Hash: Remove "oid" attributes; add "name" attribute

In PyCrypto v2.5, the "oid" attribute was added to hash objects.  In
retrospect, this was not a good idea, since the OID is not really a
property of the hash algorithm, it's a protocol-specific identifer for
the hash functions.  PKCS#1 v1.5 uses it, but other protocols (e.g.
OpenPGP, DNSSEC, SSH, etc.) use different identifiers, and it doesn't make
sense to add these to Crypto.Hash.* every time a new algorithm is added.

This also has the benefit of being compatible with the Python standard
library's "hashlib" objects, which also have a name attribute.

20 files changed, 92 insertions, 103 deletions

diff --git a/lib/Crypto/Hash/MD2.py b/lib/Crypto/Hash/MD2.py
index dac959e..a2e8b31 100644
--- a/lib/Crypto/Hash/MD2.py
+++ b/lib/Crypto/Hash/MD2.py
@@ -51,16 +51,6 @@ class MD2Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-md2 OBJECT IDENTIFIER ::= {
-    #:      iso(1) member-body(2) us(840) rsadsi(113549)
-    #:       digestAlgorithm(2) 2
-    #:  }
-    #:
-    #: This value uniquely identifies the MD2 algorithm.
-    oid = b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x02')
-
     digest_size = 16
     block_size = 16
 
diff --git a/lib/Crypto/Hash/MD4.py b/lib/Crypto/Hash/MD4.py
index e28a201..4f0b6bb 100644
--- a/lib/Crypto/Hash/MD4.py
+++ b/lib/Crypto/Hash/MD4.py
@@ -51,16 +51,6 @@ class MD4Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-md2 OBJECT IDENTIFIER ::= {
-    #:      iso(1) member-body(2) us(840) rsadsi(113549)
-    #:       digestAlgorithm(2) 4
-    #:  }
-    #:
-    #: This value uniquely identifies the MD4 algorithm.
-    oid = b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x04')
-
     digest_size = 16
     block_size = 64
 
diff --git a/lib/Crypto/Hash/MD5.py b/lib/Crypto/Hash/MD5.py
index 18e9e7b..2e6a01b 100644
--- a/lib/Crypto/Hash/MD5.py
+++ b/lib/Crypto/Hash/MD5.py
@@ -57,20 +57,11 @@ class MD5Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-md5      OBJECT IDENTIFIER ::= {
-    #:      iso(1) member-body(2) us(840) rsadsi(113549)
-    #:       digestAlgorithm(2) 5
-    #:  }
-    #:
-    #: This value uniquely identifies the MD5 algorithm.
-    oid = b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05')
-
     digest_size = 16
     block_size = 64
 
     def __init__(self, data=None):
+        self.name = "MD5"
         HashAlgo.__init__(self, hashFactory, data)
 
     def new(self, data=None):
diff --git a/lib/Crypto/Hash/RIPEMD160.py b/lib/Crypto/Hash/RIPEMD160.py
index 3abed5d..2bfb26d 100644
--- a/lib/Crypto/Hash/RIPEMD160.py
+++ b/lib/Crypto/Hash/RIPEMD160.py
@@ -54,16 +54,6 @@ class RIPEMD160Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-ripemd160 OBJECT IDENTIFIER ::= {
-    #:      iso(1) identified-organization(3) teletrust(36)
-    #:       algorithm(3) hashAlgorithm(2) ripemd160(1)
-    #:  }
-    #:
-    #: This value uniquely identifies the RIPMD-160 algorithm.
-    oid = b("\x06\x05\x2b\x24\x03\x02\x01")
-
     digest_size = 20
     block_size = 64
 
diff --git a/lib/Crypto/Hash/SHA1.py b/lib/Crypto/Hash/SHA1.py
index 334ae18..afddf1a 100644
--- a/lib/Crypto/Hash/SHA1.py
+++ b/lib/Crypto/Hash/SHA1.py
@@ -57,20 +57,11 @@ class SHA1Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-sha1    OBJECT IDENTIFIER ::= {
-    #:      iso(1) identified-organization(3) oiw(14) secsig(3)
-    #:       algorithms(2) 26
-    #:  }
-    #:
-    #: This value uniquely identifies the SHA-1 algorithm.
-    oid = b('\x06\x05\x2b\x0e\x03\x02\x1a')
-
     digest_size = 20
     block_size = 64
 
     def __init__(self, data=None):
+        self.name = "SHA1"
         HashAlgo.__init__(self, hashFactory, data)
 
