forgot to add these

cmd/help/email.go

@@ -0,0 +1,40 @@
+package main
+
+import (
+	"fmt"
+
+	"git.tilde.town/tildetown/town/email"
+	"git.tilde.town/tildetown/town/towndb"
+)
+
+const emailText = `hello!
+
+You (hopefully) requested to add a new public key to your tilde.town account.
+
+If you didn't, feel free to ignore this email (or report it to an admin).
+
+If you did, here is your auth code: %s
+
+To use this code, please open a terminal and run:
+
+ssh help@tilde.town
+
+Follow the instructions there to add your new key and restore access to your account.
+
+best,
+~vilmibm`
+
+func sendAuthCodeEmail(ac towndb.AuthCode) error {
+	pw, err := email.LoadPassword()
+	if err != nil {
+		return err
+	}
+
+	body := fmt.Sprintf(emailText, ac.Code)
+
+	mailer := email.NewExternalMailer(pw)
+	return mailer.Send(
+		ac.Email,
+		"Adding a new tilde.town public key",
+		body)
+}

codes/codes.go

@@ -0,0 +1,47 @@
+package codes
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+	"math/big"
+	"strings"
+)
+
+const codeLen = 32
+
+func NewCode(email string) string {
+	charset := "abcdefghijklmnopqrztuvwxyz"
+	charset += strings.ToUpper(charset)
+	charset += "0123456789"
+	charset += "`~!@#$%^&*()-=_+[]{}|;:,./<>?"
+
+	code := []byte{}
+
+	max := big.NewInt(int64(len(charset)))
+	for len(code) < codeLen {
+		ix, err := rand.Int(rand.Reader, max)
+		if err != nil {
+			// TODO this is bad but I'm just kind of hoping it doesn't happen...often
+			panic(err)
+		}
+		code = append(code, charset[ix.Int64()])
+	}
+
+	code = append(code, ' ')
+
+	eb := []byte(email)
+	for x := 0; x < len(eb); x++ {
+		code = append(code, eb[x])
+	}
+
+	return base64.StdEncoding.EncodeToString(code)
+}
+
+func Decode(code string) ([]string, error) {
+	decoded, err := base64.StdEncoding.DecodeString(code)
+	if err != nil {
+		return nil, err
+	}
+
+	return strings.Split(string(decoded), " "), nil
+}