[PATCH 5/9] Access cipher mode routines through routine pointers

Jussi Kivilinna jussi.kivilinna at iki.fi
Tue Jun 19 17:51:17 CEST 2018


* cipher/cipher-internal.h (gcry_cipher_handle): Add function pointers
for mode operations.
(_gcry_cipher_xts_crypt): Remove.
(_gcry_cipher_xts_encrypt, _gcry_cipher_xts_decrypt): New.
* cipher/cipher-xts.c (_gcry_cipher_xts_encrypt)
(_gcry_cipher_xts_decrypt): New.
* cipher/cipher.c (_gcry_cipher_setup_mode_ops): New.
(_gcry_cipher_open_internal): Setup mode routines.
(cipher_encrypt, cipher_decrypt): Remove.
(do_stream_encrypt, do_stream_decrypt, do_encrypt_none_unknown)
(do_decrypt_none_unknown): New.
(_gcry_cipher_encrypt, _gcry_cipher_decrypt, _gcry_cipher_setiv)
(_gcry_cipher_authenticate, _gcry_cipher_gettag)
(_gcry_cipher_checktag): Adapted to use mode routines through pointers.
--

Change to use mode operations through pointers to reduce per call
overhead for cipher operations.

Signed-off-by: Jussi Kivilinna <jussi.kivilinna at iki.fi>
---
 cipher/cipher-internal.h |  26 ++-
 cipher/cipher-xts.c      |  18 ++
 cipher/cipher.c          | 492 ++++++++++++++++++---------------------
 3 files changed, 272 insertions(+), 264 deletions(-)

diff --git a/cipher/cipher-internal.h b/cipher/cipher-internal.h
index b12c3be7e..6d87561de 100644
--- a/cipher/cipher-internal.h
+++ b/cipher/cipher-internal.h
@@ -140,6 +140,25 @@ struct gcry_cipher_handle
      interface does not easily allow to retrieve this value. */
   int algo;
 
+  /* A structure with function pointers for mode operations. */
+  struct {
+    gcry_err_code_t (*encrypt)(gcry_cipher_hd_t c,
+                               unsigned char *outbuf, size_t outbuflen,
+                               const unsigned char *inbuf, size_t inbuflen);
+    gcry_err_code_t (*decrypt)(gcry_cipher_hd_t c,
+                               unsigned char *outbuf, size_t outbuflen,
+                               const unsigned char *inbuf, size_t inbuflen);
+    gcry_err_code_t (*setiv)(gcry_cipher_hd_t c, const unsigned char *iv,
+                             size_t ivlen);
+
+    gcry_err_code_t (*authenticate)(gcry_cipher_hd_t c,
+                                    const unsigned char *abuf, size_t abuflen);
+    gcry_err_code_t (*get_tag)(gcry_cipher_hd_t c, unsigned char *outtag,
+                               size_t taglen);
+    gcry_err_code_t (*check_tag)(gcry_cipher_hd_t c, const unsigned char *intag,
+                                 size_t taglen);
+  } mode_ops;
+
   /* A structure with function pointers for bulk operations.  Due to
      limitations of the module system (we don't want to change the
      API) we need to keep these function pointers here.  The cipher
@@ -544,9 +563,12 @@ gcry_err_code_t _gcry_cipher_ocb_check_tag
 
 
 /*-- cipher-xts.c --*/
-gcry_err_code_t _gcry_cipher_xts_crypt
+gcry_err_code_t _gcry_cipher_xts_encrypt
+/*           */ (gcry_cipher_hd_t c, unsigned char *outbuf, size_t outbuflen,
+		 const unsigned char *inbuf, size_t inbuflen);
+gcry_err_code_t _gcry_cipher_xts_decrypt
 /*           */ (gcry_cipher_hd_t c, unsigned char *outbuf, size_t outbuflen,
-		 const unsigned char *inbuf, size_t inbuflen, int encrypt);
+		 const unsigned char *inbuf, size_t inbuflen);
 