     def new(self, data=None):
diff --git a/lib/Crypto/Hash/SHA224.py b/lib/Crypto/Hash/SHA224.py
index 959b56d..379bbb2 100644
--- a/lib/Crypto/Hash/SHA224.py
+++ b/lib/Crypto/Hash/SHA224.py
@@ -55,16 +55,6 @@ class SHA224Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-sha224    OBJECT IDENTIFIER ::= {
-    #:      joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3)
-    #:      nistalgorithm(4) hashalgs(2) 4
-    #:  }
-    #:
-    #: This value uniquely identifies the SHA-224 algorithm.
-    oid = b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04')
-
     digest_size = 28
     block_size = 64
 
diff --git a/lib/Crypto/Hash/SHA256.py b/lib/Crypto/Hash/SHA256.py
index b0a99b3..46b7861 100644
--- a/lib/Crypto/Hash/SHA256.py
+++ b/lib/Crypto/Hash/SHA256.py
@@ -55,16 +55,6 @@ class SHA256Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-sha256    OBJECT IDENTIFIER ::= {
-    #: 	    joint-iso-itu-t(2) country(16) us(840) organization(1)
-    #: 	     gov(101) csor(3) nistalgorithm(4) hashalgs(2) 1
-    #:  }
-    #:
-    #: This value uniquely identifies the SHA-256 algorithm.
-    oid = b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01')
-
     digest_size = 32
     block_size = 64
 
diff --git a/lib/Crypto/Hash/SHA384.py b/lib/Crypto/Hash/SHA384.py
index 3490b02..da6aca1 100644
--- a/lib/Crypto/Hash/SHA384.py
+++ b/lib/Crypto/Hash/SHA384.py
@@ -55,16 +55,6 @@ class SHA384Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-sha384    OBJECT IDENTIFIER ::= {
-    #:      joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3)
-    #:	     nistalgorithm(4) hashalgs(2) 2
-    #:  }
-    #:
-    #: This value uniquely identifies the SHA-384 algorithm.
-    oid = b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02')
-
     digest_size = 48
     block_size = 128
 
diff --git a/lib/Crypto/Hash/SHA512.py b/lib/Crypto/Hash/SHA512.py
index d57548d..d8a4c3a 100644
--- a/lib/Crypto/Hash/SHA512.py
+++ b/lib/Crypto/Hash/SHA512.py
@@ -55,16 +55,6 @@ class SHA512Hash(HashAlgo):
     :undocumented: block_size
     """
 
-    #: ASN.1 Object identifier (OID)::
-    #:
-    #:  id-sha512    OBJECT IDENTIFIER ::= {
-    #:	    joint-iso-itu-t(2)
-    #:	    country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 3
-    #:  }
-    #:
-    #: This value uniquely identifies the SHA-512 algorithm.
-    oid = b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03')
-
     digest_size = 64
     block_size = 128
 
diff --git a/lib/Crypto/Hash/hashalgo.py b/lib/Crypto/Hash/hashalgo.py
index b38b3a6..a778bf4 100644
--- a/lib/Crypto/Hash/hashalgo.py
+++ b/lib/Crypto/Hash/hashalgo.py
@@ -47,6 +47,10 @@ class HashAlgo:
             self._hash = hashFactory.new()
         else:
             self._hash = hashFactory()
+        try:
+            self.name = self._hash.name
+        except AttributeError:
+            pass
         if data:
             self.update(data)
 
diff --git a/lib/Crypto/SelfTest/Hash/common.py b/lib/Crypto/SelfTest/Hash/common.py
index f77fb0f..fa9fd22 100644
--- a/lib/Crypto/SelfTest/Hash/common.py
+++ b/lib/Crypto/SelfTest/Hash/common.py
@@ -107,16 +107,9 @@ class HashTestOID(unittest.TestCase):
         self.oid = oid
 
     def runTest(self):
+        from Crypto.Signature import PKCS1_v1_5
         h = self.hashmod.new()
-        if self.oid==None:
-            try:
-                raised = 0
-                a = h.oid
-            except AttributeError:
-                raised = 1
-            self.assertEqual(raised,1)
-        else:
-            self.assertEqual(h.oid, self.oid)
+        self.assertEqual(PKCS1_v1_5._HASH_OIDS[h.name], self.oid)
 
 class MACSelfTest(unittest.TestCase):
 
