Generate keypair from shared secrets.

snark/src/lib.rs

@@ -20,6 +20,7 @@ extern "C" {
     fn libsnarkwrap_pairing(p: *const G1, q: *const G2) -> Gt;
     fn libsnarkwrap_getcs(d: *mut libc::uint64_t, vars: *mut libc::uint64_t, omega: *mut Fr) -> *mut libc::c_void;
     fn libsnarkwrap_dropcs(cs: *mut libc::c_void);
+    fn libsnarkwrap_dropkeypair(kp: *mut libc::c_void);
     fn libsnarkwrap_eval(
         cs: *const libc::c_void,
         lc1: *const G1,
@@ -30,6 +31,17 @@ extern "C" {
         bt1: *mut G1,
         bt2: *mut G2,
         ct: *mut G1);
+    fn libsnarkwrap_test_keygen(
+        cs: *const libc::c_void,
+        tau: *const Fr,
+        alpha_a: *const Fr,
+        alpha_b: *const Fr,
+        alpha_c: *const Fr,
+        rho_a: *const Fr,
+        rho_b: *const Fr,
+        beta: *const Fr,
+        gamma: *const Fr
+    ) -> *mut libc::c_void;
     fn libsnarkwrap_test_eval(
         cs: *const libc::c_void,
         tau: *const Fr,
@@ -73,6 +85,32 @@ pub struct CS {
     pub omega: Fr
 }
 
+pub struct Keypair {
+    ptr: *mut libc::c_void
+}
+
+impl Keypair {
+    pub fn generate(
+        cs: &CS,
+        tau: &Fr,
+        alpha_a: &Fr,
+        alpha_b: &Fr,
+        alpha_c: &Fr,
+        rho_a: &Fr,
+        rho_b: &Fr,
+        beta: &Fr,
+        gamma: &Fr
+    ) -> Keypair {
+        unsafe {
+            Keypair {
+                ptr: libsnarkwrap_test_keygen(
+                    cs.ptr, tau, alpha_a, alpha_b, alpha_c, rho_a, rho_b, beta, gamma
+                )
+            }
+        }
+    }
+}
+
 impl CS {
     pub fn dummy() -> Self {
         let mut d = 0;
@@ -142,6 +180,12 @@ impl Drop for CS {
     }
 }
 
+impl Drop for Keypair {
+    fn drop(&mut self) {
+        unsafe { libsnarkwrap_dropkeypair(self.ptr) }
+    }
+}
+
 pub trait Pairing<Other: Group> {
     fn g1<'a>(&'a self, other: &'a Other) -> &'a G1;
     fn g2<'a>(&'a self, other: &'a Other) -> &'a G2;

snark/src/libsnarkwrap.cpp

@@ -7,6 +7,7 @@
 #include "relations/arithmetic_programs/qap/qap.hpp"
 #include "reductions/r1cs_to_qap/r1cs_to_qap.hpp"
 #include "relations/constraint_satisfaction_problems/r1cs/examples/r1cs_examples.hpp"
+#include "zk_proof_systems/ppzksnark/r1cs_ppzksnark/r1cs_ppzksnark.hpp"
 
 using namespace std;
 using namespace libsnark;
@@ -205,6 +206,11 @@ extern "C" void libsnarkwrap_dropcs(r1cs_constraint_system<curve_Fr> *cs)
     delete cs;
 }
 
+extern "C" void libsnarkwrap_dropkeypair(r1cs_ppzksnark_keypair<curve_pp> *kp)
+{
+    delete kp;
+}
+
 extern "C" void libsnarkwrap_eval(
     const r1cs_constraint_system<curve_Fr> *cs,
     const curve_G1 *lc1,
@@ -244,6 +250,33 @@ extern "C" void libsnarkwrap_eval(
 
 // Comparison tests
 
+extern "C" void* libsnarkwrap_test_keygen(
+    const r1cs_constraint_system<curve_Fr> *cs,
+    const curve_Fr *tau,
+    const curve_Fr *alpha_A,
+    const curve_Fr *alpha_B,
+    const curve_Fr *alpha_C,
+    const curve_Fr *rho_A,
+    const curve_Fr *rho_B,
+    const curve_Fr *beta,
+    const curve_Fr *gamma
+)
+{
+    return new r1cs_ppzksnark_keypair<curve_pp>(
+        r1cs_ppzksnark_generator<curve_pp>(
+            *cs,
+            *tau,
+            *alpha_A,
+            *alpha_B,
+            *alpha_C,
+            *rho_A,
+            *rho_B,
+            *beta,
+            *gamma
+        )
+    );
+}
+
 extern "C" bool libsnarkwrap_test_compare_tau(
     const curve_G1 *inputs1,
     const curve_G2 *inputs2,

src/protocol.rs

@@ -158,6 +158,20 @@ impl Secrets {
 
         tmp
     }
+
+    fn keypair(&self, cs: &CS) -> Keypair {
+        Keypair::generate(
+            cs,
+            &self.tau,
+            &self.alpha_a,
+            &self.alpha_b,
+            &self.alpha_c,
+            &self.rho_a,
+            &self.rho_b,
+            &self.beta,
+            &self.gamma
+        )
+    }
 }
 
 struct Player {
@@ -556,6 +570,8 @@ fn implthing() {
         vk_beta_gamma_two = new_vk_beta_gamma_two;
         pk_K = new_pk_K;
     }
+
+    // Compare against libsnark:
     
     let mut shared_secrets = Secrets::new_blank();
 
@@ -563,5 +579,5 @@ fn implthing() {
         player.test_multiply_secrets(&mut shared_secrets);
     }
 
-
+    let target_kp = shared_secrets.keypair(&cs);
 }