package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"fmt"
"io"
"io/ioutil"
)
func main() {
fmt.Println("Encryption Program v0.01")
text := []byte("this is a message need to be encrypted")
key := []byte("thisismypassword")
// generate a new aes cipher using our 32 byte long key
c, err := aes.NewCipher(key)
// if there are any errors, handle them
if err != nil {
fmt.Println(err)
}
// gcm or Galois/Counter Mode, is a mode of operation
// for symmetric key cryptographic block ciphers
// - https://en.wikipedia.org/wiki/Galois/Counter_Mode
gcm, err := cipher.NewGCM(c)
// if any error generating new GCM
// handle them
if err != nil {
fmt.Println(err)
}
// creates a new byte array the size of the nonce
// which must be passed to Seal
nonce := make([]byte, gcm.NonceSize())
// populates our nonce with a cryptographically secure
// random sequence
if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
fmt.Println(err)
}
// here we encrypt our text using the Seal function
// Seal encrypts and authenticates plaintext, authenticates the
// additional data and appends the result to dst, returning the updated
// slice. The nonce must be NonceSize() bytes long and unique for all
// time, for a given key.
fmt.Println(gcm.Seal(nonce, nonce, text, nil))
// the WriteFile method returns an error if unsuccessful
err = ioutil.WriteFile("myfile.data", gcm.Seal(nonce, nonce, text, nil), 0777)
// handle this error
if err != nil {
// print it out
fmt.Println(err)
}
}
decrypt.go 用来解密
package main
import (
"crypto/aes"
"crypto/cipher"
"fmt"
"io/ioutil"
)
func main() {
fmt.Println("Decryption Program v0.01")
key := []byte("thisismypassword")
ciphertext, err := ioutil.ReadFile("myfile.data")
// if our program was unable to read the file
// print out the reason why it can't
if err != nil {
fmt.Println(err)
}
c, err := aes.NewCipher(key)
if err != nil {
fmt.Println(err)
}
gcm, err := cipher.NewGCM(c)
if err != nil {
fmt.Println(err)
}
nonceSize := gcm.NonceSize()
if len(ciphertext) < nonceSize {
fmt.Println(err)
}
nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
fmt.Println(err)
}
fmt.Println(string(plaintext))
}
package main
import (
"crypto/aes"
"crypto/cipher"
"crypto/rand"
"fmt"
"io"
"io/ioutil"
)
func Encrypt(text []byte) {
fmt.Println("Encryption Program v0.01")
// text := []byte("this is a message need to be encrypted")
key := []byte("thisismypassword")
// generate a new aes cipher using our 32 byte long key
c, err := aes.NewCipher(key)
// if there are any errors, handle them
if err != nil {
fmt.Println(err)
}
// gcm or Galois/Counter Mode, is a mode of operation
// for symmetric key cryptographic block ciphers
// - https://en.wikipedia.org/wiki/Galois/Counter_Mode
gcm, err := cipher.NewGCM(c)
// if any error generating new GCM
// handle them
if err != nil {
fmt.Println(err)
}
// creates a new byte array the size of the nonce
// which must be passed to Seal
nonce := make([]byte, gcm.NonceSize())
// populates our nonce with a cryptographically secure
// random sequence
if _, err = io.ReadFull(rand.Reader, nonce); err != nil {
fmt.Println(err)
}
// here we encrypt our text using the Seal function
// Seal encrypts and authenticates plaintext, authenticates the
// additional data and appends the result to dst, returning the updated
// slice. The nonce must be NonceSize() bytes long and unique for all
// time, for a given key.
fmt.Println(gcm.Seal(nonce, nonce, text, nil))
// the WriteFile method returns an error if unsuccessful
err = ioutil.WriteFile("myfile.data", gcm.Seal(nonce, nonce, text, nil), 0777)
// handle this error
if err != nil {
// print it out
fmt.Println(err)
}
}
decrypt.go
package main
import (
"crypto/aes"
"crypto/cipher"
"fmt"
"io/ioutil"
)
func Decrypt(filePath string) {
fmt.Println("Decryption Program v0.01")
key := []byte("thisismypassword")
ciphertext, err := ioutil.ReadFile("myfile.data")
// if our program was unable to read the file
// print out the reason why it can't
if err != nil {
fmt.Println(err)
}
c, err := aes.NewCipher(key)
if err != nil {
fmt.Println(err)
}
gcm, err := cipher.NewGCM(c)
if err != nil {
fmt.Println(err)
}
nonceSize := gcm.NonceSize()
if len(ciphertext) < nonceSize {
fmt.Println(err)
}
nonce, ciphertext := ciphertext[:nonceSize], ciphertext[nonceSize:]
plaintext, err := gcm.Open(nil, nonce, ciphertext, nil)
if err != nil {
fmt.Println(err)
}
fmt.Println(string(plaintext))
}
