Add implementation of the RC2 block cipher (RFC 2268)

This commit is contained in:
Tobias Brunner 2013-04-10 19:24:09 +02:00
parent c734c2d875
commit 9d4fc8677f
9 changed files with 559 additions and 4 deletions

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@ -112,6 +112,7 @@ ARG_ENABL_SET([ldap], [enable LDAP fetching plugin to fetch files via
ARG_DISBL_SET([aes], [disable AES software implementation plugin.])
ARG_DISBL_SET([des], [disable DES/3DES software implementation plugin.])
ARG_ENABL_SET([blowfish], [enable Blowfish software implementation plugin.])
ARG_DISBL_SET([rc2], [disable RC2 software implementation plugin.])
ARG_ENABL_SET([md4], [enable MD4 software implementation plugin.])
ARG_DISBL_SET([md5], [disable MD5 software implementation plugin.])
ARG_DISBL_SET([sha1], [disable SHA1 software implementation plugin.])
@ -952,6 +953,7 @@ ADD_PLUGIN([pkcs11], [s charon pki nm cmd])
ADD_PLUGIN([aes], [s charon openac scepclient pki scripts nm cmd])
ADD_PLUGIN([des], [s charon openac scepclient pki scripts nm cmd])
ADD_PLUGIN([blowfish], [s charon openac scepclient pki scripts nm cmd])
ADD_PLUGIN([rc2], [s charon openac scepclient pki scripts nm cmd])
ADD_PLUGIN([sha1], [s charon openac scepclient pki scripts medsrv attest nm cmd])
ADD_PLUGIN([sha2], [s charon openac scepclient pki scripts medsrv attest nm cmd])
ADD_PLUGIN([md4], [s charon openac manager scepclient pki nm cmd])
@ -1081,6 +1083,7 @@ AM_CONDITIONAL(USE_LDAP, test x$ldap = xtrue)
AM_CONDITIONAL(USE_AES, test x$aes = xtrue)
AM_CONDITIONAL(USE_DES, test x$des = xtrue)
AM_CONDITIONAL(USE_BLOWFISH, test x$blowfish = xtrue)
AM_CONDITIONAL(USE_RC2, test x$rc2 = xtrue)
AM_CONDITIONAL(USE_MD4, test x$md4 = xtrue)
AM_CONDITIONAL(USE_MD5, test x$md5 = xtrue)
AM_CONDITIONAL(USE_SHA1, test x$sha1 = xtrue)
@ -1274,6 +1277,7 @@ AC_CONFIG_FILES([
src/libstrongswan/plugins/cmac/Makefile
src/libstrongswan/plugins/des/Makefile
src/libstrongswan/plugins/blowfish/Makefile
src/libstrongswan/plugins/rc2/Makefile
src/libstrongswan/plugins/md4/Makefile
src/libstrongswan/plugins/md5/Makefile
src/libstrongswan/plugins/sha1/Makefile

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@ -175,6 +175,13 @@ if MONOLITHIC
endif
endif
if USE_RC2
SUBDIRS += plugins/rc2
if MONOLITHIC
libstrongswan_la_LIBADD += plugins/rc2/libstrongswan-rc2.la
endif
endif
if USE_MD4
SUBDIRS += plugins/md4
if MONOLITHIC

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@ -46,12 +46,13 @@ ENUM_NEXT(encryption_algorithm_names, ENCR_CAMELLIA_CBC, ENCR_CAMELLIA_CCM_ICV16
"CAMELLIA_CCM_8",
"CAMELLIA_CCM_12",
"CAMELLIA_CCM_16");
ENUM_NEXT(encryption_algorithm_names, ENCR_UNDEFINED, ENCR_TWOFISH_CBC, ENCR_CAMELLIA_CCM_ICV16,
ENUM_NEXT(encryption_algorithm_names, ENCR_UNDEFINED, ENCR_RC2_CBC, ENCR_CAMELLIA_CCM_ICV16,
"UNDEFINED",
"DES_ECB",
"SERPENT_CBC",
"TWOFISH_CBC");
ENUM_END(encryption_algorithm_names, ENCR_TWOFISH_CBC);
"TWOFISH_CBC",
"RC2_CBC");
ENUM_END(encryption_algorithm_names, ENCR_RC2_CBC);
/*
* Described in header.

