Adding Initial action (#1)

Co-authored-by: kjuulh <contact@kjuulh.io>
Reviewed-on: kjuulh/kraken#1

internal/services/signer/openpgp.go

@@ -0,0 +1,81 @@
+package signer
+
+import (
+	"context"
+	"errors"
+	"os"
+	"strings"
+
+	"git.front.kjuulh.io/kjuulh/curre"
+	"github.com/ProtonMail/go-crypto/openpgp"
+	"go.uber.org/zap"
+)
+
+type OpenPGP struct {
+	logger     *zap.Logger
+	SigningKey *openpgp.Entity
+	config     *OpenPgpConfig
+}
+
+type OpenPgpConfig struct {
+	PrivateKeyFilePath string
+	PrivateKeyPassword string
+	PrivateKeyIdentity string
+}
+
+func NewOpenPGP(logger *zap.Logger, config *OpenPgpConfig) *OpenPGP {
+	return &OpenPGP{
+		logger: logger,
+		config: config,
+	}
+}
+
+func NewOpenPGPApp(openPGP *OpenPGP) curre.Component {
+	return curre.NewFunctionalComponent(&curre.FunctionalComponent{
+		InitFunc: func(_ *curre.FunctionalComponent, ctx context.Context) error {
+			keyring, err := buildKeyring(ctx, openPGP)
+			if err != nil {
+				openPGP.logger.Panic("could not build keyring", zap.Error(err))
+				return err
+			}
+
+			openPGP.SigningKey = keyring
+
+			return nil
+		},
+		StartFunc: func(fc *curre.FunctionalComponent, ctx context.Context) error {
+			return nil
+		},
+		StopFunc: func(fc *curre.FunctionalComponent, ctx context.Context) error {
+			return nil
+		},
+	})
+}
+
+func buildKeyring(_ context.Context, openPGP *OpenPGP) (*openpgp.Entity, error) {
+	content, err := os.ReadFile(openPGP.config.PrivateKeyFilePath)
+	if err != nil {
+		return nil, err
+	}
+	reader := strings.NewReader(string(content))
+
+	es, err := openpgp.ReadArmoredKeyRing(reader)
+	if err != nil {
+		return nil, err
+	}
+
+	for _, key := range es {
+		for k := range key.Identities {
+			if strings.Contains(k, openPGP.config.PrivateKeyIdentity) {
+				err = key.PrivateKey.Decrypt([]byte(openPGP.config.PrivateKeyPassword))
+				if err != nil {
+					return nil, err
+				}
+				return key, nil
+			}
+		}
+	}
+
+	return nil, errors.New("could not find key matching identity")
+
+}