ZIP local file header
Local header 는 아래와 같고 ![[http]](http://fehead.linuxstudy.pe.kr/ziki/imgs/http.png)
위키리스트참고
위키리스트참고
ZIP local file header
위에 나온 것을 보고 분석해봅시다.
| Offset | Bytes | Description |
| 0 | 4 | Local file header signature = 0x04034b50 (read as a little-endian number) |
| 4 | 2 | Version needed to extract (minimum) |
| 6 | 2 | General purpose bit flag |
| 8 | 2 | Compression method |
| 10 | 2 | File last modification time |
| 12 | 2 | File last modification date |
| 14 | 4 | CRC-32 |
| 18 | 4 | Compressed size |
| 22 | 4 | Uncompressed size |
| 26 | 2 | File name length (n) |
| 28 | 2 | Extra field length (m) |
| 30 | n | File name |
| 30+n | m | Extra field |
위에 나온 것을 보고 분석해봅시다.
$ xxd test.zip | head -6 0000000: 504b 0304 0a00 0000 0000 2cb2 093f b537 PK........,..?.7 0000010: 3c98 1000 0000 1000 0000 0600 1c00 6161 <.............aa 0000020: 2e74 7874 5554 0900 0363 3341 4e6a 3341 .txtUT...c3ANj3A 0000030: 4e75 780b 0001 046b 0400 0004 f901 0000 Nux....k........ 0000040: 3031 3233 3435 3637 3839 4142 4344 4546 0123456789ABCDEF 0000050: 504b 0304 0a00 0000 0000 2fb2 093f b537 PK......../..?.7
| Offset | Bytes | Description | Value |
| 0 | 4 | Local file header signature | 504b 0304 |
| 4 | 2 | Version needed to extract (minimum) | 0a00 |
| 6 | 2 | General purpose bit flag | 0000 |
| 8 | 2 | Compression method | 0000 |
| 10 | 2 | File last modification time | 5189 |
| 12 | 2 | File last modification date | 093f |
| 14 | 4 | CRC-32 | b537 3c98 |
| 18 | 4 | Compressed size | 1000 0000 |
| 22 | 4 | Uncompressed size | 1000 0000 |
| 26 | 2 | File name length (n) | 0600 |
| 28 | 2 | Extra field length (m) | 1c00 |
| 30 | n(6) | File name | 6161 2e74 7874("aa.txt") |
| 30+n | m(1c) | Extra field(1c == 28byte) | |
| 0900 0379 eb40 4e94 eb40 4e75 780b 0001 | |||
| 04e8 0300 0004 6400 0000 | |||
| 30+n+m | Data | 3031 3233 3435 3637 3839 4142 4344 4546 = "0123456789ABCDEF" | |
두번째
$ xxd test.zip |grep -A 5 0000050 0000050: 504b 0304 0a00 0000 0000 6089 093f b537 PK........`..?.7 0000060: 3c98 1000 0000 1000 0000 0600 1c00 6262 <.............bb 0000070: 2e74 7874 5554 0900 0394 eb40 4e94 eb40 .txtUT.....@N..@ 0000080: 4e75 780b 0001 04e8 0300 0004 6400 0000 Nux.........d... 0000090: 3031 3233 3435 3637 3839 4142 4344 4546 0123456789ABCDEF 00000a0: 504b 0102 1e03 0a00 0000 0000 5189 093f PK..........Q..?
| Offset | Bytes | Description | Value |
| 0 | 4 | Local file header signature | 504b 0304 |
| 4 | 2 | Version needed to extract (minimum) | 0a00 |
| 6 | 2 | General purpose bit flag | 0000 |
| 8 | 2 | Compression method | 0000 |
| 10 | 2 | File last modification time | 6089 |
| 12 | 2 | File last modification date | 093f |
| 14 | 4 | CRC-32 | b537 3c98 |
| 18 | 4 | Compressed size | 1000 0000 |
| 22 | 4 | Uncompressed size | 1000 0000 |
| 26 | 2 | File name length (n) | 0600 |
| 28 | 2 | Extra field length (m) | 1c00 |
| 30 | n(6) | File name | 6262 2e74 7874("bb.txt") |
| 30+n | m(1c) | Extra field(1c == 28byte) | |
| 5554 0900 0394 eb40 4e94 eb40 4e75 780b | |||
| 0001 04e8 0300 0004 6400 0000 | |||
| 30+n+m | Data | 3031 3233 3435 3637 3839 4142 4344 4546 = "0123456789ABCDEF" |
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