Extract authn & authz utils

Signed-off-by: Émile Ré <emile@getprobo.com>

pkg/server/api/authn/session_middleware.go

@@ -0,0 +1,117 @@
+// Copyright (c) 2025 Probo Inc <hello@getprobo.com>.
+//
+// Permission to use, copy, modify, and/or distribute this software for any
+// purpose with or without fee is hereby granted, provided that the above
+// copyright notice and this permission notice appear in all copies.
+//
+// THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+// REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+// AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+// INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+// LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+// OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+// PERFORMANCE OF THIS SOFTWARE.
+
+package authn
+
+import (
+	"errors"
+	"fmt"
+	"net"
+	"net/http"
+
+	"github.com/99designs/gqlgen/graphql"
+	"github.com/vektah/gqlparser/v2/gqlerror"
+	"go.gearno.de/kit/httpserver"
+	"go.probo.inc/probo/pkg/gid"
+	"go.probo.inc/probo/pkg/iam"
+	"go.probo.inc/probo/pkg/securecookie"
+	"go.probo.inc/probo/pkg/server/gqlutils"
+)
+
+func NewSessionMiddleware(svc *iam.Service, cookieConfig securecookie.Config) func(next http.Handler) http.Handler {
+	return func(next http.Handler) http.Handler {
+		return http.HandlerFunc(
+			func(w http.ResponseWriter, r *http.Request) {
+				ctx := r.Context()
+
+				cookieValue, err := securecookie.Get(r, cookieConfig)
+				if err != nil {
+					next.ServeHTTP(w, r)
+					return
+				}
+
+				sessionID, err := gid.ParseGID(cookieValue)
+				if err != nil {
+					securecookie.Clear(w, cookieConfig)
+					next.ServeHTTP(w, r)
+					return
+				}
+
+				apiKey := APIKeyFromContext(ctx)
+				if sessionID != gid.Nil && apiKey != nil {
+					httpserver.RenderJSON(
+						w,
+						http.StatusUnauthorized,
+						&graphql.Response{
+							Errors: gqlerror.List{
+								gqlutils.Conflictf(ctx, "session authentication cannot be used with API key authentication"),
+							},
+						},
+					)
+					return
+				}
+
+				session, err := svc.SessionService.GetSession(ctx, sessionID)
+				if err != nil {
+					var errSessionNotFound *iam.ErrSessionNotFound
+					var errSessionExpired *iam.ErrSessionExpired
+
+					if errors.As(err, &errSessionNotFound) || errors.As(err, &errSessionExpired) {
+						securecookie.Clear(w, cookieConfig)
+						next.ServeHTTP(w, r)
+						return
+					}
+
+					panic(fmt.Errorf("cannot get session: %w", err))
+				}
+
+				identity, err := svc.AccountService.GetIdentity(ctx, session.IdentityID)
+				if err != nil {
+					var errIdentityNotFound *iam.ErrIdentityNotFound
+					if errors.As(err, &errIdentityNotFound) {
+						securecookie.Clear(w, cookieConfig)
+						next.ServeHTTP(w, r)
+						return
+					}
+
+					panic(fmt.Errorf("cannot get identity: %w", err))
+				}
+
+				userAgent := r.UserAgent()
+				// TODO: will work well when no layer 7 proxy is in front of the server
+				var ipAddress net.IP
+				if host, _, err := net.SplitHostPort(r.RemoteAddr); err == nil {
+					ipAddress = net.ParseIP(host)
+				} else {
+					ipAddress = net.ParseIP(r.RemoteAddr)
+				}
+
+				err = svc.SessionService.UpdateSessionInfo(ctx, session.ID, userAgent, ipAddress)
+				if err != nil {
+					panic(fmt.Errorf("cannot update session info: %w", err))
+				}
+
+				ctx = ContextWithSession(ctx, session)
+				ctx = ContextWithIdentity(ctx, identity)
+
+				next.ServeHTTP(w, r.WithContext(ctx))
+
+				err = svc.SessionService.UpdateSessionData(ctx, session.ID, session.Data)
+				if err != nil {
+					panic(fmt.Errorf("cannot update session data: %w", err))
+				}
+			},
+		)
+	}
+}