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

1 files changed, 4 insertions, 2 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
 	}