CSI-ES-2324/Projs/PD1/internal/utils/cryptoUtils/cryptoUtils.go

155 lines
3.8 KiB
Go

package cryptoUtils
import (
"PD1/internal/client"
"crypto"
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/tls"
"crypto/x509"
"encoding/binary"
"encoding/pem"
"log"
"os"
"vendor/golang.org/x/crypto/chacha20poly1305"
"software.sslmate.com/src/go-pkcs12"
)
type KeyStore struct {
cert *x509.Certificate
caCertChain []*x509.Certificate
privKey rsa.PrivateKey
}
func (k KeyStore) GetCert() *x509.Certificate {
return k.cert
}
func (k KeyStore) GetCACertChain() []*x509.Certificate {
return k.caCertChain
}
func (k KeyStore) GetPrivKey() rsa.PrivateKey {
return k.privKey
}
func LoadKeyStore(keyStorePath string) KeyStore {
var privKey rsa.PrivateKey
certFile, err := os.ReadFile(keyStorePath)
if err != nil {
log.Panicln("Provided certificate %v couldn't be opened", keyStorePath)
}
password := client.AskUserPassword()
privKeyInterface, cert, caCerts, err := pkcs12.DecodeChain(certFile, password)
privKey = privKeyInterface.(rsa.PrivateKey)
if err != nil {
log.Panicln("PKCS12 key store couldn't be decoded")
}
if err := privKey.Validate(); err != nil {
log.Panicln("Private key is not valid")
}
return KeyStore{cert: cert, caCertChain: caCerts, privKey: privKey}
}
func (k KeyStore) GetTLSConfig() *tls.Config {
certificate, err := tls.X509KeyPair(k.cert.Raw, pem.EncodeToMemory(&pem.Block{Type: "RSA PRIVATE KEY", Bytes: x509.MarshalPKCS1PrivateKey(&k.privKey)}))
if err != nil {
log.Panicln("Could not load certificate and privkey to TLS")
}
//Add the CA certificate chain to a CertPool
caCertPool := x509.NewCertPool()
for _, caCert := range k.caCertChain {
caCertPool.AddCert(caCert)
}
config := &tls.Config{
Certificates: []tls.Certificate{certificate},
ClientCAs: caCertPool,
}
return config
}
func (k KeyStore) GetTLSConfigServer() *tls.Config {
config := k.GetTLSConfig()
config.ClientAuth = tls.RequireAndVerifyClientCert
return config
}
func (k KeyStore) GetTLSConfigClient() *tls.Config {
config := k.GetTLSConfig()
config.ServerName = "SERVER"
return config
}
func (k KeyStore) EncryptMessageContent(receiverCert *x509.Certificate, content []byte) []byte {
// Digital envolope
// Create a random symmetric key
dataKey := make([]byte, 32)
if _, err := rand.Read(dataKey); err != nil {
log.Panicln("Could not create dataKey properly: ", err)
}
cipher, err := chacha20poly1305.New(dataKey)
if err != nil {
log.Panicln("Could not create cipher: ", err)
}
nonce := make([]byte, cipher.NonceSize(), cipher.NonceSize()+len(content)+cipher.Overhead())
if _, err := rand.Read(nonce); err != nil {
log.Panicln("Could not create data nonce properly: ", err)
}
// sign the message and append the signature
hashedContent := sha256.Sum256(content)
signature, err := rsa.SignPKCS1v15(nil, &k.privKey, crypto.SHA256, hashedContent[:])
if err != nil {
log.Panicln("Could not create content signature: ", err)
}
content = pair(content, signature)
ciphertext := cipher.Seal(nonce, nonce, content, nil)
// crypto/rand.Reader is a good source of entropy for randomizing the
// encryption function.
receiverPubKey := receiverCert.PublicKey.(*rsa.PublicKey)
encryptedDataKey, err := rsa.EncryptOAEP(sha256.New(), rand.Reader, receiverPubKey, dataKey, nil)
if err != nil {
log.Panicln("Could not encrypt dataKey: ", err)
}
return pair(encryptedDataKey, ciphertext)
}
func (k KeyStore) DecryptMessageContent(senderCert *x509.Certificate, cipherContent []byte) []byte {
return nil
}
func pair(l []byte, r []byte) []byte {
length := len(l)
lenBytes := make([]byte, 2)
binary.BigEndian.PutUint16(lenBytes, uint16(length))
lWithLen := append(lenBytes, l...)
return append(lWithLen, r...)
}
func unPair(pair []byte) ([]byte, []byte) {
lenBytes := pair[:2]
pair = pair[2:]
length := binary.BigEndian.Uint16(lenBytes)
l := pair[:length]
r := pair[length:]
return l, r
}