73 lines
1.5 KiB
Go
73 lines
1.5 KiB
Go
package seal
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import (
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"crypto/aes"
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"crypto/cipher"
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"errors"
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"time"
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metrics "github.com/armon/go-metrics"
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"github.com/hashicorp/errwrap"
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uuid "github.com/hashicorp/go-uuid"
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)
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type Envelope struct{}
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type EnvelopeInfo struct {
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Ciphertext []byte
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Key []byte
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IV []byte
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}
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func NewEnvelope() *Envelope {
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return &Envelope{}
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}
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func (e *Envelope) Encrypt(plaintext []byte) (*EnvelopeInfo, error) {
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defer metrics.MeasureSince([]string{"seal", "envelope", "encrypt"}, time.Now())
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// Generate DEK
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key, err := uuid.GenerateRandomBytes(32)
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if err != nil {
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return nil, err
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}
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iv, err := uuid.GenerateRandomBytes(12)
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if err != nil {
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return nil, err
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}
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aead, err := e.aeadEncrypter(key)
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if err != nil {
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return nil, err
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}
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return &EnvelopeInfo{
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Ciphertext: aead.Seal(nil, iv, plaintext, nil),
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Key: key,
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IV: iv,
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}, nil
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}
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func (e *Envelope) Decrypt(data *EnvelopeInfo) ([]byte, error) {
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defer metrics.MeasureSince([]string{"seal", "envelope", "decrypt"}, time.Now())
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aead, err := e.aeadEncrypter(data.Key)
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if err != nil {
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return nil, err
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}
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return aead.Open(nil, data.IV, data.Ciphertext, nil)
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}
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func (e *Envelope) aeadEncrypter(key []byte) (cipher.AEAD, error) {
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aesCipher, err := aes.NewCipher(key)
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if err != nil {
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return nil, errwrap.Wrapf("failed to create cipher: {{err}}", err)
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}
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// Create the GCM mode AEAD
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gcm, err := cipher.NewGCM(aesCipher)
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if err != nil {
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return nil, errors.New("failed to initialize GCM mode")
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}
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return gcm, nil
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}
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