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@ -60,7 +60,9 @@ enum encryption_algorithm_t {
ENCR_UNDEFINED = 1024,
ENCR_DES_ECB = 1025,
ENCR_SERPENT_CBC = 1026,
ENCR_TWOFISH_CBC = 1027
ENCR_TWOFISH_CBC = 1027,
/* see macros below to handle RC2 (effective) key length */
ENCR_RC2_CBC = 1028,
};
#define DES_BLOCK_SIZE 8
@ -70,6 +72,15 @@ enum encryption_algorithm_t {
#define SERPENT_BLOCK_SIZE 16
#define TWOFISH_BLOCK_SIZE 16
/**
* For RC2, if the effective key size in bits is not key_size * 8, it should
* be encoded with the macro below. It can be decoded with the other two macros.
* After decoding the value should be validated.
*/
#define RC2_KEY_SIZE(kl, eff) ((kl) | ((eff) << 8))
#define RC2_EFFECTIVE_KEY_LEN(ks) ((ks) >> 8)
#define RC2_KEY_LEN(ks) ((ks) & 0xff)
/**
* enum name for encryption_algorithm_t.
*/

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@ -0,0 +1,15 @@
INCLUDES = -I$(top_srcdir)/src/libstrongswan
AM_CFLAGS = -rdynamic
if MONOLITHIC
noinst_LTLIBRARIES = libstrongswan-rc2.la
else
plugin_LTLIBRARIES = libstrongswan-rc2.la
endif
libstrongswan_rc2_la_SOURCES = \
rc2_plugin.h rc2_plugin.c rc2_crypter.c rc2_crypter.h
libstrongswan_rc2_la_LDFLAGS = -module -avoid-version

