/* -*-c-*-
*
- * $Id: cbc.h,v 1.1 1999/09/03 08:41:11 mdw Exp $
+ * $Id: cbc.h,v 1.4 2004/04/08 01:36:15 mdw Exp $
*
* Ciphertext block chaining 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: cbc.h,v $
- * Revision 1.1 1999/09/03 08:41:11 mdw
- * Initial import.
- *
- */
-
-#ifndef CBC_H
-#define CBC_H
+#ifndef CATACOMB_CBC_H
+#define CATACOMB_CBC_H
#ifdef __cplusplus
extern "C" {
/*----- Header files ------------------------------------------------------*/
-#include <string.h>
+#include <stddef.h>
#include <mLib/bits.h>
-#ifndef BLKC_H
-# include "blkc.h"
+#ifndef CATACOMB_GCIPHER_H
+# include "gcipher.h"
#endif
/*----- Macros ------------------------------------------------------------*/
#define CBC_DECL(PRE, pre) \
\
-typedef struct pre ## _cbcctx { \
- pre ## _ctx ctx; /* Underlying cipher context */ \
- uint32 iv[PRE ## _BLKSZ / 4]; /* Previous ciphertext or IV */ \
-} pre ## _cbcctx; \
- \
-extern void pre ## _cbcgetiv(const pre ## _cbcctx */*ctx*/, \
- void */*iv*/); \
- \
-extern void pre ## _cbcsetiv(pre ## _cbcctx */*ctx*/, \
- const void */*iv*/); \
- \
-extern void pre ## _cbcsetkey(pre ## _cbcctx */*ctx*/, \
- const pre ## _ctx */*k*/); \
- \
-extern void pre ## _cbcinit(pre ## _cbcctx */*ctx*/, \
- const void */*key*/, size_t /*sz*/, \
- const void */*iv*/); \
+/* --- Cipher block chaining context --- */ \
\
-extern void pre ## _cbcencrypt(pre ## _cbcctx */*ctx*/, \
- const void */*src*/, void */*dest*/, \
- size_t /*sz*/); \
- \
-extern void pre ## _cbcdecrypt(pre ## _cbcctx */*ctx*/, \
- const void */*src*/, void */*dest*/, \
- size_t /*sz*/); \
-
-/* --- @CBC_DEF@ --- *
- *
- * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
- *
- * Use: Creates an implementation for CBC stealing mode.
- */
-
-#define CBC_DEF(PRE, pre) \
+typedef struct pre##_cbcctx { \
+ pre##_ctx ctx; /* Underlying cipher context */ \
+ uint32 iv[PRE##_BLKSZ / 4]; /* Previous ciphertext or IV */ \
+} pre##_cbcctx; \
\
/* --- @pre_cbcgetiv@ --- * \
* \
* Arguments: @const pre_cbcctx *ctx@ = pointer to CBC context block \
- * @void *iv#@ = pointer to output data block \
+ * @void *iv@ = pointer to output data block \
* \
* Returns: --- \
* \
* process. \
*/ \
\
-void pre ## _cbcgetiv(const pre ## _cbcctx *ctx, void *iv) \
-{ \
- BLKC_STORE(PRE, iv, ctx->iv); \
-} \
+extern void pre##_cbcgetiv(const pre##_cbcctx */*ctx*/, \
+ void */*iv*/); \
\
/* --- @pre_cbcsetiv@ --- * \
* \
* Use: Sets the IV to use for subsequent encryption. \
*/ \
\
-void pre ## _cbcsetiv(pre ## _cbcctx *ctx, const void *iv) \
-{ \
- BLKC_LOAD(PRE, ctx->iv, iv); \
-} \
+extern void pre##_cbcsetiv(pre##_cbcctx */*ctx*/, \
+ const void */*iv*/); \
\
/* --- @pre_cbcsetkey@ --- * \
* \
* Use: Sets the CBC context to use a different cipher key. \
*/ \
\
-void pre ## _cbcsetkey(pre ## _cbcctx *ctx, const pre ## _ctx *k) \
-{ \
- ctx->ctx = *k; \
-} \
+extern void pre##_cbcsetkey(pre##_cbcctx */*ctx*/, \
+ const pre##_ctx */*k*/); \
\
/* --- @pre_cbcinit@ --- * \
* \
* to @pre_init@, @pre_cbcsetkey@ and @pre_cbcsetiv@. \
*/ \
\
-void pre ## _cbcinit(pre ## _cbcctx *ctx, \
- const void *key, size_t sz, \
- const void *iv) \
-{ \
- static octet zero[PRE ## _BLKSZ] = { 0 }; \
- pre ## _init(&ctx->ctx, key, sz); \
- BLKC_LOAD(PRE, ctx->iv, iv ? iv : zero); \
-} \
+extern void pre##_cbcinit(pre##_cbcctx */*ctx*/, \
+ const void */*key*/, size_t /*sz*/, \
+ const void */*iv*/); \
\
/* --- @pre_cbcencrypt@ --- * \
* \
* chunks, although decryption must use the same chunks. \
*/ \
\
-void pre ## _cbcencrypt(pre ## _cbcctx *ctx, \
- const void *src, void *dest, \
- size_t sz) \
-{ \
- const octet *s = src; \
