77 lines
1.2 KiB
Go
77 lines
1.2 KiB
Go
package utils
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import (
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"bytes"
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"crypto/md5"
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"crypto/rand"
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"fmt"
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"io"
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"os"
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)
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// Reimplemented KOReader Partial MD5 Calculation
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func CalculatePartialMD5(filePath string) (*string, error) {
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file, err := os.Open(filePath)
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if err != nil {
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return nil, err
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}
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defer file.Close()
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var step int64 = 1024
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var size int64 = 1024
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var buf bytes.Buffer
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for i := -1; i <= 10; i++ {
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byteStep := make([]byte, size)
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var newShift int64 = int64(i * 2)
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var newOffset int64
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if i == -1 {
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newOffset = 0
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} else {
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newOffset = step << newShift
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}
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_, err := file.ReadAt(byteStep, newOffset)
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if err == io.EOF {
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break
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}
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buf.Write(byteStep)
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}
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allBytes := buf.Bytes()
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fileHash := fmt.Sprintf("%x", md5.Sum(allBytes))
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return &fileHash, nil
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}
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// Creates a token of n size
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func GenerateToken(n int) ([]byte, error) {
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b := make([]byte, n)
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_, err := rand.Read(b)
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if err != nil {
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return nil, err
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}
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return b, nil
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}
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// Calculate MD5 of a file
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func CalculateMD5(filePath string) (*string, error) {
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file, err := os.Open(filePath)
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if err != nil {
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return nil, err
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}
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defer file.Close()
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hash := md5.New()
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_, err = io.Copy(hash, file)
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if err != nil {
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return nil, err
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}
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fileHash := fmt.Sprintf("%x", hash.Sum(nil))
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return &fileHash, nil
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}
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