Fix Go 1.13 requirement and make compiling SAS optional

crypto/olm/verification.go

@@ -1,15 +1,17 @@
-package olm
+// +build !nosas
 
-import (
-	"crypto/rand"
-	"unsafe"
-)
+package olm
 
 // #cgo LDFLAGS: -lolm -lstdc++
 // #include <olm/olm.h>
 // #include <olm/sas.h>
 import "C"
 
+import (
+	"crypto/rand"
+	"unsafe"
+)
+
 // SAS stores an Olm Short Authentication String (SAS) object.
 type SAS struct {
 	int *C.OlmSAS

crypto/store_test.go

@@ -13,6 +13,7 @@ import (
 	"testing"
 
 	_ "github.com/mattn/go-sqlite3"
+
 	"maunium.net/go/mautrix/crypto/olm"
 	"maunium.net/go/mautrix/id"
 )

crypto/verification.go

@@ -4,6 +4,8 @@
 // License, v. 2.0. If a copy of the MPL was not distributed with this
 // file, You can obtain one at http://mozilla.org/MPL/2.0/.
 
+// +build !nosas
+
 package crypto
 
 import (

crypto/verification_sas_methods.go

@@ -187,7 +187,7 @@ func (VerificationMethodEmoji) GetVerificationSAS(initUserID id.UserID, initDevi
 
 	for i := 0; i < len(emojis); i++ {
 		// take nth group of 6 bits
-		emojiIdx := (sasNum >> (48 - (i+1)*6)) & 0x3F
+		emojiIdx := (sasNum >> uint(48-(i+1)*6)) & 0x3F
 		emoji := allEmojis[emojiIdx]
 		emojis[i] = emoji
 	}

event/encryption.go

@@ -9,7 +9,8 @@ package event
 import (
 	"encoding/json"
 
-	"maunium.net/go/mautrix/crypto/olm"
+	"github.com/pkg/errors"
+
 	"maunium.net/go/mautrix/id"
 )
 
@@ -57,7 +58,7 @@ func (content *EncryptedEventContent) UnmarshalJSON(data []byte) error {
 		return json.Unmarshal(content.Ciphertext, &content.OlmCiphertext)
 	case id.AlgorithmMegolmV1:
 		if len(content.Ciphertext) == 0 || content.Ciphertext[0] != '"' || content.Ciphertext[len(content.Ciphertext)-1] != '"' {
-			return olm.InputNotJSONString
+			return errors.New("input doesn't look like a JSON string")
 		}
 		content.MegolmCiphertext = content.Ciphertext[1 : len(content.Ciphertext)-1]
 	}

version.go

@@ -1,3 +1,3 @@
 package mautrix
 
-const Version = "v0.7.0-rc.2"
+const Version = "v0.7.0-rc.3"