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@ -0,0 +1,349 @@
/*
* Copyright (C) 2013 Tobias Brunner
* 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.
*/
#include "rc2_crypter.h"
typedef struct private_rc2_crypter_t private_rc2_crypter_t;
#define RC2_BLOCK_SIZE 8
#define ROL16(x, k) ({ u_int16_t _x = (x); (_x << (k)) | (_x >> (16 - (k))); })
#define ROR16(x, k) ({ u_int16_t _x = (x); (_x >> (k)) | (_x << (16 - (k))); })
#define GET16(x) ({ u_char *_x = (x); (u_int16_t)_x[0] | ((u_int16_t)_x[1] << 8); })
#define PUT16(x, v) ({ u_char *_x = (x); u_int16_t _v = (v); _x[0] = _v, _x[1] = _v >> 8; })
/**
* Private data of rc2_crypter_t
*/
struct private_rc2_crypter_t {
/**
* Public interface
*/
rc2_crypter_t public;
/**
* The expanded key in 16-bit words
*/
u_int16_t K[64];
/**
* Key size in bytes
*/
size_t T;
/**
* Effective key size in bits
*/
size_t T1;
};
/**
* PITABLE
*/
static const u_char PITABLE[256] =
{
0xd9, 0x78, 0xf9, 0xc4, 0x19, 0xdd, 0xb5, 0xed,
0x28, 0xe9, 0xfd, 0x79, 0x4a, 0xa0, 0xd8, 0x9d,
0xc6, 0x7e, 0x37, 0x83, 0x2b, 0x76, 0x53, 0x8e,
0x62, 0x4c, 0x64, 0x88, 0x44, 0x8b, 0xfb, 0xa2,
0x17, 0x9a, 0x59, 0xf5, 0x87, 0xb3, 0x4f, 0x13,
0x61, 0x45, 0x6d, 0x8d, 0x09, 0x81, 0x7d, 0x32,
0xbd, 0x8f, 0x40, 0xeb, 0x86, 0xb7, 0x7b, 0x0b,
0xf0, 0x95, 0x21, 0x22, 0x5c, 0x6b, 0x4e, 0x82,
0x54, 0xd6, 0x65, 0x93, 0xce, 0x60, 0xb2, 0x1c,
0x73, 0x56, 0xc0, 0x14, 0xa7, 0x8c, 0xf1, 0xdc,
0x12, 0x75, 0xca, 0x1f, 0x3b, 0xbe, 0xe4, 0xd1,
0x42, 0x3d, 0xd4, 0x30, 0xa3, 0x3c, 0xb6, 0x26,
0x6f, 0xbf, 0x0e, 0xda, 0x46, 0x69, 0x07, 0x57,
0x27, 0xf2, 0x1d, 0x9b, 0xbc, 0x94, 0x43, 0x03,
0xf8, 0x11, 0xc7, 0xf6, 0x90, 0xef, 0x3e, 0xe7,
0x06, 0xc3, 0xd5, 0x2f, 0xc8, 0x66, 0x1e, 0xd7,
0x08, 0xe8, 0xea, 0xde, 0x80, 0x52, 0xee, 0xf7,
0x84, 0xaa, 0x72, 0xac, 0x35, 0x4d, 0x6a, 0x2a,
0x96, 0x1a, 0xd2, 0x71, 0x5a, 0x15, 0x49, 0x74,
0x4b, 0x9f, 0xd0, 0x5e, 0x04, 0x18, 0xa4, 0xec,
0xc2, 0xe0, 0x41, 0x6e, 0x0f, 0x51, 0xcb, 0xcc,
0x24, 0x91, 0xaf, 0x50, 0xa1, 0xf4, 0x70, 0x39,
0x99, 0x7c, 0x3a, 0x85, 0x23, 0xb8, 0xb4, 0x7a,
0xfc, 0x02, 0x36, 0x5b, 0x25, 0x55, 0x97, 0x31,
0x2d, 0x5d, 0xfa, 0x98, 0xe3, 0x8a, 0x92, 0xae,
0x05, 0xdf, 0x29, 0x10, 0x67, 0x6c, 0xba, 0xc9,
0xd3, 0x00, 0xe6, 0xcf, 0xe1, 0x9e, 0xa8, 0x2c,
0x63, 0x16, 0x01, 0x3f, 0x58, 0xe2, 0x89, 0xa9,
0x0d, 0x38, 0x34, 0x1b, 0xab, 0x33, 0xff, 0xb0,
0xbb, 0x48, 0x0c, 0x5f, 0xb9, 0xb1, 0xcd, 0x2e,
0xc5, 0xf3, 0xdb, 0x47, 0xe5, 0xa5, 0x9c, 0x77,
0x0a, 0xa6, 0x20, 0x68, 0xfe, 0x7f, 0xc1, 0xad,
};
/**
* Encrypt a single block of data
*/
static void encrypt_block(private_rc2_crypter_t *this, u_char R[])
{
register u_int16_t R0, R1, R2, R3, *Kj;
int rounds = 3, mix = 5;
R0 = GET16(R);
R1 = GET16(R + 2);
R2 = GET16(R + 4);
R3 = GET16(R + 6);
Kj = &this->K[0];
/* 5 mix, mash, 6 mix, mash, 5 mix */
while (TRUE)
{
/* mix */
R0 = ROL16(R0 + *(Kj++) + (R3 & R2) + (~R3 & R1), 1);
R1 = ROL16(R1 + *(Kj++) + (R0 & R3) + (~R0 & R2), 2);
R2 = ROL16(R2 + *(Kj++) + (R1 & R0) + (~R1 & R3), 3);
R3 = ROL16(R3 + *(Kj++) + (R2 & R1) + (~R2 & R0), 5);
if (--mix == 0)
{
if (--rounds == 0)
{
break;
}
mix = (rounds == 2) ? 6 : 5;
/* mash */
R0 += this->K[R3 & 63];
R1 += this->K[R0 & 63];
R2 += this->K[R1 & 63];
R3 += this->K[R2 & 63];
}
}
PUT16(R, R0);
PUT16(R + 2, R1);
PUT16(R + 4, R2);
PUT16(R + 6, R3);
}
/**
* Decrypt a single block of data.
*/
static void decrypt_block(private_rc2_crypter_t *this, u_char R[])
{
register u_int16_t R0, R1, R2, R3, *Kj;
int rounds = 3, mix = 5;
R0 = GET16(R);
R1 = GET16(R + 2);
