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author | Yves-Alexis Perez <corsac@corsac.net> | 2017-04-01 16:26:44 +0200 |
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committer | Yves-Alexis Perez <corsac@corsac.net> | 2017-04-01 16:26:44 +0200 |
commit | 05ddd767992d68bb38c7f16ece142e8c2e9ae016 (patch) | |
tree | 302c618be306d4ed3c7f9fc58a1f6aaad4dd252f /src/libcharon/sa/ikev1/iv_manager.c | |
parent | 25663e04c3ab01ef8dc9f906608282319cfea2db (diff) | |
download | vyos-strongswan-05ddd767992d68bb38c7f16ece142e8c2e9ae016.tar.gz vyos-strongswan-05ddd767992d68bb38c7f16ece142e8c2e9ae016.zip |
New upstream version 5.5.2
Diffstat (limited to 'src/libcharon/sa/ikev1/iv_manager.c')
-rw-r--r-- | src/libcharon/sa/ikev1/iv_manager.c | 355 |
1 files changed, 355 insertions, 0 deletions
diff --git a/src/libcharon/sa/ikev1/iv_manager.c b/src/libcharon/sa/ikev1/iv_manager.c new file mode 100644 index 000000000..c9f737ccd --- /dev/null +++ b/src/libcharon/sa/ikev1/iv_manager.c @@ -0,0 +1,355 @@ +/* + * Copyright (C) 2011-2016 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 "iv_manager.h" + +#include <collections/linked_list.h> + +/** + * Max. number of IVs/QMs to track. + */ +#define MAX_EXCHANGES_DEFAULT 3 + +typedef struct private_iv_manager_t private_iv_manager_t; +typedef struct iv_data_t iv_data_t; +typedef struct qm_data_t qm_data_t; + +/** + * Data stored for IVs. + */ +struct iv_data_t { + /** + * message ID + */ + uint32_t mid; + + /** + * current IV + */ + chunk_t iv; + + /** + * last block of encrypted message + */ + chunk_t last_block; +}; + +/** + * Private data of a iv_manager_t object. + */ +struct private_iv_manager_t { + /** + * Implement public interface. + */ + iv_manager_t public; + + /** + * Phase 1 IV. + */ + iv_data_t phase1_iv; + + /** + * Keep track of IVs for exchanges after phase 1. We store only a limited + * number of IVs in an MRU sort of way. Stores iv_data_t objects. + */ + linked_list_t *ivs; + + /** + * Keep track of Nonces during Quick Mode exchanges. Only a limited number + * of QMs are tracked at the same time. Stores qm_data_t objects. + */ + linked_list_t *qms; + + /** + * Max. number of IVs/Quick Modes to track. + */ + int max_exchanges; + + /** + * Hasher used for IV generation. + */ + hasher_t *hasher; + + /* + * Encryption algorithm the block size. + */ + size_t block_size; +}; + +/** + * Data stored for Quick Mode exchanges. + */ +struct qm_data_t { + /** + * Message ID. + */ + uint32_t mid; + + /** + * Ni_b (Nonce from first message). + */ + chunk_t n_i; + + /** + * Nr_b (Nonce from second message). + */ + chunk_t n_r; +}; + +/** + * Destroy an iv_data_t object. + */ +static void iv_data_destroy(iv_data_t *this) +{ + chunk_free(&this->last_block); + chunk_free(&this->iv); + free(this); +} + +/** + * Destroy a qm_data_t object. + */ +static void qm_data_destroy(qm_data_t *this) +{ + chunk_free(&this->n_i); + chunk_free(&this->n_r); + free(this); +} + +/** + * Generate an IV. + */ +static bool generate_iv(private_iv_manager_t *this, iv_data_t *iv) +{ + if (iv->mid == 0 || iv->iv.ptr) + { /* use last block of previous encrypted message */ + chunk_free(&iv->iv); + iv->iv = iv->last_block; + iv->last_block = chunk_empty; + } + else + { + /* initial phase 2 IV = hash(last_phase1_block | mid) */ + uint32_t net;; + chunk_t data; + + net = htonl(iv->mid); + data = chunk_cata("cc", this->phase1_iv.iv, chunk_from_thing(net)); + if (!this->hasher->allocate_hash(this->hasher, data, &iv->iv)) + { + return FALSE; + } + if (iv->iv.len > this->block_size) + { + iv->iv.len = this->block_size; + } + } + DBG4(DBG_IKE, "next IV for MID %u %B", iv->mid, &iv->iv); + return TRUE; +} + +/** + * Try to find an IV for the given message ID, if not found, generate it. + */ +static iv_data_t *lookup_iv(private_iv_manager_t *this, uint32_t mid) +{ + enumerator_t *enumerator; + iv_data_t *iv, *found = NULL; + + if (mid == 0) + { + return &this->phase1_iv; + } + + enumerator = this->ivs->create_enumerator(this->ivs); + while (enumerator->enumerate(enumerator, &iv)) + { + if (iv->mid == mid) + { /* IV gets moved to the front of the list */ + this->ivs->remove_at(this->ivs, enumerator); + found = iv; + break; + } + } + enumerator->destroy(enumerator); + if (!found) + { + INIT(found, + .mid = mid, + ); + if (!generate_iv(this, found)) + { + iv_data_destroy(found); + return NULL; + } + } + this->ivs->insert_first(this->ivs, found); + /* remove least recently used IV if maximum reached */ + if (this->ivs->get_count(this->ivs) > this->max_exchanges && + this->ivs->remove_last(this->ivs, (void**)&iv) == SUCCESS) + { + iv_data_destroy(iv); + } + return found; +} + +METHOD(iv_manager_t, init_iv_chain, bool, + private_iv_manager_t *this, chunk_t data, hasher_t *hasher, + size_t block_size) +{ + this->hasher = hasher; + this->block_size = block_size; + + if (!this->hasher->allocate_hash(this->hasher, data, &this->phase1_iv.iv)) + { + return FALSE; + } + if (this->phase1_iv.iv.len > this->block_size) + { + this->phase1_iv.iv.len = this->block_size; + } + DBG4(DBG_IKE, "initial IV %B", &this->phase1_iv.iv); + return TRUE; +} + +METHOD(iv_manager_t, get_iv, bool, + private_iv_manager_t *this, uint32_t mid, chunk_t *out) +{ + iv_data_t *iv; + + iv = lookup_iv(this, mid); + if (iv) + { + *out = iv->iv; + return TRUE; + } + return FALSE; +} + +METHOD(iv_manager_t, update_iv, bool, + private_iv_manager_t *this, uint32_t mid, chunk_t last_block) +{ + iv_data_t *iv = lookup_iv(this, mid); + if (iv) + { /* update last block */ + chunk_free(&iv->last_block); + iv->last_block = chunk_clone(last_block); + return TRUE; + } + return FALSE; +} + +METHOD(iv_manager_t, confirm_iv, bool, + private_iv_manager_t *this, uint32_t mid) +{ + iv_data_t *iv = lookup_iv(this, mid); + if (iv) + { + return generate_iv(this, iv); + } + return FALSE; +} + +METHOD(iv_manager_t, lookup_quick_mode, void, + private_iv_manager_t *this, uint32_t mid, chunk_t **n_i, chunk_t **n_r) +{ + enumerator_t *enumerator; + qm_data_t *qm, *found = NULL; + + enumerator = this->qms->create_enumerator(this->qms); + while (enumerator->enumerate(enumerator, &qm)) + { + if (qm->mid == mid) + { /* state gets moved to the front of the list */ + this->qms->remove_at(this->qms, enumerator); + found = qm; + break; + } + } + enumerator->destroy(enumerator); + if (!found) + { + INIT(found, + .mid = mid, + ); + } + + *n_i = &found->n_i; + *n_r = &found->n_r; + + this->qms->insert_first(this->qms, found); + /* remove least recently used state if maximum reached */ + if (this->qms->get_count(this->qms) > this->max_exchanges && + this->qms->remove_last(this->qms, (void**)&qm) == SUCCESS) + { + qm_data_destroy(qm); + } +} + +METHOD(iv_manager_t, remove_quick_mode, void, + private_iv_manager_t *this, uint32_t mid) +{ + enumerator_t *enumerator; + qm_data_t *qm; + + enumerator = this->qms->create_enumerator(this->qms); + while (enumerator->enumerate(enumerator, &qm)) + { + if (qm->mid == mid) + { + this->qms->remove_at(this->qms, enumerator); + qm_data_destroy(qm); + break; + } + } + enumerator->destroy(enumerator); +} + +METHOD(iv_manager_t, destroy, void, + private_iv_manager_t *this) +{ + chunk_free(&this->phase1_iv.iv); + chunk_free(&this->phase1_iv.last_block); + this->ivs->destroy_function(this->ivs, (void*)iv_data_destroy); + this->qms->destroy_function(this->qms, (void*)qm_data_destroy); + free(this); +} + +iv_manager_t *iv_manager_create(int max_exchanges) +{ + private_iv_manager_t *this; + + INIT(this, + .public = { + .init_iv_chain = _init_iv_chain, + .get_iv = _get_iv, + .update_iv = _update_iv, + .confirm_iv = _confirm_iv, + .lookup_quick_mode = _lookup_quick_mode, + .remove_quick_mode = _remove_quick_mode, + .destroy = _destroy, + }, + .ivs = linked_list_create(), + .qms = linked_list_create(), + .max_exchanges = max_exchanges, + ); + + if (!this->max_exchanges) + { + this->max_exchanges = lib->settings->get_int(lib->settings, + "%s.max_ikev1_exchanges", MAX_EXCHANGES_DEFAULT, lib->ns); + } + return &this->public; +} |