[PATCH] Use u64 for CCM data lengths

Jussi Kivilinna jussi.kivilinna at iki.fi
Sun Dec 15 15:04:17 CET 2013


* cipher/cipher-ccm.c: Move code inside [HAVE_U64_TYPEDEF].
[!HAVE_U64_TYPEDEF] (_gcry_cipher_ccm_encrypt)
(_gcry_cipher_ccm_decrypt, _gcry_cipher_ccm_set_nonce)
(_gcry_cipher_ccm_authenticate, _gcry_cipher_ccm_get_tag)
(_gcry_cipher_ccm_check_tag): Dummy functions returning
GPG_ERROR_NOT_SUPPORTED.
* cipher/cipher-internal.h (gcry_cipher_handle.u_mode.ccm)
(_gcry_cipher_ccm_set_lengths): Move inside [HAVE_U64_TYPEDEF] and use
u64 instead of size_t for CCM data lengths.
* cipher/cipher.c (_gcry_cipher_open_internal, cipher_reset)
(_gcry_cipher_ctl) [!HAVE_U64_TYPEDEF]: Return GPG_ERR_NOT_SUPPORTED
for CCM.
(_gcry_cipher_ctl) [HAVE_U64_TYPEDEF]: Use u64 for
GCRYCTL_SET_CCM_LENGTHS length parameters.
--

Signed-off-by: Jussi Kivilinna <jussi.kivilinna at iki.fi>
---
 cipher/cipher-ccm.c      |   88 +++++++++++++++++++++++++++++++++++++++++++---
 cipher/cipher-internal.h |   11 ++++--
 cipher/cipher.c          |   12 ++++++
 3 files changed, 100 insertions(+), 11 deletions(-)

diff --git a/cipher/cipher-ccm.c b/cipher/cipher-ccm.c
index d2b8841..47f2162 100644
--- a/cipher/cipher-ccm.c
+++ b/cipher/cipher-ccm.c
@@ -29,6 +29,9 @@
 #include "bufhelp.h"
 #include "./cipher-internal.h"
 
+/* We need a 64 bit type for this code.  */
+#ifdef HAVE_U64_TYPEDEF
+
 
 #define set_burn(burn, nburn) do { \
   unsigned int __nburn = (nburn); \
@@ -149,14 +152,14 @@ _gcry_cipher_ccm_set_nonce (gcry_cipher_hd_t c, const unsigned char *nonce,
 
 
 gcry_err_code_t
-_gcry_cipher_ccm_set_lengths (gcry_cipher_hd_t c, size_t encryptlen,
-                              size_t aadlen, size_t taglen)
+_gcry_cipher_ccm_set_lengths (gcry_cipher_hd_t c, u64 encryptlen, u64 aadlen,
+                              u64 taglen)
 {
   unsigned int burn = 0;
   unsigned char b0[16];
   size_t noncelen = 15 - (c->u_iv.iv[0] + 1);
-  size_t M = taglen;
-  size_t M_;
+  u64 M = taglen;
+  u64 M_;
   int i;
 
   M_ = (M - 2) / 2;
@@ -203,7 +206,6 @@ _gcry_cipher_ccm_set_lengths (gcry_cipher_hd_t c, size_t encryptlen,
       buf_put_be32(&b0[2], aadlen);
       set_burn (burn, do_cbc_mac (c, b0, 6, 0));
     }
-#ifdef HAVE_U64_TYPEDEF
   else if (aadlen > (unsigned int)0xffffffff)
     {
       b0[0] = 0xff;
@@ -211,7 +213,6 @@ _gcry_cipher_ccm_set_lengths (gcry_cipher_hd_t c, size_t encryptlen,
       buf_put_be64(&b0[2], aadlen);
       set_burn (burn, do_cbc_mac (c, b0, 10, 0));
     }
-#endif
 
   /* Generate S_0 and increase counter.  */
   set_burn (burn, c->spec->encrypt ( &c->context.c, c->u_mode.ccm.s0,
@@ -364,3 +365,78 @@ _gcry_cipher_ccm_decrypt (gcry_cipher_hd_t c, unsigned char *outbuf,
 
