cipher: Add constant for 8 bit CFB mode.

* src/gcrypt.h.in (GCRY_CIPHER_MODE_CFB8): New.
* tests/basic.c (check_cfb_cipher): Prepare for CFB-8 tests.
--

Note that there is no implementation for the 8 bit CFB mode yet.  We
will add that as a bug fix after the release of 1.7.0.

Signed-off-by: Werner Koch <wk@gnupg.org>

4 files changed, 17 insertions, 9 deletions

diff --git a/NEWS b/NEWS
index 9cb5e36d..7b53c1a3 100644
--- a/NEWS
+++ b/NEWS
@@ -68,6 +68,7 @@ Noteworthy changes in version 1.7.0 (unreleased)
  gcry_mpi_ec_decode_point        NEW.
  GCRY_CIPHER_MODE_POLY1305       NEW.
  GCRY_CIPHER_MODE_OCB            NEW.
+ GCRY_CIPHER_MODE_CFB8           NEW constant.
  GCRYCTL_SET_TAGLEN              NEW.
  GCRYCTL_GET_TAGLEN              NEW.
  gcry_cipher_final               NEW macro.
diff --git a/doc/gcrypt.texi b/doc/gcrypt.texi
index a78c5fd7..0171cd62 100644
--- a/doc/gcrypt.texi
+++ b/doc/gcrypt.texi
@@ -1598,9 +1598,12 @@ set, this mode may be used to bypass the actual encryption.
 Electronic Codebook mode.
 
 @item GCRY_CIPHER_MODE_CFB
+@item GCRY_CIPHER_MODE_CFB8
 @cindex CFB, Cipher Feedback mode
-Cipher Feedback mode.  The shift size equals the block size of the
-cipher (e.g. for AES it is CFB-128).
+Cipher Feedback mode.  For GCRY_CIPHER_MODE_CFB the shift size equals
+the block size of the cipher (e.g. for AES it is CFB-128).  For
+GCRY_CIPHER_MODE_CFB8 the shift size is 8 bit but that variant is not
+yet available.
 
 @item  GCRY_CIPHER_MODE_CBC
 @cindex CBC, Cipher Block Chaining mode
diff --git a/src/gcrypt.h.in b/src/gcrypt.h.in
index bd25d1b6..96d742a0 100644
--- a/src/gcrypt.h.in
+++ b/src/gcrypt.h.in
@@ -961,7 +961,8 @@ enum gcry_cipher_modes
     GCRY_CIPHER_MODE_CCM      = 8,   /* Counter with CBC-MAC.  */
     GCRY_CIPHER_MODE_GCM      = 9,   /* Galois Counter Mode. */
     GCRY_CIPHER_MODE_POLY1305 = 10,  /* Poly1305 based AEAD mode. */
-    GCRY_CIPHER_MODE_OCB      = 11   /* OCB3 mode.  */
+    GCRY_CIPHER_MODE_OCB      = 11,  /* OCB3 mode.  */
+    GCRY_CIPHER_MODE_CFB8     = 12   /* Cipher feedback (8 bit mode). */
   };
 
 /* Flags used with the open function. */
diff --git a/tests/basic.c b/tests/basic.c
index 4940f6a2..96fb4cbd 100644
--- a/tests/basic.c
+++ b/tests/basic.c
@@ -873,6 +873,7 @@ check_cfb_cipher (void)
   static const struct tv
   {
     int algo;
+    int cfb8;
     char key[MAX_DATA_LEN];
     char iv[MAX_DATA_LEN];
     struct data
@@ -885,7 +886,7 @@ check_cfb_cipher (void)
   } tv[] =
     {
       /* http://csrc.nist.gov/publications/nistpubs/800-38a/sp800-38a.pdf */
-      { GCRY_CIPHER_AES,
+      { GCRY_CIPHER_AES, 0,
         "\x2b\x7e\x15\x16\x28\xae\xd2\xa6\xab\xf7\x15\x88\x09\xcf\x4f\x3c",
         "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
         { { "\x6b\xc1\xbe\xe2\x2e\x40\x9f\x96\xe9\x3d\x7e\x11\x73\x93\x17\x2a",
@@ -902,7 +903,7 @@ check_cfb_cipher (void)
             "\xc0\x4b\x05\x35\x7c\x5d\x1c\x0e\xea\xc4\xc6\x6f\x9f\xf7\xf2\xe6" },
         }
       },
-      { GCRY_CIPHER_AES192,
+      { GCRY_CIPHER_AES192, 0,
         "\x8e\x73\xb0\xf7\xda\x0e\x64\x52\xc8\x10\xf3\x2b"
         "\x80\x90\x79\xe5\x62\xf8\xea\xd2\x52\x2c\x6b\x7b",
         "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
@@ -920,7 +921,7 @@ check_cfb_cipher (void)
             "\xc0\x5f\x9f\x9c\xa9\x83\x4f\xa0\x42\xae\x8f\xba\x58\x4b\x09\xff" },
         }
       },
-      { GCRY_CIPHER_AES256,
+      { GCRY_CIPHER_AES256, 0,
         "\x60\x3d\xeb\x10\x15\xca\x71\xbe\x2b\x73\xae\xf0\x85\x7d\x77\x81"
         "\x1f\x35\x2c\x07\x3b\x61\x08\xd7\x2d\x98\x10\xa3\x09\x14\xdf\xf4",
         "\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f",
@@ -941,7 +942,7 @@ check_cfb_cipher (void)
     };
   gcry_cipher_hd_t hde, hdd;
   unsigned char out[MAX_DATA_LEN];
-  int i, j, keylen, blklen;
+  int i, j, keylen, blklen, mode;
   gcry_error_t err = 0;
 
   if (verbose)
@@ -957,13 +958,15 @@ check_cfb_cipher (void)
           continue;
         }
 
+      mode = tv[i].cfb8? GCRY_CIPHER_MODE_CFB8 : GCRY_CIPHER_MODE_CFB;
+
       if (verbose)
         fprintf (stderr, "    checking CFB mode for %s [%i]\n",
 		 gcry_cipher_algo_name (tv[i].algo),
 		 tv[i].algo);
-      err = gcry_cipher_open (&hde, tv[i].algo, GCRY_CIPHER_MODE_CFB, 0);
+      err = gcry_cipher_open (&hde, tv[i].algo, mode, 0);
       if (!err)
-        err = gcry_cipher_open (&hdd, tv[i].algo, GCRY_CIPHER_MODE_CFB, 0);
+        err = gcry_cipher_open (&hdd, tv[i].algo, mode, 0);
       if (err)
         {
           fail ("aes-cfb, gcry_cipher_open failed: %s\n", gpg_strerror (err));