Age WASM for Uint8Array data

credit.txt

Modified from https://github.com/MarinX/agewasm

decrypt.go

package main

import (
	"bytes"
	"io"
	"strings"
	"syscall/js"

	"filippo.io/age"
)

func Decrypt(this js.Value, args []js.Value) interface{} {
	output := make(map[string]interface{})

	if len(args) != 2 {
		output["error"] = "invalid arguments. expected: identities, input"
		return output
	}

	identities := args[0].String()
	input := make([]byte, args[1].Get("length").Int())
	buff := bytes.NewBuffer(nil)
	ids, err := age.ParseIdentities(strings.NewReader(identities))

	if err != nil {
		output["error"] = err.Error()
		return output
	}

	js.CopyBytesToGo(input, args[1])

	err = decrypt(ids, bytes.NewReader(input), buff)

	if err != nil {
		output["error"] = err.Error()
		return output
	}

	result := js.Global().Get("Uint8Array").New(buff.Len())

	js.CopyBytesToJS(result, buff.Bytes())

	output["output"] = result

	return output
}

// decrypt internal helper
func decrypt(keys []age.Identity, in io.Reader, out io.Writer) error {
	r, err := age.Decrypt(in, keys...)

	if err != nil {
		return err
	}

	if _, err := io.Copy(out, r); err != nil {
		return err
	}

	return nil
}

encrypt.go

package main

import (
	"bytes"
	"io"
	"strings"
	"syscall/js"

	"filippo.io/age"
)

func Encrypt(this js.Value, args []js.Value) interface{} {
	output := make(map[string]interface{})

	if len(args) != 2 {
		output["error"] = "invalid arguments. expected: recipients, input"
		return output
	}

	recipients := args[0].String()
	buff := bytes.NewBuffer(nil)
	input := make([]byte, args[1].Get("length").Int())

	js.CopyBytesToGo(input, args[1])

	ids, err := age.ParseRecipients(strings.NewReader(recipients))

	if err != nil {
		output["error"] = err.Error()
		return output
	}

	err = encrypt(ids, bytes.NewReader(input), buff)

	if err != nil {
		output["error"] = err.Error()
		return output
	}

	result := js.Global().Get("Uint8Array").New(buff.Len())

	js.CopyBytesToJS(result, buff.Bytes())

	output["output"] = result

	return output
}

// encrypt internal helper
func encrypt(recipients []age.Recipient, in io.Reader, out io.Writer) error {
	var a io.WriteCloser

	w, err := age.Encrypt(out, recipients...)

	if err != nil {
		return err
	}

	if _, err := io.Copy(w, in); err != nil {
		return err
	}

	if err := w.Close(); err != nil {
		return err
	}

	if a != nil {
		if err := a.Close(); err != nil {
			return err
		}
	}

	return nil
}