ims-volte-vowifi
/
strongswan
9
0
Fork 0
Code Pull Requests Releases Activity

libstrongswan agent plugin to use ssh-agent for RSA signatures

This commit is contained in:
Martin Willi 2008-09-02 11:04:26 +00:00
parent 46eb41644d
commit 21c9546321
7 changed files with 725 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

15
configure.in
View File

@ -571,6 +571,16 @@ AC_ARG_ENABLE(
fi],
)
AC_ARG_ENABLE(
[agent],
AS_HELP_STRING([--enable-agent],[enables the ssh-agent signing plugin. (default is NO).]),
[if test x$enableval = xyes; then
agent=true
else
agent=false
fi],
)
AC_ARG_ENABLE(
[uci],
AS_HELP_STRING([--enable-uci],[enable OpenWRT UCI configuration plugin (default is NO).]),
@ -793,6 +803,9 @@ fi
if test x$openssl = xtrue; then
libstrongswan_plugins=${libstrongswan_plugins}" openssl"
fi
if test x$agent = xtrue; then
libstrongswan_plugins=${libstrongswan_plugins}" agent"
fi
if test x$gmp = xtrue; then
libstrongswan_plugins=${libstrongswan_plugins}" gmp"
fi
@ -823,6 +836,7 @@ AM_CONDITIONAL(USE_MYSQL, test x$mysql = xtrue)
AM_CONDITIONAL(USE_SQLITE, test x$sqlite = xtrue)
AM_CONDITIONAL(USE_PADLOCK, test x$padlock = xtrue)
AM_CONDITIONAL(USE_OPENSSL, test x$openssl = xtrue)
AM_CONDITIONAL(USE_AGENT, test x$agent = xtrue)
dnl charon plugins
dnl ==============
@ -900,6 +914,7 @@ AC_OUTPUT(
src/libstrongswan/plugins/sqlite/Makefile
src/libstrongswan/plugins/padlock/Makefile
src/libstrongswan/plugins/openssl/Makefile
src/libstrongswan/plugins/agent/Makefile
src/libstrongswan/fips/Makefile
src/libcrypto/Makefile
src/libfreeswan/Makefile

4
src/libstrongswan/Makefile.am
View File

@ -156,6 +156,10 @@ if USE_OPENSSL
SUBDIRS += plugins/openssl
endif
if USE_AGENT
SUBDIRS += plugins/agent
endif
if USE_INTEGRITY_TEST
SUBDIRS += fips
endif

12
src/libstrongswan/plugins/agent/Makefile.am Normal file
View File

@ -0,0 +1,12 @@
INCLUDES = -I$(top_srcdir)/src/libstrongswan
AM_CFLAGS = -rdynamic
plugin_LTLIBRARIES = libstrongswan-agent.la
libstrongswan_agent_la_SOURCES = agent_plugin.h agent_plugin.c \
agent_private_key.c agent_private_key.h
libstrongswan_agent_la_LDFLAGS = -module

59
src/libstrongswan/plugins/agent/agent_plugin.c Normal file
View File

@ -0,0 +1,59 @@
/*
* Copyright (C) 2008 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* 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.
*
* $Id$
*/
#include "agent_plugin.h"
#include <library.h>
#include "agent_private_key.h"
typedef struct private_agent_plugin_t private_agent_plugin_t;
/**
* private data of agent_plugin
*/
struct private_agent_plugin_t {
/**
* public functions
*/
agent_plugin_t public;
};
/**
* Implementation of agent_plugin_t.agenttroy
*/
static void destroy(private_agent_plugin_t *this)
{
lib->creds->remove_builder(lib->creds,
(builder_constructor_t)agent_private_key_builder);
free(this);
}
/*
* see header file
*/
plugin_t *plugin_create()
{
private_agent_plugin_t *this = malloc_thing(private_agent_plugin_t);
this->public.plugin.destroy = (void(*)(plugin_t*))destroy;
lib->creds->add_builder(lib->creds, CRED_PRIVATE_KEY, KEY_RSA,
(builder_constructor_t)agent_private_key_builder);
return &this->public.plugin;
}

