/* -*-c-*-
*
- * $Id: cfb.h,v 1.1 1999/09/03 08:41:11 mdw Exp $
+ * $Id: cfb.h,v 1.5 2004/04/08 01:36:15 mdw Exp $
*
* Ciphertext feedback for block ciphers
*
* (c) 1999 Straylight/Edgeware
*/
-/*----- Licensing notice --------------------------------------------------*
+/*----- Licensing notice --------------------------------------------------*
*
* This file is part of Catacomb.
*
* it under the terms of the GNU Library General Public License as
* published by the Free Software Foundation; either version 2 of the
* License, or (at your option) any later version.
- *
+ *
* Catacomb is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU Library General Public License for more details.
- *
+ *
* You should have received a copy of the GNU Library General Public
* License along with Catacomb; if not, write to the Free
* Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
* MA 02111-1307, USA.
*/
-/*----- Revision history --------------------------------------------------*
- *
- * $Log: cfb.h,v $
- * Revision 1.1 1999/09/03 08:41:11 mdw
- * Initial import.
- *
- */
-
-#ifndef CFB_H
-#define CFB_H
+#ifndef CATACOMB_CFB_H
+#define CATACOMB_CFB_H
#ifdef __cplusplus
extern "C" {
/*----- Header files ------------------------------------------------------*/
-#include <string.h>
+#include <stddef.h>
#include <mLib/bits.h>
-#ifndef BLKC_H
-# include "blkc.h"
-#endif
-
-#ifndef PARANOIA_H
-# include "paranoia.h"
+#ifndef CATACOMB_GCIPHER_H
+# include "gcipher.h"
#endif
/*----- Data structures ---------------------------------------------------*/
#define CFB_DECL(PRE, pre) \
\
-typedef struct pre ## _cfbctx { \
- pre ## _ctx ctx; /* Underlying cipher context */ \
- int off; /* Offset into @iv@ buffer */ \
- octet iv[PRE ## _BLKSZ]; /* Previous ciphertext or IV */ \
-} pre ## _cfbctx; \
- \
-extern void pre ## _cfbgetiv(const pre ## _cfbctx */*ctx*/, \
- void */*iv*/); \
- \
-extern void pre ## _cfbsetiv(pre ## _cfbctx */*ctx*/, \
- const void */*iv*/); \
+/* --- Ciphertext feedback context --- */ \
\
-extern void pre ## _cfbbdry(pre ## _cfbctx */*ctx*/); \
- \
-extern void pre ## _cfbsetkey(pre ## _cfbctx */*ctx*/, \
- const pre ## _ctx */*k*/); \
- \
-extern void pre ## _cfbinit(pre ## _cfbctx */*ctx*/, \
- const void */*key*/, size_t /*sz*/, \
- const void */*iv*/); \
- \
-extern void pre ## _cfbencrypt(pre ## _cfbctx */*ctx*/, \
- const void */*src*/, void */*dest*/, \
- size_t /*sz*/); \
- \
-extern void pre ## _cfbdecrypt(pre ## _cfbctx */*ctx*/, \
- const void */*src*/, void */*dest*/, \
- size_t /*sz*/); \
-
-
-/* --- @CFB_DEF@ --- *
- *
- * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
- *
- * Use: Creates an implementation for CFB mode.
- */
-
-#define CFB_DEF(PRE, pre) \
+typedef struct pre##_cfbctx { \
+ pre##_ctx ctx; /* Underlying cipher context */ \
+ unsigned off; /* Offset into @iv@ buffer */ \
+ octet iv[PRE##_BLKSZ]; /* Previous ciphertext or IV */ \
+} pre##_cfbctx; \
\
/* --- @pre_cfbgetiv@ --- * \
* \
* Arguments: @const pre_cfbctx *ctx@ = pointer to CFB context block \
- * @void *iv#@ = pointer to output data block \
+ * @void *iv@ = pointer to output data block \
* \
* Returns: --- \
* \
* decryption. \
*/ \
\
-void pre ## _cfbgetiv(const pre ## _cfbctx *ctx, void *iv) \
-{ \
- octet *p = iv; \
- int off = ctx->off; \
- int rest = PRE ## _BLKSZ - off; \
- memcpy(p, ctx->iv + off, rest); \
- memcpy(p + rest, ctx->iv, off); \
-} \
+extern void pre##_cfbgetiv(const pre##_cfbctx */*ctx*/, \
+ void */*iv*/); \
\
/* --- @pre_cfbsetiv@ --- * \
* \
* Use: Sets the IV to use for subsequent encryption. \
*/ \
\
-void pre ## _cfbsetiv(pre ## _cfbctx *ctx, const void *iv) \
