* shadata.c: New file, for generating SHA-256 constants.

Rev: src/nettle/shadata.c:1.1

1 files changed, 47 insertions, 0 deletions

diff --git a/shadata.c b/shadata.c
new file mode 100644
index 00000000..6934b51a
--- /dev/null
+++ b/shadata.c
@@ -0,0 +1,47 @@
+
+#include <math.h>
+#include <stdio.h>
+
+static const unsigned primes[64] =
+{
+  2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 
+  31, 37, 41, 43, 47, 53, 59, 61, 67, 71, 
+  73, 79, 83, 89, 97, 101, 103, 107, 109, 113, 
+  127, 131, 137, 139, 149, 151, 157, 163, 167, 173, 
+  179, 181, 191, 193, 197, 199, 211, 223, 227, 229, 
+  233, 239, 241, 251, 257, 263, 269, 271, 277, 281, 
+  283, 293, 307, 311
+};
+
+int main(int argc, char **argv)
+{
+  int i;
+  static const double third = 1.0/3;
+
+  printf("SHA-256 constants: \n");
+  for (i = 0; i < 64; )
+    {
+      double root = pow(primes[i++], third);
+      double fraction = root - (floor(root));
+      double value = floor(ldexp(fraction, 32));
+
+      printf("0x%lxUL, ", (unsigned long) value);
+      if (!(i % 4))
+	printf("\n");
+    }
+
+  printf("\nSHA-256 initial values: \n");
+
+  for (i = 0; i < 8; )
+    {
+      double root = pow(primes[i++], 0.5);
+      double fraction = root - (floor(root));
+      double value = floor(ldexp(fraction, 32));
+
+      printf("0x%lxUL, ", (unsigned long) value);
+      if (!(i % 4))
+	printf("\n");
+    }
+  
+  return 0;
+}