@@ -178,11 +171,10 @@ def make_hash_tests(module, module_name, test_data, digest_size, oid=None):
             description = row[2].encode('latin-1')
         name = "%s #%d: %s" % (module_name, i+1, description)
         tests.append(HashSelfTest(module, name, expected, input))
-    if oid is not None:
-        oid = b(oid)
     name = "%s #%d: digest_size" % (module_name, i+1)
     tests.append(HashDigestSizeSelfTest(module, name, digest_size))
-    tests.append(HashTestOID(module, oid))
+    if oid is not None:
+        tests.append(HashTestOID(module, b(oid)))
     return tests
 
 def make_mac_tests(module, module_name, test_data, hashmods):
diff --git a/lib/Crypto/Signature/PKCS1_v1_5.py b/lib/Crypto/Signature/PKCS1_v1_5.py
index 73ac251..22bb340 100644
--- a/lib/Crypto/Signature/PKCS1_v1_5.py
+++ b/lib/Crypto/Signature/PKCS1_v1_5.py
@@ -208,7 +208,7 @@ def EMSA_PKCS1_V1_5_ENCODE(hash, emLen):
     #       { OID id-sha512 PARAMETERS NULL }
     #   }
     #
-    digestAlgo  = DerSequence([hash.oid, DerNull().encode()])
+    digestAlgo  = DerSequence([_HASH_OIDS[hash.name], DerNull().encode()])
     digest      = DerOctetString(hash.digest())
     digestInfo  = DerSequence([
                     digestAlgo.encode(),
@@ -234,3 +234,73 @@ def new(key):
     """
     return PKCS115_SigScheme(key)
 
+# AlgorithmIdentifier OIDs for use with PKCS#1 v1.5.
+#
+# These map names to the associated OIDs.  We should try to be compatible
+# with the standard library's hashlib modules, where possible.
+#
+# XXX - These will probably be moved somewhere else soon.
+_HASH_OIDS = {
+    #:  id-md2 OBJECT IDENTIFIER ::= {
+    #:      iso(1) member-body(2) us(840) rsadsi(113549)
+    #:       digestAlgorithm(2) 2
+    #:  }
+    "MD2": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x02'),
+    "md2": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x02'),
+
+    #:  id-md4 OBJECT IDENTIFIER ::= {
+    #:      iso(1) member-body(2) us(840) rsadsi(113549)
+    #:       digestAlgorithm(2) 4
+    #:  }
+    "MD4": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x04'),
+    "md4": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x04'),
+
+    #:  id-md5      OBJECT IDENTIFIER ::= {
+    #:      iso(1) member-body(2) us(840) rsadsi(113549)
+    #:       digestAlgorithm(2) 5
+    #:  }
+    "MD5": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05'),
+    "md5": b('\x06\x08\x2a\x86\x48\x86\xf7\x0d\x02\x05'),
+
+    #:  id-ripemd160 OBJECT IDENTIFIER ::= {
+    #:      iso(1) identified-organization(3) teletrust(36)
+    #:       algorithm(3) hashAlgorithm(2) ripemd160(1)
+    #:  }
+    "RIPEMD160": b("\x06\x05\x2b\x24\x03\x02\x01"),
+    "ripemd160": b("\x06\x05\x2b\x24\x03\x02\x01"),
+
+    #:  id-sha1    OBJECT IDENTIFIER ::= {
+    #:      iso(1) identified-organization(3) oiw(14) secsig(3)
+    #:       algorithms(2) 26
+    #:  }
+    "SHA1": b('\x06\x05\x2b\x0e\x03\x02\x1a'),
+    "sha1": b('\x06\x05\x2b\x0e\x03\x02\x1a'),
+
+    #:  id-sha224    OBJECT IDENTIFIER ::= {
+    #:      joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3)
+    #:      nistalgorithm(4) hashalgs(2) 4
+    #:  }
+    "SHA224": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04'),
+    "sha224": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x04'),
+
+    #:  id-sha256    OBJECT IDENTIFIER ::= {
+    #:      joint-iso-itu-t(2) country(16) us(840) organization(1)
+    #:       gov(101) csor(3) nistalgorithm(4) hashalgs(2) 1
+    #:  }
+    "SHA256": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01'),
+    "sha256": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x01'),
+
+    #:  id-sha384    OBJECT IDENTIFIER ::= {
+    #:      joint-iso-itu-t(2) country(16) us(840) organization(1) gov(101) csor(3)
+    #:	     nistalgorithm(4) hashalgs(2) 2
+    #:  }
+    "SHA384": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02'),
+    "sha384": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x02'),
+
+    #:  id-sha512    OBJECT IDENTIFIER ::= {
+    #:	    joint-iso-itu-t(2)
+    #:	    country(16) us(840) organization(1) gov(101) csor(3) nistalgorithm(4) hashalgs(2) 3
+    #:  }
+    "SHA512": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03'),
+    "sha512": b('\x06\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03'),
+}
diff --git a/src/MD2.c b/src/MD2.c
index 3543e21..dadb999 100644
--- a/src/MD2.c
+++ b/src/MD2.c
@@ -32,6 +32,7 @@
 #include "pycrypto_compat.h"
 
