hash: test for sha1 collision attack detection

tests/core/sha1.c

+#include "clar_libgit2.h"
+#include "hash.h"
+
+#define FIXTURE_DIR "sha1"
+
+void test_core_sha1__initialize(void)
+{
+	cl_fixture_sandbox(FIXTURE_DIR);
+}
+
+void test_core_sha1__cleanup(void)
+{
+	cl_fixture_cleanup(FIXTURE_DIR);
+}
+
+static int sha1_file(git_oid *oid, const char *filename)
+{
+	git_hash_ctx ctx;
+	char buf[2048];
+	int fd, ret;
+	ssize_t read_len;
+
+	fd = p_open(filename, O_RDONLY);
+	cl_assert(fd >= 0);
+
+	cl_git_pass(git_hash_ctx_init(&ctx));
+
+	while ((read_len = p_read(fd, buf, 2048)) > 0)
+		cl_git_pass(git_hash_update(&ctx, buf, (size_t)read_len));
+
+	cl_assert_equal_i(0, read_len);
+	p_close(fd);
+
+	ret = git_hash_final(oid, &ctx);
+	git_hash_ctx_cleanup(&ctx);
+
+	return ret;
+}
+
+void test_core_sha1__sum(void)
+{
+	git_oid oid, expected;
+
+	cl_git_pass(sha1_file(&oid, FIXTURE_DIR "/hello_c"));
+	git_oid_fromstr(&expected, "4e72679e3ea4d04e0c642f029e61eb8056c7ed94");
+	cl_assert_equal_oid(&expected, &oid);
+}
+
+/* test that sha1 collision detection works when enabled */
+void test_core_sha1__detect_collision_attack(void)
+{
+	git_oid oid, expected;
+
+#ifdef GIT_SHA1_COLLISIONDETECT
+	GIT_UNUSED(expected);
+	cl_git_fail(sha1_file(&oid, FIXTURE_DIR "/shattered-1.pdf"));
+	cl_assert_equal_s("SHA1 collision attack detected", giterr_last()->message);
+#else
+	cl_git_pass(sha1_file(&oid, FIXTURE_DIR "/shattered-1.pdf"));
+	git_oid_fromstr(&expected, "38762cf7f55934b34d179ae6a4c80cadccbb7f0a");
+	cl_assert_equal_oid(&expected, &oid);
+#endif
+}
+

tests/resources/sha1/hello_c

+#include <stdio.h>
+
+int main(int argc, char **argv)
+{
+	printf("Hello, %s\n", "world");
+}