backport FROM <> fix from #291 for bug #283 (#296)

* bump nix go to 1.18

* backport FROM <> fix from #291 for bug #283

pkg/server/smtp/handler.go

@@ -58,7 +58,7 @@ const (
 // as quoted pair and in double quoted strings (?i) makes the regex case insensitive, (?:) is
 // non-grouping sub-match.  Accepts empty angle bracket value in options for 'AUTH=<>'.
 var fromRegex = regexp.MustCompile(
-	`(?i)^FROM:\s*<((?:(?:\\>|[^>])+|"[^"]+"@[^>])+)?>( [\w= ]+(?:=<>)?)?$`)
+	`(?i)^FROM:\s*<((?:(?:\\>|[^>])+|"[^"]+"@[^>])+)?>( ([\w= ]|=<>)+)?$`)
 
 func (s State) String() string {
 	switch s {
@@ -619,7 +619,7 @@ func (s *Session) parseCmd(line string) (cmd string, arg string, ok bool) {
 // The leading space is mandatory.
 func (s *Session) parseArgs(arg string) (args map[string]string, ok bool) {
 	args = make(map[string]string)
-	re := regexp.MustCompile(` (\w+)=(\w+)`)
+	re := regexp.MustCompile(` (\w+)=(\w+|<>)`)
 	pm := re.FindAllStringSubmatch(arg, -1)
 	if pm == nil {
 		s.logger.Warn().Msgf("Failed to parse arg string: %q", arg)

pkg/server/smtp/handler_test.go

@@ -197,6 +197,8 @@ func TestReadyState(t *testing.T) {
 		{"RSET", 250},
 		{"MAIL FROM:<bounces@onmicrosoft.com> SIZE=4096 AUTH=<>", 250},
 		{"RSET", 250},
+		{"MAIL FROM:<b@o.com> SIZE=4096 AUTH=<> BODY=7BIT", 250},
+		{"RSET", 250},
 		{"MAIL FROM:<host!host!user/data@foo.com>", 250},
 		{"RSET", 250},
 		{"MAIL FROM:<\"first last\"@space.com>", 250},

shell.nix

@@ -11,7 +11,7 @@ stdenv.mkDerivation rec {
     elmPackages.elm-json
     elmPackages.elm-language-server
     elmPackages.elm-test
-    go
+    go_1_18
     golint
     nodejs-16_x
     nodePackages.yarn