diff options
| -rw-r--r-- | cryptography/hazmat/backends/openssl/backend.py | 84 | ||||
| -rw-r--r-- | cryptography/hazmat/primitives/asymmetric/padding.py | 8 | ||||
| -rw-r--r-- | docs/hazmat/primitives/asymmetric/padding.rst | 14 | ||||
| -rw-r--r-- | tests/hazmat/backends/test_openssl.py | 25 | ||||
| -rw-r--r-- | tests/hazmat/primitives/test_rsa.py | 253 | ||||
| -rw-r--r-- | tests/hazmat/primitives/utils.py | 33 | ||||
| -rw-r--r-- | tests/test_utils.py | 6 | ||||
| -rw-r--r-- | tests/utils.py | 2 |
8 files changed, 417 insertions, 8 deletions
diff --git a/cryptography/hazmat/backends/openssl/backend.py b/cryptography/hazmat/backends/openssl/backend.py index b977b4c8..7c058f58 100644 --- a/cryptography/hazmat/backends/openssl/backend.py +++ b/cryptography/hazmat/backends/openssl/backend.py @@ -21,7 +21,7 @@ import six from cryptography import utils from cryptography.exceptions import ( InvalidTag, InternalError, AlreadyFinalized, UnsupportedCipher, - UnsupportedHash, UnsupportedPadding, InvalidSignature + UnsupportedAlgorithm, UnsupportedHash, UnsupportedPadding, InvalidSignature ) from cryptography.hazmat.backends.interfaces import ( CipherBackend, HashBackend, HMACBackend, PBKDF2HMACBackend, RSABackend @@ -29,6 +29,9 @@ from cryptography.hazmat.backends.interfaces import ( from cryptography.hazmat.bindings.openssl.binding import Binding from cryptography.hazmat.primitives import interfaces, hashes from cryptography.hazmat.primitives.asymmetric import rsa +from cryptography.hazmat.primitives.asymmetric.padding import ( + PKCS1v15, PSS, MGF1 +) from cryptography.hazmat.primitives.ciphers.algorithms import ( AES, Blowfish, Camellia, CAST5, TripleDES, ARC4, IDEA ) @@ -404,6 +407,12 @@ class Backend(object): return _RSAVerificationContext(self, public_key, signature, padding, algorithm) + def mgf1_hash_supported(self, algorithm): + if self._lib.Cryptography_HAS_MGF1_MD: + return self.hash_supported(algorithm) + else: + return isinstance(algorithm, hashes.SHA1) + class GetCipherByName(object): def __init__(self, fmt): @@ -787,12 +796,29 @@ class _RSAVerificationContext(object): raise TypeError( "Expected provider of interfaces.AsymmetricPadding") - if padding.name == "EMSA-PKCS1-v1_5": + if isinstance(padding, PKCS1v15): if self._backend._lib.Cryptography_HAS_PKEY_CTX: self._verify_method = self._verify_pkey_ctx self._padding_enum = self._backend._lib.RSA_PKCS1_PADDING else: self._verify_method = self._verify_pkcs1 + elif isinstance(padding, PSS): + if not isinstance(padding._mgf, MGF1): + raise UnsupportedAlgorithm( + "Only MGF1 is supported by this backend" + ) + + if not self._backend.mgf1_hash_supported(padding._mgf._algorithm): + raise UnsupportedHash( + "When OpenSSL is older than 1.0.1 then only SHA1 is " + "supported with MGF1." + ) + + if self._backend._lib.Cryptography_HAS_PKEY_CTX: + self._verify_method = self._verify_pkey_ctx + self._padding_enum = self._backend._lib.RSA_PKCS1_PSS_PADDING + else: + self._verify_method = self._verify_pss else: raise UnsupportedPadding @@ -833,6 +859,20 @@ class _RSAVerificationContext(object): res = self._backend._lib.EVP_PKEY_CTX_set_rsa_padding( pkey_ctx, self._padding_enum) assert res > 0 + if isinstance(self._padding, PSS): + res = self._backend._lib.EVP_PKEY_CTX_set_rsa_pss_saltlen( + pkey_ctx, self._get_salt_length()) + assert res > 0 + if self._backend._lib.Cryptography_HAS_MGF1_MD: + # MGF1 MD is configurable in OpenSSL 1.0.1+ + mgf1_md = self._backend._lib.EVP_get_digestbyname( + self._padding._mgf._algorithm.name.encode("ascii")) + assert mgf1_md != self._backend._ffi.NULL + res = self._backend._lib.EVP_PKEY_CTX_set_rsa_mgf1_md( + pkey_ctx, mgf1_md + ) + assert res > 0 + data_to_verify = self._hash_ctx.finalize() self._hash_ctx = None res = self._backend._lib.EVP_PKEY_verify( @@ -869,5 +909,45 @@ class _RSAVerificationContext(object): assert errors raise InvalidSignature + def _verify_pss(self, evp_pkey, evp_md): + pkey_size = self._backend._lib.EVP_PKEY_size(evp_pkey) + assert pkey_size > 0 + rsa_cdata = self._backend._lib.EVP_PKEY_get1_RSA(evp_pkey) + assert rsa_cdata != self._backend._ffi.NULL + rsa_cdata = self._backend._ffi.gc(rsa_cdata, + self._backend._lib.RSA_free) + buf = self._backend._ffi.new("unsigned char[]", pkey_size) + res = self._backend._lib.RSA_public_decrypt( + len(self._signature), + self._signature, + buf, + rsa_cdata, + self._backend._lib.RSA_NO_PADDING + ) + if res != pkey_size: + errors = self._backend._consume_errors() + assert errors + raise InvalidSignature + + data_to_verify = self._hash_ctx.finalize() + self._hash_ctx = None + res = self._backend._lib.RSA_verify_PKCS1_PSS( + rsa_cdata, + data_to_verify, + evp_md, + buf, + self._get_salt_length() + ) + if res != 1: + errors = self._backend._consume_errors() + assert errors + raise InvalidSignature + + def _get_salt_length(self): + if self._padding._mgf._salt_length is MGF1.MAX_LENGTH: + return -2 + else: + return self._padding._mgf._salt_length + backend = Backend() diff --git a/cryptography/hazmat/primitives/asymmetric/padding.py b/cryptography/hazmat/primitives/asymmetric/padding.py index 46e00b8e..02aff280 100644 --- a/cryptography/hazmat/primitives/asymmetric/padding.py +++ b/cryptography/hazmat/primitives/asymmetric/padding.py @@ -24,6 +24,14 @@ class PKCS1v15(object): name = "EMSA-PKCS1-v1_5" +@utils.register_interface(interfaces.AsymmetricPadding) +class PSS(object): + name = "EMSA-PSS" + + def __init__(self, mgf): + self._mgf = mgf + + class MGF1(object): MAX_LENGTH = object() diff --git a/docs/hazmat/primitives/asymmetric/padding.rst b/docs/hazmat/primitives/asymmetric/padding.rst index 8a034329..ab676b02 100644 --- a/docs/hazmat/primitives/asymmetric/padding.rst +++ b/docs/hazmat/primitives/asymmetric/padding.rst @@ -10,6 +10,17 @@ Padding correct padding signatures can be forged, messages decrypted, and private keys compromised. +.. class:: PSS(mgf) + + .. versionadded:: 0.3 + + PSS (Probabilistic Signature Scheme) is a signature scheme defined in + :rfc:`3447`. It is more complex than PKCS1 but possesses a `security proof`_. + This is the `recommended padding algorithm`_ for RSA signatures. + + :param mgf: A mask generation function object. At this time the only + supported MGF is :class:`MGF1`. + .. class:: PKCS1v15() .. versionadded:: 0.3 @@ -17,6 +28,7 @@ Padding PKCS1 v1.5 (also known as simply PKCS1) is a simple padding scheme developed for use with RSA keys. It is defined in :rfc:`3447`. + Mask Generation Functions ~~~~~~~~~~~~~~~~~~~~~~~~~ @@ -41,3 +53,5 @@ Mask Generation Functions .. _`Padding is critical`: http://rdist.root.org/2009/10/06/why-rsa-encryption-padding-is-critical/ +.. _`security proof`: http://eprint.iacr.org/2001/062.pdf +.. _`recommended padding algorithm`: http://www.daemonology.net/blog/2009-06-11-cryptographic-right-answers.html diff --git a/tests/hazmat/backends/test_openssl.py b/tests/hazmat/backends/test_openssl.py index 599d1531..c5d0a013 100644 --- a/tests/hazmat/backends/test_openssl.py +++ b/tests/hazmat/backends/test_openssl.py @@ -21,6 +21,7 @@ from cryptography.exceptions import ( ) from cryptography.hazmat.backends.openssl.backend import backend, Backend from cryptography.hazmat.primitives import interfaces, hashes +from cryptography.hazmat.primitives.asymmetric import rsa, padding from cryptography.hazmat.primitives.ciphers import Cipher from cryptography.hazmat.primitives.ciphers.algorithms import AES from cryptography.hazmat.primitives.ciphers.modes import CBC @@ -137,6 +138,30 @@ class TestOpenSSL(object): with pytest.raises(UnsupportedHash): backend.derive_pbkdf2_hmac(hashes.SHA256(), 10, b"", 1000, b"") + @pytest.mark.skipif( + backend._lib.OPENSSL_VERSION_NUMBER >= 0x1000100f, + reason="Requires an older OpenSSL. Must be < 1.0.1" + ) + def test_non_sha1_pss_mgf1_hash_algorithm_on_old_openssl(self): + private_key = rsa.RSAPrivateKey.generate( + public_exponent=65537, + key_size=512, + backend=backend + ) + public_key = private_key.public_key() + with pytest.raises(UnsupportedHash): + public_key.verifier( + b"sig", + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA256(), + salt_length=padding.MGF1.MAX_LENGTH + ) + ), + hashes.SHA1(), + backend + ) + # This test is not in the next class because to check if it's really # default we don't want to run the setup_method before it def test_osrandom_engine_is_default(self): diff --git a/tests/hazmat/primitives/test_rsa.py b/tests/hazmat/primitives/test_rsa.py index 0e88bb7f..955e69c9 100644 --- a/tests/hazmat/primitives/test_rsa.py +++ b/tests/hazmat/primitives/test_rsa.py @@ -21,11 +21,16 @@ import os import pytest from cryptography import exceptions, utils -from cryptography.exceptions import UnsupportedInterface +from cryptography.exceptions import ( + UnsupportedAlgorithm, UnsupportedInterface +) from cryptography.hazmat.primitives import hashes, interfaces from cryptography.hazmat.primitives.asymmetric import rsa, padding -from ...utils import load_pkcs1_vectors, load_vectors_from_file +from .utils import generate_rsa_pss_test +from ...utils import ( + load_pkcs1_vectors, load_vectors_from_file, load_rsa_nist_vectors +) @utils.register_interface(interfaces.AsymmetricPadding) @@ -33,6 +38,10 @@ class DummyPadding(object): name = "UNSUPPORTED-PADDING" +class DummyMGF(object): + pass + + def _modinv(e, m): """ Modular Multiplicative Inverse. Returns x such that: (x*e) mod m == 1 @@ -530,6 +539,122 @@ class TestRSAVerification(object): with pytest.raises(exceptions.InvalidSignature): verifier.verify() + @pytest.mark.parametrize( + "pkcs1_example", + _flatten_pkcs1_examples(load_vectors_from_file( + os.path.join( + "asymmetric", "RSA", "pkcs-1v2-1d2-vec", "pss-vect.txt"), + load_pkcs1_vectors + )) + ) + def test_pss_verification(self, pkcs1_example, backend): + private, public, example = pkcs1_example + public_key = rsa.RSAPublicKey( + public_exponent=public["public_exponent"], + modulus=public["modulus"] + ) + verifier = public_key.verifier( + binascii.unhexlify(example["signature"]), + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA1(), + salt_length=padding.MGF1.MAX_LENGTH + ) + ), + hashes.SHA1(), + backend + ) + verifier.update(binascii.unhexlify(example["message"])) + verifier.verify() + + def test_invalid_pss_signature_wrong_data(self, backend): + public_key = rsa.RSAPublicKey( + modulus=int( + b"dffc2137d5e810cde9e4b4612f5796447218bab913b3fa98bdf7982e4fa6" + b"ec4d6653ef2b29fb1642b095befcbea6decc178fb4bed243d3c3592c6854" + b"6af2d3f3", 16 + ), + public_exponent=65537 + ) + signature = binascii.unhexlify( + b"0e68c3649df91c5bc3665f96e157efa75b71934aaa514d91e94ca8418d100f45" + b"6f05288e58525f99666bab052adcffdf7186eb40f583bd38d98c97d3d524808b" + ) + verifier = public_key.verifier( + signature, + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA1(), + salt_length=padding.MGF1.MAX_LENGTH + ) + ), + hashes.SHA1(), + backend + ) + verifier.update(b"incorrect data") + with pytest.raises(exceptions.InvalidSignature): + verifier.verify() + + def test_invalid_pss_signature_wrong_key(self, backend): + signature = binascii.unhexlify( + b"3a1880165014ba6eb53cc1449d13e5132ebcc0cfd9ade6d7a2494a0503bd0826" + b"f8a46c431e0d7be0ca3e453f8b2b009e2733764da7927cc6dbe7a021437a242e" + ) + public_key = rsa.RSAPublicKey( + modulus=int( + b"381201f4905d67dfeb3dec131a0fbea773489227ec7a1448c3109189ac68" + b"5a95441be90866a14c4d2e139cd16db540ec6c7abab13ffff91443fd46a8" + b"960cbb7658ded26a5c95c86f6e40384e1c1239c63e541ba221191c4dd303" + b"231b42e33c6dbddf5ec9a746f09bf0c25d0f8d27f93ee0ae5c0d723348f4" + b"030d3581e13522e1", 16 + ), + public_exponent=65537 + ) + verifier = public_key.verifier( + signature, + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA1(), + salt_length=padding.MGF1.MAX_LENGTH + ) + ), + hashes.SHA1(), + backend + ) + verifier.update(b"sign me") + with pytest.raises(exceptions.InvalidSignature): + verifier.verify() + + def test_invalid_pss_signature_data_too_large_for_modulus(self, backend): + signature = binascii.unhexlify( + b"cb43bde4f7ab89eb4a79c6e8dd67e0d1af60715da64429d90c716a490b799c29" + b"194cf8046509c6ed851052367a74e2e92d9b38947ed74332acb115a03fcc0222" + ) + public_key = rsa.RSAPublicKey( + modulus=int( + b"381201f4905d67dfeb3dec131a0fbea773489227ec7a1448c3109189ac68" + b"5a95441be90866a14c4d2e139cd16db540ec6c7abab13ffff91443fd46a8" + b"960cbb7658ded26a5c95c86f6e40384e1c1239c63e541ba221191c4dd303" + b"231b42e33c6dbddf5ec9a746f09bf0c25d0f8d27f93ee0ae5c0d723348f4" + b"030d3581e13522", 16 + ), + public_exponent=65537 + ) + verifier = public_key.verifier( + signature, + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA1(), + salt_length=padding.MGF1.MAX_LENGTH + ) + ), + hashes.SHA1(), + backend + ) + verifier.update(b"sign me") + with pytest.raises(exceptions.InvalidSignature): + verifier.verify() + def