add working signup + login

web/app/token.go

@@ -0,0 +1,41 @@
+package app
+
+import (
+	"context"
+	"fmt"
+
+	"emperror.dev/errors"
+	"git.sleepycat.moe/sam/mercury/internal/database"
+	"github.com/golang-jwt/jwt/v4"
+)
+
+func (app *App) TokenToJWT(token database.Token) (string, error) {
+	t := jwt.NewWithClaims(jwt.SigningMethodHS256, token.ToClaims())
+
+	return t.SignedString(app.tokenKey)
+}
+
+func (app *App) ParseToken(ctx context.Context, token string) (t database.Token, err error) {
+	parsed, err := jwt.ParseWithClaims(token, &database.TokenClaims{}, func(t *jwt.Token) (interface{}, error) {
+		if _, ok := t.Method.(*jwt.SigningMethodHMAC); !ok {
+			return nil, fmt.Errorf(`unexpected signing method "%v"`, t.Header["alg"])
+		}
+
+		return app.tokenKey, nil
+	})
+
+	if err != nil {
+		return t, errors.Wrap(err, "parsing token")
+	}
+
+	c, ok := parsed.Claims.(*database.TokenClaims)
+	if !ok || !parsed.Valid {
+		return t, fmt.Errorf("unknown claims type %T", parsed.Claims)
+	}
+
+	t, err = app.Token().Get(ctx, c.TokenID)
+	if err != nil {
+		return t, errors.Wrap(err, "getting token from database")
+	}
+	return t, nil
+}