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author | Alexander Færøy <ahf@torproject.org> | 2017-04-18 03:21:53 +0200 |
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committer | Nick Mathewson <nickm@torproject.org> | 2017-04-25 08:06:01 -0400 |
commit | 04583df4520705bc171be9b720344167029292cb (patch) | |
tree | 21d5ce9cfe8eac60cf07e877e038d3a6becb5fee /src/common/torgzip.c | |
parent | 9d5bc1a9354637aa59025f61e577c6d42f8c53ba (diff) | |
download | tor-04583df4520705bc171be9b720344167029292cb.tar.gz tor-04583df4520705bc171be9b720344167029292cb.zip |
Rename the `torgzip` module to `compress`.
See https://bugs.torproject.org/21663
Diffstat (limited to 'src/common/torgzip.c')
-rw-r--r-- | src/common/torgzip.c | 220 |
1 files changed, 0 insertions, 220 deletions
diff --git a/src/common/torgzip.c b/src/common/torgzip.c deleted file mode 100644 index d760cd9546..0000000000 --- a/src/common/torgzip.c +++ /dev/null @@ -1,220 +0,0 @@ -/* Copyright (c) 2004, Roger Dingledine. - * Copyright (c) 2004-2006, Roger Dingledine, Nick Mathewson. - * Copyright (c) 2007-2017, The Tor Project, Inc. */ -/* See LICENSE for licensing information */ - -/** - * \file torgzip.c - * \brief A simple in-memory gzip implementation. - **/ - -#include "orconfig.h" - -#include <stdlib.h> -#include <stdio.h> -#include <assert.h> -#include <string.h> -#include "torint.h" - -#ifdef HAVE_NETINET_IN_H -#include <netinet/in.h> -#endif - -#include "util.h" -#include "torlog.h" -#include "torgzip.h" -#include "compress_zlib.h" - -/** @{ */ -/* These macros define the maximum allowable compression factor. Anything of - * size greater than CHECK_FOR_COMPRESSION_BOMB_AFTER is not allowed to - * have an uncompression factor (uncompressed size:compressed size ratio) of - * any greater than MAX_UNCOMPRESSION_FACTOR. - * - * Picking a value for MAX_UNCOMPRESSION_FACTOR is a trade-off: we want it to - * be small to limit the attack multiplier, but we also want it to be large - * enough so that no legitimate document --even ones we might invent in the - * future -- ever compresses by a factor of greater than - * MAX_UNCOMPRESSION_FACTOR. Within those parameters, there's a reasonably - * large range of possible values. IMO, anything over 8 is probably safe; IMO - * anything under 50 is probably sufficient. - */ -#define MAX_UNCOMPRESSION_FACTOR 25 -#define CHECK_FOR_COMPRESSION_BOMB_AFTER (1024*64) -/** @} */ - -/** Return true if uncompressing an input of size <b>in_size</b> to an input of - * size at least <b>size_out</b> looks like a compression bomb. */ -int -tor_compress_is_compression_bomb(size_t size_in, size_t size_out) -{ - if (size_in == 0 || size_out < CHECK_FOR_COMPRESSION_BOMB_AFTER) - return 0; - - return (size_out / size_in > MAX_UNCOMPRESSION_FACTOR); -} - -/** Given <b>level</b> return the memory level. The memory level is needed for - * the various compression backends used in Tor. - */ -int -tor_compress_memory_level(compression_level_t level) -{ - switch (level) { - default: - case HIGH_COMPRESSION: return 8; - case MEDIUM_COMPRESSION: return 7; - case LOW_COMPRESSION: return 6; - } -} - -/** Given <b>in_len</b> bytes at <b>in</b>, compress them into a newly - * allocated buffer, using the method described in <b>method</b>. Store the - * compressed string in *<b>out</b>, and its length in *<b>out_len</b>. - * Return 0 on success, -1 on failure. - */ -int -tor_compress(char **out, size_t *out_len, - const char *in, size_t in_len, - compress_method_t method) -{ - if (method == GZIP_METHOD || method == ZLIB_METHOD) - return tor_zlib_compress(out, out_len, in, in_len, method); - - return -1; -} - -/** Given zero or more zlib-compressed or gzip-compressed strings of - * total length - * <b>in_len</b> bytes at <b>in</b>, uncompress them into a newly allocated - * buffer, using the method described in <b>method</b>. Store the uncompressed - * string in *<b>out</b>, and its length in *<b>out_len</b>. Return 0 on - * success, -1 on failure. - * - * If <b>complete_only</b> is true, we consider a truncated input as a - * failure; otherwise we decompress as much as we can. Warn about truncated - * or corrupt inputs at <b>protocol_warn_level</b>. - */ -int -tor_uncompress(char **out, size_t *out_len, - const char *in, size_t in_len, - compress_method_t method, - int complete_only, - int protocol_warn_level) -{ - if (method == GZIP_METHOD || method == ZLIB_METHOD) - return tor_zlib_uncompress(out, out_len, in, in_len, - method, - complete_only, - protocol_warn_level); - - return -1; -} - -/** Try to tell whether the <b>in_len</b>-byte string in <b>in</b> is likely - * to be compressed or not. If it is, return the likeliest compression method. - * Otherwise, return UNKNOWN_METHOD. - */ -compress_method_t -detect_compression_method(const char *in, size_t in_len) -{ - if (in_len > 2 && fast_memeq(in, "\x1f\x8b", 2)) { - return GZIP_METHOD; - } else if (in_len > 2 && (in[0] & 0x0f) == 8 && - (ntohs(get_uint16(in)) % 31) == 0) { - return ZLIB_METHOD; - } else { - return UNKNOWN_METHOD; - } -} - -/** Internal state for an incremental compression/decompression. The body of - * this struct is not exposed. */ -struct tor_compress_state_t { - compress_method_t method; /**< The compression method. */ - - union { - tor_zlib_compress_state_t *zlib_state; - } u; /**< Compression backend state. */ -}; - -/** Construct and return a tor_compress_state_t object using <b>method</b>. If - * <b>compress</b>, it's for compression; otherwise it's for decompression. */ -tor_compress_state_t * -tor_compress_new(int compress, compress_method_t method, - compression_level_t compression_level) -{ - tor_compress_state_t *state; - - state = tor_malloc_zero(sizeof(tor_compress_state_t)); - state->method = method; - - if (method == GZIP_METHOD || method == ZLIB_METHOD) { - tor_zlib_compress_state_t *zlib_state = - tor_zlib_compress_new(compress, method, compression_level); - - if (zlib_state == NULL) - goto err; - - state->u.zlib_state = zlib_state; - } - - return state; - - err: - tor_free(state); - return NULL; -} - -/** Compress/decompress some bytes using <b>state</b>. Read up to - * *<b>in_len</b> bytes from *<b>in</b>, and write up to *<b>out_len</b> bytes - * to *<b>out</b>, adjusting the values as we go. If <b>finish</b> is true, - * we've reached the end of the input. - * - * Return TOR_COMPRESS_DONE if we've finished the entire - * compression/decompression. - * Return TOR_COMPRESS_OK if we're processed everything from the input. - * Return TOR_COMPRESS_BUFFER_FULL if we're out of space on <b>out</b>. - * Return TOR_COMPRESS_ERROR if the stream is corrupt. - */ -tor_compress_output_t -tor_compress_process(tor_compress_state_t *state, - char **out, size_t *out_len, - const char **in, size_t *in_len, - int finish) -{ - tor_assert(state != NULL); - - if (state->method == GZIP_METHOD || state->method == ZLIB_METHOD) - return tor_zlib_compress_process(state->u.zlib_state, - out, out_len, in, in_len, - finish); - - return TOR_COMPRESS_ERROR; -} - -/** Deallocate <b>state</b>. */ -void -tor_compress_free(tor_compress_state_t *state) -{ - if (state == NULL) - return; - - if (state->method == GZIP_METHOD || state->method == ZLIB_METHOD) - tor_zlib_compress_free(state->u.zlib_state); - - tor_free(state); -} - -/** Return the approximate number of bytes allocated for <b>state</b>. */ -size_t -tor_compress_state_size(const tor_compress_state_t *state) -{ - tor_assert(state != NULL); - - if (state->method == GZIP_METHOD || state->method == ZLIB_METHOD) - return tor_zlib_compress_state_size(state->u.zlib_state); - - return 0; -} - |