 
 /* Return the L-value for block N.  Note: 'cipher_ocb.c' ensures that N
diff --git a/cipher/cipher-xts.c b/cipher/cipher-xts.c
index 06cefbe0d..045b3539b 100644
--- a/cipher/cipher-xts.c
+++ b/cipher/cipher-xts.c
@@ -169,3 +169,21 @@ _gcry_cipher_xts_crypt (gcry_cipher_hd_t c,
 
   return 0;
 }
+
+
+gcry_err_code_t
+_gcry_cipher_xts_encrypt (gcry_cipher_hd_t c,
+                          unsigned char *outbuf, size_t outbuflen,
+                          const unsigned char *inbuf, size_t inbuflen)
+{
+  return _gcry_cipher_xts_crypt (c, outbuf, outbuflen, inbuf, inbuflen, 1);
+}
+
+
+gcry_err_code_t
+_gcry_cipher_xts_decrypt (gcry_cipher_hd_t c,
+                          unsigned char *outbuf, size_t outbuflen,
+                          const unsigned char *inbuf, size_t inbuflen)
+{
+  return _gcry_cipher_xts_crypt (c, outbuf, outbuflen, inbuf, inbuflen, 0);
+}
diff --git a/cipher/cipher.c b/cipher/cipher.c
index 54d00b46d..a4dfc4ddc 100644
--- a/cipher/cipher.c
+++ b/cipher/cipher.c
@@ -200,6 +200,8 @@ static gcry_cipher_spec_t * const cipher_list_algo301[] =
   };
 
 
+static void _gcry_cipher_setup_mode_ops(gcry_cipher_hd_t c, int mode);
+
 
 static int
 map_algo (int algo)
@@ -706,6 +708,9 @@ _gcry_cipher_open_internal (gcry_cipher_hd_t *handle,
               break;
             }
 
+          /* Setup mode routines. */
+          _gcry_cipher_setup_mode_ops(h, mode);
+
           /* Setup defaults depending on the mode.  */
           switch (mode)
             {
@@ -723,8 +728,7 @@ _gcry_cipher_open_internal (gcry_cipher_hd_t *handle,
             default:
               break;
             }
-
-	}
+        }
     }
 
   /* Done.  */
@@ -994,93 +998,78 @@ do_ecb_decrypt (gcry_cipher_hd_t c,
 }
 
 
-/****************
- * Encrypt INBUF to OUTBUF with the mode selected at open.
- * inbuf and outbuf may overlap or be the same.
- * Depending on the mode some constraints apply to INBUFLEN.
- */
 static gcry_err_code_t
-cipher_encrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
-		const byte *inbuf, size_t inbuflen)
+do_stream_encrypt (gcry_cipher_hd_t c,
+                unsigned char *outbuf, size_t outbuflen,
+                const unsigned char *inbuf, size_t inbuflen)
+{
+  (void)outbuflen;
+  c->spec->stencrypt (&c->context.c, outbuf, (void *)inbuf, inbuflen);
+  return 0;
+}
+
+static gcry_err_code_t
+do_stream_decrypt (gcry_cipher_hd_t c,
+                unsigned char *outbuf, size_t outbuflen,
+                const unsigned char *inbuf, size_t inbuflen)
+{
+  (void)outbuflen;
+  c->spec->stdecrypt (&c->context.c, outbuf, (void *)inbuf, inbuflen);
+  return 0;
+}
+
+
+static gcry_err_code_t
+do_encrypt_none_unknown (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
+                         const byte *inbuf, size_t inbuflen)
 {
   gcry_err_code_t rc;
 