- octet *d = dest; \
- \
- /* --- Empty blocks are trivial --- */ \
- \
- if (!sz) \
- return; \
- \
- /* --- Extra magical case for a short block --- * \
- * \
- * Encrypt the IV, then exclusive-or the plaintext with the octets \
- * of the encrypted IV, shifting ciphertext octets in instead. This \
- * basically switches over to CFB. \
- */ \
- \
- if (sz < PRE ## _BLKSZ) { \
- octet b[PRE ## _BLKSZ]; \
- unsigned i; \
- \
- pre ## _eblk(&ctx->ctx, ctx->iv, ctx->iv); \
- BLKC_STORE(PRE, b, ctx->iv); \
- for (i = 0; i < sz; i++) \
- d[i] = b[i] ^ s[i]; \
- memmove(b, b + sz, PRE ## _BLKSZ - sz); \
- memcpy(b + PRE ## _BLKSZ - sz, d, sz); \
- BLKC_LOAD(PRE, ctx->iv, b); \
- return; \
- } \
- \
- /* --- Do the main chunk of encryption --- * \
- * \
- * This will do the whole lot if it's a whole number of blocks. For \
- * each block, XOR it with the previous ciphertext in @iv@, encrypt, \
- * and keep a copy of the ciphertext for the next block. \
- */ \
- \
- while (sz >= 2 * PRE ## _BLKSZ || sz == PRE ## _BLKSZ) { \
- BLKC_XLOAD(PRE, ctx->iv, s); \
- pre ## _eblk(&ctx->ctx, ctx->iv, ctx->iv); \
- BLKC_STORE(PRE, d, ctx->iv); \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- sz -= PRE ## _BLKSZ; \
- } \
- \
- /* --- Do the tail-end block and bit-left-over --- * \
- * \
- * This isn't very efficient. That shouldn't matter much. \
- */ \
- \
- if (sz) { \
- octet b[PRE ## _BLKSZ]; \
- unsigned i; \
- \
- /* --- Let @sz@ be the size of the partial block --- */ \
- \
- sz -= PRE ## _BLKSZ; \
- \
- /* --- First stage --- * \
- * \
- * XOR the complete block with the current IV, and encrypt it. The \
- * first part of the result is the partial ciphertext block. Don't \
- * write that out yet, because I've not read the partial plaintext \
- * block. \
- */ \
- \
- BLKC_XLOAD(PRE, ctx->iv, s); \
- pre ## _eblk(&ctx->ctx, ctx->iv, ctx->iv); \
- BLKC_STORE(PRE, b, ctx->iv); \
- \
- /* --- Second stage --- * \
- * \
- * Now XOR in the partial plaintext block, writing out the \
- * ciphertext as I go. Then encrypt, and write the complete \
- * ciphertext block. \
- */ \
- \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- for (i = 0; i < sz; i++) { \
- register octet x = b[i]; \
- b[i] ^= s[i]; \
- d[i] = x; \
- } \
- BLKC_LOAD(PRE, ctx->iv, b); \
- pre ## _eblk(&ctx->ctx, ctx->iv, ctx->iv); \
- BLKC_STORE(PRE, d - PRE ## _BLKSZ, ctx->iv); \
- } \
- \
- /* --- Done --- */ \
- \
- return; \
-} \
+extern void pre##_cbcencrypt(pre##_cbcctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
\
/* --- @pre_cbcdecrypt@ --- * \
* \
* \
* Returns: --- \
* \
- * Use: Encrypts a block with a block cipher in CBC mode, with \
+ * Use: Decrypts a block with a block cipher in CBC mode, with \
* ciphertext stealing and other clever tricks. \
* Essentially, data can be encrypted in arbitrary sized \
* chunks, although decryption must use the same chunks. \
*/ \
\
-void pre ## _cbcdecrypt(pre ## _cbcctx *ctx, \
- const void *src, void *dest, \
- size_t sz) \
-{ \
- const octet *s = src; \
- octet *d = dest; \
- \
- /* --- Empty blocks are trivial --- */ \
- \
- if (!sz) \
- return; \
- \
- /* --- Extra magical case for a short block --- * \
- * \
- * Encrypt the IV, then exclusive-or the ciphertext with the octets \
- * of the encrypted IV, shifting ciphertext octets in instead. This \
- * basically switches over to CFB. \
- */ \
- \
- if (sz < PRE ## _BLKSZ) { \
- octet b[PRE ## _BLKSZ], c[PRE ## _BLKSZ]; \
- unsigned i; \
+extern void pre##_cbcdecrypt(pre##_cbcctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
\
- pre ## _eblk(&ctx->ctx, ctx->iv, ctx->iv); \
