/* Copyright 2021 The Dapr Authors Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. */ package kafka import ( ctx "context" "crypto/tls" "crypto/x509" "encoding/pem" "fmt" "net/http" "time" "github.com/IBM/sarama" "golang.org/x/oauth2" ccred "golang.org/x/oauth2/clientcredentials" ) type OAuthTokenSource struct { CachedToken oauth2.Token Extensions map[string]string TokenEndpoint oauth2.Endpoint ClientID string ClientSecret string Scopes []string httpClient *http.Client trustedCas []*x509.Certificate skipCaVerify bool } func (m KafkaMetadata) getOAuthTokenSource() *OAuthTokenSource { return &OAuthTokenSource{ TokenEndpoint: oauth2.Endpoint{TokenURL: m.OidcTokenEndpoint}, ClientID: m.OidcClientID, ClientSecret: m.OidcClientSecret, Scopes: m.internalOidcScopes, Extensions: m.internalOidcExtensions, skipCaVerify: m.TLSSkipVerify, } } var tokenRequestTimeout, _ = time.ParseDuration("30s") func (ts *OAuthTokenSource) addCa(caPem string) error { pemBytes := []byte(caPem) block, _ := pem.Decode(pemBytes) if block == nil || block.Type != "CERTIFICATE" { return fmt.Errorf("PEM data not valid or not of a valid type (CERTIFICATE)") } caCert, err := x509.ParseCertificate(block.Bytes) if err != nil { return fmt.Errorf("error parsing PEM certificate: %w", err) } if ts.trustedCas == nil { ts.trustedCas = make([]*x509.Certificate, 0) } ts.trustedCas = append(ts.trustedCas, caCert) return nil } func (ts *OAuthTokenSource) configureClient() { if ts.httpClient != nil { return } tlsConfig := &tls.Config{ MinVersion: tls.VersionTLS12, InsecureSkipVerify: ts.skipCaVerify, //nolint:gosec } if ts.trustedCas != nil { caPool, err := x509.SystemCertPool() if err != nil { caPool = x509.NewCertPool() } for _, c := range ts.trustedCas { caPool.AddCert(c) } tlsConfig.RootCAs = caPool } ts.httpClient = &http.Client{ Transport: &http.Transport{ TLSClientConfig: tlsConfig, }, } } func (ts *OAuthTokenSource) Token() (*sarama.AccessToken, error) { if ts.CachedToken.Valid() { return ts.asSaramaToken(), nil } if ts.TokenEndpoint.TokenURL == "" || ts.ClientID == "" || ts.ClientSecret == "" { return nil, fmt.Errorf("cannot generate token, OAuthTokenSource not fully configured") } oidcCfg := ccred.Config{ClientID: ts.ClientID, ClientSecret: ts.ClientSecret, Scopes: ts.Scopes, TokenURL: ts.TokenEndpoint.TokenURL, AuthStyle: ts.TokenEndpoint.AuthStyle} timeoutCtx, cancel := ctx.WithTimeout(ctx.TODO(), tokenRequestTimeout) defer cancel() ts.configureClient() timeoutCtx = ctx.WithValue(timeoutCtx, oauth2.HTTPClient, ts.httpClient) token, err := oidcCfg.Token(timeoutCtx) if err != nil { return nil, fmt.Errorf("error generating oauth2 token: %w", err) } ts.CachedToken = *token return ts.asSaramaToken(), nil } func (ts *OAuthTokenSource) asSaramaToken() *sarama.AccessToken { return &(sarama.AccessToken{Token: ts.CachedToken.AccessToken, Extensions: ts.Extensions}) }