Generic cipher and RNG interfaces.

diff --git a/rc4.c b/rc4.c
index 6417635..b1e9d67 100644 (file)
--- a/rc4.c
+++ b/rc4.c
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rc4.c,v 1.1 1999/09/03 08:41:12 mdw Exp $
+ * $Id: rc4.c,v 1.2 1999/12/10 23:27:35 mdw Exp $
  *
  * The alleged RC4 stream cipher
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: rc4.c,v $
+ * Revision 1.2  1999/12/10 23:27:35  mdw
+ * Generic cipher and RNG interfaces.
+ *
  * Revision 1.1  1999/09/03 08:41:12  mdw
  * Initial import.
  *
@@ -38,10 +41,14 @@
 /*----- Header files ------------------------------------------------------*/
 
 #include <assert.h>
+#include <stdarg.h>
 #include <stdio.h>
 
 #include <mLib/bits.h>
+#include <mLib/sub.h>
 
+#include "gcipher.h"
+#include "grand.h"
 #include "rc4.h"
 
 /*----- Main code ---------------------------------------------------------*/
@@ -77,15 +84,6 @@ void rc4_init(rc4_ctx *ctx, const void *k, size_t sz)
     if (p == q)
       p = k;
   }
-
-#ifdef notdef
-  for (i = 0; i < 256; i += 16) {
-    printf("%3d :", i);
-    for (j = i; j < i + 16; j++)
-      printf(" %02x", ctx->s[j]);
-    putchar('\n');
-  }
-#endif
 }
 
 /* --- @rc4_encrypt@ --- *
@@ -119,6 +117,150 @@ void rc4_encrypt(rc4_ctx *ctx, const void *src, void *dest, size_t sz)
             while (sz) { unsigned x; RC4_BYTE(x); *d++ = *s++ ^ x; sz--; });
 }
 
+/*----- Generic cipher interface ------------------------------------------*/
+
+typedef struct gctx {
+  gcipher c;
+  rc4_ctx rc4;
+} gctx;
+
+static const gcipher_ops gops;
+
+static gcipher *ginit(const void *k, size_t sz)
+{
+  gctx *g = CREATE(gctx);
+  g->c.ops = &gops;
+  rc4_init(&g->rc4, k, sz);
+  return (&g->c);
+}
+
+static void gencrypt(gcipher *c, const void *s, void *t, size_t sz)
+{
+  gctx *g = (gctx *)c;
+  rc4_encrypt(&g->rc4, s, t, sz);
+}
+
+static void gdestroy(gcipher *c)
+{
+  gctx *g = (gctx *)c;
+  DESTROY(g);
+}
+
+static const gcipher_ops gops = {
+  &rc4.b,
+  gencrypt, gencrypt, gdestroy, 0, 0
+};
+
+const gccipher rc4 = {
+  { "rc4", 0, 0 },
+  ginit
+};
+
+/*----- Generic random number generator interface -------------------------*/
+
+typedef struct grctx {
+  grand r;
+  rc4_ctx rc4;
+} grctx;
+
+static void grdestroy(grand *r)
+{
+  grctx *g = (grctx *)r;
+  DESTROY(g);
+}
+
+static int grmisc(grand *r, unsigned op, ...)
+{
+  grctx *g = (grctx *)r;
+  va_list ap;
+  int rc = 0;
+  octet buf[4];
+  va_start(ap, op);
+
+  switch (op) {
+    case GRAND_CHECK:
+      switch (va_arg(ap, unsigned)) {
+       case GRAND_CHECK:
+       case GRAND_SEEDINT:
+       case GRAND_SEEDUINT32:
+       case GRAND_SEEDBLOCK:
+         rc = 1;
+         break;
+       default:
+         rc = 0;
+         break;
+      }
+      break;
+    case GRAND_SEEDINT:
+      STORE32(buf, va_arg(ap, unsigned));
+      rc4_init(&g->rc4, buf, sizeof(buf));
+      break;
+    case GRAND_SEEDUINT32:
+      STORE32(buf, va_arg(ap, uint32));
+      rc4_init(&g->rc4, buf, sizeof(buf));
+      break;
+    case GRAND_SEEDBLOCK: {
+      const void *p = va_arg(ap, const void *);
+      size_t sz = va_arg(ap, size_t);
+      rc4_init(&g->rc4, p, sz);
+    } break;
+  }
+
+  va_end(ap);
+  return (rc);
+}
+
+static octet grbyte(grand *r)
+{
+  grctx *g = (grctx *)r;
+  octet o;
+  RC4_OPEN(&g->rc4, RC4_BYTE(o););
+  return (o);
+}
+
+static uint32 grword(grand *r)
+{
+  grctx *g = (grctx *)r;
+  octet b[4];
+  int i;
+  RC4_OPEN(&g->rc4,
+          for (i = 0; i < sizeof(b); i++)
+            RC4_BYTE(b[i]););
+  return (LOAD32(b));
+}
+
+static void grfill(grand *r, void *p, size_t sz)
+{
+  grctx *g = (grctx *)r;
+  rc4_encrypt(&g->rc4, 0, p, sz);
+}
+
+static const grand_ops grops = {
+  "rc4",
+  0,
+  grmisc, grdestroy,
+  grword, grbyte, grword, grand_range, grfill
+};
+
+/* --- @rc4_rand@ --- *
+ *
+ * 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
+ *             OFB-mode block cipher.
+ */
+
+grand *rc4_rand(const void *k, size_t sz)
+{
+  grctx *g = CREATE(grctx);
+  g->r.ops = &grops;
+  rc4_init(&g->rc4, k, sz);
+  return (&g->r);
+}
+
 /*----- Test rig ----------------------------------------------------------*/
 
