69 lines
1.5 KiB
C
69 lines
1.5 KiB
C
//
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// j2b.c
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// Dumb J2B Archive parser
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//
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// Created by Christopher Snowhill on 10/4/13.
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// Copyright 2013 __NoWork, Inc__. All rights reserved.
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//
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#include <stdint.h>
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#include <stdlib.h>
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#include <zlib.h>
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#include "j2b.h"
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void *unpackJ2b(const void *in, long *size) {
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uint32_t fileLength;
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uint32_t checksum;
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uint32_t lenCompressed;
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uint32_t lenUncompressed;
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const uint8_t *in8 = (const uint8_t *)in;
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Bytef *uncompressedData;
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int zErr;
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uLong dataUncompressed;
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if(*size < 8)
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return 0;
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if(in8[0] != 'M' || in8[1] != 'U' || in8[2] != 'S' || in8[3] != 'E' ||
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in8[4] != 0xDE || in8[5] != 0xAD ||
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((in8[6] != 0xBE || in8[7] != 0xAF) && (in8[6] != 0xBA || in8[7] != 0xBE))) {
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return 0;
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}
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if(*size < 12)
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return 0;
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fileLength = in8[8] | (in8[9] << 8) | (in8[10] << 16) | (in8[11] << 24);
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if(fileLength < 12 || fileLength + 12 > *size)
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return 0;
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checksum = in8[12] | (in8[13] << 8) | (in8[14] << 16) | (in8[15] << 24);
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lenCompressed = in8[16] | (in8[17] << 8) | (in8[18] << 16) | (in8[19] << 24);
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lenUncompressed = in8[20] | (in8[21] << 8) | (in8[22] << 16) | (in8[23] << 24);
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if(lenCompressed + 12 > fileLength)
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return 0;
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if(crc32(0, in8 + 24, lenCompressed) != checksum)
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return 0;
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uncompressedData = (Bytef *)malloc(lenUncompressed);
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if(!uncompressedData)
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return 0;
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dataUncompressed = lenUncompressed;
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zErr = uncompress(uncompressedData, &dataUncompressed, in8 + 24, lenCompressed);
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if(zErr != Z_OK) {
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free(uncompressedData);
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return 0;
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}
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*size = dataUncompressed;
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return uncompressedData;
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}
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