refactor: Crypter/Wallet crypto operations

pkg/didcomm/crypto/crypter.go

@@ -6,6 +6,16 @@ SPDX-License-Identifier: Apache-2.0
 
 package crypto
 
+import "github.com/hyperledger/aries-framework-go/pkg/wallet"
+
+// Provider interface for Crypter ctx
+type Provider interface {
+	CryptoWallet() wallet.Crypto
+}
+
+// CrypterCreator method to create new crypter service
+type CrypterCreator func(prov Provider) (Crypter, error)
+
 // Crypter is an Aries envelope encrypter to support
 // secure DIDComm exchange of envelopes between Aries agents
 // TODO create a higher-level crypto that switches implementations based on the algorithm - Issue #273
@@ -16,29 +26,13 @@ type Crypter interface {
 	// 		[]byte containing the encrypted envelope
 	//		error if encryption failed
 	// TODO add key type of recipients and sender keys to be validated by the implementation - Issue #272
-	Encrypt(payload []byte, sender KeyPair, recipients [][]byte) ([]byte, error)
-	// Decrypt an envelope in an Aries compliant format with the recipient's private key
-	// and the recipient's public key both set in recipientKeyPair
+	Encrypt(payload []byte, senderKey []byte, recipients [][]byte) ([]byte, error)
+	// Decrypt an envelope in an Aries compliant format.
+	// 		The recipient's key will be matched from the wallet with the list of recipients in the envelope
+	//
 	// returns:
 	// 		[]byte containing the decrypted payload
 	//		error if decryption failed
 	// TODO add key type of recipients keys to be validated by the implementation - Issue #272
-	Decrypt(envelope []byte, recipientKeyPair KeyPair) ([]byte, error)
-}
-
-// KeyPair represents a private/public key pair each with 32 bytes in size
-type KeyPair struct {
-	// Priv is a private key
-	Priv []byte
-	// Pub is a public key
-	Pub []byte
-}
-
-// IsKeyPairValid is a utility function that validates a KeyPair
-func IsKeyPairValid(kp KeyPair) bool {
-	if kp.Priv == nil || kp.Pub == nil {
-		return false
-	}
-
-	return true
+	Decrypt(envelope []byte) ([]byte, error)
 }

pkg/didcomm/crypto/jwe/authcrypt/authcrypt.go

@@ -11,6 +11,9 @@ import (
 	"errors"
 
 	chacha "golang.org/x/crypto/chacha20poly1305"
+
+	"github.com/hyperledger/aries-framework-go/pkg/didcomm/crypto"
+	"github.com/hyperledger/aries-framework-go/pkg/wallet"
 )
 
 // This package deals with Authcrypt encryption for Packing/Unpacking DID Comm exchange
@@ -30,25 +33,14 @@ const XC20P = ContentEncryption("XC20P") // XChacha20 encryption + Poly1305 auth
 //nolint:gochecknoglobals
 var randReader = rand.Reader
 
-// errEmptyRecipients is used when recipients list is empty
-var errEmptyRecipients = errors.New("empty recipients")
-
-// errInvalidKeypair is used when a keypair is invalid
-var errInvalidKeypair = errors.New("invalid keypair")
-
-// errInvalidKey is used when a key is invalid
-var errInvalidKey = errors.New("invalid key")
-
-// errRecipientNotFound is used when a recipient is not found
-var errRecipientNotFound = errors.New("recipient not found")
-
 // errUnsupportedAlg is used when a bad encryption algorithm is used
 var errUnsupportedAlg = errors.New("algorithm not supported")
 
 // Crypter represents an Authcrypt Encrypter (Decrypter) that outputs/reads JWE envelopes
 type Crypter struct {
 	alg       ContentEncryption
 	nonceSize int
+	wallet    wallet.Crypto
 }
 
 // Envelope represents a JWE envelope as per the Aries Encryption envelope specs
@@ -106,7 +98,8 @@ type jwk struct {
 // C20P (chacha20-poly1305 ietf)
 // XC20P (xchacha20-poly1305 ietf)
 // The returned crypter contains all the information required to encrypt payloads.
-func New(alg ContentEncryption) (*Crypter, error) {
+func New(ctx crypto.Provider, alg ContentEncryption) (*Crypter, error) {
+	w := ctx.CryptoWallet()
 	var nonceSize int
 	switch alg {
 	case C20P:
@@ -117,16 +110,9 @@ func New(alg ContentEncryption) (*Crypter, error) {
 		return nil, errUnsupportedAlg
 	}
 
-	c := &Crypter{
-		alg,
-		nonceSize,
-	}
-
-	return c, nil
-}
-
-// IsChachaKeyValid will return true if key size is the same as chacha20poly1305.keySize
-// false otherwise
-func IsChachaKeyValid(key []byte) bool {
-	return len(key) == chacha.KeySize
+	return &Crypter{
+		alg:       alg,
+		nonceSize: nonceSize,
+		wallet:    w,
+	}, nil
 }