100 lines
1.8 KiB
Go
100 lines
1.8 KiB
Go
// Copyright © 2016 Abcum Ltd
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package mysql
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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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"errors"
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)
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var chars = []byte("ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789")
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func encrypt(key []byte, src []byte) (dst []byte, err error) {
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if key == nil || len(key) == 0 || len(src) == 0 {
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return src, nil
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}
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// Initiate AES
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block, _ := aes.NewCipher(key)
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// Initiate cipher
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cipher, _ := cipher.NewGCM(block)
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// Initiate nonce
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nonce := random(12)
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dst = cipher.Seal(nil, nonce, src, nil)
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dst = append(nonce[:], dst[:]...)
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return
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}
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func decrypt(key []byte, src []byte) (dst []byte, err error) {
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if key == nil || len(key) == 0 || len(src) == 0 {
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return src, nil
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}
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// Corrupt
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if len(src) < 12 {
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return src, errors.New("Invalid data")
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}
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// Initiate AES
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block, _ := aes.NewCipher(key)
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// Initiate cipher
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cipher, _ := cipher.NewGCM(block)
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return cipher.Open(nil, src[:12], src[12:], nil)
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}
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func random(l int) []byte {
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if l == 0 {
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return nil
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}
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i := 0
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t := len(chars)
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m := 255 - (256 % t)
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b := make([]byte, l)
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r := make([]byte, l+(l/4))
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for {
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rand.Read(r)
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for _, rb := range r {
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c := int(rb)
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if c > m {
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continue
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}
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b[i] = chars[c%t]
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i++
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if i == l {
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return b
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}
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}
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}
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}
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