去加密/解密

Question

拥有以下代码

package main

import (
    "bytes"
    "crypto/aes"
    "crypto/cipher"
    "crypto/rand"
    "encoding/base64"
    "io"
    "log"
)

func main() {
    decrypt(
      "Zff9c+F3gZu/lsARvPhpMau50KUkMAie4j8MYfb12HMWhkLqZreTk8RPbtRB7RDG3QFw7Y0FXJsCq/EBEAz//XoeSZmqZXoyq2Cx8ZV+/Rw=",
      "u9CV7oR2w+IIk8R0hppxaw==",
      "~NB8CcOL#J!H?|Yr",
    )
    text, iv := encrypt(
      `{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!! }"`,
      "~NB8CcOL#J!H?|Yr",
    )
    println("Encrypted", text, iv)
    decrypt(
      text,
      iv,
      "~NB8CcOL#J!H?|Yr",
    )
}

func encrypt(textString, keyString string) (string, string) {
    key := []byte(keyString)
    text := []byte(textString)
    encodedText := []byte(base64.StdEncoding.EncodeToString(text))
    block, err := aes.NewCipher(key)
    check(err, "location 5 ")

    textWithPadding := addPadding(encodedText, aes.BlockSize)

    iv := make([]byte, 16)
    _, err = io.ReadFull(rand.Reader, iv)
    check(err, "location 6 ")
    mode := cipher.NewCBCEncrypter(block, iv)
    encrypted := make([]byte, len(textWithPadding))
    mode.CryptBlocks(encrypted, textWithPadding)
    encodedResult := base64.StdEncoding.EncodeToString(encrypted)
    encodedIv := base64.StdEncoding.EncodeToString(iv)
    return encodedResult, encodedIv
}

func check(err error, where string) {
    if err != nil {
      log.Panic(where, err)
    }
}

func decrypt(ciphertext, iv, password string) {
    decodedText, err := base64.StdEncoding.DecodeString(ciphertext)
    check(err, "location 1 ")
    decodedIv, err := base64.StdEncoding.DecodeString(iv)
    decodedIv = removeBadPadding(decodedIv)
    check(err, "location 2 ")
    newCipher, err := aes.NewCipher([]byte(password))
    check(err, "location 3 ")
    cfbdec := cipher.NewCBCDecrypter(newCipher, decodedIv)
    cfbdec.CryptBlocks(decodedText, decodedText)

    decodedText = removeBadPadding(decodedText)

    data, err := base64.RawStdEncoding.DecodeString(string(decodedText))
    check(err, "location 4 ")
    println("Decrypted", string(data))
}

func removeBadPadding(b64 []byte) []byte {
    last := b64[len(b64)-1]
    if last > 16 {
      return b64
    }
    return b64[:len(b64)-int(last)]
}

func addPadding(src []byte, blockSize int) []byte {
    if len(src)%blockSize == 0 {
      return src
    }
    padding := blockSize - len(src)%blockSize
    padtext := bytes.Repeat([]byte{byte(padding)}, padding)
    return append(src, padtext...)
}

引发

2017/03/30 12:20:09 location 4 illegal base64 data at input byte 75
panic: location 4 illegal base64 data at input byte 75

goroutine 1 [running]:
log.Panic(0xc420045df0, 0x2, 0x2)

但是，如果我改变

text, iv := encrypt(
  `{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!! }"`,
  "~NB8CcOL#J!H?|Yr",
)

要

text, iv := encrypt(
  `{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!!"`,
  "~NB8CcOL#J!H?|Yr",
)

代码有效。区别在于} - 空格和}。解密的相关问题是this one。我认为当前案例中的问题是加密