M Makefile → Makefile

@@ -1,13 +1,14 @@
-CC ?= clang
+CC ?= gcc
 AR ?= ar
 INCLUDE_PATH := .
 SOURCE_FILES := $(wildcard tinycrypt/*.c)
 SOURCE_OBJECTS := $(SOURCE_FILES:tinycrypt/%.c=lib/%.o)
 TEST_SOURCE_FILES := tinycrypt/tests/*.c
-COMPILER_OPTS := -O3 -ffreestanding -std=c99
+COMPILER_OPTS := -ffreestanding -std=c99
+OPTIMIZE_LEVEL := -O3
 
 test-main: $(SOURCE_OBJECTS) $(TEST_SOURCE_FILES)
-	@ $(CC) -o test-main -O3 -I$(INCLUDE_PATH) $(SOURCE_FILES) $(TEST_SOURCE_FILES)
+	@ $(CC) -o test-main -O3 -I$(INCLUDE_PATH) $(SOURCE_OBJECTS) $(TEST_SOURCE_FILES)
 
 tests: test-main
 	@ ./test-main
@@ -16,10 +17,10 @@ memcheck: test-main
 	@ valgrind ./test-main
 
 lib/%.o: tinycrypt/%.c
-	@ $(CC) -c $(COMPILER_OPTS) -I$(INCLUDE_PATH) $< -o $@
+	@ $(CC) -c $(COMPILER_OPTS) $(OPTIMIZE_LEVEL) -I$(INCLUDE_PATH) $< -o $@
 
 lib: $(SOURCE_OBJECTS)
 	@ $(AR) rcs lib/libtinycrypt.a lib/*.o
 
 clean:
-	rm lib/*.o test-main+	@- rm lib/*.o test-main

M flake.lock → flake.lock

@@ -2,16 +2,16 @@ {
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1766902085,
-        "narHash": "sha256-coBu0ONtFzlwwVBzmjacUQwj3G+lybcZ1oeNSQkgC0M=",
+        "lastModified": 1767047869,
+        "narHash": "sha256-tzYsEzXEVa7op1LTnrLSiPGrcCY6948iD0EcNLWcmzo=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "c0b0e0fddf73fd517c3471e546c0df87a42d53f4",
+        "rev": "89dbf01df72eb5ebe3b24a86334b12c27d68016a",
         "type": "github"
       },
       "original": {
         "owner": "nixos",
-        "ref": "nixos-unstable",
+        "ref": "nixos-25.11",
         "repo": "nixpkgs",
         "type": "github"
       }

M flake.nix → flake.nix

@@ -2,7 +2,7 @@ {
   description = "TinyCrypT Build Environment";
 
   inputs = {
-    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-unstable";
+    nixpkgs.url = "github:nixos/nixpkgs?ref=nixos-25.11";
   };
 
   outputs =
@@ -18,7 +18,7 @@ shl = pkgs.mkShell {
         name = "tct-tooling-env";
         packages = with pkgs; [
           cmake
-          clang
+          gcc
           clang-tools
           gnumake
           valgrind

M tinycrypt/tests/main.c → tinycrypt/tests/main.c

@@ -1,6 +1,9 @@
 #include <stdbool.h>
+#include <stddef.h>
 #include <stdio.h>
+#include <string.h>
 
+#include "tinycrypt/sha2.h"
 #include "tinycrypt/tests/harness.h"
 
 int
@@ -11,7 +14,15 @@ tct_testing_init_ctx (&ctx);
   printf ("Beginning tests\n");
   tct_testing_start (&ctx);
 
-  // Tests go here
+  uint8_t buf[32];
+  tct_sha256 (NULL, 0, buf);
+  uint8_t reference[] = {
+    0xe3, 0xb0, 0xc4, 0x42, 0x98, 0xfc, 0x1c, 0x14, 0x9a, 0xfb, 0xf4,
+    0xc8, 0x99, 0x6f, 0xb9, 0x24, 0x27, 0xae, 0x41, 0xe4, 0x64, 0x9b,
+    0x93, 0x4c, 0xa4, 0x95, 0x99, 0x1b, 0x78, 0x52, 0xb8, 0x55,
+  };
+  tct_testing_assert (&ctx, !memcmp (buf, reference, sizeof (buf)),
+                      "Empty SHA-256");
 
   tct_testing_end (&ctx);
   printf ("%lu tests passed, %lu tests failed, %lu microseconds elapsed\n",