-  if (c->mode != GCRY_CIPHER_MODE_NONE && !c->marks.key)
-    {
-      log_error ("cipher_encrypt: key not set\n");
-      return GPG_ERR_MISSING_KEY;
-    }
+  (void)outbuflen;
 
   switch (c->mode)
     {
-    case GCRY_CIPHER_MODE_ECB:
-      rc = do_ecb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+    case GCRY_CIPHER_MODE_CMAC:
+      rc = GPG_ERR_INV_CIPHER_MODE;
       break;
 
-    case GCRY_CIPHER_MODE_CBC:
-      if (!(c->flags & GCRY_CIPHER_CBC_CTS))
-        rc = _gcry_cipher_cbc_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+    case GCRY_CIPHER_MODE_NONE:
+      if (fips_mode () || !_gcry_get_debug_flag (0))
+        {
+          fips_signal_error ("cipher mode NONE used");
+          rc = GPG_ERR_INV_CIPHER_MODE;
+        }
       else
-        rc = _gcry_cipher_cbc_cts_encrypt (c, outbuf, outbuflen, inbuf,
-                                           inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CFB:
-      rc = _gcry_cipher_cfb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CFB8:
-      rc = _gcry_cipher_cfb8_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+        {
+          if (inbuf != outbuf)
+            memmove (outbuf, inbuf, inbuflen);
+          rc = 0;
+        }
       break;
 
-    case GCRY_CIPHER_MODE_OFB:
-      rc = _gcry_cipher_ofb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
+    default:
+      log_fatal ("cipher_encrypt: invalid mode %d\n", c->mode );
+      rc = GPG_ERR_INV_CIPHER_MODE;
       break;
+    }
 
-    case GCRY_CIPHER_MODE_CTR:
-      rc = _gcry_cipher_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
+  return rc;
+}
 
-    case GCRY_CIPHER_MODE_AESWRAP:
-      rc = _gcry_cipher_aeswrap_encrypt (c, outbuf, outbuflen,
-                                         inbuf, inbuflen);
-      break;
+static gcry_err_code_t
+do_decrypt_none_unknown (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
+                         const byte *inbuf, size_t inbuflen)
+{
+  gcry_err_code_t rc;
 
-    case GCRY_CIPHER_MODE_CCM:
-      rc = _gcry_cipher_ccm_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
+  (void)outbuflen;
 
+  switch (c->mode)
+    {
     case GCRY_CIPHER_MODE_CMAC:
       rc = GPG_ERR_INV_CIPHER_MODE;
       break;
 
-    case GCRY_CIPHER_MODE_EAX:
-      rc = _gcry_cipher_eax_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_GCM:
-      rc = _gcry_cipher_gcm_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_POLY1305:
-      rc = _gcry_cipher_poly1305_encrypt (c, outbuf, outbuflen,
-					  inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_OCB:
-      rc = _gcry_cipher_ocb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_XTS:
-      rc = _gcry_cipher_xts_crypt (c, outbuf, outbuflen, inbuf, inbuflen, 1);
-      break;
-
-    case GCRY_CIPHER_MODE_STREAM:
-      c->spec->stencrypt (&c->context.c,
-                          outbuf, (byte*)/*arggg*/inbuf, inbuflen);
-      rc = 0;
-      break;
-
     case GCRY_CIPHER_MODE_NONE:
       if (fips_mode () || !_gcry_get_debug_flag (0))
         {
@@ -1096,7 +1085,7 @@ cipher_encrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
       break;
 
     default:
-      log_fatal ("cipher_encrypt: invalid mode %d\n", c->mode );
+      log_fatal ("cipher_decrypt: invalid mode %d\n", c->mode );
       rc = GPG_ERR_INV_CIPHER_MODE;
       break;
     }
@@ -1121,7 +1110,13 @@ _gcry_cipher_encrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
       inlen = outsize;
     }
 
-  rc = cipher_encrypt (h, out, outsize, in, inlen);
+  if (h->mode != GCRY_CIPHER_MODE_NONE && !h->marks.key)
+    {
+      log_error ("cipher_decrypt: key not set\n");
+      return GPG_ERR_MISSING_KEY;
+    }
+
+  rc = h->mode_ops.encrypt (h, out, outsize, in, inlen);
 