47
src/libstrongswan/plugins/agent/agent_plugin.h Normal file
View File

@ -0,0 +1,47 @@
/*
* Copyright (C) 2008 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* 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.
*/
/**
* @defgroup agent_p agent
* @ingroup plugins
*
* @defgroup agent_plugin agent_plugin
* @{ @ingroup agent_p
*/
#ifndef AGENT_PLUGIN_H_
#define AGENT_PLUGIN_H_
#include <plugins/plugin.h>
typedef struct agent_plugin_t agent_plugin_t;
/**
* Plugin to use private keys loaded in a ssh-agent.
*/
struct agent_plugin_t {
/**
* implements plugin interface
*/
plugin_t plugin;
};
/**
* Create a agent_plugin instance.
*/
plugin_t *plugin_create();
#endif /* AGENT_PLUGIN_H_ @}*/

540
src/libstrongswan/plugins/agent/agent_private_key.c Normal file
View File

@ -0,0 +1,540 @@
/*
* Copyright (C) 2008 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* 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.
*
* $Id$
*/
#include "agent_private_key.h"
#include <stdlib.h>
#include <unistd.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>
#include <arpa/inet.h>
#include <errno.h>
#include <library.h>
#include <chunk.h>
#include <debug.h>
#include <asn1/asn1.h>
#include <asn1/oid.h>
#ifndef UNIX_PATH_MAX
#define UNIX_PATH_MAX 108
#endif /* UNIX_PATH_MAX */
typedef struct private_agent_private_key_t private_agent_private_key_t;
typedef enum agent_msg_type_t agent_msg_type_t;
/**
* Private data of a agent_private_key_t object.
*/
struct private_agent_private_key_t {
/**
* Public interface for this signer.
*/
agent_private_key_t public;
/**
* ssh-agent unix socket connection
*/
int socket;
/**
* key identity blob in ssh format
*/
chunk_t key;
/**
* keysize in bytes
*/
size_t key_size;
/**
* Keyid formed as a SHA-1 hash of a publicKey object
*/
identification_t* keyid;
/**
* Keyid formed as a SHA-1 hash of a publicKeyInfo object
*/
identification_t* keyid_info;
/**
* reference count
*/
refcount_t ref;
};
/**
* Message types for ssh-agent protocol
*/
enum agent_msg_type_t {
SSH_AGENT_FAILURE = 5,
SSH_AGENT_SUCCESS = 6,
SSH_AGENT_ID_REQUEST = 11,
SSH_AGENT_ID_RESPONSE = 12,
SSH_AGENT_SIGN_REQUEST = 13,
SSH_AGENT_SIGN_RESPONSE = 14,
};
/**
* read a byte from a blob
*/
static u_char read_byte(chunk_t *blob)
{
u_char val;
if (blob->len < sizeof(u_char))
{
return 0;
}
val = *(blob->ptr);
*blob = chunk_skip(*blob, sizeof(u_char));
return val;
}
/**
* read a u_int32_t from a blob
*/
static u_int32_t read_uint32(chunk_t *blob)
{
u_int32_t val;
if (blob->len < sizeof(u_int32_t))
{
return 0;
}
val = ntohl(*(u_int32_t*)blob->ptr);
*blob = chunk_skip(*blob, sizeof(u_int32_t));
return val;
}
/**
* read a ssh-agent "string" length/value from a blob
*/
static chunk_t read_string(chunk_t *blob)
{
int len;
chunk_t str;
len = read_uint32(blob);
if (len > blob->len)
{
return chunk_empty;
}
str = chunk_create(blob->ptr, len);
*blob = chunk_skip(*blob, + len);
return str;
}
/**
* open socket connection to the ssh-agent
*/
static int open_connection(char *path)
{
struct sockaddr_un addr;
int s;
s = socket(AF_UNIX, SOCK_STREAM, 0);
if (s == -1)
{
DBG1("opening ssh-agent socket %s failed: %s:", path, strerror(errno));
