diff --git a/src/common/crypto.h b/src/common/crypto.h
index bd3080f..c15bf09 100644
--- a/src/common/crypto.h
+++ b/src/common/crypto.h
@@ -148,7 +148,7 @@ namespace CCrypto
 
 	// Generate a curve25519 key pair for Diffie-Hellman secure key exchange
 	void GenerateKeyExchangeKeyPair( CECKeyExchangePublicKey *pPublicKey, CECKeyExchangePrivateKey *pPrivateKey );
-	void PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKey, const CECKeyExchangePublicKey &remotePublicKey, SHA256Digest_t *pSharedSecretOut );
+	bool PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKey, const CECKeyExchangePublicKey &remotePublicKey, SHA256Digest_t *pSharedSecretOut );
 
 	//
 	// Signing and verification (ed25519 elliptic-curve signature scheme)
diff --git a/src/common/crypto_25519_donna.cpp b/src/common/crypto_25519_donna.cpp
index bff897f..ca02688 100644
--- a/src/common/crypto_25519_donna.cpp
+++ b/src/common/crypto_25519_donna.cpp
@@ -32,7 +32,7 @@ void ed25519_sign_sse2( const unsigned char *m, size_t mlen, const ed25519_secre
 //-----------------------------------------------------------------------------
 // Purpose: Generate a shared secret from two exchanged curve25519 keys
 //-----------------------------------------------------------------------------
-void CCrypto::PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKey, const CECKeyExchangePublicKey &remotePublicKey, SHA256Digest_t *pSharedSecretOut )
+bool CCrypto::PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKey, const CECKeyExchangePublicKey &remotePublicKey, SHA256Digest_t *pSharedSecretOut )
 {
 	Assert( localPrivateKey.IsValid() );
 	Assert( remotePublicKey.IsValid() );
@@ -40,13 +40,15 @@ void CCrypto::PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKe
 	{
 		// Fail securely - generate something that won't be the same on both sides!
 		GenerateRandomBlock( *pSharedSecretOut, sizeof( SHA256Digest_t ) );
-		return;
+		return false;
 	}
 
 	uint8 bufSharedSecret[32];
 	CHOOSE_25519_IMPL( curve25519_donna )( bufSharedSecret, localPrivateKey.GetRawDataPtr(), remotePublicKey.GetRawDataPtr() );
 	GenerateSHA256Digest( bufSharedSecret, sizeof(bufSharedSecret), pSharedSecretOut );
 	SecureZeroMemory( bufSharedSecret, 32 );
+
+	return true;
 }
 
 
diff --git a/src/common/crypto_25519_openssl.cpp b/src/common/crypto_25519_openssl.cpp
index 65e1644..4ec99b5 100644
--- a/src/common/crypto_25519_openssl.cpp
+++ b/src/common/crypto_25519_openssl.cpp
@@ -55,7 +55,7 @@ uint32 CEC25519KeyBase::GetRawData( void *pData ) const
 			}
 			break;
 
-		default;
+		default:
 			AssertMsg( false, "Invalid 25519 key type" );
 			return 0;
 	}
@@ -131,17 +131,17 @@ bool CCrypto::PerformKeyExchange( const CECKeyExchangePrivateKey &localPrivateKe
 	VerifyFatal( EVP_PKEY_derive_init(ctx) == 1 );
 	VerifyFatal( EVP_PKEY_derive_set_peer(ctx, peerkey) == 1 );
 
-	size_t skeylen = sizeof(*pSharedSecretout) );
+	size_t skeylen = sizeof(*pSharedSecretOut);
 	VerifyFatal( EVP_PKEY_derive(ctx, nullptr, &skeylen ) == 1 );
 	AssertFatal( skeylen == sizeof(*pSharedSecretOut) );
 
-	EVP_PKEY_CTX_free(cxt);
+	EVP_PKEY_CTX_free(ctx);
 
 	return true;
 }
 
 
-void CECSigningPrivateKey::GenerateSignature( const void *pData, size_t cbData, CryptoSignature_t *pSignatureOut )
+void CECSigningPrivateKey::GenerateSignature( const void *pData, size_t cbData, CryptoSignature_t *pSignatureOut ) const
 {
 	EVP_PKEY *pkey = (EVP_PKEY*)m_evp_pkey;
 	if ( !pkey )
@@ -156,13 +156,13 @@ void CECSigningPrivateKey::GenerateSignature( const void *pData, size_t cbData,
 	VerifyFatal( EVP_PKEY_sign_init( ctx ) == 1 );
 
 	size_t siglen = sizeof(*pSignatureOut);
-	VerifyFatal( EVP_PKEY_sign( ctx, (unsigned char *)pSignatureOut, &siglen, pData, cbData ) == 1 )
+	VerifyFatal( EVP_PKEY_sign( ctx, (unsigned char *)pSignatureOut, &siglen, (const unsigned char *)pData, cbData ) == 1 );
 	AssertFatal( siglen == sizeof(*pSignatureOut) );
 
-	EVP_PKEY_CTX_free(cxt);
+	EVP_PKEY_CTX_free(ctx);
 }
 
-bool CECSigningPublicKey::VerifySignature( const void *pData, size_t cbData, const CryptoSignature_t &signature )
+bool CECSigningPublicKey::VerifySignature( const void *pData, size_t cbData, const CryptoSignature_t &signature ) const
 {
 	EVP_PKEY *pkey = (EVP_PKEY*)m_evp_pkey;
 	if ( !pkey )
@@ -175,9 +175,9 @@ bool CECSigningPublicKey::VerifySignature( const void *pData, size_t cbData, con
 	VerifyFatal( ctx );
 	VerifyFatal( EVP_PKEY_verify_init( ctx ) == 1 );
 
-	int r = EVP_PKEY_Verify( ctx, (const unsigned char *)signature, sizeof(signature), (const unsigned char *)pData, cbData );
+	int r = EVP_PKEY_verify( ctx, (const unsigned char *)signature, sizeof(signature), (const unsigned char *)pData, cbData );
 
-	EVP_PKEY_CTX_free(cxt);
+	EVP_PKEY_CTX_free(ctx);
 
 	return r == 1;
 }