1 files changed, 68 insertions, 0 deletions
diff --git a/tools/gf_div.c b/tools/gf_div.c
new file mode 100644
index 0000000..9797f07
--- /dev/null
+++ b/tools/gf_div.c
@@ -0,0 +1,68 @@
+/*
+ * GF-Complete: A Comprehensive Open Source Library for Galois Field Arithmetic
+ * James S. Plank, Ethan L. Miller, Kevin M. Greenan,
+ * Benjamin A. Arnold, John A. Burnum, Adam W. Disney, Allen C. McBride.
+ *
+ * gf_div.c
+ *
+ * Multiplies two numbers in gf_2^w
+ */
+
+#include <stdio.h>
+#include <getopt.h>
+#include <stdint.h>
+#include <string.h>
+#include <stdlib.h>
+
+#include "gf_complete.h"
+#include "gf_method.h"
+#include "gf_general.h"
+
+void usage(int why)
+{
+  fprintf(stderr, "usage: gf_div a b w [method] - does division of a and b in GF(2^w)\n");
+  if (why == 'W') {
+    fprintf(stderr, "Bad w.\n");
+    fprintf(stderr, "Legal w are: 1 - 32, 64 and 128.\n");
+    fprintf(stderr, "Append 'h' to w to treat a, b and the quotient as hexadecimal.\n");
+    fprintf(stderr, "w=128 is hex only (i.e. '128' will be an error - do '128h')\n");
+  }
+  if (why == 'A') fprintf(stderr, "Bad a\n");
+  if (why == 'B') fprintf(stderr, "Bad b\n");
+  if (why == 'M') {
+    fprintf(stderr, "Bad Method Specification: ");
+    gf_error();
+  }
+  exit(1);
+}
+
+int main(int argc, char **argv)
+{
+  int hex, w;
+  gf_t gf;
+  gf_general_t a, b, c;
+  char output[50];
+
+  if (argc < 4) usage(' ');
+
+  if (sscanf(argv[3], "%d", &w) == 0) usage('W');
+  if (w <= 0 || (w > 32 && w != 64 && w != 128)) usage('W');
+
+  hex = (strchr(argv[3], 'h') != NULL);
+  if (!hex && w == 128) usage('W');
+
+  if (argc == 4) {
+    if (gf_init_easy(&gf, w) == 0) usage('M');
+  } else {
+    if (create_gf_from_argv(&gf, w, argc, argv, 4) == 0) usage('M');
+  }
+ 
+  if (!gf_general_s_to_val(&a, w, argv[1], hex)) usage('A');
+  if (!gf_general_s_to_val(&b, w, argv[2], hex)) usage('B');
+
+  gf_general_divide(&gf, &a, &b, &c);
+  gf_general_val_to_s(&c, w, output, hex);
+  
+  printf("%s\n", output);
+  exit(0);
+}