X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/57f459eb156e56404ac41ed0fed9f4066e9f1c1d..HEAD:/symm/counter-def.h

diff --git a/symm/counter-def.h b/symm/counter-def.h
index 2744430c..3c949c7a 100644
--- a/symm/counter-def.h
+++ b/symm/counter-def.h
@@ -56,6 +56,10 @@
 #  include "paranoia.h"
 #endif
 
+#ifndef CATACOMB_RSVR_H
+#  include "rsvr.h"
+#endif
+
 /*----- Macros ------------------------------------------------------------*/
 
 /* --- @COUNTER_DEF@ --- *
@@ -84,9 +88,7 @@
  */									\
 									\
 void pre##_countergetiv(const pre##_counterctx *ctx, void *iv)		\
-{									\
-  BLKC_STORE(PRE, iv, ctx->n);						\
-}									\
+  { BLKC_STORE(PRE, iv, ctx->c); }					\
 									\
 /* --- @pre_countersetiv@ --- *						\
  *									\
@@ -99,10 +101,7 @@ void pre##_countergetiv(const pre##_counterctx *ctx, void *iv)		\
  */									\
 									\
 void pre##_countersetiv(pre##_counterctx *ctx, const void *iv)		\
-{									\
-  BLKC_LOAD(PRE, ctx->n, iv);						\
-  ctx->off = PRE##_BLKSZ;						\
-}									\
+  { BLKC_LOAD(PRE, ctx->c, iv); ctx->off = PRE##_BLKSZ; }		\
 									\
 /* --- @pre_counterbdry@ --- *						\
  *									\
@@ -115,10 +114,7 @@ void pre##_countersetiv(pre##_counterctx *ctx, const void *iv)		\
  */									\
 									\
 void pre##_counterbdry(pre##_counterctx *ctx)				\
-{									\
-  BLKC_STEP(PRE, ctx->n);						\
-  ctx->off = PRE##_BLKSZ;						\
-}									\
+  { BLKC_STEP(PRE, ctx->c); ctx->off = PRE##_BLKSZ; }			\
 									\
 /* --- @pre_countersetkey@ --- *					\
  *									\
@@ -131,9 +127,7 @@ void pre##_counterbdry(pre##_counterctx *ctx)				\
  */									\
 									\
 void pre##_countersetkey(pre##_counterctx *ctx, const pre##_ctx *k)	\
-{									\
-  ctx->ctx = *k;							\
-}									\
+  { ctx->ctx = *k; }							\
 									\
 /* --- @pre_counterinit@ --- *						\
  *									\
@@ -156,6 +150,7 @@ void pre##_counterinit(pre##_counterctx *ctx,				\
 		       const void *iv)					\
 {									\
   static const octet zero[PRE##_BLKSZ] = { 0 };				\
+									\
   pre##_init(&ctx->ctx, key, sz);					\
   pre##_countersetiv(ctx, iv ? iv : zero);				\
 }									\
@@ -176,81 +171,66 @@ void pre##_counterinit(pre##_counterctx *ctx,				\
  *		use the cipher as a random data generator.		\
  */									\
 									\
+static const rsvr_policy pre##_counterpolicy =				\
+  { 0, PRE##_BLKSZ, PRE##_BLKSZ };					\
+									\
 void pre##_counterencrypt(pre##_counterctx *ctx,			\
 			  const void *src, void *dest,			\
 			  size_t sz)					\
 {									\
-  const octet *s = src;							\
+  rsvr_plan plan;							\
+  const octet *s = src, *p;						\
   octet *d = dest;							\
-  unsigned off = ctx->off;						\
-									\
-  /* --- Empty blocks are trivial --- */				\
-									\
-  if (!sz)								\
-    return;								\
-									\
-  /* --- If I can deal with the block from my buffer, do that --- */	\
-									\
-  if (sz < PRE##_BLKSZ - off)						\
-    goto small;								\
-									\
-  /* --- Finish off what's left in my buffer --- */			\
-									\
-  if (!d)								\
-    sz -= PRE##_BLKSZ - off;						\
-  else {								\
-    while (off < PRE##_BLKSZ) {						\
-      register octet x = s ? *s++ : 0;					\
-      *d++ = ctx->buf[off++] ^ x;					\
-      sz--;								\
+  uint32 t[PRE##_BLKSZ/4];						\
+									\
+  /* Construct a plan and prepare to follow through. */			\
+  rsvr_mkplan(&plan, &pre##_counterpolicy, ctx->off, sz);		\
+									\
+  /* Initial portion, fulfilled from the buffer.  If the chunk is small	\
+   * enough, then this will be the only portion.  If the buffer is	\
+   * currently empty, then we must prepare it.				\
+   */									\
+  if (plan.head) {							\
+    if (!ctx->off) {							\
+      pre##_eblk(&ctx->ctx, ctx->c, t); BLKC_STEP(PRE, ctx->c);		\
+      BLKC_STORE(PRE, ctx->b, t);					\
     }									\
+    p = ctx->b + ctx->off; ctx->off += plan.head;			\
+    if (!d) /* nothing to do */;					\
+    else if (!s) { memcpy(d, p, plan.head); d += plan.head; }		\
+    else while (plan.head--) *d++ = *s++ ^ *p++;			\
   }									\
 									\
-  /* --- Main encryption loop --- */					\
-									\
-  {									\
-    uint32 n[PRE##_BLKSZ / 4];						\
-									\
-    for (;;) {								\
-      pre##_eblk(&ctx->ctx, ctx->n, n);					\
-      BLKC_STEP(PRE, ctx->n);						\