-{ \
- uint32 niv[PRE ## _BLKSZ / 4]; \
- BLKC_LOAD(PRE, niv, iv); \
- pre ## _eblk(&ctx->ctx, niv, niv); \
- BLKC_STORE(PRE, ctx->iv, niv); \
- ctx->off = 0; \
-} \
+extern void pre##_cfbsetiv(pre##_cfbctx */*ctx*/, \
+ const void */*iv*/); \
\
/* --- @pre_cfbbdry@ --- * \
* \
* decryption must place a similar boundary. \
*/ \
\
-void pre ## _cfbbdry(pre ## _cfbctx *ctx) \
-{ \
- octet iv[PRE ## _BLKSZ]; \
- pre ## _cfbgetiv(ctx, iv); \
- pre ## _cfbsetiv(ctx, iv); \
- BURN(iv); \
-} \
+extern void pre##_cfbbdry(pre##_cfbctx */*ctx*/); \
\
/* --- @pre_cfbsetkey@ --- * \
* \
* Use: Sets the CFB context to use a different cipher key. \
*/ \
\
-void pre ## _cfbsetkey(pre ## _cfbctx *ctx, const pre ## _ctx *k) \
-{ \
- ctx->ctx = *k; \
-} \
+extern void pre##_cfbsetkey(pre##_cfbctx */*ctx*/, \
+ const pre##_ctx */*k*/); \
\
/* --- @pre_cfbinit@ --- * \
* \
* @pre_cfbsetkey@ and @pre_cfbsetiv@. \
*/ \
\
-void pre ## _cfbinit(pre ## _cfbctx *ctx, \
- const void *key, size_t sz, \
- const void *iv) \
-{ \
- static octet zero[PRE ## _BLKSZ] = { 0 }; \
- pre ## _init(&ctx->ctx, key, sz); \
- pre ## _cfbsetiv(ctx, iv ? iv : zero); \
-} \
+extern void pre##_cfbinit(pre##_cfbctx */*ctx*/, \
+ const void */*key*/, size_t /*sz*/, \
+ const void */*iv*/); \
\
/* --- @pre_cfbencrypt@ --- * \
* \
* sensitive to block boundaries. \
*/ \
\
-void pre ## _cfbencrypt(pre ## _cfbctx *ctx, \
- const void *src, void *dest, \
- size_t sz) \
-{ \
- const octet *s = src; \
- octet *d = dest; \
- int off = ctx->off; \
- \
- /* --- Empty blocks are trivial --- */ \
- \
- if (!sz) \
- return; \
- \
- /* --- If I can deal with the block from my buffer, do that --- */ \
- \
- if (sz < PRE ## _BLKSZ - off) \
- goto small; \
- \
- /* --- Finish off what's left in my buffer --- */ \
- \
- while (off < PRE ## _BLKSZ) { \
- register octet x = *s++; \
- *d++ = ctx->iv[off++] ^= x; \
- sz--; \
- } \
- \
- /* --- Main encryption loop --- */ \
+extern void pre##_cfbencrypt(pre##_cfbctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
\
- { \
- uint32 iv[PRE ## _BLKSZ / 4]; \
- BLKC_LOAD(PRE, iv, ctx->iv); \
- \
- for (;;) { \
- pre ## _eblk(&ctx->ctx, iv, iv); \
- if (sz < PRE ## _BLKSZ) \
- break; \
- BLKC_XLOAD(PRE, iv, s); \
- BLKC_STORE(PRE, d, iv); \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- sz -= PRE ## _BLKSZ; \
- } \
- off = 0; \
- BLKC_STORE(PRE, ctx->iv, iv); \
- } \
- \
- /* --- Tidying up the tail end --- */ \
- \
- if (sz) { \
- small: \
- do { \
- register octet x = *s++; \
- *d++ = ctx->iv[off++] ^= x; \
- sz--; \
- } while (sz); \
- } \
- \
- /* --- Done --- */ \
- \
- ctx->off = off; \
- return; \
-} \
- \
-/* --- @pre_cfbdecrypt@ --- * \
+/* --- @pre_cfbencrypt@ --- * \
* \
* Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
* @const void *src@ = pointer to source data \
* \
* Returns: --- \
* \
- * Use: Encrypts a block with a block cipher in CFB mode, with \
- * ciphertext stealing and other clever tricks. \
- * Essentially, data can be encrypted in arbitrary sized \
- * chunks, although decryption must use the same chunks. \
+ * Use: Decrypts a block with a block cipher in CFB mode. The \
+ * input block may be arbitrary in size. CFB mode is not \
+ * sensitive to block boundaries. \
*/ \
\
-void pre ## _cfbdecrypt(pre ## _cfbctx *ctx, \
- const void *src, void *dest, \
- size_t sz) \
-{ \
- const octet *s = src; \
- octet *d = dest; \
- int off = ctx->off; \
+extern void pre##_cfbdecrypt(pre##_cfbctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
\
- /* --- Empty blocks are trivial --- */ \
+/* --- Generic cipher interface --- */ \