return -1;
}
addr.sun_family = AF_UNIX;
addr.sun_path[UNIX_PATH_MAX - 1] = '\0';
strncpy(addr.sun_path, path, UNIX_PATH_MAX - 1);
if (connect(s, (struct sockaddr*)&addr, SUN_LEN(&addr)) != 0)
{
DBG1("connecting to ssh-agent socket failed: %s", strerror(errno));
close(s);
return -1;
}
return s;
}
/**
* Get the first usable key from the agent
*/
static bool read_key(private_agent_private_key_t *this)
{
int len, count;
char buf[2048];
chunk_t blob = chunk_from_buf(buf), key, type, tmp;
len = htonl(1);
write(this->socket, &len, sizeof(len));
buf[0] = SSH_AGENT_ID_REQUEST;
write(this->socket, &buf, 1);
blob.len = read(this->socket, blob.ptr, blob.len);
if (blob.len < sizeof(u_int32_t) + sizeof(u_char) ||
read_uint32(&blob) != blob.len ||
read_byte(&blob) != SSH_AGENT_ID_RESPONSE)
{
DBG1("received invalid ssh-agent identity response");
return FALSE;
}
count = read_uint32(&blob);
while (blob.len)
{
key = read_string(&blob);
if (key.len)
{
tmp = key;
type = read_string(&tmp);
read_string(&tmp);
tmp = read_string(&tmp);
if (type.len && strneq("ssh-rsa", type.ptr, type.len) &&
tmp.len >= 512/8)
{
this->key = chunk_clone(key);
this->key_size = tmp.len;
if (tmp.ptr[0] == 0)
{
this->key_size--;
}
return TRUE;
}
continue;
}
break;
}
return FALSE;
}
/**
* Implementation of agent_private_key.destroy.
*/
static bool sign(private_agent_private_key_t *this, signature_scheme_t scheme,
chunk_t data, chunk_t *signature)
{
u_int32_t len, flags;
char buf[2048];
chunk_t blob = chunk_from_buf(buf);
if (scheme != SIGN_DEFAULT && scheme != SIGN_RSA_EMSA_PKCS1_SHA1)
{
DBG1("signature scheme %N not supported by ssh-agent",
signature_scheme_names, scheme);
return FALSE;
}
len = htonl(1 + sizeof(u_int32_t) * 3 + this->key.len + data.len);
write(this->socket, &len, sizeof(len));
buf[0] = SSH_AGENT_SIGN_REQUEST;
write(this->socket, &buf, 1);
len = htonl(this->key.len);
write(this->socket, &len, sizeof(len));
write(this->socket, this->key.ptr, this->key.len);
len = htonl(data.len);
write(this->socket, &len, sizeof(len));
write(this->socket, data.ptr, data.len);
flags = htonl(0);
write(this->socket, &flags, sizeof(flags));
blob.len = read(this->socket, blob.ptr, blob.len);
if (blob.len < sizeof(u_int32_t) + sizeof(u_char) ||
read_uint32(&blob) != blob.len ||
read_byte(&blob) != SSH_AGENT_SIGN_RESPONSE)
{
DBG1("received invalid ssh-agent signature response");
return FALSE;
}
/* parse length */
blob = read_string(&blob);
/* skip sig type */
read_string(&blob);
/* parse length */
blob = read_string(&blob);
if (!blob.len)
{
DBG1("received invalid ssh-agent signature response");
return FALSE;
}
*signature = chunk_clone(blob);
return TRUE;
}
/**
* Implementation of agent_private_key.destroy.
*/
static key_type_t get_type(private_agent_private_key_t *this)
{
return KEY_RSA;
}
/**
* Implementation of agent_private_key.destroy.
*/
static bool decrypt(private_agent_private_key_t *this,
chunk_t crypto, chunk_t *plain)
{
DBG1("private key decryption not supported by ssh-agent");
return FALSE;
}
/**
* Implementation of agent_private_key.destroy.
*/
static size_t get_keysize(private_agent_private_key_t *this)
