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compress.gzip: support `gzip.decompress(data, verify_length: false, verify_checksum: false)?`

master
Delyan Angelov 2022-06-12 11:24:41 +03:00
parent 5c104cf981
commit ff8e286c88
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GPG Key ID: 66886C0F12D595ED
1 changed files with 11 additions and 4 deletions
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15
vlib/compress/gzip/gzip.v
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@ -40,9 +40,16 @@ pub fn compress(data []u8) ?[]u8 {
return result
}
[params]
pub struct DecompressParams {
verify_header_checksum bool = true
verify_length bool = true
verify_checksum bool = true
}
// decompresses an array of bytes using zlib and returns the decompressed bytes in a new array
// Example: decompressed := gzip.decompress(b)?
pub fn decompress(data []u8) ?[]u8 {
pub fn decompress(data []u8, params DecompressParams) ?[]u8 {
if data.len < 18 {
return error('data is too short, not gzip compressed?')
} else if data[0] != 0x1f || data[1] != 0x8b {
@ -91,7 +98,7 @@ pub fn decompress(data []u8) ?[]u8 {
checksum_header := crc32.sum(data[..header_length])
checksum_header_expected := (u32(data[header_length]) << 24) | (u32(data[header_length + 1]) << 16) | (u32(data[
header_length + 2]) << 8) | data[header_length + 3]
if checksum_header != checksum_header_expected {
if params.verify_header_checksum && checksum_header != checksum_header_expected {
return error('header checksum verification failed')
}
header_length += 4
@ -102,12 +109,12 @@ pub fn decompress(data []u8) ?[]u8 {
decompressed := compress.decompress(data[header_length..data.len - 8], 0)?
length_expected := (u32(data[data.len - 4]) << 24) | (u32(data[data.len - 3]) << 16) | (u32(data[data.len - 2]) << 8) | data[data.len - 1]
if decompressed.len != length_expected {
if params.verify_length && decompressed.len != length_expected {
return error('length verification failed, got $decompressed.len, expected $length_expected')
}
checksum := crc32.sum(decompressed)
checksum_expected := (u32(data[data.len - 8]) << 24) | (u32(data[data.len - 7]) << 16) | (u32(data[data.len - 6]) << 8) | data[data.len - 5]
if checksum != checksum_expected {
if params.verify_checksum && checksum != checksum_expected {
return error('checksum verification failed')
}
return decompressed