- BLKC_STORE(PRE, b, ctx->iv); \
- for (i = 0; i < sz; i++) { \
- register octet x = s[i]; \
- d[i] = b[i] ^ x; \
- c[i] = x; \
- } \
- memmove(b, b + sz, PRE ## _BLKSZ - sz); \
- memcpy(b + PRE ## _BLKSZ - sz, c, sz); \
- BLKC_LOAD(PRE, ctx->iv, b); \
- return; \
- } \
+/* --- Generic cipher interface --- */ \
\
- /* --- Do the main chunk of decryption --- * \
- * \
- * This will do the whole lot if it's a whole number of blocks. For \
- * each block, decrypt, XOR it with the previous ciphertext in @iv@, \
- * and keep a copy of the ciphertext for the next block. \
- */ \
- \
- while (sz >= 2 * PRE ## _BLKSZ || sz == PRE ## _BLKSZ) { \
- uint32 b[PRE ## _BLKSZ / 4], niv[PRE ## _BLKSZ / 4]; \
- BLKC_LOAD(PRE, niv, s); \
- pre ## _dblk(&ctx->ctx, niv, b); \
- BLKC_XSTORE(PRE, d, b, ctx->iv); \
- BLKC_MOVE(PRE, ctx->iv, niv); \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- sz -= PRE ## _BLKSZ; \
- } \
- \
- /* --- Do the tail-end block and bit-left-over --- * \
- * \
- * This isn't very efficient. That shouldn't matter much. \
- */ \
- \
- if (sz) { \
- octet b[PRE ## _BLKSZ]; \
- uint32 bk[PRE ## _BLKSZ / 4], niv[PRE ## _BLKSZ / 4]; \
- unsigned i; \
- \
- /* --- Let @sz@ be the size of the partial block --- */ \
- \
- sz -= PRE ## _BLKSZ; \
- \
- /* --- First stage --- * \
- * \
- * Take the complete ciphertext block, and decrypt it. This block \
- * is carried over for the next encryption operation. \
- */ \
- \
- BLKC_LOAD(PRE, niv, s); \
- pre ## _dblk(&ctx->ctx, niv, bk); \
- \
- /* --- Second stage --- * \
- * \
- * XORing the first few bytes of this with the partial ciphertext \
- * block recovers the partial plaintext block. At the same time, \
- * write the partial ciphertext block's contents in ready for stage \
- * three. \
- */ \
- \
- BLKC_STORE(PRE, b, bk); \
- s += PRE ## _BLKSZ; \
- d += PRE ## _BLKSZ; \
- for (i = 0; i < sz; i++) { \
- register octet x = s[i]; \
- d[i] = b[i] ^ x; \
- b[i] = x; \
- } \
- \
- /* --- Third stage --- * \
- * \
- * Decrypt the block we've got left, and XOR with the initial IV to \
- * recover the complete plaintext block. \
- */ \
- \
- BLKC_LOAD(PRE, bk, b); \
- pre ## _dblk(&ctx->ctx, bk, bk); \
- BLKC_XSTORE(PRE, d - PRE ## _BLKSZ, bk, ctx->iv); \
- BLKC_MOVE(PRE, ctx->iv, niv); \
- } \
- \
- /* --- Done --- */ \
- \
- return; \
-} \
- \
-CBC_TEST(PRE, pre)
-
-/*----- Test rig ----------------------------------------------------------*/
-
-#ifdef TEST_RIG
-
-#include <stdio.h>
-
-#include "daftstory.h"
-
-/* --- @CBC_TEST@ --- *
- *
- * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
- *
- * Use: Standard test rig for CBC functions.
- */
-
-#define CBC_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 ## _cbcctx ctx; \
- pre ## _ctx k; \
- int status = 0; \
- int done = 0; \
- \
- size_t keysz = PRE ## _KEYSZ ? \
- PRE ## _KEYSZ : strlen((const char *)key); \
- \
- fputs(#pre "-cbc: ", stdout); \
- \
- pre ## _init(&k, key, keysz); \
- pre ## _cbcsetkey(&ctx, &k); \
- \
- while (sz <= sizeof(text)) { \
- rest = sizeof(text) - sz; \
- memcpy(ct, text, sizeof(text)); \
- pre ## _cbcsetiv(&ctx, iv); \
- pre ## _cbcencrypt(&ctx, ct, ct, sz); \
- pre ## _cbcencrypt(&ctx, ct + sz, ct + sz, rest); \
- memcpy(pt, ct, sizeof(text)); \
- pre ## _cbcsetiv(&ctx, iv); \
- pre ## _cbcdecrypt(&ctx, pt, pt, sz); \
- pre ## _cbcdecrypt(&ctx, pt + sz, pt + sz, rest); \
- 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 CBC_TEST(PRE, pre)
-#endif
+extern const gccipher pre##_cbc;
/*----- That's all, folks -------------------------------------------------*/
projects / u / mdw / catacomb / blobdiff