Specialize compute_rsa_hash_digest into compute_rsa_hash_digest_sha256

Author: jahkosha

tests/hazmat/primitives/test_rsa.py

@@ -51,7 +51,7 @@
 )
 from .utils import (
     _check_rsa_private_numbers,
-    compute_rsa_hash_digest,
+    compute_rsa_hash_digest_sha256,
     generate_rsa_verification_test,
     generate_rsa_verification_without_digest_test,
     skip_fips_traditional_openssl,
@@ -488,9 +488,7 @@ def test_pkcs1v15_signing_without_digest(self, backend, subtests):
                 ).private_key(backend, unsafe_skip_rsa_key_validation=True)
                 signature = private_key.sign(
                     binascii.unhexlify(
-                        compute_rsa_hash_digest(
-                            backend, hashes.SHA256(), params["msg"]
-                        )
+                        compute_rsa_hash_digest_sha256(backend, params["msg"])
                     ),
                     padding.PKCS1v15(),
                     asym_utils.NoDigestInfo(),

tests/hazmat/primitives/utils.py

@@ -56,9 +56,9 @@ def _load_all_params(path, file_names, param_loader):
     return all_params
 
 
-def compute_rsa_hash_digest(backend, hash_alg, msg):
-    oid = _hash_alg_oids[hash_alg.name]
-    h = hashes.Hash(hash_alg, backend=backend)
+def compute_rsa_hash_digest_sha256(backend, msg):
+    oid = binascii.unhexlify(b"3031300d060960864801650304020105000420")
+    h = hashes.Hash(hashes.SHA256(), backend=backend)
     h.update(binascii.unhexlify(msg))
     return binascii.hexlify(oid) + binascii.hexlify(h.finalize())
 
@@ -527,8 +527,8 @@ def test_rsa_verification(self, backend, subtests):
         ]
         for params in all_params:
             with subtests.test():
-                params["msg"] = compute_rsa_hash_digest(
-                    backend, hash_alg, params["msg"]
+                params["msg"] = compute_rsa_hash_digest_sha256(
+                    backend, params["msg"]
                 )
                 rsa_verification_test(
                     backend, params, asym_utils.NoDigestInfo(), pad_factory