1 // Unzip library by Per Bothner and Joonas Pihlajamaa.
2 // See junzip.h for license and details.
11 #define ZIP_CENTRAL_SIGNATURE 0
12 #define ZIP_CENTRAL_VERSION_MADE_BY 4
13 #define ZIP_CENTRAL_VERSION_NEEDED_TO_EXTRACT 6
14 #define ZIP_CENTRAL_GENERAL_PURPOSE_BIT_FLAG 8
15 #define ZIP_CENTRAL_COMPRESSION_METHOD 10
16 #define ZIP_CENTRAL_LAST_MOD_FILE_TIME 12
17 #define ZIP_CENTRAL_LAST_MOD_FILE_DATE 14
18 #define ZIP_CENTRAL_CRC32 16
19 #define ZIP_CENTRAL_COMPRESSED_SIZE 20
20 #define ZIP_CENTRAL_UNCOMPRESSED_SIZE 24
21 #define ZIP_CENTRAL_FILE_NAME_LENGTH 28
22 #define ZIP_CENTRAL_EXTRA_FIELD_LENGTH 30
23 #define ZIP_CENTRAL_FILE_COMMENT_LENGTH 32
24 #define ZIP_CENTRAL_DISK_NUMBER_START 34
25 #define ZIP_CENTRAL_INTERNAL_FILE_ATTRIBUTES 36
26 #define ZIP_CENTRAL_EXTERNAL_FILE_ATTRIBUTES 38
27 #define ZIP_CENTRAL_RELATIVE_OFFSET_OF_LOCAL_HEADER 42
28 #define ZIP_CENTRAL_DIRECTORY_LENGTH 46
30 #define ZIP_END_SIGNATURE_OFFSET 0
31 #define ZIP_END_DESK_NUMBER 4
32 #define ZIP_END_CENTRAL_DIRECTORY_DISK_NUMBER 6
33 #define ZIP_END_NUM_ENTRIES_THIS_DISK 8
34 #define ZIP_END_NUM_ENTRIES 10
35 #define ZIP_END_CENTRAL_DIRECTORY_SIZE 12
36 #define ZIP_END_CENTRAL_DIRECTORY_OFFSET 16
37 #define ZIP_END_ZIP_COMMENT_LENGTH 20
38 #define ZIP_END_DIRECTORY_LENGTH 22
40 #define get_u16(PTR) ((PTR)[0] | ((PTR)[1] << 8))
41 #define get_u32(PTR) ((PTR)[0] | ((PTR)[1]<<8) | ((PTR)[2]<<16) | ((PTR)[3]<<24))
44 zf_seek_set(JZFile *zfile, size_t offset)
46 int new_position = offset;
47 if (new_position < 0 || new_position > zfile->length)
49 zfile->position = new_position;
54 zf_seek_cur(JZFile *zfile, size_t offset)
56 int new_position = zfile->position + offset;
57 if (new_position < 0 || new_position > zfile->length)
59 zfile->position = new_position;
64 zf_seek_end(JZFile *zfile, size_t offset)
66 int new_position = zfile->length + offset;
67 if (new_position < 0 || new_position > zfile->length)
69 zfile->position = new_position;
73 size_t zf_read(JZFile *zfile, void *buf, size_t size)
75 size_t avail = zfile->length - zfile->position;
78 memcpy(buf, zfile->start + zfile->position, size);
79 zfile->position += size;
83 // Read ZIP file end record. Will move within file.
84 int jzReadEndRecord(JZFile *zip) {
85 long fileSize, readBytes, i;
87 if(zf_seek_end(zip, -ZIP_END_DIRECTORY_LENGTH)) {
91 unsigned char *ptr = zf_current(zip);
92 while (ptr[0] != 0x50 || ptr[1] != 0x4B || ptr[2] != 0x05 || ptr[3] != 0x06) {
93 if (ptr == zip->start) {
98 zip->numEntries = get_u16(ptr + ZIP_END_NUM_ENTRIES);
99 zip->centralDirectoryOffset= get_u32(ptr + ZIP_END_CENTRAL_DIRECTORY_OFFSET);
100 if (get_u16(ptr + ZIP_END_DESK_NUMBER)
101 || get_u16(ptr + ZIP_END_CENTRAL_DIRECTORY_DISK_NUMBER)
102 || zip->numEntries != get_u16(ptr + ZIP_END_NUM_ENTRIES_THIS_DISK)) {
109 // Read ZIP file global directory. Will move within file.
