feat(libcrypto): crypto_random

configure.ac

@@ -35,11 +35,10 @@ AC_CHECK_INCLUDES_DEFAULT
 AC_C_CONST
 AC_C_INLINE
 
-AC_CHECK_FUNCS_ONCE(strtoull)
-
 AC_CHECK_HEADERS(m4_normalize([
 	libgen.h
 	getopt.h
+	sys/random.h
 ]))
 
 AC_CHECK_TYPES([struct option], [], [],
@@ -49,6 +48,8 @@ AC_CHECK_TYPES([struct option], [], [],
 
 AC_CHECK_FUNCS(m4_normalize([
 	getopt_long
+	strtoull
+	getrandom
 ]))
 
 AC_CONFIG_FILES([Makefile

libcrypto/Makefile.am

@@ -2,4 +2,4 @@ SUBDIRS = tests
 
 noinst_LIBRARIES = libcrypto.a
 AM_CFLAGS = -I$(top_srcdir)
-libcrypto_a_SOURCES = hchacha.c xchacha.c
+libcrypto_a_SOURCES = hchacha.c xchacha.c random.c

libcrypto/random.c

@@ -0,0 +1,57 @@
+#include "random.h"
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif /* HAVE_CONFIG_H */
+#ifdef _WIN32
+# include <windows.h>
+# include <ntsecapi.h>
+#else
+# ifdef HAVE_SYS_RANDOM_H
+#  include <sys/random.h>
+# else
+#  include <stdio.h>
+# endif /* HAVE_SYS_RANDOM_H */
+#endif /* _WIN32 */
+
+int
+crypto_random(uint8_t *buff, size_t size)
+{
+#ifdef _WIN32
+	return (RtlGenRandom(buff, size));
+#else
+# ifdef HAVE_GETRANDOM
+	ssize_t ret;
+
+	ret = getrandom(buff, size, 0)
+	if (ret < size)
+	{
+		return (-1);
+	}
+# else
+	FILE *fp;
+	size_t total;
+	size_t byte_read;
+
+	fp = fopen("/dev/urandom", "rb");
+	if (fp == NULL)
+	{
+		return (-1);
+	}
+
+	total = 0;
+	do {
+		byte_read = fread(buff + total, 1, size - total, fp);
+		if (byte_read == 0)
+		{
+			fclose(fp);
+			return (-1);
+		}
+
+		total += byte_read;
+	} while (total < size);
+
+	fclose(fp);
+# endif /* HAVE_GETRANDOM */
+#endif /* _WIN32 */
+	return (0);
+}

libcrypto/random.h

@@ -0,0 +1,8 @@
+#ifndef CRYPTO_RANDOM_H
+# define CRYPTO_RANDOM_H 1
+
+# include <stdint.h>
+
+int crypto_random(uint8_t *buff, size_t size);
+
+#endif /* CRYPTO_RANDOM_H */

libcrypto/tests/Makefile.am

@@ -1,9 +1,11 @@
-TESTS = test_hchacha test_xchacha
-check_PROGRAMS = test_hchacha test_xchacha
+TESTS = test_hchacha test_xchacha test_random
+check_PROGRAMS = test_hchacha test_xchacha test_random
 
 AM_CFLAGS = -I../
 LDADD = -lcmocka ../libcrypto.a
 
 test_hchacha_SOURCES = test_hchacha.c
 
-test_xchacha_SOURCES = test_xchacha.c
+test_xchacha_SOURCES = test_xchacha.c
+
+test_random_SOURCES = test_random.c

libcrypto/tests/test_random.c

@@ -0,0 +1,28 @@
+#include <stdarg.h>
+#include <stddef.h>
+#include <stdint.h>
+#include <setjmp.h>
+#include <cmocka.h>
+
+#include "random.h"
+
+/* test from https://datatracker.ietf.org/doc/html/draft-irtf-cfrg-xchacha-03#section-2.2  */
+
+
+static void
+test_random(void **state)
+{
+	uint8_t buff[512];
+
+	assert_return_code(crypto_random(buff, 512), 0);
+}
+
+int
+main(void)
+{
+	const struct CMUnitTest tests[] = {
+		cmocka_unit_test(test_random),
+	};
+ 
+	return cmocka_run_group_tests(tests, NULL, NULL);
+}