{
return this->key_size;
}
/**
* Implementation of agent_private_key.destroy.
*/
static identification_t* get_id(private_agent_private_key_t *this,
id_type_t type)
{
switch (type)
{
case ID_PUBKEY_INFO_SHA1:
return this->keyid_info;
case ID_PUBKEY_SHA1:
return this->keyid;
default:
return NULL;
}
}
/**
* Implementation of agent_private_key.get_public_key.
*/
static public_key_t* get_public_key(private_agent_private_key_t *this)
{
chunk_t key, n, e, encoded;
public_key_t *public;
key = this->key;
read_string(&key);
e = read_string(&key);
n = read_string(&key);
encoded = asn1_wrap(ASN1_SEQUENCE, "mm",
asn1_wrap(ASN1_INTEGER, "c", n),
asn1_wrap(ASN1_INTEGER, "c", e));
public = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_RSA,
BUILD_BLOB_ASN1_DER, encoded, BUILD_END);
free(encoded.ptr);
return public;
}
/**
* Implementation of agent_private_key.belongs_to.
*/
static bool belongs_to(private_agent_private_key_t *this, public_key_t *public)
{
identification_t *keyid;
if (public->get_type(public) != KEY_RSA)
{
return FALSE;
}
keyid = public->get_id(public, ID_PUBKEY_SHA1);
if (keyid && keyid->equals(keyid, this->keyid))
{
return TRUE;
}
keyid = public->get_id(public, ID_PUBKEY_INFO_SHA1);
if (keyid && keyid->equals(keyid, this->keyid_info))
{
return TRUE;
}
return FALSE;
}
/**
* Build the RSA key identifier from n and e using SHA1 hashed publicKey(Info).
*/
static bool build_ids(private_agent_private_key_t *this)
{
chunk_t publicKeyInfo, publicKey, hash, key, n, e;
hasher_t *hasher;
key = this->key;
e = read_string(&key);
n = read_string(&key);
hasher = lib->crypto->create_hasher(lib->crypto, HASH_SHA1);
if (hasher == NULL)
{
DBG1("SHA1 hash algorithm not supported, unable to use RSA");
return FALSE;
}
publicKey = asn1_wrap(ASN1_SEQUENCE, "cc", n, e);
hasher->allocate_hash(hasher, publicKey, &hash);
this->keyid = identification_create_from_encoding(ID_PUBKEY_SHA1, hash);
chunk_free(&hash);
publicKeyInfo = asn1_wrap(ASN1_SEQUENCE, "cm",
asn1_algorithmIdentifier(OID_RSA_ENCRYPTION),
asn1_bitstring("m", publicKey));
hasher->allocate_hash(hasher, publicKeyInfo, &hash);
this->keyid_info = identification_create_from_encoding(ID_PUBKEY_INFO_SHA1, hash);
chunk_free(&hash);
hasher->destroy(hasher);
chunk_free(&publicKeyInfo);
return TRUE;
}
/**
* Implementation of private_key_t.get_encoding.
*/
static chunk_t get_encoding(private_agent_private_key_t *this)
{
return chunk_empty;
}
/**
* Implementation of agent_private_key.get_ref.
*/
static private_agent_private_key_t* get_ref(private_agent_private_key_t *this)
{
ref_get(&this->ref);
return this;
}
/**
* Implementation of agent_private_key.destroy.
*/
static void destroy(private_agent_private_key_t *this)
{
if (ref_put(&this->ref))
{
close(this->socket);
DESTROY_IF(this->keyid);
DESTROY_IF(this->keyid_info);
free(this->key.ptr);
free(this);
}
}
/**
* Internal constructor
*/
static agent_private_key_t *agent_private_key_create(char *path)
{
private_agent_private_key_t *this = malloc_thing(private_agent_private_key_t);
this->public.interface.get_type = (key_type_t (*)(private_key_t *this))get_type;