-      if (sz < PRE##_BLKSZ)						\
-	break;								\
-      if (d) {								\
-	if (!s)								\
-	  BLKC_STORE(PRE, d, n);					\
-	else {								\
-	  uint32 x[PRE##_BLKSZ / 4];					\
-	  BLKC_LOAD(PRE, x, s);						\
-	  BLKC_XSTORE(PRE, d, n, x);					\
-	  s += PRE##_BLKSZ;						\
-	}								\
-	d += PRE##_BLKSZ;						\
-      }									\
-      sz -= PRE##_BLKSZ;						\
-    }									\
+  /* If the buffer is all used, then reset it ready for next time. */	\
+  ctx->off -= plan.from_rsvr;						\
 									\
-    BLKC_STORE(PRE, ctx->buf, n);					\
-    off = 0;								\
+  /* Handle multiple whole blocks. */					\
+  if (!d)								\
+    BLKC_ADD(PRE, ctx->c, plan.from_input/PRE##_BLKSZ);			\
+  else if (!s) while (plan.from_input) {				\
+    pre##_eblk(&ctx->ctx, ctx->c, t); BLKC_STEP(PRE, ctx->c);		\
+    BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ;				\
+    plan.from_input -= PRE##_BLKSZ;					\
+  } else while (plan.from_input) {					\
+    pre##_eblk(&ctx->ctx, ctx->c, t); BLKC_STEP(PRE, ctx->c);		\
+    BLKC_XLOAD(PRE, t, s); s += PRE##_BLKSZ;				\
+    BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ;				\
+    plan.from_input -= PRE##_BLKSZ;					\
   }									\
 									\
-  /* --- Tidying up the tail end --- */					\
-									\
-  if (sz) {								\
-  small:								\
-    if (!d)								\
-      off += sz;							\
-    else do {								\
-      register octet x = s ? *s++ : 0;					\
-      *d++ = ctx->buf[off++] ^ x;					\
-      sz--;								\
-    } while (sz);							\
+  /* Final portion.  Note that the buffer must be empty if there is a	\
+   * tail, since otherwise the input data would have been part of the	\
+   * head portion instad. */						\
+  if (!plan.tail)							\
+    BLKC_STORE(PRE, ctx->b, t);						\
+  else {								\
+    pre##_eblk(&ctx->ctx, ctx->c, t); BLKC_STEP(PRE, ctx->c);		\
+    BLKC_STORE(PRE, ctx->b, t);						\
+    p = ctx->b; ctx->off += plan.tail;					\
+    if (!d) /* nothing to do */;					\
+    else if (!s) { memcpy(d, p, plan.tail); d += plan.tail; }		\
+    else while (plan.tail--) *d++ = *s++ ^ *p++;			\
   }									\
-									\
-  /* --- Done --- */							\
-									\
-  ctx->off = off;							\
-  return;								\
 }									\
 									\
 /* --- Generic cipher interface --- */					\
@@ -271,29 +251,16 @@ static gcipher *ginit(const void *k, size_t sz)				\
 }									\
 									\
 static void gencrypt(gcipher *c, const void *s, void *t, size_t sz)	\
-{									\
-  gctx *g = (gctx *)c;							\
-  pre##_counterencrypt(&g->k, s, t, sz);				\
-}									\
+  { gctx *g = (gctx *)c; pre##_counterencrypt(&g->k, s, t, sz); }	\
 									\
 static void gdestroy(gcipher *c)					\
-{									\
-  gctx *g = (gctx *)c;							\
-  BURN(*g);								\
-  S_DESTROY(g);								\
-}									\
+  { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); }			\
 									\
 static void gsetiv(gcipher *c, const void *iv)				\
-{									\
-  gctx *g = (gctx *)c;							\
-  pre##_countersetiv(&g->k, iv);					\
-}									\
+  { gctx *g = (gctx *)c; pre##_countersetiv(&g->k, iv); }		\
 									\
 static void gbdry(gcipher *c)						\
-{									\
-  gctx *g = (gctx *)c;							\
-  pre##_counterbdry(&g->k);						\
-}									\
+  { gctx *g = (gctx *)c; pre##_counterbdry(&g->k); }			\
 									\
 static const gcipher_ops gops = {					\
   &pre##_counter,							\
@@ -343,11 +310,11 @@ static int grmisc(grand *r, unsigned op, ...)				\
       }									\
       break;								\
     case GRAND_SEEDINT:							\
-      BLKC_SET(PRE, g->k.n, va_arg(ap, unsigned));			\
+      BLKC_SET(PRE, g->k.c, va_arg(ap, unsigned));			\
       g->k.off = PRE##_BLKSZ;						\
       break;								\
     case GRAND_SEEDUINT32:						\
-      BLKC_SET(PRE, g->k.n, va_arg(ap, uint32));			\
+      BLKC_SET(PRE, g->k.c, va_arg(ap, uint32));			\
       g->k.off = PRE##_BLKSZ;						\
       break;								\
     case GRAND_SEEDBLOCK: {						\
@@ -391,10 +358,7 @@ static uint32 grword(grand *r)						\
 }									\
 									\
 static void grfill(grand *r, void *p, size_t sz)			\
-{									\
-  grctx *g = (grctx *)r;						\
-  pre##_counterencrypt(&g->k, 0, p, sz);				\
-}									\
+  { grctx *g = (grctx *)r; pre##_counterencrypt(&g->k, 0, p, sz); }	\
 									\
 static const grand_ops grops = {					\
   name "-counter",							\