From 10d671956a6f0e64d10340d313a2b115f5093dd3 Mon Sep 17 00:00:00 2001
From: Livio Amstutz <livio.a@gmail.com>
Date: Thu, 28 Nov 2019 08:56:53 +0100
Subject: [PATCH] some error handling

---
 pkg/op/default_op.go   | 10 ++--------
 pkg/op/error.go        | 10 ++++++++--
 pkg/op/tokenrequest.go | 33 ++++++++++++++++++++++-----------
 3 files changed, 32 insertions(+), 21 deletions(-)

diff --git a/pkg/op/default_op.go b/pkg/op/default_op.go
index e80a129..7060d18 100644
--- a/pkg/op/default_op.go
+++ b/pkg/op/default_op.go
@@ -1,7 +1,6 @@
 package op
 
 import (
-	"encoding/json"
 	"errors"
 	"net/http"
 	"net/url"
@@ -234,16 +233,11 @@ func (p *DefaultOP) HandleAuthorizeCallback(w http.ResponseWriter, r *http.Reque
 func (p *DefaultOP) HandleExchange(w http.ResponseWriter, r *http.Request) {
 	reqType := r.FormValue("grant_type")
 	if reqType == "" {
-		ExchangeRequestError(w, r, nil, ErrInvalidRequest("grant_type missing"))
+		ExchangeRequestError(w, r, ErrInvalidRequest("grant_type missing"))
 		return
 	}
 	if reqType == string(oidc.GrantTypeCode) {
-		token, err := CodeExchange(w, r, p.storage, p.decoder)
-		if err != nil {
-
-		}
-		b, _ := json.Marshal(token)
-		w.Write(b)
+		CodeExchange(w, r, p.storage, p.decoder)
 		return
 	}
 	p.handleTokenExchange(w, r)
diff --git a/pkg/op/error.go b/pkg/op/error.go
index 1aacc27..d794518 100644
--- a/pkg/op/error.go
+++ b/pkg/op/error.go
@@ -4,6 +4,7 @@ import (
 	"net/http"
 
 	"github.com/caos/oidc/pkg/oidc"
+	"github.com/caos/oidc/pkg/utils"
 )
 
 const (
@@ -47,8 +48,13 @@ func AuthRequestError(w http.ResponseWriter, r *http.Request, authReq *oidc.Auth
 	http.Redirect(w, r, url, http.StatusFound)
 }
 
-func ExchangeRequestError(w http.ResponseWriter, r *http.Request, exchangeReq *oidc.AuthRequest, err error) {
-
+func ExchangeRequestError(w http.ResponseWriter, r *http.Request, err error) {
+	e, ok := err.(*OAuthError)
+	if !ok {
+		e.ErrorType = ServerError
+		e.Description = err.Error()
+	}
+	utils.MarshalJSON(w, e)
 }
 
 type OAuthError struct {
diff --git a/pkg/op/tokenrequest.go b/pkg/op/tokenrequest.go
index 6f9664e..74594cb 100644
--- a/pkg/op/tokenrequest.go
+++ b/pkg/op/tokenrequest.go
@@ -5,6 +5,8 @@ import (
 	"net/http"
 	"time"
 
+	"github.com/caos/oidc/pkg/utils"
+
 	"github.com/gorilla/schema"
 
 	"github.com/caos/oidc/pkg/oidc"
@@ -21,46 +23,55 @@ import (
 // 	return ParseTokenExchangeRequest(w, r)
 // }
 
-func CodeExchange(w http.ResponseWriter, r *http.Request, storage Storage, decoder *schema.Decoder) (*oidc.AccessTokenResponse, error) {
+func CodeExchange(w http.ResponseWriter, r *http.Request, storage Storage, decoder *schema.Decoder) {
 	err := r.ParseForm()
 	if err != nil {
-		return nil, errors.New("Unimplemented") //TODO: impl
+		ExchangeRequestError(w, r, ErrInvalidRequest("error parsing form"))
+		return
 	}
 	tokenReq := new(oidc.AccessTokenRequest)
 
 	err = decoder.Decode(tokenReq, r.Form)
 	if err != nil {
-		return nil, err
+		ExchangeRequestError(w, r, ErrInvalidRequest("error decoding form"))
+		return
 	}
 	if tokenReq.Code == "" {
-		return nil, errors.New("code missing")
+		ExchangeRequestError(w, r, ErrInvalidRequest("code missing"))
+		return
 	}
 
 	client, err := AuthorizeClient(r, tokenReq, storage)
 	if err != nil {
-		return nil, err
+		ExchangeRequestError(w, r, err)
+		return
 	}
 	authReq, err := storage.AuthRequestByCode(client, tokenReq.Code, tokenReq.RedirectURI)
 	if err != nil {
-
+		ExchangeRequestError(w, r, err)
+		return
 	}
 	err = storage.DeleteAuthRequestAndCode(authReq.ID, tokenReq.Code)
 	if err != nil {
-
+		ExchangeRequestError(w, r, err)
+		return
 	}
 	accessToken, err := CreateAccessToken()
 	if err != nil {
-
+		ExchangeRequestError(w, r, err)
+		return
 	}
 	idToken, err := CreateIDToken(nil, "", nil)
 	if err != nil {
-
+		ExchangeRequestError(w, r, err)
+		return
 	}
 
-	return &oidc.AccessTokenResponse{
+	resp := &oidc.AccessTokenResponse{
 		AccessToken: accessToken,
 		IDToken:     idToken,
-	}, nil
+	}
+	utils.MarshalJSON(w, resp)
 }
 
 func CreateAccessToken() (string, error) {