test_use_after_finalize(self, backend): private_key = rsa.RSAPrivateKey.generate( public_exponent=65537, @@ -583,6 +708,130 @@ class TestRSAVerification(object): public_key.verifier( b"foo", padding.PKCS1v15(), hashes.SHA256(), pretend_backend) + def test_unsupported_pss_mgf(self, backend): + private_key = rsa.RSAPrivateKey.generate( + public_exponent=65537, + key_size=512, + backend=backend + ) + public_key = private_key.public_key() + with pytest.raises(UnsupportedAlgorithm): + public_key.verifier(b"sig", padding.PSS(mgf=DummyMGF()), + hashes.SHA1(), backend) + + def test_pss_verify_salt_length_too_long(self, backend): + signature = binascii.unhexlify( + b"8b9a3ae9fb3b64158f3476dd8d8a1f1425444e98940e0926378baa9944d219d8" + b"534c050ef6b19b1bdc6eb4da422e89161106a6f5b5cc16135b11eb6439b646bd" + ) + public_key = rsa.RSAPublicKey( + modulus=int( + b"d309e4612809437548b747d7f9eb9cd3340f54fe42bb3f84a36933b0839c" + b"11b0c8b7f67e11f7252370161e31159c49c784d4bc41c42a78ce0f0b40a3" + b"ca8ffb91", 16 + ), + public_exponent=65537 + ) + verifier = public_key.verifier( + signature, + padding.PSS( + mgf=padding.MGF1( + algorithm=hashes.SHA1(), + salt_length=1000000 + ) + ), + hashes.SHA1(), + backend + ) + verifier.update(b"sign me") + with pytest.raises(exceptions.InvalidSignature): + verifier.verify() + + +@pytest.mark.supported( + only_if=lambda backend: backend.mgf1_hash_supported(hashes.SHA1()), + skip_message="Does not support SHA1 with MGF1." +) +@pytest.mark.rsa +class TestRSAPSSMGF1VerificationSHA1(object): + test_rsa_pss_mgf1_sha1 = generate_rsa_pss_test( + load_rsa_nist_vectors, + os.path.join("asymmetric", "RSA", "FIPS_186-2"), + [ + "SigGenPSS_186-2.rsp", + "SigGenPSS_186-3.rsp", + ], + hashes.SHA1() + ) + + +@pytest.mark.supported( + only_if=lambda backend: backend.mgf1_hash_supported(hashes.SHA224()), + skip_message="Does not support SHA224 with MGF1." +) +@pytest.mark.rsa +class TestRSAPSSMGF1VerificationSHA224(object): + test_rsa_pss_mgf1_sha224 = generate_rsa_pss_test( + load_rsa_nist_vectors, + os.path.join("asymmetric", "RSA", "FIPS_186-2"), + [ + "SigGenPSS_186-2.rsp", + "SigGenPSS_186-3.rsp", + ], + hashes.SHA224() + ) + + +@pytest.mark.supported( + only_if=lambda backend: backend.mgf1_hash_supported(hashes.SHA256()), + skip_message="Does not support SHA256 with MGF1." +) +@pytest.mark.rsa +class TestRSAPSSMGF1VerificationSHA256(object): + test_rsa_pss_mgf1_sha256 = generate_rsa_pss_test( + load_rsa_nist_vectors, + os.path.join("asymmetric", "RSA", "FIPS_186-2"), + [ + "SigGenPSS_186-2.rsp", + "SigGenPSS_186-3.rsp", + ], + hashes.SHA256() + ) + + +@pytest.mark.supported( + only_if=lambda backend: backend.mgf1_hash_supported(hashes.SHA384()), + skip_message="Does not support SHA384 with MGF1." +) +@pytest.mark.rsa +class TestRSAPSSMGF1VerificationSHA384(object): + test_rsa_pss_mgf1_sha384 = generate_rsa_pss_test( + load_rsa_nist_vectors, + os.path.join("asymmetric", "RSA", "FIPS_186-2"), + [ + "SigGenPSS_186-2.rsp", + "SigGenPSS_186-3.rsp", + ], + hashes.SHA384() + ) + + +@pytest.mark.supported( + only_if=lambda backend: backend.mgf1_hash_supported(hashes.SHA512()), + skip_message="Does not support SHA512 with