1 files changed, 73 insertions, 0 deletions
diff --git a/tests/random.c b/tests/random.c
new file mode 100644
index 0000000..eec83c5
--- /dev/null
+++ b/tests/random.c
@@ -0,0 +1,73 @@
+#include "../src/random.c"
+#include "../src/testing.h"
+
+
+static int
+test_urandom_bytes(void) {
+	int rc = 0;
+
+	test_start("urandom_bytes()");
+
+	{
+		testing("we get to pick the size that comes out");
+
+		const size_t LEN = 256;
+		uint8_t arr[256 /* LEN */] = { 0 };
+
+		for (size_t n = 0; n < LEN; n++) {
+			if (urandom_bytes(n, &arr)) {
+				logerr("urandom_bytes(n, &arr);\n");
+				rc = -1;
+				goto out;
+			}
+			for (size_t i = n; i < LEN; i++) {
+				assert(arr[i] == 0);
+			}
+		}
+
+		test_ok();
+	}
+
+	{
+		testing("we always get a new value as a result");
+
+		const size_t LEN = 64;
+		uint8_t arr1[64 /* LEN */] = { 0 };
+		uint8_t arr2[64 /* LEN */] = { 0 };
+
+		if (urandom_bytes(LEN, &arr1)) {
+			logerr("urandom_bytes(LEN, &arr1);\n");
+			rc = -1;
+			goto out;
+		}
+
+		const size_t attempts = 10;
+		for (size_t n = 0; n < attempts; n++) {
+			if (urandom_bytes(LEN, &arr2)) {
+				logerr("urandom_bytes(LEN, &arr2);\n");
+				rc = -1;
+				goto out;
+			}
+			assert(memcmp(arr1, arr2, LEN) != 0);
+		}
+
+		test_ok();
+	}
+
+out:
+	return rc;
+}
+
+int
+main(void) {
+	int rc = 0;
+
+	if (test_urandom_bytes()) {
+		logerr("test_urandom_bytes();\n");
+		rc = -1;
+		goto out;
+	}
+
+out:
+	return !!rc;
+}