R2 = GET16(R + 4);
R3 = GET16(R + 6);
Kj = &this->K[63];
/* 5 r-mix, r-mash, 6 r-mix, r-mash, 5 r-mix */
while (TRUE)
{
/* r-mix */
R3 = ROR16(R3, 5);
R3 = R3 - *(Kj--) - (R2 & R1) - (~R2 & R0);
R2 = ROR16(R2, 3);
R2 = R2 - *(Kj--) - (R1 & R0) - (~R1 & R3);
R1 = ROR16(R1, 2);
R1 = R1 - *(Kj--) - (R0 & R3) - (~R0 & R2);
R0 = ROR16(R0, 1);
R0 = R0 - *(Kj--) - (R3 & R2) - (~R3 & R1);
if (--mix == 0)
{
if (--rounds == 0)
{
break;
}
mix = (rounds == 2) ? 6 : 5;
/* r-mash */
R3 -= this->K[R2 & 63];
R2 -= this->K[R1 & 63];
R1 -= this->K[R0 & 63];
R0 -= this->K[R3 & 63];
}
}
PUT16(R, R0);
PUT16(R + 2, R1);
PUT16(R + 4, R2);
PUT16(R + 6, R3);
}
METHOD(crypter_t, decrypt, bool,
private_rc2_crypter_t *this, chunk_t data, chunk_t iv, chunk_t *decrypted)
{
u_int8_t *in, *out, *prev;
if (data.len % RC2_BLOCK_SIZE || iv.len != RC2_BLOCK_SIZE)
{
return FALSE;
}
in = data.ptr + data.len - RC2_BLOCK_SIZE;
out = data.ptr;
if (decrypted)
{
*decrypted = chunk_alloc(data.len);
out = decrypted->ptr;
}
out += data.len - RC2_BLOCK_SIZE;
prev = in;
for (; in >= data.ptr; in -= RC2_BLOCK_SIZE, out -= RC2_BLOCK_SIZE)
{
if (decrypted)
{
memcpy(out, in, RC2_BLOCK_SIZE);
}
decrypt_block(this, out);
prev -= RC2_BLOCK_SIZE;
if (prev < data.ptr)
{
prev = iv.ptr;
}
memxor(out, prev, RC2_BLOCK_SIZE);
}
return TRUE;
}
METHOD(crypter_t, encrypt, bool,
private_rc2_crypter_t *this, chunk_t data, chunk_t iv, chunk_t *encrypted)
{
u_int8_t *in, *out, *end, *prev;
if (data.len % RC2_BLOCK_SIZE || iv.len != RC2_BLOCK_SIZE)
{
return FALSE;
}
in = data.ptr;
end = data.ptr + data.len;
out = data.ptr;
if (encrypted)
{
*encrypted = chunk_alloc(data.len);
out = encrypted->ptr;
}
prev = iv.ptr;
for (; in < end; in += RC2_BLOCK_SIZE, out += RC2_BLOCK_SIZE)
{
if (encrypted)
{
memcpy(out, in, RC2_BLOCK_SIZE);
}
memxor(out, prev, RC2_BLOCK_SIZE);
encrypt_block(this, out);
prev = out;
}
return TRUE;
}
METHOD(crypter_t, get_block_size, size_t,
private_rc2_crypter_t *this)
{
return RC2_BLOCK_SIZE;
}
METHOD(crypter_t, get_iv_size, size_t,
private_rc2_crypter_t *this)
{
return RC2_BLOCK_SIZE;
}
METHOD(crypter_t, get_key_size, size_t,
private_rc2_crypter_t *this)
{
return this->T;
}
METHOD(crypter_t, set_key, bool,
private_rc2_crypter_t *this, chunk_t key)
{
u_int8_t L[128], T8, TM, idx;
int i;
if (key.len != this->T)
{
return FALSE;
}
for (i = 0; i < key.len; i++)
{
L[i] = key.ptr[i];
}
for (; i < 128; i++)
{
idx = L[i-1] + L[i-key.len];
L[i] = PITABLE[idx];
}
T8 = (this->T1 + 7) / 8;
TM = ~(0xff << (8 - (8*T8 - this->T1)));
L[128-T8] = PITABLE[L[128-T8] & TM];
for (i = 127-T8; i >= 0; i--)
{
idx = L[i+1] ^ L[i+T8];
L[i] = PITABLE[idx];
}
for (i = 0; i < 64; i++)
{
this->K[i] = GET16(&L[i << 1]);
}
memwipe(L, sizeof(L));
return TRUE;
}
METHOD(crypter_t, destroy, void,
private_rc2_crypter_t *this)
{
memwipe(this->K, sizeof(this->K));
free(this);
}
/*
* Described in header
*/
rc2_crypter_t *rc2_crypter_create(encryption_algorithm_t algo, size_t key_size)
{
private_rc2_crypter_t *this;
size_t effective;
if (algo != ENCR_RC2_CBC)
{
return NULL;
}
key_size = max(1, key_size);
effective = RC2_EFFECTIVE_KEY_LEN(key_size);
key_size = min(128, RC2_KEY_LEN(key_size));
effective = max(1, min(1024, effective ?: key_size * 8));
INIT(this,
.public = {
.crypter = {
.encrypt = _encrypt,
.decrypt = _decrypt,
.get_block_size = _get_block_size,
.get_iv_size = _get_iv_size,
.get_key_size = _get_key_size,
.set_key = _set_key,
.destroy = _destroy,
},
},
.T = key_size,
.T1 = effective,
);
return &this->public;
}

