refactor Diger to simplify

Author: SmithSamuelM

src/keri/core/coring.py

@@ -55,6 +55,9 @@
 ECDSA_256r1_SEEDBYTES = 32
 ECDSA_256k1_SEEDBYTES = 32
 
+# digest algorithm  klas, digest size (not default), digest length
+# size and length are needed for some digest types as function parameters
+Digestage = namedtuple("Digestage", "klas size length")
 
 # SAID field labels
 Saidage = namedtuple("Saidage", "dollar at id_ i d")
@@ -269,6 +272,8 @@ def __delitem__(self, name):
 
 
 
+
+
 @dataclass(frozen=True)
 class MatterCodex:
     """
@@ -3094,68 +3099,77 @@ class Diger(Matter):
 
     """
 
-    def __init__(self, raw=None, ser=None, code=MtrDex.Blake3_256, **kwa):
-        """
-        Assign digest verification function to ._verify
+    # Maps digest codes to Digestages of algorithms for computing digest.
+    # Should be based on the same set of codes as in DigestCodex
+    # so Matter.digestive property works.
+    # Use unit tests to ensure codex elements sets match
 
-        See Matter for inherited parameters
+    Digests = {
+        DigDex.Blake3_256: Digestage(klas=blake3.blake3, size=None, length=None),
+        DigDex.Blake2b_256: Digestage(klas=hashlib.blake2b, size=32, length=None),
+        DigDex.Blake2s_256: Digestage(klas=hashlib.blake2s, size=None, length=None),
+        DigDex.SHA3_256: Digestage(klas=hashlib.sha3_256, size=None, length=None),
+        DigDex.SHA2_256: Digestage(klas=hashlib.sha256, size=None, length=None),
+        DigDex.Blake3_512: Digestage(klas=blake3.blake3, size=None, length=64),
+        DigDex.Blake2b_512: Digestage(klas=hashlib.blake2b, size=None, length=None),
+        DigDex.SHA3_512: Digestage(klas=hashlib.sha3_512, size=None, length=None),
+        DigDex.SHA2_512: Digestage(klas=hashlib.sha512, size=None, length=None),
+    }
+
+    def __init__(self, raw=None, ser=None, code=DigDex.Blake3_256, **kwa):
+        """Initialize attributes
 
         Inherited Parameters:
-            raw is bytes of unqualified crypto material usable for crypto operations
-            qb64b is bytes of fully qualified crypto material
-            qb64 is str or bytes  of fully qualified crypto material
-            qb2 is bytes of fully qualified crypto material
-            code is str of derivation code
-            index is int of count of attached receipts for CryCntDex codes
+            See Matter
 
         Parameters:
-           ser is bytes serialization from which raw is computed if not raw
+           ser (bytes): serialization from which raw is computed if not raw
 
         """
-        # Should implement all digests in DigCodex instance DigDex
+
         try:
             super(Diger, self).__init__(raw=raw, code=code, **kwa)
         except EmptyMaterialError as ex:
             if not ser:
                 raise ex
-            if code == MtrDex.Blake3_256:
-                dig = blake3.blake3(ser).digest()
-            elif code == MtrDex.Blake2b_256:
-                dig = hashlib.blake2b(ser, digest_size=32).digest()
-            elif code == MtrDex.Blake2s_256:
-                dig = hashlib.blake2s(ser, digest_size=32).digest()
-            elif code == MtrDex.SHA3_256:
-                dig = hashlib.sha3_256(ser).digest()
-            elif code == MtrDex.SHA2_256:
-                dig = hashlib.sha256(ser).digest()
-            else:
-                raise InvalidValueError("Unsupported code={code} for diger.")
-
-            super(Diger, self).__init__(raw=dig, code=code, **kwa)
-
-        if self.code == MtrDex.Blake3_256:
-            self._verify = self._blake3_256
-        elif self.code == MtrDex.Blake2b_256:
-            self._verify = self._blake2b_256
-        elif self.code == MtrDex.Blake2s_256:
-            self._verify = self._blake2s_256
-        elif self.code == MtrDex.SHA3_256:
-            self._verify = self._sha3_256
-        elif self.code == MtrDex.SHA2_256:
-            self._verify = self._sha2_256
-        else:
-            raise InvalidValueError("Unsupported code={self.code} for diger.")
+
+            raw = self._digest(ser, code=code)
+
+            super(Diger, self).__init__(raw=raw, code=code, **kwa)
+
+        if self.code not in DigDex:
+            raise InvalidCodeError(f"Unsupported Digest {code=}.")
+
+
+    def _digest(self, ser, code=DigDex.Blake3_256):
+        """Returns raw digest of ser using digest algorithm given by code
+
+        Parameters:
+            ser (bytes): serialization from which raw digest is computed
+            code (str): derivation code used to lookup digest algorithm
+        """
+        if code not in self.Digests:
+            raise InvalidCodeError(f"Unsupported Digest {code=}.")
+
+        klas, size, length = self.Digests[code]  # digest algo size & length
+        ikwa = dict(digest_size=size) if size else dict()  # opt digest size
+        dkwa = dict(length=length) if length else dict() # opt digest length
+        raw = klas(ser, **ikwa).digest(**dkwa)
+        return (raw)
+
 
