Deduplicate the message signing code

The logic of signing a message was duplicated in 3 places:

src/qt/signverifymessagedialog.cpp
  SignVerifyMessageDialog::on_signMessageButton_SM_clicked()

src/rpc/misc.cpp
  signmessagewithprivkey()

src/wallet/rpcwallet.cpp
  signmessage()

Move the logic into

src/util/message.cpp
  MessageSign()

and call it from all the 3 places.

1 files changed, 12 insertions, 0 deletions

diff --git a/src/util/message.h b/src/util/message.h
index 6adda5d3ff..1a1ba88daf 100644
--- a/src/util/message.h
+++ b/src/util/message.h
@@ -6,6 +6,8 @@
 #ifndef BITCOIN_UTIL_MESSAGE_H
 #define BITCOIN_UTIL_MESSAGE_H
 
+#include <key.h> // For CKey
+
 #include <string>
 
 extern const std::string strMessageMagic;
@@ -46,4 +48,14 @@ MessageVerificationResult MessageVerify(
     const std::string& signature,
     const std::string& message);
 
+/** Sign a message.
+ * @param[in] privkey Private key to sign with.
+ * @param[in] message The message to sign.
+ * @param[out] signature Signature, base64 encoded, only set if true is returned.
+ * @return true if signing was successful. */
+bool MessageSign(
+    const CKey& privkey,
+    const std::string& message,
+    std::string& signature);
+
 #endif // BITCOIN_UTIL_MESSAGE_H