From 3fc686ea06d4c2dcaf6b363ec1c54a72d995df88 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 30 Apr 2014 09:07:27 -0500 Subject: dss_sig_value: Pure python conversion of (r, s) to byte stream --- tests/utils.py | 27 +++++++++++++++++++++++++++ 1 file changed, 27 insertions(+) (limited to 'tests/utils.py') diff --git a/tests/utils.py b/tests/utils.py index 60b6f5a2..d8565130 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -80,6 +80,33 @@ def raises_unsupported_algorithm(reason): assert exc_info.value._reason is reason +def _int_to_asn1_int(i): + """ + Used by dss_sig_value to convert python integers to ASN.1 integer bytes. + """ + if i == 0: + return b'\x02\x01\x00' + if i < 0: + raise ValueError("This only supports positive integers right now.") + result = [] + while i: + result.append(six.int2byte(i & 0xFF)) + i >>= 8 + # ASN.1 integers are stored big endian two's complement, so add a byte if + # the ordinal value of the last byte is over 0x7f. + if ord(result[-1]) > 127: + result.append(b"\x00") + result.reverse() + packed = b''.join(result) + return b"\x02" + chr(len(packed)).encode("ascii") + packed + + +def dss_sig_value(r, s): + combined = _int_to_asn1_int(r) + _int_to_asn1_int(s) + sig = b"0" + chr(len(combined)).encode("ascii") + combined + return sig + + def load_vectors_from_file(filename, loader): with cryptography_vectors.open_vector_file(filename) as vector_file: return loader(vector_file) -- cgit v1.2.3 From d3e3df9308498153e795f6421b83b97c493c1aba Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 30 Apr 2014 11:13:17 -0500 Subject: use pyasn1 for creating the dss-sig-value structure --- tests/utils.py | 34 ++++++++++++---------------------- 1 file changed, 12 insertions(+), 22 deletions(-) (limited to 'tests/utils.py') diff --git a/tests/utils.py b/tests/utils.py index d8565130..37565b4d 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -18,6 +18,9 @@ import collections import re from contextlib import contextmanager +from pyasn1.codec.ber import encoder +from pyasn1.type import namedtype, univ + import pytest import six @@ -80,31 +83,18 @@ def raises_unsupported_algorithm(reason): assert exc_info.value._reason is reason -def _int_to_asn1_int(i): - """ - Used by dss_sig_value to convert python integers to ASN.1 integer bytes. - """ - if i == 0: - return b'\x02\x01\x00' - if i < 0: - raise ValueError("This only supports positive integers right now.") - result = [] - while i: - result.append(six.int2byte(i & 0xFF)) - i >>= 8 - # ASN.1 integers are stored big endian two's complement, so add a byte if - # the ordinal value of the last byte is over 0x7f. - if ord(result[-1]) > 127: - result.append(b"\x00") - result.reverse() - packed = b''.join(result) - return b"\x02" + chr(len(packed)).encode("ascii") + packed +class DSSSigValue(univ.Sequence): + componentType = namedtype.NamedTypes( + namedtype.NamedType('r', univ.Integer()), + namedtype.NamedType('s', univ.Integer()) + ) def dss_sig_value(r, s): - combined = _int_to_asn1_int(r) + _int_to_asn1_int(s) - sig = b"0" + chr(len(combined)).encode("ascii") + combined - return sig + sig = DSSSigValue() + sig.setComponentByName('r', r) + sig.setComponentByName('s', s) + return encoder.encode(sig) def load_vectors_from_file(filename, loader): -- cgit v1.2.3 From d0dc6a36a5747208c7a5ced15521fef033ce7880 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 30 Apr 2014 12:12:50 -0500 Subject: make DSSSigValue class private --- tests/utils.py | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'tests/utils.py') diff --git a/tests/utils.py b/tests/utils.py index 37565b4d..483291e3 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -83,7 +83,7 @@ def raises_unsupported_algorithm(reason): assert exc_info.value._reason is reason -class DSSSigValue(univ.Sequence): +class _DSSSigValue(univ.Sequence): componentType = namedtype.NamedTypes( namedtype.NamedType('r', univ.Integer()), namedtype.NamedType('s', univ.Integer()) @@ -91,7 +91,7 @@ class DSSSigValue(univ.Sequence): def dss_sig_value(r, s): - sig = DSSSigValue() + sig = _DSSSigValue() sig.setComponentByName('r', r) sig.setComponentByName('s', s) return encoder.encode(sig) -- cgit v1.2.3 From 14951f4252814c0cfcde5db05b4af12e93f570a9 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 30 Apr 2014 12:14:48 -0500 Subject: rename dss_sig_value -> der_encode_dsa_signature --- tests/utils.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tests/utils.py') diff --git a/tests/utils.py b/tests/utils.py index 483291e3..c80e97b7 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -90,7 +90,7 @@ class _DSSSigValue(univ.Sequence): ) -def dss_sig_value(r, s): +def der_encode_dsa_signature(r, s): sig = _DSSSigValue() sig.setComponentByName('r', r) sig.setComponentByName('s', s) -- cgit v1.2.3 From a409ae1dcbfef839eee80182f5c1de964a517b58 Mon Sep 17 00:00:00 2001 From: Paul Kehrer Date: Wed, 30 Apr 2014 13:28:28 -0500 Subject: we should use der rather than ber Doesn't make a difference in this specific case but it is correct. --- tests/utils.py | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) (limited to 'tests/utils.py') diff --git a/tests/utils.py b/tests/utils.py index c80e97b7..5c0e2343 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -18,7 +18,7 @@ import collections import re from contextlib import contextmanager -from pyasn1.codec.ber import encoder +from pyasn1.codec.der import encoder from pyasn1.type import namedtype, univ import pytest -- cgit v1.2.3