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-rw-r--r--moon-abe/pbc-0.5.14/example/bls.c133
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
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+++ b/moon-abe/pbc-0.5.14/example/bls.c
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+// 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;
+}