   /* Failsafe: Make sure that the plaintext will never make it into
      OUT if the encryption returned an error.  */
@@ -1132,118 +1127,10 @@ _gcry_cipher_encrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
 }
 
 
-
 /****************
- * Decrypt INBUF to OUTBUF with the mode selected at open.
- * inbuf and outbuf may overlap or be the same.
- * Depending on the mode some some constraints apply to INBUFLEN.
+ * Decrypt IN and write it to OUT.  If IN is NULL, in-place encryption has
+ * been requested.
  */
-static gcry_err_code_t
-cipher_decrypt (gcry_cipher_hd_t c, byte *outbuf, size_t outbuflen,
-                const byte *inbuf, size_t inbuflen)
-{
-  gcry_err_code_t rc;
-
-  if (c->mode != GCRY_CIPHER_MODE_NONE && !c->marks.key)
-    {
-      log_error ("cipher_decrypt: key not set\n");
-      return GPG_ERR_MISSING_KEY;
-    }
-
-  switch (c->mode)
-    {
-    case GCRY_CIPHER_MODE_ECB:
-      rc = do_ecb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CBC:
-      if (!(c->flags & GCRY_CIPHER_CBC_CTS))
-        rc = _gcry_cipher_cbc_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      else
-        rc = _gcry_cipher_cbc_cts_decrypt (c, outbuf, outbuflen, inbuf,
-                                          inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CFB:
-      rc = _gcry_cipher_cfb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CFB8:
-      rc = _gcry_cipher_cfb8_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_OFB:
-      rc = _gcry_cipher_ofb_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CTR:
-      rc = _gcry_cipher_ctr_encrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_AESWRAP:
-      rc = _gcry_cipher_aeswrap_decrypt (c, outbuf, outbuflen,
-                                         inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CCM:
-      rc = _gcry_cipher_ccm_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_CMAC:
-      rc = GPG_ERR_INV_CIPHER_MODE;
-      break;
-
-    case GCRY_CIPHER_MODE_EAX:
-      rc = _gcry_cipher_eax_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_GCM:
-      rc = _gcry_cipher_gcm_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_POLY1305:
-      rc = _gcry_cipher_poly1305_decrypt (c, outbuf, outbuflen,
-					  inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_OCB:
-      rc = _gcry_cipher_ocb_decrypt (c, outbuf, outbuflen, inbuf, inbuflen);
-      break;
-
-    case GCRY_CIPHER_MODE_XTS:
-      rc = _gcry_cipher_xts_crypt (c, outbuf, outbuflen, inbuf, inbuflen, 0);
-      break;
-
-    case GCRY_CIPHER_MODE_STREAM:
-      c->spec->stdecrypt (&c->context.c,
-                          outbuf, (byte*)/*arggg*/inbuf, inbuflen);
-      rc = 0;
-      break;
-
-    case GCRY_CIPHER_MODE_NONE:
-      if (fips_mode () || !_gcry_get_debug_flag (0))
-        {
-          fips_signal_error ("cipher mode NONE used");
-          rc = GPG_ERR_INV_CIPHER_MODE;
-        }
-      else
-        {
-          if (inbuf != outbuf)
-            memmove (outbuf, inbuf, inbuflen);
-          rc = 0;
-        }
-      break;
-
-    default:
-      log_fatal ("cipher_decrypt: invalid mode %d\n", c->mode );
-      rc = GPG_ERR_INV_CIPHER_MODE;
-      break;
-    }
-
-  return rc;
-}
-
-
 gcry_err_code_t
 _gcry_cipher_decrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
                       const void *in, size_t inlen)
@@ -1254,9 +1141,14 @@ _gcry_cipher_decrypt (gcry_cipher_hd_t h, void *out, size_t outsize,
       inlen = outsize;
     }
 
