You've already forked img-proxy-url-generator
63 lines
1.3 KiB
Go
63 lines
1.3 KiB
Go
package generator
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import (
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"bytes"
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"crypto/aes"
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"crypto/cipher"
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"crypto/rand"
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"encoding/base64"
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"io"
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)
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func pkcs7pad(data []byte, blockSize int) []byte {
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padLen := blockSize - len(data)%blockSize
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padding := bytes.Repeat([]byte{byte(padLen)}, padLen)
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return append(data, padding...)
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}
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func (g *Generator) Decrypt(s string) (string, error) {
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c, err := aes.NewCipher(g.encryptionKey)
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if err != nil {
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return "", err
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}
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decoded, err := base64.RawURLEncoding.DecodeString(s)
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if err != nil {
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return "", err
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}
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iv := decoded[:aes.BlockSize]
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cryptText := decoded[aes.BlockSize:]
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cbc := cipher.NewCBCDecrypter(c, iv)
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cbc.CryptBlocks(cryptText, cryptText)
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return string(cryptText), err
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}
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func (g *Generator) generateBaseAesEncUrl(file []byte) (string, error) {
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c, err := aes.NewCipher(g.encryptionKey)
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if err != nil {
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return "", err
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}
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data := pkcs7pad(file, aes.BlockSize)
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ciphertext := make([]byte, aes.BlockSize+len(data))
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iv := ciphertext[:aes.BlockSize]
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if _, err = io.ReadFull(rand.Reader, iv); err != nil {
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return "", err
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}
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mode := cipher.NewCBCEncrypter(c, iv)
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mode.CryptBlocks(ciphertext[aes.BlockSize:], data)
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encryptedURL, err := g.generateBase64Url(ciphertext)
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if err != nil {
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return "", err
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}
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return "enc/" + encryptedURL, nil
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}
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