 #ifdef TEST_RIG

diff --git a/rc4.h b/rc4.h
index adaf731..b1acc23 100644 (file)
--- a/rc4.h
+++ b/rc4.h
@@ -1,6 +1,6 @@
 /* -*-c-*-
  *
- * $Id: rc4.h,v 1.1 1999/09/03 08:41:12 mdw Exp $
+ * $Id: rc4.h,v 1.2 1999/12/10 23:27:46 mdw Exp $
  *
  * The alleged RC4 stream cipher
  *
@@ -30,6 +30,9 @@
 /*----- Revision history --------------------------------------------------* 
  *
  * $Log: rc4.h,v $
+ * Revision 1.2  1999/12/10 23:27:46  mdw
+ * Generic cipher and RNG interfaces.
+ *
  * Revision 1.1  1999/09/03 08:41:12  mdw
  * Initial import.
  *
@@ -43,8 +46,8 @@
  * list.
  */
 
-#ifndef RC4_H
-#define RC4_H
+#ifndef CATACOMB_RC4_H
+#define CATACOMB_RC4_H
 
 #ifdef __cplusplus
   extern "C" {
@@ -56,6 +59,14 @@
 
 #include <mLib/bits.h>
 
+#ifndef CATACOMB_GCIPHER_H
+#  include "gcipher.h"
+#endif
+
+#ifndef CATACOMB_GRAND_H
+#  include "grand.h"
+#endif
+
 /*----- Data structures ---------------------------------------------------*/
 
 typedef struct rc4_ctx {
@@ -151,6 +162,25 @@ extern void rc4_encrypt(rc4_ctx */*ctx*/,
                        const void */*src*/, void */*dest*/,
                        size_t /*sz*/);
 
+/*----- Generic cipher interface ------------------------------------------*/
+
+extern const gccipher rc4;
+
+/*----- Generic random number generator interface -------------------------*/
+
+/* --- @rc4_rand@ --- *
+ *
+ * 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
+ *             OFB-mode block cipher.
+ */
+
+extern grand *rc4_rand(const void */*k*/, size_t /*sz*/);
+
 /*----- That's all, folks -------------------------------------------------*/
 
 #ifdef __cplusplus