-  return cipher_decrypt (h, out, outsize, in, inlen);
-}
+  if (h->mode != GCRY_CIPHER_MODE_NONE && !h->marks.key)
+    {
+      log_error ("cipher_decrypt: key not set\n");
+      return GPG_ERR_MISSING_KEY;
+    }
 
+  return h->mode_ops.decrypt (h, out, outsize, in, inlen);
+}
 
 
 /****************
@@ -1287,37 +1179,10 @@ _gcry_cipher_setkey (gcry_cipher_hd_t hd, const void *key, size_t keylen)
 gcry_err_code_t
 _gcry_cipher_setiv (gcry_cipher_hd_t hd, const void *iv, size_t ivlen)
 {
-  gcry_err_code_t rc = 0;
-
-  switch (hd->mode)
-    {
-      case GCRY_CIPHER_MODE_CCM:
-        rc = _gcry_cipher_ccm_set_nonce (hd, iv, ivlen);
-        break;
-
-      case GCRY_CIPHER_MODE_EAX:
-        rc =  _gcry_cipher_eax_set_nonce (hd, iv, ivlen);
-        break;
-
-      case GCRY_CIPHER_MODE_GCM:
-        rc =  _gcry_cipher_gcm_setiv (hd, iv, ivlen);
-        break;
-
-      case GCRY_CIPHER_MODE_POLY1305:
-        rc =  _gcry_cipher_poly1305_setiv (hd, iv, ivlen);
-        break;
-
-      case GCRY_CIPHER_MODE_OCB:
-        rc = _gcry_cipher_ocb_set_nonce (hd, iv, ivlen);
-        break;
-
-      default:
-        rc = cipher_setiv (hd, iv, ivlen);
-        break;
-    }
-  return rc;
+  return hd->mode_ops.setiv (hd, iv, ivlen);
 }
 
+
 /* Set counter for CTR mode.  (CTR,CTRLEN) must denote a buffer of
    block size length, or (NULL,0) to set the CTR to the all-zero
    block. */
@@ -1351,127 +1216,230 @@ _gcry_cipher_getctr (gcry_cipher_hd_t hd, void *ctr, size_t ctrlen)
   return 0;
 }
 
+
 gcry_err_code_t
 _gcry_cipher_authenticate (gcry_cipher_hd_t hd, const void *abuf,
                            size_t abuflen)
 {
   gcry_err_code_t rc;
 
-  switch (hd->mode)
+  if (hd->mode_ops.authenticate)
     {
-    case GCRY_CIPHER_MODE_CCM:
-      rc = _gcry_cipher_ccm_authenticate (hd, abuf, abuflen);
+      rc = hd->mode_ops.authenticate (hd, abuf, abuflen);
+    }
+  else
+    {
+      log_error ("gcry_cipher_authenticate: invalid mode %d\n", hd->mode);
+      rc = GPG_ERR_INV_CIPHER_MODE;
+    }
+
+  return rc;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_gettag (gcry_cipher_hd_t hd, void *outtag, size_t taglen)
+{
+  gcry_err_code_t rc;
+
+  if (hd->mode_ops.get_tag)
+    {
+      rc = hd->mode_ops.get_tag (hd, outtag, taglen);
+    }
+  else
+    {
+      log_error ("gcry_cipher_gettag: invalid mode %d\n", hd->mode);
+      rc = GPG_ERR_INV_CIPHER_MODE;
+    }
+
+  return rc;
+}
+
+
+gcry_err_code_t
+_gcry_cipher_checktag (gcry_cipher_hd_t hd, const void *intag, size_t taglen)
+{
+  gcry_err_code_t rc;
+
+  if (hd->mode_ops.check_tag)
+    {
+      rc = hd->mode_ops.check_tag (hd, intag, taglen);
+    }
+  else
+    {
+      log_error ("gcry_cipher_checktag: invalid mode %d\n", hd->mode);
+      rc = GPG_ERR_INV_CIPHER_MODE;
+    }
+
+  return rc;
+}
+
+
+
+static void
+_gcry_cipher_setup_mode_ops(gcry_cipher_hd_t c, int mode)
+{
+  /* Setup encryption and decryption routines. */
+  switch (mode)
+    {
+    case GCRY_CIPHER_MODE_STREAM:
+      c->mode_ops.encrypt = do_stream_encrypt;
+      c->mode_ops.decrypt = do_stream_decrypt;
       break;
 
