.Version(self.versionValue).subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 0)
)
def getSerialNumber(self):
return decoder.decode(self.serialNumber)[0]
def getIssuer(self):
return stringToDN(self.issuer)
def getValidity(self):
validity = rfc2459.Validity()
validity["notBefore"] = self.getNotBefore()
validity["notAfter"] = self.getNotAfter()
return validity
def getNotBefore(self):
return datetimeToTime(self.notBefore)
def getNotAfter(self):
return datetimeToTime(self.notAfter)
def getSubject(self):
return stringToDN(self.subject)
def getTBSCertificate(self):
(signatureOID, _) = stringToAlgorithmIdentifiers(self.signature)
tbsCertificate = rfc2459.TBSCertificate()
tbsCertificate["version"] = self.getVersion()
tbsCertificate["serialNumber"] = self.getSerialNumber()
tbsCertificate["signature"] = signatureOID
tbsCertificate["issuer"] = self.getIssuer()
tbsCertificate["validity"] = self.getValidity()
tbsCertificate["subject"] = self.getSubject()
tbsCertificate[
"subjectPublicKeyInfo"
] = self.subjectKey.asSubjectPublicKeyInfo()
if self.extensions:
extensions = rfc2459.Extensions().subtype(
explicitTag=tag.Tag(tag.tagClassContext, tag.tagFormatSimple, 3)
)
for count, extension in enumerate(self.extensions):
extensions.setComponentByPosition(count, extension)
tbsCertificate["extensions"] = extensions
return tbsCertificate
def toDER(self):
(signatureOID, hashAlgorithm) = stringToAlgorithmIdentifiers(self.signature)
certificate = rfc2459.Certificate()
tbsCertificate = self.getTBSCertificate()
certificate["tbsCertificate"] = tbsCertificate
certificate["signatureAlgorithm"] = signatureOID
tbsDER = encoder.encode(tbsCertificate)
certificate["signatureValue"] = self.issuerKey.sign(tbsDER, hashAlgorithm)
return encoder.encode(certificate)
def toPEM(self):
output = "-----BEGIN CERTIFICATE-----"
der = self.toDER()
b64 = six.ensure_text(base64.b64encode(der))
while b64:
output += "\n" + b64[:64]
b64 = b64[64:]
output += "\n-----END CERTIFICATE-----"
return output
# The build harness will call this function with an output
# file-like object and a path to a file containing a
# specification. This will read the specification and output
# the certificate as PEM.
def main(output, inputPath):
with open(inputPath) as configStream:
output.write(Certificate(configStream).toPEM() + "\n")
# When run as a standalone program, this will read a specification from
# stdin and output the certificate as PEM to stdout.
if __name__ == "__main__":
print(Certificate(sys.stdin).toPEM())