use improved GoTEE RPC API

go.mod

@@ -13,7 +13,7 @@ require (
 	github.com/transparency-dev/armored-witness-common v0.0.0-20240313170947-0b19d0fb8b95
 	github.com/transparency-dev/merkle v0.0.2
 	github.com/transparency-dev/serverless-log v0.0.0-20231215122707-66f68a7705f5
-	github.com/usbarmory/GoTEE v0.0.0-20240215171108-77a6b38432d5
+	github.com/usbarmory/GoTEE v0.0.0-20240314122327-40179239ad36
 	github.com/usbarmory/armory-boot v0.0.0-20230922092524-e66d926bc36c
 	github.com/usbarmory/crucible v0.0.0-20240221192724-1595f2219655
 	github.com/usbarmory/imx-usbnet v0.0.0-20240304152630-ca189bf3b3c1

go.sum

@@ -70,6 +70,8 @@ github.com/u-root/u-root v0.11.0 h1:6gCZLOeRyevw7gbTwMj3fKxnr9+yHFlgF3N7udUVNO8=
 github.com/u-root/u-root v0.11.0/go.mod h1:DBkDtiZyONk9hzVEdB/PWI9B4TxDkElWlVTHseglrZY=
 github.com/usbarmory/GoTEE v0.0.0-20240215171108-77a6b38432d5 h1:XJjhY/+my6o+h4hll02s7rMJrNtI2XqQBBcrx7Lp/2U=
 github.com/usbarmory/GoTEE v0.0.0-20240215171108-77a6b38432d5/go.mod h1:YlZVucqxy/z5QWKerml3Vm5T14UOzZEs2kXfS1nilx8=
+github.com/usbarmory/GoTEE v0.0.0-20240314122327-40179239ad36 h1:rZfhjJpgKuwos6KBdHKouDJmYmpV/FJv4q34eIjtPjw=
+github.com/usbarmory/GoTEE v0.0.0-20240314122327-40179239ad36/go.mod h1:YlZVucqxy/z5QWKerml3Vm5T14UOzZEs2kXfS1nilx8=
 github.com/usbarmory/armory-boot v0.0.0-20230922092524-e66d926bc36c h1:qQL3CljMNrk9TyG8EUvCAPU7/bTVitJMhqlKSNhskis=
 github.com/usbarmory/armory-boot v0.0.0-20230922092524-e66d926bc36c/go.mod h1:20DIzHJntbLDOptGT7TOm8DkT5mL2jRyzPzVXAYVHJ8=
 github.com/usbarmory/crucible v0.0.0-20240221192724-1595f2219655 h1:n3JkWqsxKsbX2SKy+ac3v2rgEmTWfA/s0SC5kHlJGBY=

trusted_os/net.go

@@ -15,7 +15,7 @@
 package main
 
 import (
-	"errors"
+	"fmt"
 	"net"
 
 	"github.com/usbarmory/tamago/soc/nxp/enet"
@@ -71,36 +71,39 @@ func asyncTx() (buf []byte) {
 }
 
 func rxFromApplet(ctx *monitor.ExecCtx) (err error) {
-	var n uint
-
 	select {
 	case buf := <-rxQueue:
-		off := ctx.A1() - ctx.Memory.Start()
-		n = uint(len(buf))
+		off, n, err := ctx.TransferRegion()
 
-		if !(off >= 0 && off < (ctx.Memory.Size()-n)) {
-			return errors.New("invalid offset")
+		if err != nil {
+			return err
 		}
 
-		ctx.Memory.Write(ctx.Memory.Start(), int(off), buf)
+		r := len(buf)
+
+		if r > n {
+			return fmt.Errorf("invalid transfer size (%d > %d)", r, n)
+		}
+
+		ctx.Memory.Write(ctx.Memory.Start(), off, buf)
+		ctx.Ret(r)
 	default:
+		ctx.Ret(0)
 	}
 
-	ctx.Ret(n)
-
 	return
 }
 
 func txFromApplet(ctx *monitor.ExecCtx) (err error) {
-	off := ctx.A1() - ctx.Memory.Start()
-	n := ctx.A2()
-	buf := make([]byte, n)
+	off, n, err := ctx.TransferRegion()
 
-	if !(off >= 0 && off < (ctx.Memory.Size()-uint(n))) {
-		return errors.New("invalid offset")
+	if err != nil {
+		return
 	}
 
-	ctx.Memory.Read(ctx.Memory.Start(), int(off), buf)
+	buf := make([]byte, n)
+
+	ctx.Memory.Read(ctx.Memory.Start(), off, buf)
 
 	switch {
 	case LAN != nil: