crypto: add btcec fallback for sign/recover without cgo (#3680)

* vendor: add github.com/btcsuite/btcd/btcec

* crypto: add btcec fallback for sign/recover without cgo

This commit adds a non-cgo fallback implementation of secp256k1
operations.

* crypto, core/vm: remove wrappers for sha256, ripemd160

3 files changed, 11 insertions, 9 deletions

diff --git a/whisper/whisperv2/message.go b/whisper/whisperv2/message.go
index 7ef9d0912..e55544ffc 100644
--- a/whisper/whisperv2/message.go
+++ b/whisper/whisperv2/message.go
@@ -21,11 +21,13 @@ package whisperv2
 
 import (
 	"crypto/ecdsa"
+	crand "crypto/rand"
 	"math/rand"
 	"time"
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/ecies"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 )
@@ -131,13 +133,13 @@ func (self *Message) Recover() *ecdsa.PublicKey {
 
 // encrypt encrypts a message payload with a public key.
 func (self *Message) encrypt(key *ecdsa.PublicKey) (err error) {
-	self.Payload, err = crypto.Encrypt(key, self.Payload)
+	self.Payload, err = ecies.Encrypt(crand.Reader, ecies.ImportECDSAPublic(key), self.Payload, nil, nil)
 	return
 }
 
 // decrypt decrypts an encrypted payload with a private key.
 func (self *Message) decrypt(key *ecdsa.PrivateKey) error {
-	cleartext, err := crypto.Decrypt(key, self.Payload)
+	cleartext, err := ecies.ImportECDSA(key).Decrypt(crand.Reader, self.Payload, nil, nil)
 	if err == nil {
 		self.Payload = cleartext
 	}
diff --git a/whisper/whisperv2/message_test.go b/whisper/whisperv2/message_test.go
index d3b307d2a..c760ac54c 100644
--- a/whisper/whisperv2/message_test.go
+++ b/whisper/whisperv2/message_test.go
@@ -23,7 +23,6 @@ import (
 	"time"
 
 	"github.com/ethereum/go-ethereum/crypto"
-	"github.com/ethereum/go-ethereum/crypto/secp256k1"
 )
 
 // Tests whether a message can be wrapped without any identity or encryption.
@@ -73,8 +72,8 @@ func TestMessageCleartextSignRecover(t *testing.T) {
 	if pubKey == nil {
 		t.Fatalf("failed to recover public key")
 	}
-	p1 := elliptic.Marshal(secp256k1.S256(), key.PublicKey.X, key.PublicKey.Y)
-	p2 := elliptic.Marshal(secp256k1.S256(), pubKey.X, pubKey.Y)
+	p1 := elliptic.Marshal(crypto.S256(), key.PublicKey.X, key.PublicKey.Y)
+	p2 := elliptic.Marshal(crypto.S256(), pubKey.X, pubKey.Y)
 	if !bytes.Equal(p1, p2) {
 		t.Fatalf("public key mismatch: have 0x%x, want 0x%x", p2, p1)
 	}
@@ -151,8 +150,8 @@ func TestMessageFullCrypto(t *testing.T) {
 	if pubKey == nil {
 		t.Fatalf("failed to recover public key")
 	}
-	p1 := elliptic.Marshal(secp256k1.S256(), fromKey.PublicKey.X, fromKey.PublicKey.Y)
-	p2 := elliptic.Marshal(secp256k1.S256(), pubKey.X, pubKey.Y)
+	p1 := elliptic.Marshal(crypto.S256(), fromKey.PublicKey.X, fromKey.PublicKey.Y)
+	p2 := elliptic.Marshal(crypto.S256(), pubKey.X, pubKey.Y)
 	if !bytes.Equal(p1, p2) {
 		t.Fatalf("public key mismatch: have 0x%x, want 0x%x", p2, p1)
 	}
diff --git a/whisper/whisperv5/message.go b/whisper/whisperv5/message.go
index a095f7c0c..255ad380d 100644
--- a/whisper/whisperv5/message.go
+++ b/whisper/whisperv5/message.go
@@ -30,6 +30,7 @@ import (
 
 	"github.com/ethereum/go-ethereum/common"
 	"github.com/ethereum/go-ethereum/crypto"
+	"github.com/ethereum/go-ethereum/crypto/ecies"
 	"github.com/ethereum/go-ethereum/logger"
 	"github.com/ethereum/go-ethereum/logger/glog"
 	"golang.org/x/crypto/pbkdf2"
@@ -163,7 +164,7 @@ func (msg *SentMessage) encryptAsymmetric(key *ecdsa.PublicKey) error {
 	if !ValidatePublicKey(key) {
 		return fmt.Errorf("Invalid public key provided for asymmetric encryption")
 	}
-	encrypted, err := crypto.Encrypt(key, msg.Raw)
+	encrypted, err := ecies.Encrypt(crand.Reader, ecies.ImportECDSAPublic(key), msg.Raw, nil, nil)
 	if err == nil {
 		msg.Raw = encrypted
 	}
@@ -293,7 +294,7 @@ func (msg *ReceivedMessage) decryptSymmetric(key []byte, salt []byte, nonce []by
 
 // decryptAsymmetric decrypts an encrypted payload with a private key.
 func (msg *ReceivedMessage) decryptAsymmetric(key *ecdsa.PrivateKey) error {
-	decrypted, err := crypto.Decrypt(key, msg.Raw)
+	decrypted, err := ecies.ImportECDSA(key).Decrypt(crand.Reader, msg.Raw, nil, nil)
 	if err == nil {
 		msg.Raw = decrypted
 	}