MGF1." +) +@pytest.mark.rsa +class TestRSAPSSMGF1VerificationSHA512(object): + test_rsa_pss_mgf1_sha512 = generate_rsa_pss_test( + load_rsa_nist_vectors, + os.path.join("asymmetric", "RSA", "FIPS_186-2"), + [ + "SigGenPSS_186-2.rsp", + "SigGenPSS_186-3.rsp", + ], + hashes.SHA512() + ) + class TestMGF1(object): def test_invalid_hash_algorithm(self): diff --git a/tests/hazmat/primitives/utils.py b/tests/hazmat/primitives/utils.py index f0a00319..31491023 100644 --- a/tests/hazmat/primitives/utils.py +++ b/tests/hazmat/primitives/utils.py @@ -21,6 +21,7 @@ import itertools import pytest from cryptography.hazmat.primitives import hashes, hmac +from cryptography.hazmat.primitives.asymmetric import rsa, padding from cryptography.hazmat.primitives.kdf.pbkdf2 import PBKDF2HMAC from cryptography.hazmat.primitives.ciphers import Cipher from cryptography.hazmat.primitives.kdf.hkdf import HKDF @@ -373,3 +374,35 @@ def generate_hkdf_test(param_loader, path, file_names, algorithm): hkdf_test(backend, algorithm, params) return test_hkdf + + +def generate_rsa_pss_test(param_loader, path, file_names, hash_alg): + all_params = _load_all_params(path, file_names, param_loader) + all_params = [i for i in all_params + if i["algorithm"] == hash_alg.name.upper()] + + @pytest.mark.parametrize("params", all_params) + def test_rsa_pss(self, backend, params): + rsa_pss_test(backend, params, hash_alg) + + return test_rsa_pss + + +def rsa_pss_test(backend, params, hash_alg): + public_key = rsa.RSAPublicKey( + public_exponent=params["public_exponent"], + modulus=params["modulus"] + ) + verifier = public_key.verifier( + binascii.unhexlify(params["s"]), + padding.PSS( + mgf=padding.MGF1( + algorithm=hash_alg, + salt_length=params["salt_length"] + ) + ), + hash_alg, + backend + ) + verifier.update(binascii.unhexlify(params["msg"])) + verifier.verify() diff --git a/tests/test_utils.py b/tests/test_utils.py index 433dab04..6d2ef362 100644 --- a/tests/test_utils.py +++ b/tests/test_utils.py @@ -1075,7 +1075,7 @@ def test_load_rsa_nist_vectors(): "modulus": int("bcb47b2e0dafcba81ff2a2b5cb115ca7e757184c9d72bcdcda" "707a146b3b4e29989d", 16), "public_exponent": 65537, - "algorithm": b"SHA1", + "algorithm": "SHA1", "salt_length": 20, "msg": b"1248f62a4389f42f7b4bb131053d6c88a994db2075b912ccbe3ea7dc6" b"11714f14e", @@ -1086,7 +1086,7 @@ def test_load_rsa_nist_vectors(): "modulus": int("bcb47b2e0dafcba81ff2a2b5cb115ca7e757184c9d72bcdcda" "707a146b3b4e29989d", 16), "public_exponent": 65537, - "algorithm": b"SHA384", + "algorithm": "SHA384", "salt_length": 20, "msg": b"e511903c2f1bfba245467295ac95413ac4746c984c3750a728c388aa6" b"28b0ebf", @@ -1096,7 +1096,7 @@ def test_load_rsa_nist_vectors(): { "modulus": 78187493520, "public_exponent": 65537, - "algorithm": b"SHA512", + "algorithm": "SHA512", "salt_length": 20, "msg": b"3456781293fab829", "s": b"deadbeef0000" diff --git a/tests/utils.py b/tests/utils.py index 720a9054..6a8a2b5e 100644 --- a/tests/utils.py +++ b/tests/utils.py @@ -329,7 +329,7 @@ def load_rsa_nist_vectors(vector_data): "modulus": n, "public_exponent": e, "salt_length": salt_length, - "algorithm": value.encode("ascii") + "algorithm": value } data.append(test_data) continue |