Prepare for radical source tree reorganization.zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 98 insertions, 0 deletions

diff --git a/REORG.TODO/crypt/sha256-block.c b/REORG.TODO/crypt/sha256-block.c
new file mode 100644
index 0000000000..a44fe01d5b
--- /dev/null
+++ b/REORG.TODO/crypt/sha256-block.c
@@ -0,0 +1,98 @@
+#include <stdint.h>
+
+/* Process LEN bytes of BUFFER, accumulating context into CTX.
+   It is assumed that LEN % 64 == 0.  */
+void
+__sha256_process_block (const void *buffer, size_t len, struct sha256_ctx *ctx)
+{
+  const uint32_t *words = buffer;
+  size_t nwords = len / sizeof (uint32_t);
+  uint32_t a = ctx->H[0];
+  uint32_t b = ctx->H[1];
+  uint32_t c = ctx->H[2];
+  uint32_t d = ctx->H[3];
+  uint32_t e = ctx->H[4];
+  uint32_t f = ctx->H[5];
+  uint32_t g = ctx->H[6];
+  uint32_t h = ctx->H[7];
+
+  /* First increment the byte count.  FIPS 180-2 specifies the possible
+     length of the file up to 2^64 bits.  Here we only compute the
+     number of bytes.  */
+  ctx->total64 += len;
+
+  /* Process all bytes in the buffer with 64 bytes in each round of
+     the loop.  */
+  while (nwords > 0)
+    {
+      uint32_t W[64];
+      uint32_t a_save = a;
+      uint32_t b_save = b;
+      uint32_t c_save = c;
+      uint32_t d_save = d;
+      uint32_t e_save = e;
+      uint32_t f_save = f;
+      uint32_t g_save = g;
+      uint32_t h_save = h;
+
+      /* Operators defined in FIPS 180-2:4.1.2.  */
+#define Ch(x, y, z) ((x & y) ^ (~x & z))
+#define Maj(x, y, z) ((x & y) ^ (x & z) ^ (y & z))
+#define S0(x) (CYCLIC (x, 2) ^ CYCLIC (x, 13) ^ CYCLIC (x, 22))
+#define S1(x) (CYCLIC (x, 6) ^ CYCLIC (x, 11) ^ CYCLIC (x, 25))
+#define R0(x) (CYCLIC (x, 7) ^ CYCLIC (x, 18) ^ (x >> 3))
+#define R1(x) (CYCLIC (x, 17) ^ CYCLIC (x, 19) ^ (x >> 10))
+
+      /* It is unfortunate that C does not provide an operator for
+	 cyclic rotation.  Hope the C compiler is smart enough.  */
+#define CYCLIC(w, s) ((w >> s) | (w << (32 - s)))
+
+      /* Compute the message schedule according to FIPS 180-2:6.2.2 step 2.  */
+      for (unsigned int t = 0; t < 16; ++t)
+	{
+	  W[t] = SWAP (*words);
+	  ++words;
+	}
+      for (unsigned int t = 16; t < 64; ++t)
+	W[t] = R1 (W[t - 2]) + W[t - 7] + R0 (W[t - 15]) + W[t - 16];
+
+      /* The actual computation according to FIPS 180-2:6.2.2 step 3.  */
+      for (unsigned int t = 0; t < 64; ++t)
+	{
+	  uint32_t T1 = h + S1 (e) + Ch (e, f, g) + K[t] + W[t];
+	  uint32_t T2 = S0 (a) + Maj (a, b, c);
+	  h = g;
+	  g = f;
+	  f = e;
+	  e = d + T1;
+	  d = c;
+	  c = b;
+	  b = a;
+	  a = T1 + T2;
+	}
+
+      /* Add the starting values of the context according to FIPS 180-2:6.2.2
+	 step 4.  */
+      a += a_save;
+      b += b_save;
+      c += c_save;
+      d += d_save;
+      e += e_save;
+      f += f_save;
+      g += g_save;
+      h += h_save;
+
+      /* Prepare for the next round.  */
+      nwords -= 16;
+    }
+
+  /* Put checksum in context given as argument.  */
+  ctx->H[0] = a;
+  ctx->H[1] = b;
+  ctx->H[2] = c;
+  ctx->H[3] = d;
+  ctx->H[4] = e;
+  ctx->H[5] = f;
+  ctx->H[6] = g;
+  ctx->H[7] = h;
+}