[she] add PrecomputedPublicKey api for c

3 files changed, 87 insertions, 0 deletions

diff --git a/include/mcl/she.h b/include/mcl/she.h
index 1467adc..9b6866a 100644
--- a/include/mcl/she.h
+++ b/include/mcl/she.h
@@ -154,6 +154,15 @@ MCLSHE_DLL_API int sheReRandGT(sheCipherTextGT *c, const shePublicKey *pub);
 MCLSHE_DLL_API int sheConvertG1(sheCipherTextGT *y, const shePublicKey *pub, const sheCipherTextG1 *x);
 MCLSHE_DLL_API int sheConvertG2(sheCipherTextGT *y, const shePublicKey *pub, const sheCipherTextG2 *x);
 
+struct shePrecomputedPublicKey;
+MCLSHE_DLL_API shePrecomputedPublicKey *shePrecomputedPublicKeyCreate();
+MCLSHE_DLL_API void shePrecomputedPublicKeyDestroy(shePrecomputedPublicKey *ppub);
+// return 0 if success
+MCLSHE_DLL_API int shePrecomputedPublicKeyInit(shePrecomputedPublicKey *ppub, const shePublicKey *pub);
+MCLSHE_DLL_API int shePrecomputedPublicKeyEncG1(sheCipherTextG1 *c, const shePrecomputedPublicKey *ppub, mclInt m);
+MCLSHE_DLL_API int shePrecomputedPublicKeyEncG2(sheCipherTextG2 *c, const shePrecomputedPublicKey *ppub, mclInt m);
+MCLSHE_DLL_API int shePrecomputedPublicKeyEncGT(sheCipherTextGT *c, const shePrecomputedPublicKey *ppub, mclInt m);
+
 #ifdef __cplusplus
 }
 #endif
diff --git a/src/she_c_impl.hpp b/src/she_c_impl.hpp
index 0000795..db87659 100644
--- a/src/she_c_impl.hpp
+++ b/src/she_c_impl.hpp
@@ -27,6 +27,9 @@ static const SecretKey *cast(const sheSecretKey *p) { return reinterpret_cast<co
 static PublicKey *cast(shePublicKey *p) { return reinterpret_cast<PublicKey*>(p); }
 static const PublicKey *cast(const shePublicKey *p) { return reinterpret_cast<const PublicKey*>(p); }
 
+static PrecomputedPublicKey *cast(shePrecomputedPublicKey *p) { return reinterpret_cast<PrecomputedPublicKey*>(p); }
+static const PrecomputedPublicKey *cast(const shePrecomputedPublicKey *p) { return reinterpret_cast<const PrecomputedPublicKey*>(p); }
+
 static CipherTextG1 *cast(sheCipherTextG1 *p) { return reinterpret_cast<CipherTextG1*>(p); }
 static const CipherTextG1 *cast(const sheCipherTextG1 *p) { return reinterpret_cast<const CipherTextG1*>(p); }
 
@@ -396,3 +399,51 @@ int sheConvertG2(sheCipherTextGT *y, const shePublicKey *pub, const sheCipherTex
 {
 	return convert(y, pub, x);
 }
+
+shePrecomputedPublicKey *shePrecomputedPublicKeyCreate()
+	try
+{
+	return reinterpret_cast<shePrecomputedPublicKey*>(new PrecomputedPublicKey());
+} catch (...) {
+	return 0;
+}
+
+void shePrecomputedPublicKeyDestroy(shePrecomputedPublicKey *ppub)
+{
+	delete cast(ppub);
+}
+
+int shePrecomputedPublicKeyInit(shePrecomputedPublicKey *ppub, const shePublicKey *pub)
+	try
+{
+	cast(ppub)->init(*cast(pub));
+	return 0;
+} catch (...) {
+	return 1;
+}
+
+template<class CT>
+int pEncT(CT *c, const shePrecomputedPublicKey *pub, mclInt m)
+	try
+{
+	cast(pub)->enc(*cast(c), m);
+	return 0;
+} catch (std::exception& e) {
+	fprintf(stderr, "err %s\n", e.what());
+	return -1;
+}
+
+int shePrecomputedPublicKeyEncG1(sheCipherTextG1 *c, const shePrecomputedPublicKey *pub, mclInt m)
+{
+	return pEncT(c, pub, m);
+}
+
+int shePrecomputedPublicKeyEncG2(sheCipherTextG2 *c, const shePrecomputedPublicKey *pub, mclInt m)
+{
+	return pEncT(c, pub, m);
+}
+
+int shePrecomputedPublicKeyEncGT(sheCipherTextGT *c, const shePrecomputedPublicKey *pub, mclInt m)
+{
+	return pEncT(c, pub, m);
+}
diff --git a/test/she_c_test.hpp b/test/she_c_test.hpp
index 425b600..7bc3256 100644
--- a/test/she_c_test.hpp
+++ b/test/she_c_test.hpp
@@ -235,3 +235,30 @@ CYBOZU_TEST_AUTO(convert)
 	CYBOZU_TEST_EQUAL(dec, 123);
 }
 
+CYBOZU_TEST_AUTO(precomputed)
+{
+	sheSecretKey sec;
+	sheSecretKeySetByCSPRNG(&sec);
+	shePublicKey pub;
+	sheGetPublicKey(&pub, &sec);
+	shePrecomputedPublicKey *ppub = shePrecomputedPublicKeyCreate();
+	CYBOZU_TEST_EQUAL(shePrecomputedPublicKeyInit(ppub, &pub), 0);
+	const int64_t m = 152;
+	sheCipherTextG1 c1;
+	sheCipherTextG2 c2;
+	sheCipherTextGT ct;
+	int64_t dec = 0;
+	CYBOZU_TEST_EQUAL(shePrecomputedPublicKeyEncG1(&c1, ppub, m), 0);
+	CYBOZU_TEST_EQUAL(sheDecG1(&dec, &sec, &c1), 0);
+	CYBOZU_TEST_EQUAL(dec, m);
+	dec = 0;
+	CYBOZU_TEST_EQUAL(shePrecomputedPublicKeyEncG2(&c2, ppub, m), 0);
+	CYBOZU_TEST_EQUAL(sheDecG2(&dec, &sec, &c2), 0);
+	CYBOZU_TEST_EQUAL(dec, m);
+	dec = 0;
+	CYBOZU_TEST_EQUAL(shePrecomputedPublicKeyEncGT(&ct, ppub, m), 0);
+	CYBOZU_TEST_EQUAL(sheDecGT(&dec, &sec, &ct), 0);
+	CYBOZU_TEST_EQUAL(dec, m);
+
+	shePrecomputedPublicKeyDestroy(ppub);
+}