110 int jzReadCentralDirectory(JZFile *zip, JZRecordCallback callback) {
114 if(zf_seek_set(zip, zip->centralDirectoryOffset)) {
118 for(i=0; i < zip->numEntries; i++) {
119 unsigned char *ptr = zf_current(zip);
120 if (zf_available(zip) < ZIP_CENTRAL_DIRECTORY_LENGTH) {
123 zf_seek_cur(zip, ZIP_CENTRAL_DIRECTORY_LENGTH);
124 if (get_u32(ptr + ZIP_CENTRAL_SIGNATURE) != 0x02014B50) {
127 // Construct JZFileHeader from global file header
128 header.compressionMethod = get_u16(ptr + ZIP_CENTRAL_COMPRESSION_METHOD);
129 header.crc32 = get_u32(ptr + ZIP_CENTRAL_CRC32);
130 header.compressedSize = get_u32(ptr + ZIP_CENTRAL_COMPRESSED_SIZE);
131 header.uncompressedSize = get_u32(ptr + ZIP_CENTRAL_UNCOMPRESSED_SIZE);
132 header.fileNameLength = get_u16(ptr + ZIP_CENTRAL_FILE_NAME_LENGTH);
133 header.extraFieldLength = get_u16(ptr + ZIP_CENTRAL_EXTRA_FIELD_LENGTH);
134 header.offset = get_u32(ptr + ZIP_CENTRAL_RELATIVE_OFFSET_OF_LOCAL_HEADER);
136 header.fileNameStart = zf_tell(zip);
137 if (zf_seek_cur(zip, header.fileNameLength + header.extraFieldLength + get_u16(ptr + ZIP_CENTRAL_FILE_COMMENT_LENGTH))) {
141 if(!callback(zip, i, &header))
142 break; // end if callback returns zero
148 int jzSeekData(JZFile *zip, JZFileHeader *entry) {
149 size_t offset = entry->offset;
150 offset += ZIP_LOCAL_FILE_HEADER_LENGTH;
151 offset += entry->fileNameLength + entry->extraFieldLength;
152 if (offset < 0 || offset > zip->length)
154 zip->position = offset;
158 // Read data from file stream, described by header, to preallocated buffer
159 int jzReadData(JZFile *zip, JZFileHeader *header, void *buffer) {
160 unsigned char *bytes = (unsigned char *)buffer; // cast
161 long compressedLeft, uncompressedLeft;
165 if(header->compressionMethod == 0) { // Store - just read it
166 if (zf_read(zip, buffer, header->uncompressedSize) <
167 header->uncompressedSize)
169 } else if (header->compressionMethod == 8) { // Deflate - using zlib
170 strm.zalloc = Z_NULL;
172 strm.opaque = Z_NULL;
175 strm.next_in = Z_NULL;
177 // Use inflateInit2 with negative window bits to indicate raw data
178 if ((ret = inflateInit2(&strm, -MAX_WBITS)) != Z_OK)
179 return ret; // Zlib errors are negative
181 // Inflate compressed data
182 for (compressedLeft = header->compressedSize,
183 uncompressedLeft = header->uncompressedSize;
184 compressedLeft && uncompressedLeft && ret != Z_STREAM_END;
185 compressedLeft -= strm.avail_in) {
187 unsigned char *ptr = zf_current(zip);
188 strm.avail_in = compressedLeft;
189 zf_seek_cur(zip, compressedLeft);
190 if(strm.avail_in == 0) {
196 strm.avail_out = uncompressedLeft;
197 strm.next_out = bytes;
199 compressedLeft -= strm.avail_in; // inflate will change avail_in
201 ret = inflate(&strm, Z_NO_FLUSH);
203 if(ret == Z_STREAM_ERROR) return ret; // shouldn't happen
207 ret = Z_DATA_ERROR; /* and fall through */
208 case Z_DATA_ERROR: case Z_MEM_ERROR:
209 (void)inflateEnd(&strm);
213 bytes += uncompressedLeft - strm.avail_out; // bytes uncompressed
214 uncompressedLeft = strm.avail_out;