1 files changed, 133 insertions, 0 deletions
diff --git a/moon-abe/pbc-0.5.14/example/bls.c b/moon-abe/pbc-0.5.14/example/bls.c
new file mode 100644
index 00000000..8b62a097
--- /dev/null
+++ b/moon-abe/pbc-0.5.14/example/bls.c
@@ -0,0 +1,133 @@
+// Boneh-Lynn-Shacham short signatures demo.
+//
+// See the PBC_sig library for a practical implementation.
+//
+// Ben Lynn
+#include <pbc.h>
+#include <pbc_test.h>
+
+int main(int argc, char **argv) {
+  pairing_t pairing;
+  element_t g, h;
+  element_t public_key, sig;
+  element_t secret_key;
+  element_t temp1, temp2;
+
+  pbc_demo_pairing_init(pairing, argc, argv);
+
+  element_init_G2(g, pairing);
+  element_init_G2(public_key, pairing);
+  element_init_G1(h, pairing);
+  element_init_G1(sig, pairing);
+  element_init_GT(temp1, pairing);
+  element_init_GT(temp2, pairing);
+  element_init_Zr(secret_key, pairing);
+
+  printf("Short signature test\n");
+
+  //generate system parameters
+  element_random(g);
+  element_printf("system parameter g = %B\n", g);
+
+  //generate private key
+  element_random(secret_key);
+  element_printf("private key = %B\n", secret_key);
+
+  //compute corresponding public key
+  element_pow_zn(public_key, g, secret_key);
+  element_printf("public key = %B\n", public_key);
+
+  //generate element from a hash
+  //for toy pairings, should check that pairing(g, h) != 1
+  element_from_hash(h, "hashofmessage", 13);
+  element_printf("message hash = %B\n", h);
+
+  //h^secret_key is the signature
+  //in real life: only output the first coordinate
+  element_pow_zn(sig, h, secret_key);
+  element_printf("signature = %B\n", sig);
+
+  {
+    int n = pairing_length_in_bytes_compressed_G1(pairing);
+    //int n = element_length_in_bytes_compressed(sig);
+    int i;
+    unsigned char *data = pbc_malloc(n);
+
+    element_to_bytes_compressed(data, sig);
+    printf("compressed = ");
+    for (i = 0; i < n; i++) {
+      printf("%02X", data[i]);
+    }
+    printf("\n");
+
+    element_from_bytes_compressed(sig, data);
+    element_printf("decompressed = %B\n", sig);
+
+    pbc_free(data);
+  }
+
+  //verification part 1
+  element_pairing(temp1, sig, g);
+  element_printf("f(sig, g) = %B\n", temp1);
+
+  //verification part 2
+  //should match above
+  element_pairing(temp2, h, public_key);
+  element_printf("f(message hash, public_key) = %B\n", temp2);
+
+  if (!element_cmp(temp1, temp2)) {
+    printf("signature verifies\n");
+  } else {
+    printf("*BUG* signature does not verify *BUG*\n");
+  }
+
+  {
+    int n = pairing_length_in_bytes_x_only_G1(pairing);
+    //int n = element_length_in_bytes_x_only(sig);
+    int i;
+    unsigned char *data = pbc_malloc(n);
+
+    element_to_bytes_x_only(data, sig);
+    printf("x-coord = ");
+    for (i = 0; i < n; i++) {
+      printf("%02X", data[i]);
+    }
+    printf("\n");
+
+    element_from_bytes_x_only(sig, data);
+    element_printf("de-x-ed = %B\n", sig);
+
+    element_pairing(temp1, sig, g);
+    if (!element_cmp(temp1, temp2)) {
+      printf("signature verifies on first guess\n");
+    } else {
+      element_invert(temp1, temp1);
+      if (!element_cmp(temp1, temp2)) {
+        printf("signature verifies on second guess\n");
+      } else {
+        printf("*BUG* signature does not verify *BUG*\n");
+      }
+    }
+
+    pbc_free(data);
+  }
+
+  //a random signature shouldn't verify
+  element_random(sig);
+  element_pairing(temp1, sig, g);
+  if (element_cmp(temp1, temp2)) {
+    printf("random signature doesn't verify\n");
+  } else {
+    printf("*BUG* random signature verifies *BUG*\n");
+  }
+
+  element_clear(sig);
+  element_clear(public_key);
+  element_clear(secret_key);
+  element_clear(g);
+  element_clear(h);
+  element_clear(temp1);
+  element_clear(temp2);
+  pairing_clear(pairing);
+  return 0;
+}