-    case GCRY_CIPHER_MODE_CMAC:
-      rc = _gcry_cipher_cmac_authenticate (hd, abuf, abuflen);
+    case GCRY_CIPHER_MODE_ECB:
+      c->mode_ops.encrypt = do_ecb_encrypt;
+      c->mode_ops.decrypt = do_ecb_decrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_CBC:
+      if (!(c->flags & GCRY_CIPHER_CBC_CTS))
+        {
+          c->mode_ops.encrypt = _gcry_cipher_cbc_encrypt;
+          c->mode_ops.decrypt = _gcry_cipher_cbc_decrypt;
+        }
+      else
+        {
+          c->mode_ops.encrypt = _gcry_cipher_cbc_cts_encrypt;
+          c->mode_ops.decrypt = _gcry_cipher_cbc_cts_decrypt;
+        }
+      break;
+
+    case GCRY_CIPHER_MODE_CFB:
+      c->mode_ops.encrypt = _gcry_cipher_cfb_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_cfb_decrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_CFB8:
+      c->mode_ops.encrypt = _gcry_cipher_cfb8_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_cfb8_decrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_OFB:
+      c->mode_ops.encrypt = _gcry_cipher_ofb_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_ofb_encrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_CTR:
+      c->mode_ops.encrypt = _gcry_cipher_ctr_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_ctr_encrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_AESWRAP:
+      c->mode_ops.encrypt = _gcry_cipher_aeswrap_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_aeswrap_decrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_CCM:
+      c->mode_ops.encrypt = _gcry_cipher_ccm_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_ccm_decrypt;
       break;
 
     case GCRY_CIPHER_MODE_EAX:
-      rc = _gcry_cipher_eax_authenticate (hd, abuf, abuflen);
+      c->mode_ops.encrypt = _gcry_cipher_eax_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_eax_decrypt;
       break;
 
     case GCRY_CIPHER_MODE_GCM:
-      rc = _gcry_cipher_gcm_authenticate (hd, abuf, abuflen);
+      c->mode_ops.encrypt = _gcry_cipher_gcm_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_gcm_decrypt;
       break;
 
     case GCRY_CIPHER_MODE_POLY1305:
-      rc = _gcry_cipher_poly1305_authenticate (hd, abuf, abuflen);
+      c->mode_ops.encrypt = _gcry_cipher_poly1305_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_poly1305_decrypt;
       break;
 
     case GCRY_CIPHER_MODE_OCB:
-      rc = _gcry_cipher_ocb_authenticate (hd, abuf, abuflen);
+      c->mode_ops.encrypt = _gcry_cipher_ocb_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_ocb_decrypt;
+      break;
+
+    case GCRY_CIPHER_MODE_XTS:
+      c->mode_ops.encrypt = _gcry_cipher_xts_encrypt;
+      c->mode_ops.decrypt = _gcry_cipher_xts_decrypt;
       break;
 
     default:
-      log_error ("gcry_cipher_authenticate: invalid mode %d\n", hd->mode);
-      rc = GPG_ERR_INV_CIPHER_MODE;
+      c->mode_ops.encrypt = do_encrypt_none_unknown;
+      c->mode_ops.decrypt = do_decrypt_none_unknown;
       break;
     }
 
