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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-28 14:29:10 +0000 |
commit | 2aa4a82499d4becd2284cdb482213d541b8804dd (patch) | |
tree | b80bf8bf13c3766139fbacc530efd0dd9d54394c /security/manager/ssl/tests/unit/pyct.py | |
parent | Initial commit. (diff) | |
download | firefox-upstream.tar.xz firefox-upstream.zip |
Adding upstream version 86.0.1.upstream/86.0.1upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | security/manager/ssl/tests/unit/pyct.py | 103 |
1 files changed, 103 insertions, 0 deletions
diff --git a/security/manager/ssl/tests/unit/pyct.py b/security/manager/ssl/tests/unit/pyct.py new file mode 100644 index 0000000000..125b626fc2 --- /dev/null +++ b/security/manager/ssl/tests/unit/pyct.py @@ -0,0 +1,103 @@ +#!/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 +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +""" +Helper library for creating a Signed Certificate Timestamp given the +details of a signing key, when to sign, and the certificate data to +sign. Currently only supports precert_entry types. See RFC 6962. +""" + +from pyasn1.codec.der import encoder +from struct import pack +import binascii +import calendar +import hashlib + +import pykey + + +class InvalidKeyError(Exception): + """Helper exception to handle unknown key types.""" + + def __init__(self, key): + self.key = key + + def __str__(self): + return 'Invalid key: "%s"' % str(self.key) + + +class SCT(object): + """SCT represents a Signed Certificate Timestamp.""" + + def __init__(self, key, date, tbsCertificate, issuerKey): + self.key = key + self.timestamp = calendar.timegm(date.timetuple()) * 1000 + self.tbsCertificate = tbsCertificate + self.issuerKey = issuerKey + + def signAndEncode(self): + """Returns a signed and encoded representation of the SCT as a + string.""" + # The signature is over the following data: + # sct_version (one 0 byte) + # signature_type (one 0 byte) + # timestamp (8 bytes, milliseconds since the epoch) + # entry_type (two bytes [0, 1] - currently only precert_entry is + # supported) + # signed_entry (bytes of PreCert) + # extensions (2-byte-length-prefixed, currently empty (so two 0 + # bytes)) + # A PreCert is: + # issuer_key_hash (32 bytes of SHA-256 hash of the issuing + # public key, as DER-encoded SPKI) + # tbs_certificate (3-byte-length-prefixed data) + timestamp = pack("!Q", self.timestamp) + hasher = hashlib.sha256() + hasher.update(encoder.encode(self.issuerKey.asSubjectPublicKeyInfo())) + issuer_key_hash = hasher.digest() + len_prefix = pack("!L", len(self.tbsCertificate))[1:] + data = ( + b"\0\0" + + timestamp + + b"\0\1" + + issuer_key_hash + + len_prefix + + self.tbsCertificate + + b"\0\0" + ) + if isinstance(self.key, pykey.ECCKey): + signatureByte = b"\3" + elif isinstance(self.key, pykey.RSAKey): + signatureByte = b"\1" + else: + raise InvalidKeyError(self.key) + # sign returns a hex string like "'<hex bytes>'H", but we want + # bytes here + hexSignature = self.key.sign(data, pykey.HASH_SHA256) + signature = binascii.unhexlify(hexSignature[1:-2]) + # The actual data returned is the following: + # sct_version (one 0 byte) + # id (32 bytes of SHA-256 hash of the signing key, as + # DER-encoded SPKI) + # timestamp (8 bytes, milliseconds since the epoch) + # extensions (2-byte-length-prefixed data, currently + # empty) + # hash (one 4 byte representing sha256) + # signature (one byte - 1 for RSA and 3 for ECDSA) + # signature (2-byte-length-prefixed data) + hasher = hashlib.sha256() + hasher.update(encoder.encode(self.key.asSubjectPublicKeyInfo())) + key_id = hasher.digest() + signature_len_prefix = pack("!H", len(signature)) + return ( + b"\0" + + key_id + + timestamp + + b"\0\0\4" + + signatureByte + + signature_len_prefix + + signature + ) |