Index: srtp/crypto/replay/rdbx.c |
diff --git a/srtp/crypto/replay/rdbx.c b/srtp/crypto/replay/rdbx.c |
deleted file mode 100644 |
index 153676f33969f73c553070b5b071321d429d5d19..0000000000000000000000000000000000000000 |
--- a/srtp/crypto/replay/rdbx.c |
+++ /dev/null |
@@ -1,356 +0,0 @@ |
-/* |
- * rdbx.c |
- * |
- * a replay database with extended range, using a rollover counter |
- * |
- * David A. McGrew |
- * Cisco Systems, Inc. |
- */ |
- |
-/* |
- * |
- * Copyright (c) 2001-2006, 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 "rdbx.h" |
- |
- |
-/* |
- * from RFC 3711: |
- * |
- * A receiver reconstructs the index i of a packet with sequence |
- * number SEQ using the estimate |
- * |
- * i = 2^16 * v + SEQ, |
- * |
- * where v is chosen from the set { ROC-1, ROC, ROC+1 } such that i is |
- * closest to the value 2^16 * ROC + s_l. If the value r+1 is used, |
- * then the rollover counter r in the cryptographic context is |
- * incremented by one (if the packet containing s is authentic). |
- */ |
- |
- |
- |
-/* |
- * rdbx implementation notes |
- * |
- * A xtd_seq_num_t is essentially a sequence number for which some of |
- * the data on the wire are implicit. It logically consists of a |
- * rollover counter and a sequence number; the sequence number is the |
- * explicit part, and the rollover counter is the implicit part. |
- * |
- * Upon receiving a sequence_number (e.g. in a newly received SRTP |
- * packet), the complete xtd_seq_num_t can be estimated by using a |
- * local xtd_seq_num_t as a basis. This is done using the function |
- * index_guess(&local, &guess, seq_from_packet). This function |
- * returns the difference of the guess and the local value. The local |
- * xtd_seq_num_t can be moved forward to the guess using the function |
- * index_advance(&guess, delta), where delta is the difference. |
- * |
- * |
- * A rdbx_t consists of a xtd_seq_num_t and a bitmask. The index is highest |
- * sequence number that has been received, and the bitmask indicates |
- * which of the recent indicies have been received as well. The |
- * highest bit in the bitmask corresponds to the index in the bitmask. |
- */ |
- |
- |
-void |
-index_init(xtd_seq_num_t *pi) { |
-#ifdef NO_64BIT_MATH |
- *pi = make64(0,0); |
-#else |
- *pi = 0; |
-#endif |
-} |
- |
-void |
-index_advance(xtd_seq_num_t *pi, sequence_number_t s) { |
-#ifdef NO_64BIT_MATH |
- /* a > ~b means a+b will generate a carry */ |
- /* s is uint16 here */ |
- *pi = make64(high32(*pi) + (s > ~low32(*pi) ? 1 : 0),low32(*pi) + s); |
-#else |
- *pi += s; |
-#endif |
-} |
- |
- |
-/* |
- * index_guess(local, guess, s) |
- * |
- * given a xtd_seq_num_t local (which represents the last |
- * known-to-be-good received xtd_seq_num_t) and a sequence number s |
- * (from a newly arrived packet), sets the contents of *guess to |
- * contain the best guess of the packet index to which s corresponds, |
- * and returns the difference between *guess and *local |
- * |
- * nota bene - the output is a signed integer, DON'T cast it to a |
- * unsigned integer! |
- */ |
- |
-int |
-index_guess(const xtd_seq_num_t *local, |
- xtd_seq_num_t *guess, |
- sequence_number_t s) { |
-#ifdef NO_64BIT_MATH |
- uint32_t local_roc = ((high32(*local) << 16) | |
- (low32(*local) >> 16)); |
- uint16_t local_seq = (uint16_t) (low32(*local)); |
-#else |
- uint32_t local_roc = (uint32_t)(*local >> 16); |
- uint16_t local_seq = (uint16_t) *local; |
-#endif |
-#ifdef NO_64BIT_MATH |
- uint32_t guess_roc = ((high32(*guess) << 16) | |
- (low32(*guess) >> 16)); |
- uint16_t guess_seq = (uint16_t) (low32(*guess)); |
-#else |
- uint32_t guess_roc = (uint32_t)(*guess >> 16); |
- uint16_t guess_seq = (uint16_t) *guess; |
-#endif |
- int difference; |
- |
- if (local_seq < seq_num_median) { |
- if (s - local_seq > seq_num_median) { |
- guess_roc = local_roc - 1; |
- difference = s - local_seq - seq_num_max; |
- } else { |
- guess_roc = local_roc; |
- difference = s - local_seq; |
- } |
- } else { |
- if (local_seq - seq_num_median > s) { |
- guess_roc = local_roc + 1; |
- difference = s - local_seq + seq_num_max; |
- } else { |
- guess_roc = local_roc; |
- difference = s - local_seq; |
- } |
- } |
- guess_seq = s; |
- |
- /* Note: guess_roc is 32 bits, so this generates a 48-bit result! */ |
-#ifdef NO_64BIT_MATH |
- *guess = make64(guess_roc >> 16, |
- (guess_roc << 16) | guess_seq); |
-#else |
- *guess = (((uint64_t) guess_roc) << 16) | guess_seq; |
-#endif |
- |
- return difference; |
-} |
- |
-/* |
- * rdbx |
- * |
- */ |
- |
- |
-/* |
- * rdbx_init(&r, ws) initializes the rdbx_t pointed to by r with window size ws |