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@ -0,0 +1,50 @@
/*
* Copyright (C) 2013 Tobias Brunner
* 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 rc2_crypter rc2_crypter
* @{ @ingroup rc2_p
*/
#ifndef RC2_CRYPTER_H_
#define RC2_CRYPTER_H_
typedef struct rc2_crypter_t rc2_crypter_t;
#include <crypto/crypters/crypter.h>
/**
* Class implementing the RC2 block cipher as defined in RFC 2268.
*/
struct rc2_crypter_t {
/**
* Implements crypter_t interface.
*/
crypter_t crypter;
};
/**
* Constructor to create rc2_crypter_t objects.
*
* @param algo algorithm to implement (ENCR_RC2_CBC)
* @param key_size use the RC2_KEY_SIZE macro if the effective key size
* in bits is different than the actual length of the key
* @return rc2_crypter_t object, NULL if not supported
*/
rc2_crypter_t *rc2_crypter_create(encryption_algorithm_t algo,
size_t key_size);
#endif /** RC2_CRYPTER_H_ @}*/

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@ -0,0 +1,76 @@
/*
* Copyright (C) 2013 Tobias Brunner
* 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.
*/
#include "rc2_plugin.h"
#include <library.h>
#include "rc2_crypter.h"
typedef struct private_rc2_plugin_t private_rc2_plugin_t;
/**
* Private data of rc2_plugin
*/
struct private_rc2_plugin_t {
/**
* Public interface
*/
rc2_plugin_t public;
};
METHOD(plugin_t, get_name, char*,
private_rc2_plugin_t *this)
{
return "rc2";
}
METHOD(plugin_t, get_features, int,
private_rc2_plugin_t *this, plugin_feature_t *features[])
{
static plugin_feature_t f[] = {
PLUGIN_REGISTER(CRYPTER, rc2_crypter_create),
PLUGIN_PROVIDE(CRYPTER, ENCR_RC2_CBC, 0),
};
*features = f;
return countof(f);
}
METHOD(plugin_t, destroy, void,
private_rc2_plugin_t *this)
{
free(this);
}
/*
* Described in header
*/
plugin_t *rc2_plugin_create()
{
private_rc2_plugin_t *this;
INIT(this,
.public = {
.plugin = {
.get_name = _get_name,
.get_features = _get_features,
.destroy = _destroy,
},
},
);
return &this->public.plugin;
}

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@ -0,0 +1,42 @@
/*
* Copyright (C) 2013 Tobias Brunner
* 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 rc2_p rc2
* @ingroup plugins
*
* @defgroup rc2_plugin rc2_plugin
* @{ @ingroup rc2_p
*/
#ifndef RC2_PLUGIN_H_
#define RC2_PLUGIN_H_
#include <plugins/plugin.h>
typedef struct rc2_plugin_t rc2_plugin_t;
/**
* Plugin implementing RC2 (RFC 2268).
*/
struct rc2_plugin_t {
/**
* Implements plugin interface
*/
plugin_t plugin;
};
#endif /** RC2_PLUGIN_H_ @}*/