   return err;
 }
+
+#else
+
+/*
+ * Provide dummy functions so that we avoid adding too much #ifdefs in
+ * cipher.c.
+ */
+
+gcry_err_code_t
+_gcry_cipher_ccm_encrypt(gcry_cipher_hd_t c, unsigned char *outbuf,
+			 size_t outbuflen, const unsigned char *inbuf,
+			 size_t inbuflen)
+{
+  (void)c;
+  (void)outbuf;
+  (void)outbuflen;
+  (void)inbuf;
+  (void)inbuflen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+gcry_err_code_t
+_gcry_cipher_ccm_decrypt(gcry_cipher_hd_t c, unsigned char *outbuf,
+			 size_t outbuflen, const unsigned char *inbuf,
+			 size_t inbuflen)
+{
+  (void)c;
+  (void)outbuf;
+  (void)outbuflen;
+  (void)inbuf;
+  (void)inbuflen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+gcry_err_code_t
+_gcry_cipher_ccm_set_nonce(gcry_cipher_hd_t c, const unsigned char *nonce,
+			   size_t noncelen)
+{
+  (void)c;
+  (void)nonce;
+  (void)noncelen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+gcry_err_code_t
+_gcry_cipher_ccm_authenticate(gcry_cipher_hd_t c, const unsigned char *abuf,
+			      size_t abuflen)
+{
+  (void)c;
+  (void)abuf;
+  (void)abuflen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+gcry_err_code_t
+_gcry_cipher_ccm_get_tag(gcry_cipher_hd_t c, unsigned char *outtag,
+			 size_t taglen)
+{
+  (void)c;
+  (void)outtag;
+  (void)taglen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+gcry_err_code_t
+_gcry_cipher_ccm_check_tag(gcry_cipher_hd_t c, const unsigned char *intag,
+			   size_t taglen)
+{
+  (void)c;
+  (void)intag;
+  (void)taglen;
+  return GPG_ERR_NOT_SUPPORTED;
+}
+
+#endif /*HAVE_U64_TYPEDEF*/
diff --git a/cipher/cipher-internal.h b/cipher/cipher-internal.h
index 6fb3bac..cdac445 100644
--- a/cipher/cipher-internal.h
+++ b/cipher/cipher-internal.h
@@ -135,10 +135,11 @@ struct gcry_cipher_handle
   int unused;  /* Number of unused bytes in LASTIV. */
 
   union {
+#ifdef HAVE_U64_TYPEDEF
     /* Mode specific storage for CCM mode. */
     struct {
-      size_t encryptlen;
-      size_t aadlen;
+      u64 encryptlen;
+      u64 aadlen;
       unsigned int authlen;
 
       /* Space to save partial input lengths for MAC. */
@@ -151,6 +152,7 @@ struct gcry_cipher_handle
       unsigned int lengths:1; /* Set to 1 if CCM length parameters has been
                                  processed.  */
     } ccm;
+#endif
 
     /* Mode specific storage for CMAC mode. */
     struct {
@@ -280,9 +282,10 @@ gcry_err_code_t _gcry_cipher_ccm_set_nonce
                  size_t noncelen);
 gcry_err_code_t _gcry_cipher_ccm_authenticate
 /*           */ (gcry_cipher_hd_t c, const unsigned char *abuf, size_t abuflen);
+#ifdef HAVE_U64_TYPEDEF
 gcry_err_code_t _gcry_cipher_ccm_set_lengths
-/*           */ (gcry_cipher_hd_t c, size_t encryptedlen, size_t aadlen,
-                 size_t taglen);
+/*           */ (gcry_cipher_hd_t c, u64 encryptedlen, u64 aadlen, u64 taglen);
+#endif
 gcry_err_code_t _gcry_cipher_ccm_get_tag
 /*           */ (gcry_cipher_hd_t c,
                  unsigned char *outtag, size_t taglen);
diff --git a/cipher/cipher.c b/cipher/cipher.c
index 8b47abc..4c7b5b5 100644
--- a/cipher/cipher.c
+++ b/cipher/cipher.c
@@ -394,11 +394,15 @@ _gcry_cipher_open_internal (gcry_cipher_hd_t *handle,
     switch (mode)
       {
       case GCRY_CIPHER_MODE_CCM:
+#ifdef HAVE_U64_TYPEDEF
 	if (spec->blocksize != GCRY_CCM_BLOCK_LEN)
 	  err = GPG_ERR_INV_CIPHER_MODE;
 	if (!spec->encrypt || !spec->decrypt)
 	  err = GPG_ERR_INV_CIPHER_MODE;
 	break;
+#else
+        err = GPG_ERR_NOT_SUPPORTED;
+#endif
 
       case GCRY_CIPHER_MODE_ECB:
       case GCRY_CIPHER_MODE_CBC:
@@ -686,9 +690,11 @@ cipher_reset (gcry_cipher_hd_t c)
       }
       break;
 
+#ifdef HAVE_U64_TYPEDEF
     case GCRY_CIPHER_MODE_CCM:
       memset (&c->u_mode.ccm, 0, sizeof c->u_mode.ccm);
       break;
+#endif
 
     default:
       break; /* u_mode unused by other modes. */
@@ -1139,8 +1145,9 @@ _gcry_cipher_ctl (gcry_cipher_hd_t h, int cmd, void *buffer, size_t buflen)
       break;
 
     case GCRYCTL_SET_CCM_LENGTHS:
+#ifdef HAVE_U64_TYPEDEF
       {
-        size_t params[3];
+        u64 params[3];
         size_t encryptedlen;
         size_t aadlen;
         size_t authtaglen;
@@ -1160,6 +1167,9 @@ _gcry_cipher_ctl (gcry_cipher_hd_t h, int cmd, void *buffer, size_t buflen)
 
         rc = _gcry_cipher_ccm_set_lengths (h, encryptedlen, aadlen, authtaglen);
       }
+#else
+      rc = GPG_ERR_NOT_SUPPORTED;
+#endif
       break;
 
     case GCRYCTL_DISABLE_ALGO:




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