Move trust GraphQL API under complianceportal v1

Relocate the public trust center GraphQL surface, OAuth handlers,
and SPA serving into the compliance portal API package and remove
the legacy trust v1 server tree.

Signed-off-by: Bryan Frimin <bryan@probo.com>

pkg/server/api/complianceportal/v1/oauth_callback_handler.go

@@ -0,0 +1,173 @@
+// Copyright (c) 2026 Probo Inc <hello@probo.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 complianceportal_v1
+
+import (
+	"errors"
+	"net/http"
+
+	"go.gearno.de/kit/httpserver"
+	"go.gearno.de/kit/log"
+	"go.probo.inc/probo/pkg/complianceportal/visitor"
+	"go.probo.inc/probo/pkg/coredata"
+	"go.probo.inc/probo/pkg/iam"
+	"go.probo.inc/probo/pkg/iam/oauth2"
+	"go.probo.inc/probo/pkg/saferedirect"
+	"go.probo.inc/probo/pkg/securecookie"
+	"go.probo.inc/probo/pkg/server/api/authn"
+	"go.probo.inc/probo/pkg/server/api/complianceportal"
+)
+
+var (
+	errNotFound            = errors.New("not found")
+	errInvalidContinueURL  = errors.New("invalid continue URL")
+	errInternal            = errors.New("internal server error")
+	errInvalidOAuthRequest = errors.New("invalid oauth request")
+)
+
+type OAuthCallbackHandler struct {
+	iam           *iam.Service
+	visitor       *visitor.Service
+	sessionCookie *authn.Cookie
+	safeRedirect  *saferedirect.SafeRedirect
+	logger        *log.Logger
+}
+
+func NewOAuthCallbackHandler(
+	iamSvc *iam.Service,
+	visitorSvc *visitor.Service,
+	cookieConfig securecookie.Config,
+	allowedHost saferedirect.AllowedHostFunc,
+	logger *log.Logger,
+) *OAuthCallbackHandler {
+	return &OAuthCallbackHandler{
+		iam:           iamSvc,
+		visitor:       visitorSvc,
+		sessionCookie: authn.NewCookie(&cookieConfig),
+		safeRedirect:  saferedirect.New(allowedHost),
+		logger:        logger,
+	}
+}
+
+func (h *OAuthCallbackHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
+	ctx := r.Context()
+
+	if oauthErr := r.URL.Query().Get("error"); oauthErr != "" {
+		h.logger.WarnCtx(
+			ctx,
+			"oauth callback returned error",
+			log.String("error", oauthErr),
+			log.String("error_description", r.URL.Query().Get("error_description")),
+		)
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+
+		return
+	}
+
+	code := r.URL.Query().Get("code")
+	stateToken := r.URL.Query().Get("state")
+	if code == "" || stateToken == "" {
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+		return
+	}
+
+	state, err := h.visitor.ConsumeOAuthState(ctx, stateToken)
+	if err != nil {
+		h.logger.WarnCtx(ctx, "invalid oauth state", log.Error(err))
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+
+		return
+	}
+
+	portal := complianceportal.CompliancePageFromContext(ctx)
+	portalBaseURL := complianceportal.CompliancePageBaseURLFromContext(ctx)
+	if portal == nil || portalBaseURL == nil {
+		httpserver.RenderError(w, http.StatusNotFound, errNotFound)
+		return
+	}
+
+	clientID, err := complianceportal.CIMDClientIDURL(*portalBaseURL)
+	if err != nil {
+		h.logger.ErrorCtx(ctx, "cannot build cimd client_id", log.Error(err))
+		httpserver.RenderError(w, http.StatusInternalServerError, errInternal)
+
+		return
+	}
+
+	redirectURI, err := complianceportal.OAuthCallbackURL(*portalBaseURL)
+	if err != nil {
+		h.logger.ErrorCtx(ctx, "cannot build oauth redirect_uri", log.Error(err))
+		httpserver.RenderError(w, http.StatusInternalServerError, errInternal)
+
+		return
+	}
+
+	tokenResult, err := h.iam.OAuth2ServerService.ExchangeAuthorizationCode(
+		ctx,
+		clientID,
+		code,
+		redirectURI,
+		state.CodeVerifier,
+	)
+	if err != nil {
+		h.logger.WarnCtx(ctx, "cannot exchange authorization code", log.Error(err))
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+
+		return
+	}
+
+	identityID, err := oauth2.ParseIDTokenIdentity(tokenResult.IDToken, state.Nonce)
+	if err != nil {
+		h.logger.WarnCtx(ctx, "cannot validate id token", log.Error(err))
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+
+		return
+	}
+
+	host, ok := complianceportal.TrustedRequestHost(r)
+	if !ok {
+		httpserver.RenderError(w, http.StatusBadRequest, errInvalidOAuthRequest)
+		return
+	}
+
+	session, err := h.iam.AuthService.OpenRootSession(
+		ctx,
+		identityID,
+		coredata.AuthMethodOIDC,
+		coredata.SessionDataForHost(host),
+	)
+	if err != nil {
+		h.logger.ErrorCtx(ctx, "cannot open session", log.Error(err))
+		httpserver.RenderError(w, http.StatusInternalServerError, errInternal)
+
+		return
+	}
+
+	if _, err := h.visitor.ProvisionPortalMember(ctx, portal.ID, identityID); err != nil {
+		h.logger.ErrorCtx(ctx, "cannot provision portal member", log.Error(err))
+		httpserver.RenderError(w, http.StatusInternalServerError, errInternal)
+
+		return
+	}
+
+	h.sessionCookie.Set(w, session)
+
+	continueURL := state.ContinueURL
+	if continueURL == "" {
+		continueURL = "/"
+	}
+
+	h.safeRedirect.Redirect(w, r, continueURL, "/", http.StatusFound)
+}