- */ |
- |
-err_status_t |
-rdbx_init(rdbx_t *rdbx, unsigned long ws) { |
- if (ws == 0) |
- return err_status_bad_param; |
- |
- if (bitvector_alloc(&rdbx->bitmask, ws) != 0) |
- return err_status_alloc_fail; |
- |
- index_init(&rdbx->index); |
- |
- return err_status_ok; |
-} |
- |
-/* |
- * rdbx_dealloc(&r) frees memory for the rdbx_t pointed to by r |
- */ |
- |
-err_status_t |
-rdbx_dealloc(rdbx_t *rdbx) { |
- bitvector_dealloc(&rdbx->bitmask); |
- |
- return err_status_ok; |
-} |
- |
-/* |
- * rdbx_set_roc(rdbx, roc) initalizes the rdbx_t at the location rdbx |
- * to have the rollover counter value roc. If that value is less than |
- * the current rollover counter value, then the function returns |
- * err_status_replay_old; otherwise, err_status_ok is returned. |
- * |
- */ |
- |
-err_status_t |
-rdbx_set_roc(rdbx_t *rdbx, uint32_t roc) { |
- bitvector_set_to_zero(&rdbx->bitmask); |
- |
-#ifdef NO_64BIT_MATH |
- #error not yet implemented |
-#else |
- |
- /* make sure that we're not moving backwards */ |
- if (roc < (rdbx->index >> 16)) |
- return err_status_replay_old; |
- |
- rdbx->index &= 0xffff; /* retain lowest 16 bits */ |
- rdbx->index |= ((uint64_t)roc) << 16; /* set ROC */ |
-#endif |
- |
- return err_status_ok; |
-} |
- |
-/* |
- * rdbx_get_packet_index(rdbx) returns the value of the packet index |
- * for the rdbx_t pointed to by rdbx |
- * |
- */ |
- |
-xtd_seq_num_t |
-rdbx_get_packet_index(const rdbx_t *rdbx) { |
- return rdbx->index; |
-} |
- |
-/* |
- * rdbx_get_window_size(rdbx) returns the value of the window size |
- * for the rdbx_t pointed to by rdbx |
- * |
- */ |
- |
-unsigned long |
-rdbx_get_window_size(const rdbx_t *rdbx) { |
- return bitvector_get_length(&rdbx->bitmask); |
-} |
- |
-/* |
- * rdbx_check(&r, delta) checks to see if the xtd_seq_num_t |
- * which is at rdbx->index + delta is in the rdb |
- */ |
- |
-err_status_t |
-rdbx_check(const rdbx_t *rdbx, int delta) { |
- |
- if (delta > 0) { /* if delta is positive, it's good */ |
- return err_status_ok; |
- } else if ((int)(bitvector_get_length(&rdbx->bitmask) - 1) + delta < 0) { |
- /* if delta is lower than the bitmask, it's bad */ |
- return err_status_replay_old; |
- } else if (bitvector_get_bit(&rdbx->bitmask, |
- (int)(bitvector_get_length(&rdbx->bitmask) - 1) + delta) == 1) { |
- /* delta is within the window, so check the bitmask */ |
- return err_status_replay_fail; |
- } |
- /* otherwise, the index is okay */ |
- |
- return err_status_ok; |
-} |
- |
-/* |
- * rdbx_add_index adds the xtd_seq_num_t at rdbx->window_start + d to |
- * replay_db (and does *not* check if that xtd_seq_num_t appears in db) |
- * |
- * this function should be called only after replay_check has |
- * indicated that the index does not appear in the rdbx, e.g., a mutex |
- * should protect the rdbx between these calls if need be |
- */ |
- |
-err_status_t |
-rdbx_add_index(rdbx_t *rdbx, int delta) { |
- |
- if (delta > 0) { |
- /* shift forward by delta */ |
- index_advance(&rdbx->index, delta); |
- bitvector_left_shift(&rdbx->bitmask, delta); |
- bitvector_set_bit(&rdbx->bitmask, bitvector_get_length(&rdbx->bitmask) - 1); |
- } else { |
- /* delta is in window */ |
- bitvector_set_bit(&rdbx->bitmask, bitvector_get_length(&rdbx->bitmask) -1 + delta); |
- } |
- |
- /* note that we need not consider the case that delta == 0 */ |
- |
- return err_status_ok; |
-} |
- |
- |
- |
-/* |
- * rdbx_estimate_index(rdbx, guess, s) |
- * |
- * given an rdbx and a sequence number s (from a newly arrived packet), |
- * sets the contents of *guess to contain the best guess of the packet |
- * index to which s corresponds, and returns the difference between |
- * *guess and the locally stored synch info |
- */ |
- |
-int |
-rdbx_estimate_index(const rdbx_t *rdbx, |
- xtd_seq_num_t *guess, |
- sequence_number_t s) { |
- |
- /* |
- * if the sequence number and rollover counter in the rdbx are |
- * non-zero, then use the index_guess(...) function, otherwise, just |
- * set the rollover counter to zero (since the index_guess(...) |
- * function might incorrectly guess that the rollover counter is |
- * 0xffffffff) |
- */ |
- |
-#ifdef NO_64BIT_MATH |
- /* seq_num_median = 0x8000 */ |
- if (high32(rdbx->index) > 0 || |
- low32(rdbx->index) > seq_num_median) |
-#else |
- if (rdbx->index > seq_num_median) |
-#endif |
- return index_guess(&rdbx->index, guess, s); |
- |
-#ifdef NO_64BIT_MATH |
- *guess = make64(0,(uint32_t) s); |
-#else |
- *guess = s; |
-#endif |
- |
-#ifdef NO_64BIT_MATH |
- return s - (uint16_t) low32(rdbx->index); |
-#else |
- return s - (uint16_t) rdbx->index; |
-#endif |
-} |