From f36e7a52dfe48e7dd80d84b403efbe75be896140 Mon Sep 17 00:00:00 2001
From: Martin Willi <martin@revosec.ch>
Date: Wed, 28 Jan 2015 13:39:02 +0100
Subject: [PATCH] pki: Add a --cga command to generate CGA parameters for a
 public key and prefix

---
 src/pki/Makefile.am    |   1 +
 src/pki/command.h      |   2 +-
 src/pki/commands/cga.c | 178 +++++++++++++++++++++++++++++++++++++++++
 3 files changed, 180 insertions(+), 1 deletion(-)
 create mode 100644 src/pki/commands/cga.c

diff --git a/src/pki/Makefile.am b/src/pki/Makefile.am
index ab407e0212..cb6d9fa7dc 100644
--- a/src/pki/Makefile.am
+++ b/src/pki/Makefile.am
@@ -14,6 +14,7 @@ pki_SOURCES = pki.c pki.h command.c command.h \
 	commands/acert.c \
 	commands/pkcs7.c \
 	commands/pkcs12.c \
+	commands/cga.c \
 	commands/verify.c
 
 pki_LDADD = $(top_builddir)/src/libstrongswan/libstrongswan.la
diff --git a/src/pki/command.h b/src/pki/command.h
index d49adda099..e55c579e46 100644
--- a/src/pki/command.h
+++ b/src/pki/command.h
@@ -24,7 +24,7 @@
 /**
  * Maximum number of commands (+1).
  */
-#define MAX_COMMANDS 13
+#define MAX_COMMANDS 14
 
 /**
  * Maximum number of options in a command (+3)
diff --git a/src/pki/commands/cga.c b/src/pki/commands/cga.c
new file mode 100644
index 0000000000..809ff16b62
--- /dev/null
+++ b/src/pki/commands/cga.c
@@ -0,0 +1,178 @@
+/*
+ * Copyright (C) 2015 Martin Willi
+ * Copyright (C) 2015 revosec AG
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.  See <http://www.fsf.org/copyleft/gpl.txt>.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+ * or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * for more details.
+ */
+
+#include <errno.h>
+
+#include "pki.h"
+
+#include <utils/debug.h>
+#include <credentials/certificates/certificate.h>
+
+/**
+ * Make a 8-byte /64 prefix from a given IPv6 address string
+ */
+static bool make_prefix(char *str, chunk_t *prefix)
+{
+	host_t *host;
+	chunk_t enc;
+	char zero[8] = {};
+
+	host = host_create_from_string(str, 0);
+	if (!host)
+	{
+		return FALSE;
+	}
+	if (host->get_family(host) != AF_INET6)
+	{
+		host->destroy(host);
+		return FALSE;
+	}
+	enc = host->get_address(host);
+	if (enc.len != 16 || !memeq(enc.ptr + 8, zero, 8))
+	{
+		host->destroy(host);
+		return FALSE;
+	}
+	*prefix = chunk_clone(chunk_create(enc.ptr, 8));
+	host->destroy(host);
+	return TRUE;
+}
+
+/**
+ * Generate a CGA and parameters
+ */
+static int cga()
+{
+	certificate_t *cert = NULL;
+	public_key_t *public = NULL;
+	char *file = NULL, *error = NULL, *arg;
+	chunk_t prefix = chunk_empty, encoding = chunk_empty, chunk;
+	int sec = 0;
+
+	while (TRUE)
+	{
+		switch (command_getopt(&arg))
+		{
+			case 'h':
+				goto usage;
+			case 'i':
+				file = arg;
+				continue;
+			case 's':
+				sec = atoi(arg);
+				continue;
+			case 'p':
+				if (!make_prefix(arg, &prefix))
+				{
+					error = "invalid --prefix";
+					goto usage;
+				}
+				continue;
+			case EOF:
+				break;
+			default:
+				error = "invalid --cga option";
+				goto usage;
+		}
+		break;
+	}
+
+	if (!prefix.len)
+	{
+		error = "--prefix is required";
+		goto usage;
+	}
+
+	DBG2(DBG_LIB, "Reading public key:");
+	if (file)
+	{
+		public = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_ANY,
+									BUILD_FROM_FILE, file, BUILD_END);
+	}
+	else
+	{
+		if (!chunk_from_fd(0, &chunk))
+		{
+			fprintf(stderr, "%s: ", strerror(errno));
+			error = "reading public key failed";
+			goto end;
+		}
+		public = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_ANY,
+									 BUILD_BLOB, chunk, BUILD_END);
+		free(chunk.ptr);
+	}
+
+	if (!public)
+	{
+		error = "parsing public key failed";
+		goto end;
+	}
+
+	cert = lib->creds->create(lib->creds, CRED_CERTIFICATE, CERT_CGA_PARAMS,
+							  BUILD_PUBLIC_KEY, public, BUILD_CGA_SEC, sec,
+							  BUILD_CGA_PREFIX, prefix, BUILD_END);
+	if (!cert)
+	{
+		error = "generating CGA parameters failed";
+		goto end;
+	}
+	if (!cert->get_encoding(cert, CERT_CGA_ENCODING, &encoding))
+	{
+		error = "encoding CGA parameters failed";
+		goto end;
+	}
+	set_file_mode(stdout, CERT_CGA_ENCODING);
+	if (fwrite(encoding.ptr, encoding.len, 1, stdout) != 1)
+	{
+		error = "writing CGA parameters key failed";
+		goto end;
+	}
+	fprintf(stderr, "%Y\n", cert->get_subject(cert));
+
+end:
+	DESTROY_IF(cert);
+	DESTROY_IF(public);
+	free(encoding.ptr);
+	free(prefix.ptr);
+
+	if (error)
+	{
+		fprintf(stderr, "%s\n", error);
+		return 1;
+	}
+	return 0;
+
+usage:
+	free(prefix.ptr);
+	return command_usage(error);
+}
+
+/**
+ * Register the command.
+ */
+static void __attribute__ ((constructor))reg()
+{
+	command_register((command_t) {
+		cga, '6', "cga",
+		"generate an IPv6 CGA for a public key and prefix",
+		{"[--in file] --prefix prefix [--sec Sec]"},
+		{
+			{"help",			'h', 0, "show usage information"},
+			{"in",				'i', 1, "public key to generate CGA for, default: stdin"},
+			{"prefix",			'p', 1, "CGA /64 address prefix as IPv6 address"},
+			{"sec",				's', 1, "CGA Sec brute force difficulty, 0-7"},
+		}
+	});
+}
-- 
2.47.2