go-micro.dev/v5@v5.12.0/config/secrets/box/box.go (about)

     1  // Package box is an asymmetric implementation of config/secrets using nacl/box
     2  package box
     3  
     4  import (
     5  	"crypto/rand"
     6  
     7  	"github.com/pkg/errors"
     8  	"go-micro.dev/v5/config/secrets"
     9  	naclbox "golang.org/x/crypto/nacl/box"
    10  )
    11  
    12  const keyLength = 32
    13  
    14  type box struct {
    15  	options secrets.Options
    16  
    17  	publicKey  [keyLength]byte
    18  	privateKey [keyLength]byte
    19  }
    20  
    21  // NewSecrets returns a nacl-box codec.
    22  func NewSecrets(opts ...secrets.Option) secrets.Secrets {
    23  	b := &box{}
    24  	for _, o := range opts {
    25  		o(&b.options)
    26  	}
    27  	return b
    28  }
    29  
    30  func (b *box) Init(opts ...secrets.Option) error {
    31  	for _, o := range opts {
    32  		o(&b.options)
    33  	}
    34  	if len(b.options.PrivateKey) != keyLength || len(b.options.PublicKey) != keyLength {
    35  		return errors.Errorf("a public key and a private key of length %d must both be provided", keyLength)
    36  	}
    37  	copy(b.privateKey[:], b.options.PrivateKey)
    38  	copy(b.publicKey[:], b.options.PublicKey)
    39  	return nil
    40  }
    41  
    42  // Options returns options.
    43  func (b *box) Options() secrets.Options {
    44  	return b.options
    45  }
    46  
    47  // String returns nacl-box.
    48  func (*box) String() string {
    49  	return "nacl-box"
    50  }
    51  
    52  // Encrypt encrypts a message with the sender's private key and the receipient's public key.
    53  func (b *box) Encrypt(in []byte, opts ...secrets.EncryptOption) ([]byte, error) {
    54  	var options secrets.EncryptOptions
    55  	for _, o := range opts {
    56  		o(&options)
    57  	}
    58  	if len(options.RecipientPublicKey) != keyLength {
    59  		return []byte{}, errors.New("recepient's public key must be provided")
    60  	}
    61  	var recipientPublicKey [keyLength]byte
    62  	copy(recipientPublicKey[:], options.RecipientPublicKey)
    63  	var nonce [24]byte
    64  	if _, err := rand.Reader.Read(nonce[:]); err != nil {
    65  		return []byte{}, errors.Wrap(err, "couldn't obtain a random nonce from crypto/rand")
    66  	}
    67  	return naclbox.Seal(nonce[:], in, &nonce, &recipientPublicKey, &b.privateKey), nil
    68  }
    69  
    70  // Decrypt Decrypts a message with the receiver's private key and the sender's public key.
    71  func (b *box) Decrypt(in []byte, opts ...secrets.DecryptOption) ([]byte, error) {
    72  	var options secrets.DecryptOptions
    73  	for _, o := range opts {
    74  		o(&options)
    75  	}
    76  	if len(options.SenderPublicKey) != keyLength {
    77  		return []byte{}, errors.New("sender's public key bust be provided")
    78  	}
    79  	var nonce [24]byte
    80  	var senderPublicKey [32]byte
    81  	copy(nonce[:], in[:24])
    82  	copy(senderPublicKey[:], options.SenderPublicKey)
    83  	decrypted, ok := naclbox.Open(nil, in[24:], &nonce, &senderPublicKey, &b.privateKey)
    84  	if !ok {
    85  		return []byte{}, errors.New("incoming message couldn't be verified / decrypted")
    86  	}
    87  	return decrypted, nil
    88  }