1 files changed, 33 insertions, 0 deletions
diff --git a/src/tools/pubkey.c b/src/tools/pubkey.c
new file mode 100644
index 0000000..d9a97d9
--- /dev/null
+++ b/src/tools/pubkey.c
@@ -0,0 +1,33 @@
+/* Copyright 2015-2016 Jason A. Donenfeld <Jason@zx2c4.com>. All Rights Reserved. */
+
+#include <errno.h>
+#include <resolv.h>
+#include <stdio.h>
+
+#include "curve25519.h"
+#include "base64.h"
+
+int pubkey_main(__attribute__((unused)) int argc, __attribute__((unused)) char *argv[])
+{
+	unsigned char private_key[CURVE25519_POINT_SIZE + 1] = { 0 }, public_key[CURVE25519_POINT_SIZE] = { 0 };
+	char private_key_base64[b64_len(CURVE25519_POINT_SIZE)] = { 0 }, public_key_base64[b64_len(CURVE25519_POINT_SIZE)] = { 0 };
+
+	if (fread(private_key_base64, 1, sizeof(private_key_base64) - 1, stdin) != sizeof(private_key_base64) - 1) {
+		errno = EINVAL;
+		perror("fread(private key)");
+		return 1;
+	}
+	if (b64_pton(private_key_base64, private_key, sizeof(private_key)) < 0) {
+		errno = EINVAL;
+		perror("b64");
+		return 1;
+	}
+	curve25519_generate_public(public_key, private_key);
+	if (b64_ntop(public_key, sizeof(public_key), public_key_base64, sizeof(public_key_base64)) < 0) {
+		errno = EINVAL;
+		perror("b64");
+		return 1;
+	}
+	puts(public_key_base64);
+	return 0;
+}