upgrade deps; rewrite smtp session

vendor/gitlab.com/etke.cc/go/secgen/README.md

@@ -3,6 +3,7 @@
 Secrets generator, supported types:
 
 * Passwords
+* Random bytes
 * ED25519 SSH keypairs
 
 Simple go environment variables reader, for env-based configs
@@ -10,6 +11,8 @@ Simple go environment variables reader, for env-based configs
 ```go
 // password
 securePassword := secgen.Password(64)
+// base64-encode random bytes (openssl rand -base64 replacement)
+randomBytes := secgen.Base64Bytes(64)
 
 // ssh key
 publicSSHkey, privateSSHkey, err := secgen.Keypair()

vendor/gitlab.com/etke.cc/go/secgen/justfile

@@ -0,0 +1,22 @@
+# show help by default
+default:
+    @just --list --justfile {{ justfile() }}
+
+# update go deps
+update *flags:
+    go get {{flags}} .
+    go mod tidy
+
+# run linter
+lint:
+    golangci-lint run ./...
+
+# automatically fix liter issues
+lintfix:
+    golangci-lint run --fix ./...
+
+# run unit tests
+test:
+    @go test -cover -coverprofile=cover.out -coverpkg=./... -covermode=set ./...
+    @go tool cover -func=cover.out
+    -@rm -f cover.out

vendor/gitlab.com/etke.cc/go/secgen/password.go

@@ -2,6 +2,7 @@ package secgen
 
 import (
 	"crypto/rand"
+	"encoding/base64"
 	"math/big"
 	"strings"
 )
@@ -20,3 +21,10 @@ func Password(length int) string {
 
 	return password.String()
 }
+
+// Base64Bytes generates secure bytes with the given length and returns it as a base64 string
+func Base64Bytes(length int) string {
+	randomBytes := make([]byte, length)
+	rand.Read(randomBytes) //nolint:errcheck // nothing could be done anyway
+	return base64.StdEncoding.EncodeToString(randomBytes)
+}