X-Git-Url: https://git.distorted.org.uk/~mdw/catacomb/blobdiff_plain/e6912e4438388021222b7b449d1e84709d943572..1778ca95377e045bd56a0a99d4d27b476ed85345:/symm/chacha.c

diff --git a/symm/chacha.c b/symm/chacha.c
index 5fc1c12c..655ecd02 100644
--- a/symm/chacha.c
+++ b/symm/chacha.c
@@ -163,10 +163,11 @@ void chacha_init(chacha_ctx *ctx, const void *key, size_t ksz,
   chacha_setnonce(ctx, nonce ? nonce : zerononce);
 }
 
-/* --- @chacha_setnonce@ --- *
+/* --- @chacha_setnonce{,_ietf}@ --- *
  *
  * Arguments:	@chacha_ctx *ctx@ = pointer to context
- *		@const void *nonce@ = the nonce (@CHACHA_NONCESZ@ bytes)
+ *		@const void *nonce@ = the nonce (@CHACHA_NONCESZ@ or
+ *			@CHACHA_IETF_NONCESZ@ bytes)
  *
  * Returns:	---
  *
@@ -184,10 +185,20 @@ void chacha_setnonce(chacha_ctx *ctx, const void *nonce)
   chacha_seek(ctx, 0);
 }
 
-/* --- @chacha_seek{,u64}@ --- *
+void chacha_setnonce_ietf(chacha_ctx *ctx, const void *nonce)
+{
+  const octet *n = nonce;
+
+  ctx->a[13] = LOAD32_L(n + 0);
+  ctx->a[14] = LOAD32_L(n + 4);
+  ctx->a[15] = LOAD32_L(n + 8);
+  chacha_seek_ietf(ctx, 0);
+}
+
+/* --- @chacha_seek{,u64,_ietf}@ --- *
  *
  * Arguments:	@chacha_ctx *ctx@ = pointer to context
- *		@unsigned long i@, @kludge64 i@ = new position to set
+ *		@unsigned long i@, @kludge64 i@, @uint32 i@ = new position
  *
  * Returns:	---
  *
@@ -206,7 +217,10 @@ void chacha_seeku64(chacha_ctx *ctx, kludge64 i)
   ctx->bufi = CHACHA_OUTSZ;
 }
 
-/* --- @chacha_tell{,u64}@ --- *
+void chacha_seek_ietf(chacha_ctx *ctx, uint32 i)
+  { ctx->a[12] = i; }
+
+/* --- @chacha_tell{,u64,_ietf}@ --- *
  *
  * Arguments:	@chacha_ctx *ctx@ = pointer to context
  *
@@ -220,6 +234,9 @@ unsigned long chacha_tell(chacha_ctx *ctx)
 kludge64 chacha_tellu64(chacha_ctx *ctx)
   { kludge64 i; SET64(i, ctx->a[13], ctx->a[12]); return (i); }
 
+uint32 chacha_tell_ietf(chacha_ctx *ctx)
+  { return (ctx->a[12]); }
+
 /* --- @chacha{20,12,8}_encrypt@ --- *
  *
  * Arguments:	@chacha_ctx *ctx@ = pointer to context
@@ -482,6 +499,9 @@ typedef struct gctx { gcipher c; chacha_ctx ctx; } gctx;
 static void gsetiv(gcipher *c, const void *iv)
   { gctx *g = (gctx *)c; chacha_setnonce(&g->ctx, iv); }
 
+static void gsetiv_ietf(gcipher *c, const void *iv)
+  { gctx *g = (gctx *)c; chacha_setnonce_ietf(&g->ctx, iv); }
+
 static void gdestroy(gcipher *c)
   { gctx *g = (gctx *)c; BURN(*g); S_DESTROY(g); }
 
@@ -495,11 +515,14 @@ static gcipher *ginit(const void *k, size_t sz, const gcipher_ops *ops)
 
