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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-12 10:39:00 +00:00
trezor-firmware/embed/extmod/modtrezorui/inflate.c
2018-02-26 14:07:37 +01:00

467 lines
12 KiB
C

/*
* This file is part of the TREZOR project, https://trezor.io/
*
* Copyright (c) SatoshiLabs
*
* 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 3 of the License, or
* (at your option) any later version.
*
* 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.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
/*
* stream_inflate - tiny inflate library with output streaming
*
* Copyright (c) 2003 by Joergen Ibsen / Jibz
* All Rights Reserved
* http://www.ibsensoftware.com/
*
* Copyright (c) 2014 by Paul Sokolovsky
*
* Copyright (c) 2016 by Pavol Rusnak
*
* This software is provided 'as-is', without any express
* or implied warranty. In no event will the authors be
* held liable for any damages arising from the use of
* this software.
*
* Permission is granted to anyone to use this software
* for any purpose, including commercial applications,
* and to alter it and redistribute it freely, subject to
* the following restrictions:
*
* 1. The origin of this software must not be
* misrepresented; you must not claim that you
* wrote the original software. If you use this
* software in a product, an acknowledgment in
* the product documentation would be appreciated
* but is not required.
*
* 2. Altered source versions must be plainly marked
* as such, and must not be misrepresented as
* being the original software.
*
* 3. This notice may not be removed or altered from
* any source distribution.
*/
#include "inflate.h"
// maximum possible window size (in bits) used during compression/deflate
#define SINF_WBITS 10
#define SINF_OK 0
#define SINF_ERROR (-3)
typedef struct {
uint16_t table[16]; /* table of code length counts */
uint16_t trans[288]; /* code -> symbol translation table */
} SINF_TREE;
typedef struct {
const uint8_t *source;
uint32_t sourcelen;
uint32_t tag;
uint32_t bitcount;
uint8_t cbuf[1 << SINF_WBITS];
int cbufi;
SINF_TREE ltree; /* dynamic length/symbol tree */
SINF_TREE dtree; /* dynamic distance tree */
void (* write)(uint8_t byte, uint32_t pos, void *userdata);
void *userdata;
uint32_t written;
} SINF_CTX;
/* --------------------------------------------------- *
* -- uninitialized global data (static structures) -- *
* --------------------------------------------------- */
static const uint8_t SINF_LENGTH_BITS[30] = {
0, 0, 0, 0, 0, 0, 0, 0,
1, 1, 1, 1, 2, 2, 2, 2,
3, 3, 3, 3, 4, 4, 4, 4,
5, 5, 5, 5
};
static const uint16_t SINF_LENGTH_BASE[30] = {
3, 4, 5, 6, 7, 8, 9, 10,
11, 13, 15, 17, 19, 23, 27, 31,
35, 43, 51, 59, 67, 83, 99, 115,
131, 163, 195, 227, 258
};
static const uint8_t SINF_DIST_BITS[30] = {
0, 0, 0, 0, 1, 1, 2, 2,
3, 3, 4, 4, 5, 5, 6, 6,
7, 7, 8, 8, 9, 9, 10, 10,
11, 11, 12, 12, 13, 13
};
static const uint16_t SINF_DIST_BASE[30] = {
1, 2, 3, 4, 5, 7, 9, 13,
17, 25, 33, 49, 65, 97, 129, 193,
257, 385, 513, 769, 1025, 1537, 2049, 3073,
4097, 6145, 8193, 12289, 16385, 24577
};
/* special ordering of code length codes */
static const uint8_t SINF_CLCIDX[] = {
16, 17, 18, 0, 8, 7, 9, 6,
10, 5, 11, 4, 12, 3, 13, 2,
14, 1, 15
};
/* ----------------------- *
* -- utility functions -- *
* ----------------------- */
static void sinf_write(SINF_CTX *ctx, uint8_t byte)
{
ctx->cbuf[ctx->cbufi] = byte;
ctx->cbufi = (ctx->cbufi + 1) % (1 << SINF_WBITS);
ctx->write(byte, ctx->written, ctx->userdata);
