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padding.go
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padding.go
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// padding.go
package gocrypto
import "bytes"
func ZeroPadding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{0}, padding)
return append(ciphertext, padtext...)
}
func ZeroUnPadding(origData []byte) []byte {
return bytes.TrimRightFunc(origData, func(r rune) bool {
return r == rune(0)
})
}
func PKCS5Padding(ciphertext []byte, blockSize int) []byte {
padding := blockSize - len(ciphertext)%blockSize
padtext := bytes.Repeat([]byte{byte(padding)}, padding)
return append(ciphertext, padtext...)
}
func PKCS5UnPadding(origData []byte) []byte {
length := len(origData)
// 去掉最后一个字节 unpadding 次
unpadding := int(origData[length-1])
return origData[:(length - unpadding)]
}