diff options
Diffstat (limited to 'netwerk/srtp/src/crypto/kernel/key.c')
| -rw-r--r-- | netwerk/srtp/src/crypto/kernel/key.c | 122 |
1 files changed, 122 insertions, 0 deletions
diff --git a/netwerk/srtp/src/crypto/kernel/key.c b/netwerk/srtp/src/crypto/kernel/key.c new file mode 100644 index 0000000000..0466195046 --- /dev/null +++ b/netwerk/srtp/src/crypto/kernel/key.c @@ -0,0 +1,122 @@ +/* + * key.c + * + * key usage limits enforcement + * + * David A. Mcgrew + * Cisco Systems, Inc. + */ +/* + * + * Copyright (c) 2001-2017 Cisco Systems, Inc. + * All rights reserved. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * + * Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * + * 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. + * + * Neither the name of the Cisco Systems, Inc. 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 COPYRIGHT HOLDERS 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 + * COPYRIGHT HOLDERS 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. + * + */ + +#ifdef HAVE_CONFIG_H +#include <config.h> +#endif + +#include "key.h" + +#define soft_limit 0x10000 + +srtp_err_status_t srtp_key_limit_set(srtp_key_limit_t key, + const srtp_xtd_seq_num_t s) +{ +#ifdef NO_64BIT_MATH + if (high32(s) == 0 && low32(s) < soft_limit) { + return srtp_err_status_bad_param; + } +#else + if (s < soft_limit) { + return srtp_err_status_bad_param; + } +#endif + key->num_left = s; + key->state = srtp_key_state_normal; + return srtp_err_status_ok; +} + +srtp_err_status_t srtp_key_limit_clone(srtp_key_limit_t original, + srtp_key_limit_t *new_key) +{ + if (original == NULL) { + return srtp_err_status_bad_param; + } + *new_key = original; + return srtp_err_status_ok; +} + +srtp_err_status_t srtp_key_limit_check(const srtp_key_limit_t key) +{ + if (key->state == srtp_key_state_expired) { + return srtp_err_status_key_expired; + } + return srtp_err_status_ok; +} + +srtp_key_event_t srtp_key_limit_update(srtp_key_limit_t key) +{ +#ifdef NO_64BIT_MATH + if (low32(key->num_left) == 0) { + // carry + key->num_left = + make64(high32(key->num_left) - 1, low32(key->num_left) - 1); + } else { + // no carry + key->num_left = make64(high32(key->num_left), low32(key->num_left) - 1); + } + if (high32(key->num_left) != 0 || low32(key->num_left) >= soft_limit) { + return srtp_key_event_normal; /* we're above the soft limit */ + } +#else + key->num_left--; + if (key->num_left >= soft_limit) { + return srtp_key_event_normal; /* we're above the soft limit */ + } +#endif + if (key->state == srtp_key_state_normal) { + /* we just passed the soft limit, so change the state */ + key->state = srtp_key_state_past_soft_limit; + } +#ifdef NO_64BIT_MATH + if (low32(key->num_left) == 0 && high32(key->num_left == 0)) +#else + if (key->num_left < 1) +#endif + { /* we just hit the hard limit */ + key->state = srtp_key_state_expired; + return srtp_key_event_hard_limit; + } + return srtp_key_event_soft_limit; +} |