ctx->written++;
}
/* build the fixed huffman trees */
static void sinf_build_fixed_trees(SINF_TREE *lt, SINF_TREE *dt)
{
int i;
/* build fixed length tree */
for (i = 0; i < 7; ++i) lt->table[i] = 0;
lt->table[7] = 24;
lt->table[8] = 152;
lt->table[9] = 112;
for (i = 0; i < 24; ++i) lt->trans[i] = 256 + i;
for (i = 0; i < 144; ++i) lt->trans[24 + i] = i;
for (i = 0; i < 8; ++i) lt->trans[24 + 144 + i] = 280 + i;
for (i = 0; i < 112; ++i) lt->trans[24 + 144 + 8 + i] = 144 + i;
/* build fixed distance tree */
for (i = 0; i < 5; ++i) dt->table[i] = 0;
dt->table[5] = 32;
for (i = 0; i < 32; ++i) dt->trans[i] = i;
}
/* given an array of code lengths, build a tree */
static void sinf_build_tree(SINF_TREE *t, const uint8_t *lengths, uint32_t num)
{
uint16_t offs[16];
uint32_t i, sum;
/* clear code length count table */
for (i = 0; i < 16; ++i) t->table[i] = 0;
/* scan symbol lengths, and sum code length counts */
for (i = 0; i < num; ++i) t->table[lengths[i]]++;
t->table[0] = 0;
/* compute offset table for distribution sort */
for (sum = 0, i = 0; i < 16; ++i)
{
offs[i] = sum;
sum += t->table[i];
}
/* create code->symbol translation table (symbols sorted by code) */
for (i = 0; i < num; ++i)
{
if (lengths[i]) t->trans[offs[lengths[i]]++] = i;
}
}
/* ---------------------- *
* -- decode functions -- *
* ---------------------- */
/* get one bit from source stream */
static int sinf_getbit(SINF_CTX *ctx)
{
uint32_t bit;
/* check if tag is empty */
if (!ctx->bitcount--)
{
/* load next tag */
ctx->tag = *ctx->source++;
ctx->bitcount = 7;
}
/* shift bit out of tag */
bit = ctx->tag & 0x01;
ctx->tag >>= 1;
return bit;
}
/* read a num bit value from a stream and add base */
static uint32_t sinf_read_bits(SINF_CTX *ctx, int num, int base)
{
uint32_t val = 0;
/* read num bits */
if (num)
{
uint32_t limit = 1 << (num);
uint32_t mask;
for (mask = 1; mask < limit; mask *= 2)
if (sinf_getbit(ctx)) val += mask;
}
return val + base;
}
/* given a data stream and a tree, decode a symbol */
static int sinf_decode_symbol(SINF_CTX *ctx, SINF_TREE *t)
{
int sum = 0, cur = 0, len = 0;
/* get more bits while code value is above sum */
do {
cur = 2*cur + sinf_getbit(ctx);
++len;
sum += t->table[len];
cur -= t->table[len];
} while (cur >= 0);
return t->trans[sum + cur];
}
/* given a data stream, decode dynamic trees from it */
static void sinf_decode_trees(SINF_CTX *ctx, SINF_TREE *lt, SINF_TREE *dt)
{
uint8_t lengths[288+32];
uint32_t hlit, hdist, hclen;
uint32_t i, num, length;
/* get 5 bits HLIT (257-286) */
hlit = sinf_read_bits(ctx, 5, 257);
/* get 5 bits HDIST (1-32) */
hdist = sinf_read_bits(ctx, 5, 1);
/* get 4 bits HCLEN (4-19) */
hclen = sinf_read_bits(ctx, 4, 4);
for (i = 0; i < 19; ++i) lengths[i] = 0;
/* read code lengths for code length alphabet */
for (i = 0; i < hclen; ++i)
{
/* get 3 bits code length (0-7) */
uint32_t clen = sinf_read_bits(ctx, 3, 0);
lengths[SINF_CLCIDX[i]] = clen;
}
/* build code length tree, temporarily use length tree */
sinf_build_tree(lt, lengths, 19);
/* decode code lengths for the dynamic trees */
for (num = 0; num < hlit + hdist; )
{
int sym = sinf_decode_symbol(ctx, lt);
switch (sym)
{
case 16:
/* copy previous code length 3-6 times (read 2 bits) */
{
uint8_t prev = lengths[num - 1];
for (length = sinf_read_bits(ctx, 2, 3); length; --length)
{
lengths[num++] = prev;
}
}
break;
case 17:
/* repeat code length 0 for 3-10 times (read 3 bits) */
for (length = sinf_read_bits(ctx, 3, 3); length; --length)
{
lengths[num++] = 0;
}
break;
