From d161ffcb643576d695e8cc2d64763b6000ca86a4 Mon Sep 17 00:00:00 2001 From: kkrentz Date: Mon, 21 Apr 2014 03:33:34 -0700 Subject: [PATCH] llsec: Allow for sharing CCM* --- core/net/llsec/ccm.c | 190 +++++++++++++++++++++++++++++++++++++++++++ core/net/llsec/ccm.h | 85 +++++++++++++++++++ 2 files changed, 275 insertions(+) create mode 100644 core/net/llsec/ccm.c create mode 100644 core/net/llsec/ccm.h diff --git a/core/net/llsec/ccm.c b/core/net/llsec/ccm.c new file mode 100644 index 000000000..afae5ed25 --- /dev/null +++ b/core/net/llsec/ccm.c @@ -0,0 +1,190 @@ +/** + * \addtogroup llsec802154 + * @{ + */ + +/* + * Copyright (c) 2013, Hasso-Plattner-Institut. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * This file is part of the Contiki operating system. + * + */ + +/** + * \file + * AES_128-based CCM* implementation. + * \author + * Konrad Krentz + */ + +#include "net/llsec/ccm.h" +#include "net/llsec/llsec802154.h" +#include "net/packetbuf.h" +#include "lib/aes-128.h" +#include + +/*---------------------------------------------------------------------------*/ +static void +set_nonce(uint8_t *nonce, + uint8_t flags, + const uint8_t *extended_source_address, + uint8_t counter) +{ + /* 1 byte|| 8 bytes || 4 bytes || 1 byte || 2 bytes */ + /* flags || extended_source_address || frame_counter || sec_lvl || counter */ + + nonce[0] = flags; + memcpy(nonce + 1, extended_source_address, 8); + nonce[9] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) >> 8; + nonce[10] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_2_3) & 0xff; + nonce[11] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) >> 8; + nonce[12] = packetbuf_attr(PACKETBUF_ATTR_FRAME_COUNTER_BYTES_0_1) & 0xff; + nonce[13] = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL); + nonce[14] = 0; + nonce[15] = counter; +} +/*---------------------------------------------------------------------------*/ +/* XORs the block m[pos] ... m[pos + 15] with K_{counter} */ +static void +ctr_step(const uint8_t *extended_source_address, + uint8_t pos, + uint8_t *m_and_result, + uint8_t m_len, + uint8_t counter) +{ + uint8_t a[AES_128_BLOCK_SIZE]; + uint8_t i; + + set_nonce(a, CCM_ENCRYPTION_FLAGS, extended_source_address, counter); + AES_128.encrypt(a); + + for(i = 0; (pos + i < m_len) && (i < AES_128_BLOCK_SIZE); i++) { + m_and_result[pos + i] ^= a[i]; + } +} +/*---------------------------------------------------------------------------*/ +static void +mic(const uint8_t *extended_source_address, + uint8_t *result, + uint8_t mic_len) +{ + uint8_t x[AES_128_BLOCK_SIZE]; + uint8_t pos; + uint8_t i; + uint8_t a_len; + uint8_t *a; +#if LLSEC802154_USES_ENCRYPTION + uint8_t shall_encrypt; + uint8_t m_len; + uint8_t *m; + + shall_encrypt = packetbuf_attr(PACKETBUF_ATTR_SECURITY_LEVEL) & (1 << 2); + if(shall_encrypt) { + a_len = packetbuf_hdrlen(); + m_len = packetbuf_datalen(); + } else { + a_len = packetbuf_totlen(); + m_len = 0; + } + set_nonce(x, + CCM_AUTH_FLAGS(a_len, mic_len), + extended_source_address, + m_len); +#else /* LLSEC802154_USES_ENCRYPTION */ + a_len = packetbuf_totlen(); + set_nonce(x, + CCM_AUTH_FLAGS(a_len, mic_len), + extended_source_address, + 0); +#endif /* LLSEC802154_USES_ENCRYPTION */ + AES_128.encrypt(x); + + a = packetbuf_hdrptr(); + if(a_len) { + x[1] = x[1] ^ a_len; + for(i = 2; (i - 2 < a_len) && (i < AES_128_BLOCK_SIZE); i++) { + x[i] ^= a[i - 2]; + } + + AES_128.encrypt(x); + + pos = 14; + while(pos < a_len) { + for(i = 0; (pos + i < a_len) && (i < AES_128_BLOCK_SIZE); i++) { + x[i] ^= a[pos + i]; + } + pos += AES_128_BLOCK_SIZE; + AES_128.encrypt(x); + } + } + +#if LLSEC802154_USES_ENCRYPTION + if(shall_encrypt) { + m = a + a_len; + pos = 0; + while(pos < m_len) { + for(i = 0; (pos + i < m_len) && (i < AES_128_BLOCK_SIZE); i++) { + x[i] ^= m[pos + i]; + } + pos += AES_128_BLOCK_SIZE; + AES_128.encrypt(x); + } + } +#endif /* LLSEC802154_USES_ENCRYPTION */ + + ctr_step(extended_source_address, 0, x, AES_128_BLOCK_SIZE, 0); + + memcpy(result, x, mic_len); +} +/*---------------------------------------------------------------------------*/ +static void +ctr(const uint8_t *extended_source_address) +{ + uint8_t m_len; + uint8_t *m; + uint8_t pos; + uint8_t counter; + + m_len = packetbuf_datalen(); + m = (uint8_t *) packetbuf_dataptr(); + + pos = 0; + counter = 1; + while(pos < m_len) { + ctr_step(extended_source_address, pos, m, m_len, counter++); + pos += AES_128_BLOCK_SIZE; + } +} +/*---------------------------------------------------------------------------*/ +const struct ccm_driver ccm_driver = { + mic, + ctr +}; +/*---------------------------------------------------------------------------*/ + +/** @} */ diff --git a/core/net/llsec/ccm.h b/core/net/llsec/ccm.h new file mode 100644 index 000000000..cd4eca8f1 --- /dev/null +++ b/core/net/llsec/ccm.h @@ -0,0 +1,85 @@ +/** + * \addtogroup llsec802154 + * @{ + */ + +/* + * Copyright (c) 2013, Hasso-Plattner-Institut. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the Institute nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + * + * This file is part of the Contiki operating system. + * + */ + +/** + * \file + * CCM* header file. + * \author + * Konrad Krentz + */ + +#ifndef CCM_H_ +#define CCM_H_ + +#include "contiki.h" +#include "net/mac/frame802154.h" + +/* see RFC 3610 */ +#define CCM_AUTH_FLAGS(Adata, M) ((Adata ? (1 << 6) : 0) | (((M - 2) >> 1) << 3) | 1) +#define CCM_ENCRYPTION_FLAGS 1 + +#ifdef CCM_CONF +#define CCM CCM_CONF +#else /* CCM_CONF */ +#define CCM ccm_driver +#endif /* CCM_CONF */ + +/** + * Structure of CCM drivers. + */ +struct ccm_driver { + + /** + * \brief Generates a MIC over the frame in the packetbuf. + * \param result The generated MIC will be put here + * \param mic_len <= 16; set to LLSEC802154_MIC_LENGTH to be compliant + */ + void (* mic)(const uint8_t *extended_source_address, + uint8_t *result, + uint8_t mic_len); + + /** + * \brief XORs the frame in the packetbuf with the key stream. + */ + void (* ctr)(const uint8_t *extended_source_address); +}; + +extern const struct ccm_driver CCM; + +#endif /* CCM_H_ */ + +/** @} */