48 lines
1.0 KiB
Go
48 lines
1.0 KiB
Go
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package cryptext
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import (
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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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"errors"
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"io"
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)
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// https://stackoverflow.com/a/18819040/1761622
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func EncryptAES(key, text []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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b := base64.StdEncoding.EncodeToString(text)
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ciphertext := make([]byte, aes.BlockSize+len(b))
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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 nil, err
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}
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cfb := cipher.NewCFBEncrypter(block, iv)
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cfb.XORKeyStream(ciphertext[aes.BlockSize:], []byte(b))
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return ciphertext, nil
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}
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func DecryptAES(key, text []byte) ([]byte, error) {
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block, err := aes.NewCipher(key)
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if err != nil {
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return nil, err
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}
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if len(text) < aes.BlockSize {
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return nil, errors.New("ciphertext too short")
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}
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iv := text[:aes.BlockSize]
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text = text[aes.BlockSize:]
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cfb := cipher.NewCFBDecrypter(block, iv)
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cfb.XORKeyStream(text, text)
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data, err := base64.StdEncoding.DecodeString(string(text))
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if err != nil {
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return nil, err
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}
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return data, nil
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}
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