\
- if (!sz) \
- return; \
- \
- /* --- If I can deal with the block from my buffer, do that --- */ \
- \
- if (sz < PRE ## _BLKSZ - off) \
- goto small; \
- \
- /* --- Finish off what's left in my buffer --- */ \
- \
- while (off < PRE ## _BLKSZ) { \
- register octet x = *s++; \
- *d++ = ctx->iv[off] ^ x; \
- ctx->iv[off++] = x; \
- sz--; \
- } \
- \
- /* --- Main encryption loop --- */ \
- \
- { \
- uint32 iv[PRE ## _BLKSZ / 4]; \
- BLKC_LOAD(PRE, iv, ctx->iv); \
- \
- for (;;) { \
- uint32 x[PRE ## _BLKSZ / 4]; \
- pre ## _eblk(&ctx->ctx, iv, iv); \
- if (sz < PRE ## _BLKSZ) \
- break; \
- BLKC_LOAD(PRE, x, s); \
- BLKC_XSTORE(PRE, d, iv, x); \
- BLKC_MOVE(PRE, iv, x); \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- sz -= PRE ## _BLKSZ; \
- } \
- off = 0; \
- BLKC_STORE(PRE, ctx->iv, iv); \
- } \
- \
- /* --- Tidying up the tail end --- */ \
- \
- if (sz) { \
- small: \
- do { \
- register octet x = *s++; \
- *d++ = ctx->iv[off] ^ x; \
- ctx->iv[off++] = x; \
- sz--; \
- } while (sz); \
- } \
- \
- /* --- Done --- */ \
- \
- ctx->off = off; \
- return; \
-} \
- \
-CFB_TEST(PRE, pre)
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-#include <stdio.h>
-
-#include "daftstory.h"
-
-/* --- @CFB_TEST@ --- *
- *
- * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
- *
- * Use: Standard test rig for CFB functions.
- */
-
-#define CFB_TEST(PRE, pre) \
- \
-/* --- Initial plaintext for the test --- */ \
- \
-static const octet text[] = TEXT; \
- \
-/* --- Key and IV to use --- */ \
- \
-static const octet key[] = KEY; \
-static const octet iv[] = IV; \
- \
-/* --- Buffers for encryption and decryption output --- */ \
- \
-static octet ct[sizeof(text)]; \
-static octet pt[sizeof(text)]; \
- \
-static void hexdump(const octet *p, size_t sz) \
-{ \
- const octet *q = p + sz; \
- for (sz = 0; p < q; p++, sz++) { \
- printf("%02x", *p); \
- if ((sz + 1) % PRE ## _BLKSZ == 0) \
- putchar(':'); \
- } \
-} \
- \
-int main(void) \
-{ \
- size_t sz = 0, rest; \
- pre ## _cfbctx ctx; \
- int status = 0; \
- int done = 0; \
- pre ## _ctx k; \
- \
- size_t keysz = PRE ## _KEYSZ ? \
- PRE ## _KEYSZ : strlen((const char *)key); \
- \
- fputs(#pre "-cfb: ", stdout); \
- \
- pre ## _init(&k, key, keysz); \
- pre ## _cfbsetkey(&ctx, &k); \
- \
- while (sz <= sizeof(text)) { \
- rest = sizeof(text) - sz; \
- memcpy(ct, text, sizeof(text)); \
- pre ## _cfbsetiv(&ctx, iv); \
- pre ## _cfbencrypt(&ctx, ct, ct, sz); \
- pre ## _cfbencrypt(&ctx, ct + sz, ct + sz, rest); \
- memcpy(pt, ct, sizeof(text)); \
- pre ## _cfbsetiv(&ctx, iv); \
- pre ## _cfbdecrypt(&ctx, pt, pt, rest); \
- pre ## _cfbdecrypt(&ctx, pt + rest, pt + rest, sz); \
- if (memcmp(pt, text, sizeof(text)) == 0) { \
- done++; \
- if (sizeof(text) < 40 || done % 8 == 0) \
- fputc('.', stdout); \
- if (done % 480 == 0) \
- fputs("\n\t", stdout); \
- fflush(stdout); \
- } else { \
- printf("\nError (sz = %lu)\n", (unsigned long)sz); \
- status = 1; \
- printf("\tplaintext = "); hexdump(text, sz); \
- printf(", "); hexdump(text + sz, rest); \
- fputc('\n', stdout); \
- printf("\tciphertext = "); hexdump(ct, sz); \
- printf(", "); hexdump(ct + sz, rest); \
- fputc('\n', stdout); \
- printf("\trecovered text = "); hexdump(pt, sz); \
- printf(", "); hexdump(pt + sz, rest); \
- fputc('\n', stdout); \
- fputc('\n', stdout); \
- } \
- if (sz < 63) \
- sz++; \
- else \
- sz += 9; \
- } \
- \
- fputs(status ? " failed\n" : " ok\n", stdout); \
- return (status); \
-}
-
-#else
-# define CFB_TEST(PRE, pre)
-#endif
+extern const gccipher pre##_cfb;
/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff