/
rsa.go
72 lines (67 loc) · 1.55 KB
/
rsa.go
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package encrypt
import (
"crypto/rand"
"crypto/rsa"
"crypto/sha256"
"crypto/x509"
"encoding/pem"
"errors"
)
// BytesToPrivateKey bytes to private key
func BytesToPrivateKey(priv []byte) (*rsa.PrivateKey, error) {
block, _ := pem.Decode(priv)
enc := x509.IsEncryptedPEMBlock(block)
b := block.Bytes
var err error
if enc {
b, err = x509.DecryptPEMBlock(block, nil)
if err != nil {
return nil, err
}
}
key, err := x509.ParsePKCS1PrivateKey(b)
if err != nil {
return nil, err
}
return key, nil
}
// BytesToPublicKey bytes to public key
func BytesToPublicKey(pub []byte) (*rsa.PublicKey, error) {
block, _ := pem.Decode(pub)
enc := x509.IsEncryptedPEMBlock(block)
b := block.Bytes
var err error
if enc {
b, err = x509.DecryptPEMBlock(block, nil)
if err != nil {
return nil, err
}
}
ifc, err := x509.ParsePKIXPublicKey(b)
if err != nil {
return nil, err
}
key, ok := ifc.(*rsa.PublicKey)
if !ok {
return nil, errors.New("not ok")
}
return key, nil
}
// EncryptWithPublicKey encrypts data with public key
func EncryptWithPublicKey(msg []byte, pub *rsa.PublicKey) ([]byte, error) {
hash := sha256.New()
ciphertext, err := rsa.EncryptOAEP(hash, rand.Reader, pub, msg, nil)
if err != nil {
return nil, err
}
return ciphertext, nil
}
// DecryptWithPrivateKey decrypts data with private key
func DecryptWithPrivateKey(ciphertext []byte, priv *rsa.PrivateKey) ([]byte, error) {
hash := sha256.New()
plaintext, err := rsa.DecryptOAEP(hash, rand.Reader, priv, ciphertext, nil)
if err != nil {
return nil, err
}
return plaintext, nil
}