case 18:
/* repeat code length 0 for 11-138 times (read 7 bits) */
for (length = sinf_read_bits(ctx, 7, 11); length; --length)
{
lengths[num++] = 0;
}
break;
default:
/* values 0-15 represent the actual code lengths */
lengths[num++] = sym;
break;
}
}
/* build dynamic trees */
sinf_build_tree(lt, lengths, hlit);
sinf_build_tree(dt, lengths + hlit, hdist);
}
/* ----------------------------- *
* -- block inflate functions -- *
* ----------------------------- */
/* given a stream and two trees, inflate a block of data */
static int sinf_inflate_block_data(SINF_CTX *ctx, SINF_TREE *lt, SINF_TREE *dt)
{
while (1)
{
int sym = sinf_decode_symbol(ctx, lt);
/* check for end of block */
if (sym == 256)
{
return SINF_OK;
}
if (sym < 256)
{
sinf_write(ctx, sym);
} else {
uint32_t length, offs, i;
int dist;
sym -= 257;
/* possibly get more bits from length code */
length = sinf_read_bits(ctx, SINF_LENGTH_BITS[sym], SINF_LENGTH_BASE[sym]);
dist = sinf_decode_symbol(ctx, dt);
/* possibly get more bits from distance code */
offs = sinf_read_bits(ctx, SINF_DIST_BITS[dist], SINF_DIST_BASE[dist]);
/* copy match */
for (i = 0; i < length; ++i)
{
sinf_write(ctx, ctx->cbuf[(ctx->cbufi + (1 << SINF_WBITS) - offs) % (1 << SINF_WBITS)]);
}
}
}
}
/* inflate an uncompressed block of data */
static int sinf_inflate_uncompressed_block(SINF_CTX *ctx)
{
uint32_t length, invlength;
uint32_t i;
/* get length */
length = ctx->source[1];
length = 256*length + ctx->source[0];
/* get one's complement of length */
invlength = ctx->source[3];
invlength = 256*invlength + ctx->source[2];
/* check length */
if (length != (~invlength & 0x0000ffff)) return SINF_ERROR;
ctx->source += 4;
/* copy block */
for (i = length; i; --i) sinf_write(ctx, *ctx->source++);
/* make sure we start next block on a byte boundary */
ctx->bitcount = 0;
return SINF_OK;
}
/* inflate a block of data compressed with fixed huffman trees */
static int sinf_inflate_fixed_block(SINF_CTX *ctx)
{
/* build fixed huffman trees */
sinf_build_fixed_trees(&ctx->ltree, &ctx->dtree);
/* decode block using fixed trees */
return sinf_inflate_block_data(ctx, &ctx->ltree, &ctx->dtree);
}
/* inflate a block of data compressed with dynamic huffman trees */
static int sinf_inflate_dynamic_block(SINF_CTX *ctx)
{
/* decode trees from stream */
sinf_decode_trees(ctx, &ctx->ltree, &ctx->dtree);
/* decode block using decoded trees */
return sinf_inflate_block_data(ctx, &ctx->ltree, &ctx->dtree);
}
/* ---------------------- *
* -- public functions -- *
* ---------------------- */
/* inflate stream from source */
int sinf_inflate(const uint8_t *data, uint32_t datalen, void (*write_callback)(uint8_t byte, uint32_t pos, void *userdata), void *userdata)
{
SINF_CTX ctx;
int bfinal;
/* initialise data */
ctx.bitcount = 0;
ctx.cbufi = 0;
ctx.source = data;
ctx.sourcelen = datalen;
ctx.write = write_callback;
ctx.userdata = userdata;
ctx.written = 0;
do {
uint32_t btype;
int res;
/* read final block flag */
bfinal = sinf_getbit(&ctx);
/* read block type (2 bits) */
btype = sinf_read_bits(&ctx, 2, 0);
/* decompress block */
switch (btype)
{
case 0:
/* decompress uncompressed block */
res = sinf_inflate_uncompressed_block(&ctx);
break;
case 1:
/* decompress block with fixed huffman trees */
res = sinf_inflate_fixed_block(&ctx);
break;
case 2:
/* decompress block with dynamic huffman trees */
res = sinf_inflate_dynamic_block(&ctx);
break;
default:
return SINF_ERROR;
}
if (res != SINF_OK) return SINF_ERROR;
} while (!bfinal);
return SINF_OK;
}