--- /dev/null
+/* -*-c-*-
+ *
+ * Ciphertext feedback for block ciphers
+ *
+ * (c) 1999 Straylight/Edgeware
+ */
+
+/*----- Licensing notice --------------------------------------------------*
+ *
+ * This file is part of Catacomb.
+ *
+ * Catacomb is free software; you can redistribute it and/or modify
+ * 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.
+ */
+
+#ifndef CATACOMB_CFB_H
+#define CATACOMB_CFB_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+#ifndef CATACOMB_GCIPHER_H
+# include "gcipher.h"
+#endif
+
+/*----- Data structures ---------------------------------------------------*/
+
+/* --- @CFB_DECL@ --- *
+ *
+ * Arguments: @PRE@, @pre@ = prefixes for the underlying block cipher
+ *
+ * Use: Creates declarations for CFB mode.
+ */
+
+#define CFB_DECL(PRE, pre) \
+ \
+/* --- Ciphertext feedback context --- */ \
+ \
+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 \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Reads the currently set IV. Reading and setting an IV \
+ * is not transparent to the cipher. It will add a `step' \
+ * which must be matched by a similar operation during \
+ * decryption. \
+ */ \
+ \
+extern void pre##_cfbgetiv(const pre##_cfbctx */*ctx*/, \
+ void */*iv*/); \
+ \
+/* --- @pre_cfbsetiv@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
+ * @cnost void *iv@ = pointer to IV to set \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Sets the IV to use for subsequent encryption. \
+ */ \
+ \
+extern void pre##_cfbsetiv(pre##_cfbctx */*ctx*/, \
+ const void */*iv*/); \
+ \
+/* --- @pre_cfbbdry@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Inserts a boundary during encryption. Successful \
+ * decryption must place a similar boundary. \
+ */ \
+ \
+extern void pre##_cfbbdry(pre##_cfbctx */*ctx*/); \
+ \
+/* --- @pre_cfbsetkey@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
+ * @const pre_ctx *k@ = pointer to cipher context \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Sets the CFB context to use a different cipher key. \
+ */ \
+ \
+extern void pre##_cfbsetkey(pre##_cfbctx */*ctx*/, \
+ const pre##_ctx */*k*/); \
+ \
+/* --- @pre_cfbinit@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to cipher context \
+ * @const void *key@ = pointer to the key buffer \
+ * @size_t sz@ = size of the key \
+ * @const void *iv@ = pointer to initialization vector \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Initializes a CFB context ready for use. You should \
+ * ensure that the IV chosen is unique: reusing an IV will \
+ * compromise the security of at least the first block \
+ * encrypted. This is equivalent to calls to @pre_init@, \
+ * @pre_cfbsetkey@ and @pre_cfbsetiv@. \
+ */ \
+ \
+extern void pre##_cfbinit(pre##_cfbctx */*ctx*/, \
+ const void */*key*/, size_t /*sz*/, \
+ const void */*iv*/); \
+ \
+/* --- @pre_cfbencrypt@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
+ * @const void *src@ = pointer to source data \
+ * @void *dest@ = pointer to destination data \
+ * @size_t sz@ = size of block to be encrypted \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Encrypts 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. \
+ */ \
+ \
+extern void pre##_cfbencrypt(pre##_cfbctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
+ \
+/* --- @pre_cfbencrypt@ --- * \
+ * \
+ * Arguments: @pre_cfbctx *ctx@ = pointer to CFB context block \
+ * @const void *src@ = pointer to source data \
+ * @void *dest@ = pointer to destination data \
+ * @size_t sz@ = size of block to be encrypted \
+ * \
+ * Returns: --- \
+ * \
+ * 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. \
+ */ \
+ \
+extern void pre##_cfbdecrypt(pre##_cfbctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
+ \
+/* --- Generic cipher interface --- */ \
+ \
+extern const gccipher pre##_cfb;
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
projects / u / mdw / catacomb / blobdiff