-  return rc;
-}
-
-
-gcry_err_code_t
-_gcry_cipher_gettag (gcry_cipher_hd_t hd, void *outtag, size_t taglen)
-{
-  gcry_err_code_t rc;
-
-  switch (hd->mode)
+  /* Setup IV setting routine. */
+  switch (mode)
     {
     case GCRY_CIPHER_MODE_CCM:
-      rc = _gcry_cipher_ccm_get_tag (hd, outtag, taglen);
-      break;
-
-    case GCRY_CIPHER_MODE_CMAC:
-      rc = _gcry_cipher_cmac_get_tag (hd, outtag, taglen);
+      c->mode_ops.setiv = _gcry_cipher_ccm_set_nonce;
       break;
 
     case GCRY_CIPHER_MODE_EAX:
-      rc = _gcry_cipher_eax_get_tag (hd, outtag, taglen);
+      c->mode_ops.setiv = _gcry_cipher_eax_set_nonce;
       break;
 
     case GCRY_CIPHER_MODE_GCM:
-      rc = _gcry_cipher_gcm_get_tag (hd, outtag, taglen);
+      c->mode_ops.setiv =  _gcry_cipher_gcm_setiv;
       break;
 
     case GCRY_CIPHER_MODE_POLY1305:
-      rc = _gcry_cipher_poly1305_get_tag (hd, outtag, taglen);
+      c->mode_ops.setiv = _gcry_cipher_poly1305_setiv;
       break;
 
     case GCRY_CIPHER_MODE_OCB:
-      rc = _gcry_cipher_ocb_get_tag (hd, outtag, taglen);
+      c->mode_ops.setiv = _gcry_cipher_ocb_set_nonce;
       break;
 
     default:
-      log_error ("gcry_cipher_gettag: invalid mode %d\n", hd->mode);
-      rc = GPG_ERR_INV_CIPHER_MODE;
+      c->mode_ops.setiv = cipher_setiv;
       break;
     }
 
-  return rc;
-}
-
 
-gcry_err_code_t
-_gcry_cipher_checktag (gcry_cipher_hd_t hd, const void *intag, size_t taglen)
-{
-  gcry_err_code_t rc;
-
-  switch (hd->mode)
+  /* Setup authentication routines for AEAD modes. */
+  switch (mode)
     {
     case GCRY_CIPHER_MODE_CCM:
-      rc = _gcry_cipher_ccm_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_ccm_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_ccm_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_ccm_check_tag;
       break;
 
     case GCRY_CIPHER_MODE_CMAC:
-      rc = _gcry_cipher_cmac_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_cmac_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_cmac_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_cmac_check_tag;
       break;
 
     case GCRY_CIPHER_MODE_EAX:
-      rc = _gcry_cipher_eax_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_eax_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_eax_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_eax_check_tag;
       break;
 
     case GCRY_CIPHER_MODE_GCM:
-      rc = _gcry_cipher_gcm_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_gcm_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_gcm_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_gcm_check_tag;
       break;
 
     case GCRY_CIPHER_MODE_POLY1305:
-      rc = _gcry_cipher_poly1305_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_poly1305_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_poly1305_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_poly1305_check_tag;
       break;
 
     case GCRY_CIPHER_MODE_OCB:
-      rc = _gcry_cipher_ocb_check_tag (hd, intag, taglen);
+      c->mode_ops.authenticate = _gcry_cipher_ocb_authenticate;
+      c->mode_ops.get_tag      = _gcry_cipher_ocb_get_tag;
+      c->mode_ops.check_tag    = _gcry_cipher_ocb_check_tag;
       break;
 
     default:
-      log_error ("gcry_cipher_checktag: invalid mode %d\n", hd->mode);
-      rc = GPG_ERR_INV_CIPHER_MODE;
+      c->mode_ops.authenticate = NULL;
+      c->mode_ops.get_tag      = NULL;
+      c->mode_ops.check_tag    = NULL;
       break;
     }
-
-  return rc;
 }
 
 
-- 
2.17.1




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