1 files changed, 105 insertions, 0 deletions
diff --git a/crypto/secp256k1/libsecp256k1/src/modules/ecdh/tests_impl.h b/crypto/secp256k1/libsecp256k1/src/modules/ecdh/tests_impl.h
new file mode 100644
index 000000000..85a5d0a9a
--- /dev/null
+++ b/crypto/secp256k1/libsecp256k1/src/modules/ecdh/tests_impl.h
@@ -0,0 +1,105 @@
+/**********************************************************************
+ * Copyright (c) 2015 Andrew Poelstra                                 *
+ * Distributed under the MIT software license, see the accompanying   *
+ * file COPYING or http://www.opensource.org/licenses/mit-license.php.*
+ **********************************************************************/
+
+#ifndef _SECP256K1_MODULE_ECDH_TESTS_
+#define _SECP256K1_MODULE_ECDH_TESTS_
+
+void test_ecdh_api(void) {
+    /* Setup context that just counts errors */
+    secp256k1_context *tctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN);
+    secp256k1_pubkey point;
+    unsigned char res[32];
+    unsigned char s_one[32] = { 0 };
+    int32_t ecount = 0;
+    s_one[31] = 1;
+
+    secp256k1_context_set_error_callback(tctx, counting_illegal_callback_fn, &ecount);
+    secp256k1_context_set_illegal_callback(tctx, counting_illegal_callback_fn, &ecount);
+    CHECK(secp256k1_ec_pubkey_create(tctx, &point, s_one) == 1);
+
+    /* Check all NULLs are detected */
+    CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1);
+    CHECK(ecount == 0);
+    CHECK(secp256k1_ecdh(tctx, NULL, &point, s_one) == 0);
+    CHECK(ecount == 1);
+    CHECK(secp256k1_ecdh(tctx, res, NULL, s_one) == 0);
+    CHECK(ecount == 2);
+    CHECK(secp256k1_ecdh(tctx, res, &point, NULL) == 0);
+    CHECK(ecount == 3);
+    CHECK(secp256k1_ecdh(tctx, res, &point, s_one) == 1);
+    CHECK(ecount == 3);
+
+    /* Cleanup */
+    secp256k1_context_destroy(tctx);
+}
+
+void test_ecdh_generator_basepoint(void) {
+    unsigned char s_one[32] = { 0 };
+    secp256k1_pubkey point[2];
+    int i;
+
+    s_one[31] = 1;
+    /* Check against pubkey creation when the basepoint is the generator */
+    for (i = 0; i < 100; ++i) {
+        secp256k1_sha256_t sha;
+        unsigned char s_b32[32];
+        unsigned char output_ecdh[32];
+        unsigned char output_ser[32];
+        unsigned char point_ser[33];
+        size_t point_ser_len = sizeof(point_ser);
+        secp256k1_scalar s;
+
+        random_scalar_order(&s);
+        secp256k1_scalar_get_b32(s_b32, &s);
+
+        /* compute using ECDH function */
+        CHECK(secp256k1_ec_pubkey_create(ctx, &point[0], s_one) == 1);
+        CHECK(secp256k1_ecdh(ctx, output_ecdh, &point[0], s_b32) == 1);
+        /* compute "explicitly" */
+        CHECK(secp256k1_ec_pubkey_create(ctx, &point[1], s_b32) == 1);
+        CHECK(secp256k1_ec_pubkey_serialize(ctx, point_ser, &point_ser_len, &point[1], SECP256K1_EC_COMPRESSED) == 1);
+        CHECK(point_ser_len == sizeof(point_ser));
+        secp256k1_sha256_initialize(&sha);
+        secp256k1_sha256_write(&sha, point_ser, point_ser_len);
+        secp256k1_sha256_finalize(&sha, output_ser);
+        /* compare */
+        CHECK(memcmp(output_ecdh, output_ser, sizeof(output_ser)) == 0);
+    }
+}
+
+void test_bad_scalar(void) {
+    unsigned char s_zero[32] = { 0 };
+    unsigned char s_overflow[32] = {
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+        0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe,
+        0xba, 0xae, 0xdc, 0xe6, 0xaf, 0x48, 0xa0, 0x3b,
+        0xbf, 0xd2, 0x5e, 0x8c, 0xd0, 0x36, 0x41, 0x41
+    };
+    unsigned char s_rand[32] = { 0 };
+    unsigned char output[32];
+    secp256k1_scalar rand;
+    secp256k1_pubkey point;
+
+    /* Create random point */
+    random_scalar_order(&rand);
+    secp256k1_scalar_get_b32(s_rand, &rand);
+    CHECK(secp256k1_ec_pubkey_create(ctx, &point, s_rand) == 1);
+
+    /* Try to multiply it by bad values */
+    CHECK(secp256k1_ecdh(ctx, output, &point, s_zero) == 0);
+    CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 0);
+    /* ...and a good one */
+    s_overflow[31] -= 1;
+    CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 1);
+}
+
+void run_ecdh_tests(void) {
+    test_ecdh_api();
+    test_ecdh_generator_basepoint();
+    test_bad_scalar();
+}
+
+#endif