Merge "init attribute-based encryption"

1 files changed, 49 insertions, 0 deletions

diff --git a/moon-abe/pbc-0.5.14/arith/fp.c b/moon-abe/pbc-0.5.14/arith/fp.c
new file mode 100644
index 00000000..e0127a8e
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/arith/fp.c
@@ -0,0 +1,49 @@
+// F_p initialization.
+//
+// Specific implementations of F_p are found in naivefp.c, fastfp.c, fasterfp.c
+// and montfp.c. For pairing-based cryptosystems, montfp.c is the fastest.
+// I keep all versions around for testing, and also to show off the modularity
+// of the code.
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdint.h> // for intptr_t
+#include <gmp.h>
+#include <string.h>
+#include "pbc_utils.h"
+#include "pbc_field.h"
+#include "pbc_fp.h"
+
+// By default, use the montfp.c implementation of F_p. After
+// pbc_tweak_use_fp(), future field_init_fp calls will use the specified
+// implementation. This is useful for benchmarking and testing.
+static void (*option_fpinit) (field_ptr f, mpz_t prime) = field_init_mont_fp;
+
+void pbc_tweak_use_fp(char *s) {
+  if (!strcmp(s, "naive")) {
+    option_fpinit = field_init_naive_fp;
+  } else if (!strcmp(s, "fast")) {
+    option_fpinit = field_init_fast_fp;
+  } else if (!strcmp(s, "faster")) {
+    option_fpinit = field_init_faster_fp;
+  } else if (!strcmp(s, "mont")) {
+    option_fpinit = field_init_mont_fp;
+  } else {
+    pbc_error("no such Fp implementation: %s", s);
+  }
+}
+
+void field_init_fp(field_ptr f, mpz_t modulus) {
+  if (mpz_fits_ulong_p(modulus)) {
+    // If this case mattered, I'd have written a F_p implementation specialized
+    // for moduli that fits into machine words.
+    field_init_naive_fp(f, modulus);
+  } else {
+    if (mpz_odd_p(modulus)) {
+      option_fpinit(f, modulus);
+    } else {
+      // montfp.c only supports odd moduli.
+      field_init_faster_fp(f, modulus);
+    }
+  }
+}