also add d0_blind_id_verify_private_id

[xonotic/d0_blind_id.git] / d0_blind_id.c

diff --git a/d0_blind_id.c b/d0_blind_id.c
index 68d3c64e5cba3263e451ea7ed9498e407c48b184..57ca8fd0594242d11c3f8507571321f16edb3e02 100644 (file)
--- a/d0_blind_id.c
+++ b/d0_blind_id.c
@@ -1440,6 +1440,23 @@ fail:
        return 0;
 }
 
+D0_WARN_UNUSED_RESULT D0_BOOL d0_blind_id_verify_private_id(const d0_blind_id_t *ctx)
+{
+       USINGTEMPS(); // temps: temp0 = order, temp1 = g^s
+       USING(schnorr_G); USING(schnorr_s); USING(schnorr_g_to_s);
+
+       LOCKTEMPS();
+       CHECK(d0_dl_get_order(temp0, ctx->schnorr_G));
+       CHECK(d0_bignum_mod_pow(temp1, four, ctx->schnorr_s, ctx->schnorr_G));
+       CHECK(!d0_bignum_cmp(temp1, ctx->schnorr_g_to_s));
+       UNLOCKTEMPS();
+       return 1;
+
+fail:
+       UNLOCKTEMPS();
+       return 0;
+}
+
 d0_blind_id_t *d0_blind_id_new(void)
 {
        d0_blind_id_t *b = d0_malloc(sizeof(d0_blind_id_t));