vendor/k8s.io/kubernetes/pkg/credentialprovider/azure/azure_acr_helper.go - cloudstack-kubernetes-provider - Git at Google

 /*
 Copyright 2016 The Kubernetes 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.
 */

 /*
 Copyright 2017 Microsoft Corporation

 MIT License

 Copyright (c) Microsoft Corporation. All rights reserved.

 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal
 in the Software without restriction, including without limitation the rights
 to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
 copies of the Software, and to permit persons to whom the Software is
 furnished to do so, subject to the following conditions:

 The above copyright notice and this permission notice shall be included in all
 copies or substantial portions of the Software.

 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
 OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
 SOFTWARE
 */

 // Source: https://github.com/Azure/acr-docker-credential-helper/blob/a79b541f3ee761f6cc4511863ed41fb038c19464/src/docker-credential-acr/acr_login.go

 package azure

 import (
 	"bytes"
 	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"net/url"
 	"strconv"
 	"strings"
 	"unicode"

 	jwt "github.com/dgrijalva/jwt-go"
 )

 type authDirective struct {
 	service string
 	realm   string
 }

 type accessTokenPayload struct {
 	TenantID string `json:"tid"`
 }

 type acrTokenPayload struct {
 	Expiration int64  `json:"exp"`
 	TenantID   string `json:"tenant"`
 	Credential string `json:"credential"`
 }

 type acrAuthResponse struct {
 	RefreshToken string `json:"refresh_token"`
 }

 // 5 minutes buffer time to allow timeshift between local machine and AAD
 const timeShiftBuffer = 300
 const userAgentHeader = "User-Agent"
 const userAgent = "kubernetes-credentialprovider-acr"

 const dockerTokenLoginUsernameGUID = "00000000-0000-0000-0000-000000000000"

 var client = &http.Client{}

 func receiveChallengeFromLoginServer(serverAddress string) (*authDirective, error) {
 	challengeURL := url.URL{
 		Scheme: "https",
 		Host:   serverAddress,
 		Path:   "v2/",
 	}
 	var err error
 	var r *http.Request
 	r, _ = http.NewRequest("GET", challengeURL.String(), nil)
 	r.Header.Add(userAgentHeader, userAgent)

 	var challenge *http.Response
 	if challenge, err = client.Do(r); err != nil {
 		return nil, fmt.Errorf("Error reaching registry endpoint %s, error: %s", challengeURL.String(), err)
 	}
 	defer challenge.Body.Close()

 	if challenge.StatusCode != 401 {
 		return nil, fmt.Errorf("Registry did not issue a valid AAD challenge, status: %d", challenge.StatusCode)
 	}

 	var authHeader []string
 	var ok bool
 	if authHeader, ok = challenge.Header["Www-Authenticate"]; !ok {
 		return nil, fmt.Errorf("Challenge response does not contain header 'Www-Authenticate'")
 	}

 	if len(authHeader) != 1 {
 		return nil, fmt.Errorf("Registry did not issue a valid AAD challenge, authenticate header [%s]",
 			strings.Join(authHeader, ", "))
 	}

 	authSections := strings.SplitN(authHeader[0], " ", 2)
 	authType := strings.ToLower(authSections[0])
 	var authParams *map[string]string
 	if authParams, err = parseAssignments(authSections[1]); err != nil {
 		return nil, fmt.Errorf("Unable to understand the contents of Www-Authenticate header %s", authSections[1])
 	}

 	// verify headers
 	if !strings.EqualFold("Bearer", authType) {
 		return nil, fmt.Errorf("Www-Authenticate: expected realm: Bearer, actual: %s", authType)
 	}
 	if len((*authParams)["service"]) == 0 {
 		return nil, fmt.Errorf("Www-Authenticate: missing header \"service\"")
 	}
 	if len((*authParams)["realm"]) == 0 {
 		return nil, fmt.Errorf("Www-Authenticate: missing header \"realm\"")
 	}

 	return &authDirective{
 		service: (*authParams)["service"],
 		realm:   (*authParams)["realm"],
 	}, nil
 }

 func parseAcrToken(identityToken string) (token *acrTokenPayload, err error) {
 	tokenSegments := strings.Split(identityToken, ".")
 	if len(tokenSegments) < 2 {
 		return nil, fmt.Errorf("Invalid existing refresh token length: %d", len(tokenSegments))
 	}
 	payloadSegmentEncoded := tokenSegments[1]
 	var payloadBytes []byte
 	if payloadBytes, err = jwt.DecodeSegment(payloadSegmentEncoded); err != nil {
 		return nil, fmt.Errorf("Error decoding payload segment from refresh token, error: %s", err)
 	}
 	var payload acrTokenPayload
 	if err = json.Unmarshal(payloadBytes, &payload); err != nil {
 		return nil, fmt.Errorf("Error unmarshalling acr payload, error: %s", err)
 	}
 	return &payload, nil
 }

