# include "paranoia.h"
#endif
+#ifndef CATACOMB_RSVR_H
+# include "rsvr.h"
+#endif
+
/*----- Macros ------------------------------------------------------------*/
/* --- @OFB_DEF@ --- *
octet *p = iv; \
unsigned off = ctx->off; \
unsigned rest = PRE##_BLKSZ - off; \
- memcpy(p, ctx->iv + off, rest); \
- memcpy(p + rest, ctx->iv, off); \
+ \
+ memcpy(p, ctx->b + off, rest); \
+ memcpy(p + rest, ctx->b, off); \
} \
\
/* --- @pre_ofbsetiv@ --- * \
*/ \
\
void pre##_ofbsetiv(pre##_ofbctx *ctx, const void *iv) \
-{ \
- memcpy(ctx->iv, iv, PRE##_BLKSZ); \
- ctx->off = PRE##_BLKSZ; \
-} \
+ { memcpy(ctx->b, iv, PRE##_BLKSZ); ctx->off = 0; } \
\
/* --- @pre_ofbbdry@ --- * \
* \
\
void pre##_ofbbdry(pre##_ofbctx *ctx) \
{ \
- uint32 niv[PRE##_BLKSZ / 4]; \
- BLKC_LOAD(PRE, niv, ctx->iv); \
- pre##_eblk(&ctx->ctx, niv, niv); \
- BLKC_STORE(PRE, ctx->iv, niv); \
- ctx->off = PRE##_BLKSZ; \
- BURN(niv); \
+ uint32 t[PRE##_BLKSZ/4]; \
+ \
+ BLKC_LOAD(PRE, t, ctx->b); \
+ pre##_eblk(&ctx->ctx, t, t); \
+ BLKC_STORE(PRE, ctx->b, t); \
+ ctx->off = 0; \
+ BURN(t); \
} \
\
/* --- @pre_ofbsetkey@ --- * \
*/ \
\
void pre##_ofbsetkey(pre##_ofbctx *ctx, const pre##_ctx *k) \
-{ \
- ctx->ctx = *k; \
-} \
+ { ctx->ctx = *k; } \
\
/* --- @pre_ofbinit@ --- * \
* \
const void *iv) \
{ \
static const octet zero[PRE##_BLKSZ] = { 0 }; \
+ \
pre##_init(&ctx->ctx, key, sz); \
pre##_ofbsetiv(ctx, iv ? iv : zero); \
} \
* cipher as a random data generator. \
*/ \
\
+static const rsvr_policy pre##_ofbpolicy = { 0, PRE##_BLKSZ, PRE##_BLKSZ }; \
+ \
void pre##_ofbencrypt(pre##_ofbctx *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->iv[off++] ^ x; \
- sz--; \
+ uint32 t[PRE##_BLKSZ/4], u[PRE##_BLKSZ/4]; \
+ \
+ /* Construct a plan and prepare to follow through. */ \
+ rsvr_mkplan(&plan, &pre##_ofbpolicy, ctx->off, sz); \
+ BLKC_LOAD(PRE, t, ctx->b); \
+ \
+ /* 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, t, t); \
+ 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 iv[PRE##_BLKSZ / 4]; \
- BLKC_LOAD(PRE, iv, ctx->iv); \
- \
- for (;;) { \
- pre##_eblk(&ctx->ctx, iv, iv); \
- if (sz < PRE##_BLKSZ) \
- break; \
- if (d) { \
- if (!s) \
- BLKC_STORE(PRE, d, iv); \
- else { \
- uint32 x[PRE##_BLKSZ / 4]; \
- BLKC_LOAD(PRE, x, s); \
- BLKC_XSTORE(PRE, d, iv, x); \
- s += PRE##_BLKSZ; \
- } \
- d += PRE##_BLKSZ; \
- } \
- sz -= PRE##_BLKSZ; \
- } \
- \
- BLKC_STORE(PRE, ctx->iv, iv); \
- off = 0; \
+ /* If the buffer is all used, then reset it ready for next time. */ \
+ ctx->off -= plan.from_rsvr; \
+ \
+ /* Handle multiple whole blocks. */ \
+ if (!d) while (plan.from_input) { \
+ pre##_eblk(&ctx->ctx, t, t); \
+ plan.from_input -= PRE##_BLKSZ; \
+ } else if (!s) while (plan.from_input) { \
+ pre##_eblk(&ctx->ctx, t, t); \
+ BLKC_STORE(PRE, d, t); d += PRE##_BLKSZ; \
+ plan.from_input -= PRE##_BLKSZ; \
+ } else while (plan.from_input) { \
+ pre##_eblk(&ctx->ctx, t, t); \
+ BLKC_LOAD(PRE, u, s); s += PRE##_BLKSZ; \
+ BLKC_XSTORE(PRE, d, t, u); 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->iv[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, t, t); \
+ 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 --- */ \
} \
\
static void gencrypt(gcipher *c, const void *s, void *t, size_t sz) \
-{ \
- gctx *g = (gctx *)c; \
- pre##_ofbencrypt(&g->k, s, t, sz); \
-} \
+ { gctx *g = (gctx *)c; pre##_ofbencrypt(&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##_ofbsetiv(&g->k, iv); \
-} \
+ { gctx *g = (gctx *)c; pre##_ofbsetiv(&g->k, iv); } \
\
static void gbdry(gcipher *c) \
{ \
} grctx; \
\
static void grdestroy(grand *r) \
-{ \
- grctx *g = (grctx *)r; \
- BURN(*g); \
- S_DESTROY(g); \
-} \
+ { grctx *g = (grctx *)r; BURN(*g); S_DESTROY(g); } \
\
static int grmisc(grand *r, unsigned op, ...) \
{ \
} \
\
static void grfill(grand *r, void *p, size_t sz) \
-{ \
- grctx *g = (grctx *)r; \
- pre##_ofbencrypt(&g->k, 0, p, sz); \
-} \
+ { grctx *g = (grctx *)r; pre##_ofbencrypt(&g->k, 0, p, sz); } \
\
static const grand_ops grops = { \
name "-ofb", \
~mdw / catacomb / blobdiff