     def verify(self, ser):
         """
         Returns True if raw digest of ser bytes (serialization) matches .raw
-        using .raw as reference digest for ._verify digest algorithm determined
+        using .raw as reference digest for digest algorithm determined
         by .code
 
         Parameters:
-            ser (bytes): serialization to be digested and compared to .ser
+            ser (bytes): serialization to be digested and compared to .raw
+
         """
-        return (self._verify(ser=ser, raw=self.raw))
+        return (self._digest(ser=ser, code=self.code) == self.raw)
+
 
     def compare(self, ser, dig=None, diger=None):
         """
@@ -3202,65 +3216,6 @@ def compare(self, ser, dig=None, diger=None):
 
         return (False)
 
-    @staticmethod
-    def _blake3_256(ser, raw):
-        """
-        Returns True if verified False otherwise
-        Verifiy blake3_256 digest of ser matches raw
-
-        Parameters:
-            ser is bytes serialization
-            dig is bytes reference digest
-        """
-        return (blake3.blake3(ser).digest() == raw)
-
-    @staticmethod
-    def _blake2b_256(ser, raw):
-        """
-        Returns True if verified False otherwise
-        Verifiy blake2b_256 digest of ser matches raw
-
-        Parameters:
-            ser is bytes serialization
-            dig is bytes reference digest
-        """
-        return (hashlib.blake2b(ser, digest_size=32).digest() == raw)
-
-    @staticmethod
-    def _blake2s_256(ser, raw):
-        """
-        Returns True if verified False otherwise
-        Verifiy blake2s_256 digest of ser matches raw
-
-        Parameters:
-            ser is bytes serialization
-            dig is bytes reference digest
-        """
-        return (hashlib.blake2s(ser, digest_size=32).digest() == raw)
-
-    @staticmethod
-    def _sha3_256(ser, raw):
-        """
-        Returns True if verified False otherwise
-        Verifiy blake2s_256 digest of ser matches raw
-
-        Parameters:
-            ser is bytes serialization
-            dig is bytes reference digest
-        """
-        return (hashlib.sha3_256(ser).digest() == raw)
-
-    @staticmethod
-    def _sha2_256(ser, raw):
-        """
-        Returns True if verified False otherwise
-        Verifiy blake2s_256 digest of ser matches raw
-
-        Parameters:
-            ser is bytes serialization
-            dig is bytes reference digest
-        """
-        return (hashlib.sha256(ser).digest() == raw)
 
 
 class Prefixer(Matter):
@@ -3291,9 +3246,6 @@ def __init__(self, **kwa):
 
 
 
-# digest algorithm  klas, digest size (not default), digest length
-# size and length are needed for some digest types as function parameters
-Digestage = namedtuple("Digestage", "klas size length")
 
 
 class Saider(Matter):

tests/core/test_coring.py

@@ -4439,11 +4439,9 @@ def test_diger():
     ser = b'abcdefghijklmnopqrstuvwxyz0123456789'
 
     dig = blake3.blake3(ser).digest()
-    with pytest.raises(coring.InvalidValueError):
+    with pytest.raises(kering.InvalidCodeError):
         diger = Diger(raw=dig, code=MtrDex.Ed25519)
 
-    with pytest.raises(coring.InvalidValueError):
-        diger = Diger(ser=ser, code=MtrDex.Ed25519)
 
     diger = Diger(raw=dig)  # defaults provide Blake3_256 digester
     assert diger.code == MtrDex.Blake3_256
@@ -5389,6 +5387,7 @@ def test_tholder():
     test_ilker()
     test_traitor()
     test_verser()
+    test_diger()
     #test_texter()
     #test_prodex()
     #test_indexer()