Merge "Making iv generation configurable for pkcs11 plugin"

barbican/plugin/crypto/p11_crypto.py

@@ -72,6 +72,9 @@ p11_crypto_plugin_opts = [
     cfg.StrOpt('plugin_name',
                help=u._('User friendly plugin name'),
                default='PKCS11 HSM'),
+    cfg.BoolOpt('generate_iv',
+                help=u._('Flag for plugin generated iv case'),
+                default=False),
 ]
 CONF.register_group(p11_crypto_plugin_group)
 CONF.register_opts(p11_crypto_plugin_opts, group=p11_crypto_plugin_group)
@@ -286,6 +289,7 @@ class P11CryptoPlugin(plugin.CryptoPluginBase):
             ffi=ffi,
             algorithm=plugin_conf.algorithm,
             seed_random_buffer=seed_random_buffer,
+            generate_iv=plugin_conf.generate_iv,
         )
 
     def _reinitialize_pkcs11(self):

barbican/plugin/crypto/pkcs11.py

@@ -325,7 +325,8 @@ def build_ffi():
 class PKCS11(object):
     def __init__(self, library_path, login_passphrase, rw_session, slot_id,
                  ffi=None, algorithm='CKM_AES_GCM',
-                 seed_random_buffer=None):
+                 seed_random_buffer=None,
+                 generate_iv=None):
         self.ffi = ffi or build_ffi()
         self.lib = self.ffi.dlopen(library_path)
         rv = self.lib.C_Initialize(self.ffi.NULL)
@@ -341,6 +342,7 @@ class PKCS11(object):
         self.blocksize = 16
         self.noncesize = 12
         self.gcmtagsize = 16
+        self.generate_iv = generate_iv
 
         # Validate configuration and RNG
         session = self.get_session()
@@ -391,21 +393,33 @@ class PKCS11(object):
         return key
 
     def encrypt(self, key, pt_data, session):
-        ck_mechanism = self._build_gcm_mechanism()
+        iv = None
+        if self.generate_iv:
+            iv = self._generate_random(self.noncesize, session)
+        ck_mechanism = self._build_gcm_mechanism(iv)
         rv = self.lib.C_EncryptInit(session, ck_mechanism.mech, key)
         self._check_error(rv)
 
         pt_len = len(pt_data)
-        ct_len = self.ffi.new("CK_ULONG *", pt_len + self.gcmtagsize * 2)
+        if self.generate_iv:
+            ct_len = self.ffi.new("CK_ULONG *", pt_len + self.gcmtagsize)
+        else:
+            ct_len = self.ffi.new("CK_ULONG *", pt_len + self.gcmtagsize * 2)
         ct = self.ffi.new("CK_BYTE[{0}]".format(ct_len[0]))
         rv = self.lib.C_Encrypt(session, pt_data, pt_len, ct, ct_len)
         self._check_error(rv)
 
-        # HSM-generated IVs are appended to the end of the ciphertext
-        return {
-            "iv": self.ffi.buffer(ct, ct_len[0])[-self.gcmtagsize:],
-            "ct": self.ffi.buffer(ct, ct_len[0])[:-self.gcmtagsize]
-        }
+        if self.generate_iv:
+            return {
+                "iv": self.ffi.buffer(iv)[:],
+                "ct": self.ffi.buffer(ct, ct_len[0])[:]
+                }
+        else:
+            # HSM-generated IVs are appended to the end of the ciphertext
+            return {
+                "iv": self.ffi.buffer(ct, ct_len[0])[-self.gcmtagsize:],
+                "ct": self.ffi.buffer(ct, ct_len[0])[:-self.gcmtagsize]
+                }
 
     def decrypt(self, key, iv, ct_data, session):
         iv = self.ffi.new("CK_BYTE[{0}]".format(len(iv)), iv)

barbican/tests/plugin/crypto/test_pkcs11.py

@@ -108,7 +108,11 @@ class WhenTestingPKCS11(utils.BaseTestCase):
         return pkcs11.CKR_OK
 
     def _encrypt(self, session, pt, pt_len, ct, ct_len):
-        self.ffi.buffer(ct)[:] = pt[::-1] + b'0' * (self.pkcs11.gcmtagsize * 2)
+        if self.pkcs11.generate_iv:
+            self.ffi.buffer(ct)[:] = pt[::-1] + b'0' * self.pkcs11.gcmtagsize
+        else:
+            self.ffi.buffer(ct)[:] = pt[::-1] + b'0' * (self.pkcs11.gcmtagsize
+                                                        * 2)
         return pkcs11.CKR_OK
 
     def _decrypt(self, session, ct, ct_len, pt, pt_len):
@@ -232,8 +236,9 @@ class WhenTestingPKCS11(utils.BaseTestCase):
                           mock.MagicMock(), mock.MagicMock(),
                           encrypt=True, master_key=True)
 
-    def test_encrypt(self):
+    def test_encrypt_with_no_iv_generation(self):
         pt = b'0123456789ABCDEF'
+        self.pkcs11.generate_iv = False
         ct = self.pkcs11.encrypt(mock.MagicMock(), pt, mock.MagicMock())
 
         self.assertEqual(ct['ct'][:len(pt)], pt[::-1])
@@ -243,6 +248,18 @@ class WhenTestingPKCS11(utils.BaseTestCase):
         self.assertEqual(1, self.lib.C_EncryptInit.call_count)
         self.assertEqual(1, self.lib.C_Encrypt.call_count)
 
+    def test_encrypt_with_iv_generation(self):
+        pt = b'0123456789ABCDEF'
+        self.pkcs11.generate_iv = True
+        ct = self.pkcs11.encrypt(mock.MagicMock(), pt, mock.MagicMock())
+
+        self.assertEqual(ct['ct'][:len(pt)], pt[::-1])
+        self.assertGreater(len(ct['iv']), 0)
+
+        self.assertEqual(2, self.lib.C_GenerateRandom.call_count)
+        self.assertEqual(1, self.lib.C_EncryptInit.call_count)
+        self.assertEqual(1, self.lib.C_Encrypt.call_count)
+
     def test_decrypt(self):
         ct = b'FEDCBA9876543210' + b'0' * self.pkcs11.gcmtagsize
         iv = b'0' * self.pkcs11.noncesize