X-Git-Url: https://git.distorted.org.uk/u/mdw/catacomb/blobdiff_plain/ba6e6b64033b1f9de49feccb5c9cd438354481f7..0f00dc4c8eb47e67bc0f148c2dd109f73a451e0a:/symm/blowfish.c?ds=sidebyside

diff --git a/symm/blowfish.c b/symm/blowfish.c
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+/* -*-c-*-
+ *
+ * The Blowfish block cipher
+ *
+ * (c) 1998 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.
+ */
+
+/*----- Header files ------------------------------------------------------*/
+
+#include <mLib/bits.h>
+
+#include "blowfish.h"
+#include "blowfish-tab.h"
+#include "blkc.h"
+#include "gcipher.h"
+#include "paranoia.h"
+
+/*----- Global variables --------------------------------------------------*/
+
+static const blowfish_ctx ikey = BLOWFISH_IKEY;
+
+const octet blowfish_keysz[] = { KSZ_RANGE, BLOWFISH_KEYSZ, 1, 56, 1 };
+
+/*----- Macros ------------------------------------------------------------*/
+
+#define ROUND(k, x, y, r) do {						\
+  x ^= *r;								\
+  y ^= ((k->s0[U8(x >> 24)] +						\
+	 k->s1[U8(x >> 16)]) ^						\
+	 k->s2[U8(x >>	8)]) +						\
+	 k->s3[U8(x >>	0)];						\
+} while (0)
+
+#define EBLK(k, a, b, c, d) do {					\
+  const uint32 *_r = k->p;						\
+  uint32 _x = a;							\
+  uint32 _y = b;							\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  ROUND(k, _x, _y, _r++);						\
+  ROUND(k, _y, _x, _r++);						\
+  c = _y ^ k->p[17];							\
+  d = _x ^ k->p[16];							\
+} while (0)
+
+#define DBLK(k, a, b, c, d) do {					\
+  const uint32 *_r = k->p + 18;						\
+  uint32 _x = a;							\
+  uint32 _y = b;							\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  ROUND(k, _x, _y, --_r);						\
+  ROUND(k, _y, _x, --_r);						\
+  c = _y ^ k->p[0];							\
+  d = _x ^ k->p[1];							\
+} while (0)
+
+/*----- Low-level encryption interface ------------------------------------*/
+
+/* --- @blowfish_init@ --- *
+ *
+ * Arguments:	@blowfish_ctx *k@ = pointer to key block to fill in
+ *		@const void *buf@ = pointer to buffer of key material
+ *		@size_t sz@ = size of key material
+ *
+ * Returns:	---
+ *
+ * Use:		Initializes a Blowfish key buffer.  Blowfish accepts
+ *		a more-or-less arbitrary size key.
+ */
+
+void blowfish_init(blowfish_ctx *k, const void *buf, size_t sz)
+{
+  KSZ_ASSERT(blowfish, sz);
+
+  /* --- Copy the initial value over --- */
+
+  memcpy(k, &ikey, sizeof(ikey));
+
+  /* --- Initialize the %$P$% array --- */
+
+  {
+    const octet *p = buf;
+    const octet *q = p + sz;
+    int i = 0, j = 0;
+    uint32 x = 0;
+
+    while (i < 18) {
+      x = (x << 8) | U8(*p++);
+      if (p >= q)
+	p = buf;
+      if (++j >= 4) {
+	k->p[i++] ^= x;
+	x = 0;
+	j = 0;
+      }
+    }
+
+    x = 0;
+  }
+
+  /* --- Now mangle the complete array of keys --- */
+
+  {
+    uint32 b[2];
+    int i;
+
+    b[0] = b[1] = 0;
+
+    for (i = 0; i < 18; i += 2) {
+      blowfish_eblk(k, b, b);
+      k->p[i] = b[0]; k->p[i + 1] = b[1];
+    }
+
+    for (i = 0; i < 256; i += 2) {
+      blowfish_eblk(k, b, b);
+      k->s0[i] = b[0]; k->s0[i + 1] = b[1];
+    }
+
+    for (i = 0; i < 256; i += 2) {
+      blowfish_eblk(k, b, b);
+      k->s1[i] = b[0]; k->s1[i + 1] = b[1];
+    }
+
+    for (i = 0; i < 256; i += 2) {
+      blowfish_eblk(k, b, b);
+      k->s2[i] = b[0]; k->s2[i + 1] = b[1];
+    }
+
+    for (i = 0; i < 256; i += 2) {
+      blowfish_eblk(k, b, b);
+      k->s3[i] = b[0]; k->s3[i + 1] = b[1];
+    }
+
+    BURN(b);
+  }
+}
+
+/* --- @blowfish_eblk@, @blowfish_dblk@ --- *
+ *
+ * Arguments:	@const blowfish_ctx *k@ = pointer to key block
+ *		@const uint32 s[2]@ = pointer to source block
+ *		@uint32 d[2]@ = pointer to destination block
+ *
+ * Returns:	---
+ *
+ * Use:		Low-level block encryption and decryption.
+ */
+
+void blowfish_eblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
+{
+  EBLK(k, s[0], s[1], d[0], d[1]);
+}
+
+void blowfish_dblk(const blowfish_ctx *k, const uint32 *s, uint32 *d)
+{
+  DBLK(k, s[0], s[1], d[0], d[1]);
+}
+
+BLKC_TEST(BLOWFISH, blowfish)
+
+/*----- That's all, folks -------------------------------------------------*/