--- /dev/null
+/* -*-c-*-
+ *
+ * Block cipher counter mode (or long cycle mode)
+ *
+ * (c) 2000 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_COUNTER_H
+#define CATACOMB_COUNTER_H
+
+#ifdef __cplusplus
+ extern "C" {
+#endif
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <stddef.h>
+
+#include <mLib/bits.h>
+
+#ifndef CATACOMB_GCIPHER_H
+# include "gcipher.h"
+#endif
+
+#ifndef CATACOMB_GRAND_H
+# include "grand.h"
+#endif
+
+/*----- Macros ------------------------------------------------------------*/
+
+/* --- @COUNTER_DECL@ --- *
+ *
+ * Arguments: @PRE@, @pre@ = prefixes for block cipher definitions
+ *
+ * Use: Makes declarations for counter mode.
+ */
+
+#define COUNTER_DECL(PRE, pre) \
+ \
+/* --- Counter mode context --- */ \
+ \
+typedef struct pre##_counterctx { \
+ pre##_ctx ctx; /* Underlying cipher context */ \
+ unsigned off; /* Current offset in buffer */ \
+ octet buf[PRE##_BLKSZ]; /* Output buffer */ \
+ uint32 n[PRE##_BLKSZ / 4]; /* Counter */ \
+} pre##_counterctx; \
+ \
+/* --- @pre_countergetiv@ --- * \
+ * \
+ * Arguments: @const pre_counterctx *ctx@ = pointer to counter \
+ * context \
+ * @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##_countergetiv(const pre##_counterctx */*ctx*/, \
+ void */*iv*/); \
+ \
+/* --- @pre_countersetiv@ --- * \
+ * \
+ * Arguments: @pre_counterctx *ctx@ = pointer to counter context \
+ * @cnost void *iv@ = pointer to IV to set \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Sets the IV to use for subsequent encryption. \
+ */ \
+ \
+extern void pre##_countersetiv(pre##_counterctx */*ctx*/, \
+ const void */*iv*/); \
+ \
+/* --- @pre_counterbdry@ --- * \
+ * \
+ * Arguments: @pre_counterctx *ctx@ = pointer to counter context \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Inserts a boundary during encryption. Successful \
+ * decryption must place a similar boundary. \
+ */ \
+ \
+extern void pre##_counterbdry(pre##_counterctx */*ctx*/); \
+ \
+/* --- @pre_countersetkey@ --- * \
+ * \
+ * Arguments: @pre_counterctx *ctx@ = pointer to counter context \
+ * @const pre_ctx *k@ = pointer to cipher context \
+ * \
+ * Returns: --- \
+ * \
+ * Use: Sets the counter context to use a different cipher key. \
+ */ \
+ \
+extern void pre##_countersetkey(pre##_counterctx */*ctx*/, \
+ const pre##_ctx */*k*/); \
+ \
+/* --- @pre_counterinit@ --- * \
+ * \
+ * Arguments: @pre_counterctx *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 counter context ready for use. You \
+ * should ensure that the IV chosen is unique: reusing an \
+ * IV will compromise the security of the entire \
+ * plaintext. This is equivalent to calls to @pre_init@, \
+ * @pre_countersetkey@ and @pre_countersetiv@. \
+ */ \
+ \
+extern void pre##_counterinit(pre##_counterctx */*ctx*/, \
+ const void */*key*/, size_t /*sz*/, \
+ const void */*iv*/); \
+ \
+/* --- @pre_counterencrypt@ --- * \
+ * \
+ * Arguments: @pre_counterctx *ctx@ = pointer to counter context \
+ * @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 or decrypts a block with a block cipher in \
+ * counter mode: encryption and decryption are the same in \
+ * counter. The destination may be null to just churn the \
+ * feedback round for a bit. The source may be null to \
+ * use the cipher as a random data generator. \
+ */ \
+ \
+extern void pre##_counterencrypt(pre##_counterctx */*ctx*/, \
+ const void */*src*/, void */*dest*/, \
+ size_t /*sz*/); \
+ \
+/* --- @pre_counterrand@ --- * \
+ * \
+ * Arguments: @const void *k@ = pointer to key material \
+ * @size_t sz@ = size of key material \
+ * \
+ * Returns: Pointer to generic random number generator interface. \
+ * \
+ * Use: Creates a random number interface wrapper around an \
+ * counter-mode block cipher. \
+ */ \
+ \
+extern grand *pre##_counterrand(const void */*k*/, size_t /*sz*/); \
+ \
+/* --- Generic cipher interface --- */ \
+ \
+extern const gccipher pre##_counter;
+
+/*----- That's all, folks -------------------------------------------------*/
+
+#ifdef __cplusplus
+ }
+#endif
+
+#endif
projects / u / mdw / catacomb / blobdiff