Having the following code
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...) } throws
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) However, if I change
text, iv := encrypt( `{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!! }"`, "~NB8CcOL#J!H?|Yr", ) To
text, iv := encrypt( `{"data":{"value":300}, "SEQN":700 , "msg":"IT WORKS!!"`, "~NB8CcOL#J!H?|Yr", ) the code works. the difference is } - space and }. Related question for decryption is this one. I would assume that the problem in the current case is with the encryption