 #define DEFGCIPHER(r)							\
 									\
-  static const gcipher_ops gops_##r;					\
+  static const gcipher_ops gops_##r, gops_##r##_ietf;			\
 									\
   static gcipher *ginit_##r(const void *k, size_t sz)			\
     { return (ginit(k, sz, &gops_##r)); }				\
 									\
+  static gcipher *ginit_##r##_ietf(const void *k, size_t sz)		\
+    { return (ginit(k, sz, &gops_##r##_ietf)); }			\
+									\
   static void gencrypt_##r(gcipher *c, const void *s,			\
 			   void *t, size_t sz)				\
     { gctx *g = (gctx *)c; CHACHA_ENCRYPT(r, &g->ctx, s, t, sz); }	\
@@ -509,9 +532,19 @@ static gcipher *ginit(const void *k, size_t sz, const gcipher_ops *ops)
     gencrypt_##r, gencrypt_##r, gdestroy, gsetiv, 0			\
   };									\
 									\
+  static const gcipher_ops gops_##r##_ietf = {				\
+    &chacha##r##_ietf,							\
+    gencrypt_##r, gencrypt_##r, gdestroy, gsetiv_ietf, 0		\
+  };									\
+									\
   const gccipher chacha##r = {						\
     "chacha" #r, chacha_keysz,						\
     CHACHA_NONCESZ, ginit_##r						\
+  };									\
+									\
+  const gccipher chacha##r##_ietf = {					\
+    "chacha" #r "-ietf", chacha_keysz,					\
+    CHACHA_IETF_NONCESZ, ginit_##r##_ietf				\
   };
 
 CHACHA_VARS(DEFGCIPHER)
@@ -683,12 +716,27 @@ typedef struct grctx {
 static void gr_seek(void *r, kludge64 pos)
   { grctx *g = r; chacha_seeku64(&g->ctx, pos); }
 
+static void gr_seek_ietf(void *r, kludge64 pos)
+  { grctx *g = r; chacha_seek_ietf(&g->ctx, LO64(pos)); }
+
 static kludge64 gr_tell(void *r)
   { grctx *g = r; return (chacha_tellu64(&g->ctx)); }
 
+static kludge64 gr_tell_ietf(void *r)
+{
+  grctx *g = r;
+  kludge64 pos;
+
+  SET64(pos, 0, chacha_tell_ietf(&g->ctx));
+  return (pos);
+}
+
 static void gr_setnonce(void *r, const void *n)
   { grctx *g = r; chacha_setnonce(&g->ctx, n); }
 
+static void gr_setnonce_ietf(void *r, const void *n)
+  { grctx *g = r; chacha_setnonce_ietf(&g->ctx, n); }
+
 static void grdestroy(grand *r)
   { grctx *g = (grctx *)r; BURN(*g); S_DESTROY(g); }
 
@@ -712,14 +760,33 @@ static grand *grinit(const void *k, size_t ksz, const void *n,
     { CHACHA_NONCESZ, gr_seek, gr_tell,					\
       gr_setnonce, gr_generate_##rr };					\
 									\
+  static const grops grops_##rr##_ietf =				\
+    { CHACHA_IETF_NONCESZ, gr_seek_ietf, gr_tell_ietf,			\
+      gr_setnonce_ietf, gr_generate_##rr };				\
+									\
   static const grand_ops grops_rand_##rr = {				\
     "chacha" #rr, GRAND_CRYPTO, 0,					\
     grmisc, grdestroy, grword,						\
     grbyte, grword, grand_defaultrange, grfill				\
   };									\
 									\
+  static const grand_ops grops_rand_##rr##_ietf = {			\
+    "chacha" #rr "-ietf", GRAND_CRYPTO, 0,				\
+    grmisc, grdestroy, grword,						\
+    grbyte, grword, grand_defaultrange, grfill				\
+  };									\
+									\
   grand *chacha##rr##_rand(const void *k, size_t ksz, const void *n)	\
-    { return (grinit(k, ksz, n, &grops_rand_##rr, &grops_##rr)); }
+    { return (grinit(k, ksz, n, &grops_rand_##rr, &grops_##rr)); }	\
+									\
+  grand *chacha##rr##_ietf_rand(const void *k, size_t ksz,		\
+				const void *n)				\
+  {									\
+    return (grinit(k, ksz, n,						\
+		   &grops_rand_##rr##_ietf,				\
+		   &grops_##rr##_ietf));				\
+  }
+
 CHACHA_VARS(DEFGRAND)
 
 #define DEFXGRAND(rr)							\
@@ -816,7 +883,9 @@ CHACHA_VARS(DEFVCORE)
   kludge64 pos64;							\
   chacha_init(ctx, k, ksz, 0);						\
   if (nsz == 8) chacha_setnonce(ctx, n);				\
+  else if (nsz == 12) chacha_setnonce_ietf(ctx, n);			\
   if (psz == 8) { LOAD64_(pos64, p); chacha_seeku64(ctx, pos64); }	\
+  else if (psz == 4) chacha_seek_ietf(ctx, LOAD32(p));			\
 } while (0)
 
 #define XCHACHA_TESTSETUP(r, ctx, k, ksz, n, nsz, p, psz) do {		\