1 files changed, 59 insertions, 0 deletions
diff --git a/src/tools/genkey.c b/src/tools/genkey.c
new file mode 100644
index 0000000..1602ae1
--- /dev/null
+++ b/src/tools/genkey.c
@@ -0,0 +1,59 @@
+/* Copyright 2015-2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
+
+#include <errno.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/types.h>
+#include <sys/stat.h>
+#include <syscall.h>
+#include <unistd.h>
+#include <string.h>
+
+#include "curve25519.h"
+#include "base64.h"
+
+#ifdef __NR_getrandom
+static inline ssize_t get_random_bytes(uint8_t *out, size_t len)
+{
+	return syscall(__NR_getrandom, out, len, 0);
+}
+#else
+#include <fcntl.h>
+static inline ssize_t get_random_bytes(uint8_t *out, size_t len)
+{
+	ssize_t ret;
+	int fd = open("/dev/urandom", O_RDONLY);
+	if (fd < 0)
+		return fd;
+	ret = read(fd, out, len);
+	close(fd);
+	return ret;
+}
+#endif
+
+int genkey_main(int argc, char *argv[])
+{
+	unsigned char private_key[CURVE25519_POINT_SIZE];
+	char private_key_base64[b64_len(CURVE25519_POINT_SIZE)];
+	struct stat stat;
+
+	if (!fstat(STDOUT_FILENO, &stat) && S_ISREG(stat.st_mode) && stat.st_mode & S_IRWXO)
+		fputs("Warning: writing to world accessible file.\nConsider setting the umask to 077 and trying again.\n", stderr);
+
+	if (get_random_bytes(private_key, CURVE25519_POINT_SIZE) != CURVE25519_POINT_SIZE) {
+		perror("getrandom");
+		return 1;
+	}
+	if (argc && !strcmp(argv[0], "genkey"))
+		curve25519_normalize_secret(private_key);
+
+	if (b64_ntop(private_key, sizeof(private_key), private_key_base64, sizeof(private_key_base64)) < 0) {
+		errno = EINVAL;
+		perror("b64");
+		return 1;
+	}
+
+	puts(private_key_base64);
+	return 0;
+
+}