diff options
Diffstat (limited to 'thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmpv3.c')
-rw-r--r-- | thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmpv3.c | 136 |
1 files changed, 136 insertions, 0 deletions
diff --git a/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmpv3.c b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmpv3.c new file mode 100644 index 0000000..69fb3a0 --- /dev/null +++ b/thirdparty/nRF5_SDK_15.0.0_a53641a/external/lwip/src/apps/snmp/snmpv3.c @@ -0,0 +1,136 @@ +/** + * @file + * Additional SNMPv3 functionality RFC3414 and RFC3826. + */ + +/* + * Copyright (c) 2016 Elias Oenal. + * 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. The name of the author may not be used to endorse or promote products + * derived from this software without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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. + * + * Author: Elias Oenal <lwip@eliasoenal.com> + */ + +#include "snmpv3_priv.h" +#include "lwip/apps/snmpv3.h" +#include "lwip/sys.h" +#include <string.h> + +#if LWIP_SNMP && LWIP_SNMP_V3 + +#ifdef LWIP_SNMPV3_INCLUDE_ENGINE +#include LWIP_SNMPV3_INCLUDE_ENGINE +#endif + +#define SNMP_MAX_TIME_BOOT 2147483647UL + +/** Call this if engine has been changed. Has to reset boots, see below */ +void +snmpv3_engine_id_changed(void) +{ + snmpv3_set_engine_boots(0); +} + +/** According to RFC3414 2.2.2. + * + * The number of times that the SNMP engine has + * (re-)initialized itself since snmpEngineID + * was last configured. + */ +u32_t +snmpv3_get_engine_boots_internal(void) +{ + if (snmpv3_get_engine_boots() == 0 || + snmpv3_get_engine_boots() < SNMP_MAX_TIME_BOOT) { + return snmpv3_get_engine_boots(); + } + + snmpv3_set_engine_boots(SNMP_MAX_TIME_BOOT); + return snmpv3_get_engine_boots(); +} + +/** RFC3414 2.2.2. + * + * Once the timer reaches 2147483647 it gets reset to zero and the + * engine boot ups get incremented. + */ +u32_t +snmpv3_get_engine_time_internal(void) +{ + if (snmpv3_get_engine_time() >= SNMP_MAX_TIME_BOOT) { + snmpv3_reset_engine_time(); + + if (snmpv3_get_engine_boots() < SNMP_MAX_TIME_BOOT - 1) { + snmpv3_set_engine_boots(snmpv3_get_engine_boots() + 1); + } else { + snmpv3_set_engine_boots(SNMP_MAX_TIME_BOOT); + } + } + + return snmpv3_get_engine_time(); +} + +#if LWIP_SNMP_V3_CRYPTO + +/* This function ignores the byte order suggestion in RFC3414 + * since it simply doesn't influence the effectiveness of an IV. + * + * Implementing RFC3826 priv param algorithm if LWIP_RAND is available. + * + * @todo: This is a potential thread safety issue. + */ +err_t +snmpv3_build_priv_param(u8_t* priv_param) +{ +#ifdef LWIP_RAND /* Based on RFC3826 */ + static u8_t init; + static u32_t priv1, priv2; + + /* Lazy initialisation */ + if (init == 0) { + init = 1; + priv1 = LWIP_RAND(); + priv2 = LWIP_RAND(); + } + + SMEMCPY(&priv_param[0], &priv1, sizeof(priv1)); + SMEMCPY(&priv_param[4], &priv2, sizeof(priv2)); + + /* Emulate 64bit increment */ + priv1++; + if (!priv1) { /* Overflow */ + priv2++; + } +#else /* Based on RFC3414 */ + static u32_t ctr; + u32_t boots = LWIP_SNMPV3_GET_ENGINE_BOOTS(); + SMEMCPY(&priv_param[0], &boots, 4); + SMEMCPY(&priv_param[4], &ctr, 4); + ctr++; +#endif + return ERR_OK; +} +#endif /* LWIP_SNMP_V3_CRYPTO */ + +#endif |