Refactored, reorganized, fixed issues, and implemented functionality

internal/oidc/oidc.go

@@ -1,8 +1,13 @@
 package oidc
 
 import (
+	"bytes"
 	"context"
+	"encoding/json"
 	"fmt"
+	"io"
+	"net/http"
+	"os"
 
 	"github.com/lestrrat-go/jwx/jwk"
 )
@@ -15,7 +20,7 @@ type IdentityProvider struct {
 }
 
 type Endpoints struct {
-	Authorize     string `json:"authorize_endpoint" yaml:"authorize"`
+	Authorization string `json:"authorization_endpoint" yaml:"authorization"`
 	Token         string `json:"token_endpoint" yaml:"token"`
 	Revocation    string `json:"revocation_endpoint" yaml:"revocation"`
 	Introspection string `json:"introspection_endpoint" yaml:"introspection"`
@@ -36,7 +41,7 @@ type Supported struct {
 func NewIdentityProvider() *IdentityProvider {
 	p := &IdentityProvider{Issuer: "127.0.0.1"}
 	p.Endpoints = Endpoints{
-		Authorize:     p.Issuer + "/oauth/authorize",
+		Authorization: p.Issuer + "/oauth/authorize",
 		Token:         p.Issuer + "/oauth/token",
 		Revocation:    p.Issuer + "/oauth/revocation",
 		Introspection: p.Issuer + "/oauth/introspect",
@@ -69,12 +74,70 @@ func NewIdentityProvider() *IdentityProvider {
 	return p
 }
 
-func (p *IdentityProvider) FetchServerConfig(url string) {
+func (p *IdentityProvider) ParseServerConfig(data []byte) error {
+	// parse JSON into IdentityProvider fields
+	var ep Endpoints
+	var s Supported
+	var e error
+	epErr := json.Unmarshal(data, &ep)
+	if epErr != nil {
+		e = fmt.Errorf("%v", epErr)
+	}
+	sErr := json.Unmarshal(data, &s)
+	if sErr != nil {
+		e = fmt.Errorf("%v %v", e, sErr)
+	}
+	err := json.Unmarshal(data, p)
+	if err != nil {
+		e = fmt.Errorf("%v %v", e, err)
+	}
+	p.Endpoints = ep
+	p.Supported = s
+	return e
+}
+
+func (p *IdentityProvider) LoadServerConfig(path string) error {
+	// load server config from local file i
+	data, err := os.ReadFile(path)
+	if err != nil {
+		return fmt.Errorf("failed to read server config: %v", err)
+	}
+	err = p.ParseServerConfig(data)
+	if err != nil {
+		return fmt.Errorf("failed to parse server config: %v", err)
+	}
+	return nil
+}
+
+func (p *IdentityProvider) FetchServerConfig(url string) error {
 	// make a request to a server's openid-configuration
+	req, err := http.NewRequest("GET", url, bytes.NewBuffer([]byte{}))
+	if err != nil {
+		return fmt.Errorf("failed to create a new request: %v", err)
+	}
+
+	client := &http.Client{}
+	res, err := client.Do(req)
+	if err != nil {
+		return fmt.Errorf("failed to do request: %v", err)
+	}
+
+	body, err := io.ReadAll(res.Body)
+	if err != nil {
+		return fmt.Errorf("failed to read response body: %v", err)
+	}
+	err = p.ParseServerConfig(body)
+	if err != nil {
+		return fmt.Errorf("failed to parse server config: %v", err)
+	}
+	return nil
 }
 
 func (p *IdentityProvider) FetchJwk(url string) error {
-	//
+	if url == "" {
+		url = p.Endpoints.Jwks
+	}
+	// fetch JWKS from identity provider
 	ctx, cancel := context.WithCancel(context.Background())
 	defer cancel()
 	set, err := jwk.Fetch(ctx, url)