 #define MODULE_NAME _MD2
+#define ALGORITHM_NAME "MD2"
 #define DIGEST_SIZE 16
 #define BLOCK_SIZE 64
 
diff --git a/src/MD4.c b/src/MD4.c
index b08b095..d5c20f4 100644
--- a/src/MD4.c
+++ b/src/MD4.c
@@ -32,6 +32,7 @@
 #include "pycrypto_compat.h"
 
 #define MODULE_NAME _MD4
+#define ALGORITHM_NAME "MD4"
 #define DIGEST_SIZE 16
 #define BLOCK_SIZE 64
 
diff --git a/src/RIPEMD160.c b/src/RIPEMD160.c
index 8ff3fc5..37d4c73 100644
--- a/src/RIPEMD160.c
+++ b/src/RIPEMD160.c
@@ -402,6 +402,7 @@ static int ripemd160_digest(const ripemd160_state *self, unsigned char *out)
 
 /* Template definitions */
 #define MODULE_NAME _RIPEMD160
+#define ALGORITHM_NAME "RIPEMD160"
 #define DIGEST_SIZE RIPEMD160_DIGEST_SIZE
 #define hash_state ripemd160_state
 #define hash_init ripemd160_init
diff --git a/src/SHA224.c b/src/SHA224.c
index ca70fbd..99e2f7c 100644
--- a/src/SHA224.c
+++ b/src/SHA224.c
@@ -28,6 +28,7 @@
  */
 
 #define MODULE_NAME _SHA224
+#define ALGORITHM_NAME "SHA224"
 #define DIGEST_SIZE (224/8)
 #define BLOCK_SIZE (512/8)
 #define WORD_SIZE 4
diff --git a/src/SHA256.c b/src/SHA256.c
index 61a2d74..8cc3265 100644
--- a/src/SHA256.c
+++ b/src/SHA256.c
@@ -27,6 +27,7 @@
  *
  */
 #define MODULE_NAME _SHA256
+#define ALGORITHM_NAME "SHA256"
 #define DIGEST_SIZE (256/8)
 #define BLOCK_SIZE (512/8)
 #define WORD_SIZE 4
diff --git a/src/SHA384.c b/src/SHA384.c
index 05dfe25..24b200c 100644
--- a/src/SHA384.c
+++ b/src/SHA384.c
@@ -28,6 +28,7 @@
  */
 
 #define MODULE_NAME _SHA384
+#define ALGORITHM_NAME "SHA384"
 #define DIGEST_SIZE (384/8)
 #define BLOCK_SIZE (1024/8)
 #define WORD_SIZE 8
diff --git a/src/SHA512.c b/src/SHA512.c
index 3370e8e..3b227ab 100644
--- a/src/SHA512.c
+++ b/src/SHA512.c
@@ -28,6 +28,7 @@
  */
 
 #define MODULE_NAME _SHA512
+#define ALGORITHM_NAME "SHA512"
 #define DIGEST_SIZE (512/8)
 #define BLOCK_SIZE (1024/8)
 #define WORD_SIZE 8
diff --git a/src/hash_template.c b/src/hash_template.c
index 10b1b1c..afffbfb 100644
--- a/src/hash_template.c
+++ b/src/hash_template.c
@@ -209,9 +209,13 @@ ALG_getattr(PyObject *self, char *name)
  
 	if (PyUnicode_CompareWithASCIIString(attr, "digest_size")==0)
 		return PyLong_FromLong(DIGEST_SIZE);
+	if (PyUnicode_CompareWithASCIIString(attr, "name")==0)
+		return PyUnicode_FromString(ALGORITHM_NAME);
 #else
 	if (strcmp(name, "digest_size")==0)
 		return PyInt_FromLong(DIGEST_SIZE);
+	if (strcmp(name, "name")==0)
+		return PyString_FromString(ALGORITHM_NAME);
 #endif
 
 #ifdef IS_PY3K