45 lines
1.2 KiB
Go
45 lines
1.2 KiB
Go
//go:build windows
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package safeio
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import (
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"io"
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"os"
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"golang.org/x/sys/windows"
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)
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func readCanonicalPrivateRegular(path string, maximum int64) ([]byte, error) {
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if maximum < 0 || maximum == int64(^uint64(0)>>1) {
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return nil, ErrUnsafeFile
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}
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value, err := openWindowsPrivateRegular(path, 1)
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if err != nil {
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return nil, ErrUnsafeFile
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}
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defer value.Close()
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file := os.NewFile(uintptr(value.handle), "tht-safeio-private-read")
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if file == nil {
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return nil, ErrUnsafeFile
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}
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before := value.info
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contents, readErr := io.ReadAll(io.LimitReader(file, maximum+1))
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var after = value.info
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identityErr := windows.GetFileInformationByHandle(value.handle, &after)
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daclErr := validateOwnerOnlyDACL(value.handle)
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closeErr := file.Close()
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value.handle = 0
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if readErr != nil || identityErr != nil || daclErr != nil || !sameWindowsPrivateFile(before, after) || after.NumberOfLinks != 1 || closeErr != nil || int64(len(contents)) > maximum {
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return nil, ErrUnsafeFile
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}
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current, err := openWindowsPrivateRegular(path, 1)
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if err != nil {
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return nil, ErrUnsafeFile
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}
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current.Close()
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if !sameWindowsPrivateFile(before, current.info) {
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return nil, ErrUnsafeFile
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}
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return contents, nil
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}
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