auth: Add KbdintResult definition to define result values explicitly

kbdint result vfunc may return various values, so use an enum to make it
clearer what each result means without having to dig into the struct
documentation.

Origin: https://github.com/openssh/openssh-portable/pull/452

Gbp-Pq: Name auth-Add-KbdintResult-definition-to-define-result-values-.patch

auth-bsdauth.c

@@ -111,7 +111,7 @@ bsdauth_respond(void *ctx, u_int numresponses, char **responses)
 	authctxt->as = NULL;
 	debug3("bsdauth_respond: <%s> = <%d>", responses[0], authok);
 
-	return (authok == 0) ? -1 : 0;
+	return (authok == 0) ? KbdintResultFailure : KbdintResultSuccess;
 }
 
 static void

auth-pam.c

@@ -990,15 +990,15 @@ sshpam_respond(void *ctx, u_int num, char **resp)
 	switch (ctxt->pam_done) {
 	case 1:
 		sshpam_authenticated = 1;
-		return (0);
+		return KbdintResultSuccess;
 	case 0:
 		break;
 	default:
-		return (-1);
+		return KbdintResultFailure;
 	}
 	if (num != 1) {
 		error("PAM: expected one response, got %u", num);
-		return (-1);
+		return KbdintResultFailure;
 	}
 	if ((buffer = sshbuf_new()) == NULL)
 		fatal("%s: sshbuf_new failed", __func__);
@@ -1015,10 +1015,10 @@ sshpam_respond(void *ctx, u_int num, char **resp)
 	}
 	if (ssh_msg_send(ctxt->pam_psock, PAM_AUTHTOK, buffer) == -1) {
 		sshbuf_free(buffer);
-		return (-1);
+		return KbdintResultFailure;
 	}
 	sshbuf_free(buffer);
-	return (1);
+	return KbdintResultAgain;
 }
 
 static void

auth.h

@@ -51,6 +51,7 @@ struct sshauthopt;
 typedef struct Authctxt Authctxt;
 typedef struct Authmethod Authmethod;
 typedef struct KbdintDevice KbdintDevice;
+typedef int KbdintResult;
 
 struct Authctxt {
 	sig_atomic_t	 success;
@@ -112,6 +113,10 @@ struct Authmethod {
 	int	*enabled;
 };
 
+#define KbdintResultFailure -1
+#define KbdintResultSuccess 0
+#define KbdintResultAgain 1
+
 /*
  * Keyboard interactive device:
  * init_ctx	returns: non NULL upon success

auth2-chall.c

@@ -331,11 +331,11 @@ input_userauth_info_response(int type, u_int32_t seq, struct ssh *ssh)
 	free(response);
 
 	switch (res) {
-	case 0:
+	case KbdintResultSuccess:
 		/* Success! */
 		authenticated = authctxt->valid ? 1 : 0;
 		break;
-	case 1:
+	case KbdintResultAgain:
 		/* Authentication needs further interaction */
 		if (send_userauth_info_request(ssh) == 1)
 			authctxt->postponed = 1;