this->public.interface.sign = (bool (*)(private_key_t *this, signature_scheme_t scheme, chunk_t data, chunk_t *signature))sign;
this->public.interface.decrypt = (bool (*)(private_key_t *this, chunk_t crypto, chunk_t *plain))decrypt;
this->public.interface.get_keysize = (size_t (*) (private_key_t *this))get_keysize;
this->public.interface.get_id = (identification_t* (*) (private_key_t *this,id_type_t))get_id;
this->public.interface.get_public_key = (public_key_t* (*)(private_key_t *this))get_public_key;
this->public.interface.belongs_to = (bool (*) (private_key_t *this, public_key_t *public))belongs_to;
this->public.interface.get_encoding = (chunk_t(*)(private_key_t*))get_encoding;
this->public.interface.get_ref = (private_key_t* (*)(private_key_t *this))get_ref;
this->public.interface.destroy = (void (*)(private_key_t *this))destroy;
this->socket = open_connection(path);
if (this->socket < 0)
{
free(this);
return NULL;
}
this->keyid = NULL;
this->keyid_info = NULL;
this->ref = 1;
if (!read_key(this) || !build_ids(this))
{
destroy(this);
return NULL;
}
return &this->public;
}
typedef struct private_builder_t private_builder_t;
/**
* Builder implementation for key loading/generation
*/
struct private_builder_t {
/** implements the builder interface */
builder_t public;
/** loaded/generated private key */
agent_private_key_t *key;
};
/**
* Implementation of builder_t.build
*/
static agent_private_key_t *build(private_builder_t *this)
{
agent_private_key_t *key = this->key;
free(this);
return key;
}
/**
* Implementation of builder_t.add
*/
static void add(private_builder_t *this, builder_part_t part, ...)
{
va_list args;
if (this->key)
{
DBG1("ignoring surplus build part %N", builder_part_names, part);
return;
}
switch (part)
{
case BUILD_AGENT_SOCKET:
{
va_start(args, part);
this->key = agent_private_key_create(va_arg(args, char*));
va_end(args);
break;
}
default:
DBG1("ignoring unsupported build part %N", builder_part_names, part);
break;
}
}
/**
* Builder construction function
*/
builder_t *agent_private_key_builder(key_type_t type)
{
private_builder_t *this;
if (type != KEY_RSA)
{
return NULL;
}
this = malloc_thing(private_builder_t);
this->key = NULL;
this->public.add = (void(*)(builder_t *this, builder_part_t part, ...))add;
this->public.build = (void*(*)(builder_t *this))build;
return &this->public;
}

48
src/libstrongswan/plugins/agent/agent_private_key.h Normal file
View File

@ -0,0 +1,48 @@
/*
* Copyright (C) 2008 Martin Willi
* Hochschule fuer Technik Rapperswil
*
* 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.
*/
/**
* @defgroup agent_private_key agent_private_key
* @{ @ingroup agent_p
*/
#ifndef AGENT_PRIVATE_KEY_H_
#define AGENT_PRIVATE_KEY_H_
#include <credentials/keys/private_key.h>
typedef struct agent_private_key_t agent_private_key_t;
/**
* private_key_t implementation using an ssh-agent.
*/
struct agent_private_key_t {
/**
* Implements private_key_t interface
*/
private_key_t interface;
};
/**
* Create the builder for a private key.
*
* @param type type of the key
* @return builder instance
*/
builder_t *agent_private_key_builder(key_type_t type);
#endif /*AGENT_PRIVATE_KEY_H_ @}*/