 func performTokenExchange(
 	serverAddress string,
 	directive *authDirective,
 	tenant string,
 	accessToken string) (string, error) {
 	var err error
 	data := url.Values{
 		"service":       []string{directive.service},
 		"grant_type":    []string{"access_token_refresh_token"},
 		"access_token":  []string{accessToken},
 		"refresh_token": []string{accessToken},
 		"tenant":        []string{tenant},
 	}

 	var realmURL *url.URL
 	if realmURL, err = url.Parse(directive.realm); err != nil {
 		return "", fmt.Errorf("Www-Authenticate: invalid realm %s", directive.realm)
 	}
 	authEndpoint := fmt.Sprintf("%s://%s/oauth2/exchange", realmURL.Scheme, realmURL.Host)

 	datac := data.Encode()
 	var r *http.Request
 	r, _ = http.NewRequest("POST", authEndpoint, bytes.NewBufferString(datac))
 	r.Header.Add(userAgentHeader, userAgent)
 	r.Header.Add("Content-Type", "application/x-www-form-urlencoded")
 	r.Header.Add("Content-Length", strconv.Itoa(len(datac)))

 	var exchange *http.Response
 	if exchange, err = client.Do(r); err != nil {
 		return "", fmt.Errorf("Www-Authenticate: failed to reach auth url %s", authEndpoint)
 	}

 	defer exchange.Body.Close()
 	if exchange.StatusCode != 200 {
 		return "", fmt.Errorf("Www-Authenticate: auth url %s responded with status code %d", authEndpoint, exchange.StatusCode)
 	}

 	var content []byte
 	if content, err = ioutil.ReadAll(exchange.Body); err != nil {
 		return "", fmt.Errorf("Www-Authenticate: error reading response from %s", authEndpoint)
 	}

 	var authResp acrAuthResponse
 	if err = json.Unmarshal(content, &authResp); err != nil {
 		return "", fmt.Errorf("Www-Authenticate: unable to read response %s", content)
 	}

 	return authResp.RefreshToken, nil
 }

 // Try and parse a string of assignments in the form of:
 // key1 = value1, key2 = "value 2", key3 = ""
 // Note: this method and handle quotes but does not handle escaping of quotes
 func parseAssignments(statements string) (*map[string]string, error) {
 	var cursor int
 	result := make(map[string]string)
 	var errorMsg = fmt.Errorf("malformed header value: %s", statements)
 	for {
 		// parse key
 		equalIndex := nextOccurrence(statements, cursor, "=")
 		if equalIndex == -1 {
 			return nil, errorMsg
 		}
 		key := strings.TrimSpace(statements[cursor:equalIndex])

 		// parse value
 		cursor = nextNoneSpace(statements, equalIndex+1)
 		if cursor == -1 {
 			return nil, errorMsg
 		}
 		// case: value is quoted
 		if statements[cursor] == '"' {
 			cursor = cursor + 1
 			// like I said, not handling escapes, but this will skip any comma that's
 			// within the quotes which is somewhat more likely
 			closeQuoteIndex := nextOccurrence(statements, cursor, "\"")
 			if closeQuoteIndex == -1 {
 				return nil, errorMsg
 			}
 			value := statements[cursor:closeQuoteIndex]
 			result[key] = value

 			commaIndex := nextNoneSpace(statements, closeQuoteIndex+1)
 			if commaIndex == -1 {
 				// no more comma, done
 				return &result, nil
 			} else if statements[commaIndex] != ',' {
 				// expect comma immediately after close quote
 				return nil, errorMsg
 			} else {
 				cursor = commaIndex + 1
 			}
 		} else {
 			commaIndex := nextOccurrence(statements, cursor, ",")
 			endStatements := commaIndex == -1
 			var untrimmed string
 			if endStatements {
 				untrimmed = statements[cursor:commaIndex]
 			} else {
 				untrimmed = statements[cursor:]
 			}
 			value := strings.TrimSpace(untrimmed)

 			if len(value) == 0 {
 				// disallow empty value without quote
 				return nil, errorMsg
 			}

 			result[key] = value

 			if endStatements {
 				return &result, nil
 			}
 			cursor = commaIndex + 1
 		}
 	}
 }

 func nextOccurrence(str string, start int, sep string) int {
 	if start >= len(str) {
 		return -1
 	}
 	offset := strings.Index(str[start:], sep)
 	if offset == -1 {
 		return -1
 	}
 	return offset + start
 }

 func nextNoneSpace(str string, start int) int {
 	if start >= len(str) {
 		return -1
 	}
 	offset := strings.IndexFunc(str[start:], func(c rune) bool { return !unicode.IsSpace(c) })
 	if offset == -1 {
 		return -1
 	}
 	return offset + start
 }
	/*
	Copyright 2016 The Kubernetes 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.
	*/

	/*
	Copyright 2017 Microsoft Corporation

	MIT License

	Copyright (c) Microsoft Corporation. All rights reserved.

	Permission is hereby granted, free of charge, to any person obtaining a copy
	of this software and associated documentation files (the "Software"), to deal
	in the Software without restriction, including without limitation the rights
	to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
	copies of the Software, and to permit persons to whom the Software is
	furnished to do so, subject to the following conditions:

	The above copyright notice and this permission notice shall be included in all
	copies or substantial portions of the Software.

	THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
	IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
	FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
	AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
	LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
	OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
	SOFTWARE
	*/

	// Source: https://github.com/Azure/acr-docker-credential-helper/blob/a79b541f3ee761f6cc4511863ed41fb038c19464/src/docker-credential-acr/acr_login.go

	package azure

	import (
	"bytes"
	"encoding/json"
	"fmt"
	"io/ioutil"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"unicode"

	jwt "github.com/dgrijalva/jwt-go"
	)

	type authDirective struct {
	service string
	realm string
	}

	type accessTokenPayload struct {
	TenantID string `json:"tid"`
	}

	type acrTokenPayload struct {
	Expiration int64 `json:"exp"`
	TenantID string `json:"tenant"`
	Credential string `json:"credential"`
	}

	type acrAuthResponse struct {
	RefreshToken string `json:"refresh_token"`
	}

	// 5 minutes buffer time to allow timeshift between local machine and AAD
	const timeShiftBuffer = 300
	const userAgentHeader = "User-Agent"
	const userAgent = "kubernetes-credentialprovider-acr"

	const dockerTokenLoginUsernameGUID = "00000000-0000-0000-0000-000000000000"

	var client = &http.Client{}

	func receiveChallengeFromLoginServer(serverAddress string) (*authDirective, error) {
	challengeURL := url.URL{
	Scheme: "https",
	Host: serverAddress,
	Path: "v2/",
	}
	var err error
	var r *http.Request
	r, _ = http.NewRequest("GET", challengeURL.String(), nil)
	r.Header.Add(userAgentHeader, userAgent)

	var challenge *http.Response
	if challenge, err = client.Do(r); err != nil {
	return nil, fmt.Errorf("Error reaching registry endpoint %s, error: %s", challengeURL.String(), err)
	}
	defer challenge.Body.Close()

	if challenge.StatusCode != 401 {
	return nil, fmt.Errorf("Registry did not issue a valid AAD challenge, status: %d", challenge.StatusCode)
	}

	var authHeader []string
	var ok bool
	if authHeader, ok = challenge.Header["Www-Authenticate"]; !ok {
	return nil, fmt.Errorf("Challenge response does not contain header 'Www-Authenticate'")
	}

	if len(authHeader) != 1 {
	return nil, fmt.Errorf("Registry did not issue a valid AAD challenge, authenticate header [%s]",
	strings.Join(authHeader, ", "))
	}

	authSections := strings.SplitN(authHeader[0], " ", 2)
	authType := strings.ToLower(authSections[0])
	var authParams *map[string]string
	if authParams, err = parseAssignments(authSections[1]); err != nil {
	return nil, fmt.Errorf("Unable to understand the contents of Www-Authenticate header %s", authSections[1])
	}

	// verify headers
	if !strings.EqualFold("Bearer", authType) {
	return nil, fmt.Errorf("Www-Authenticate: expected realm: Bearer, actual: %s", authType)
	}
	if len((*authParams)["service"]) == 0 {
	return nil, fmt.Errorf("Www-Authenticate: missing header \"service\"")
	}
	if len((*authParams)["realm"]) == 0 {
	return nil, fmt.Errorf("Www-Authenticate: missing header \"realm\"")
	}

	return &authDirective{
	service: (*authParams)["service"],
	realm: (*authParams)["realm"],
	}, nil
	}

	func parseAcrToken(identityToken string) (token *acrTokenPayload, err error) {
	tokenSegments := strings.Split(identityToken, ".")
	if len(tokenSegments) < 2 {
	return nil, fmt.Errorf("Invalid existing refresh token length: %d", len(tokenSegments))
	}
	payloadSegmentEncoded := tokenSegments[1]
	var payloadBytes []byte
	if payloadBytes, err = jwt.DecodeSegment(payloadSegmentEncoded); err != nil {
	return nil, fmt.Errorf("Error decoding payload segment from refresh token, error: %s", err)
	}
	var payload acrTokenPayload
	if err = json.Unmarshal(payloadBytes, &payload); err != nil {
	return nil, fmt.Errorf("Error unmarshalling acr payload, error: %s", err)
	}
	return &payload, nil
	}

	func performTokenExchange(
	serverAddress string,
	directive *authDirective,
	tenant string,
	accessToken string) (string, error) {
	var err error
	data := url.Values{
	"service": []string{directive.service},
	"grant_type": []string{"access_token_refresh_token"},
	"access_token": []string{accessToken},
	"refresh_token": []string{accessToken},
	"tenant": []string{tenant},
	}

	var realmURL *url.URL
	if realmURL, err = url.Parse(directive.realm); err != nil {
	return "", fmt.Errorf("Www-Authenticate: invalid realm %s", directive.realm)
	}
	authEndpoint := fmt.Sprintf("%s://%s/oauth2/exchange", realmURL.Scheme, realmURL.Host)

	datac := data.Encode()
	var r *http.Request
	r, _ = http.NewRequest("POST", authEndpoint, bytes.NewBufferString(datac))
	r.Header.Add(userAgentHeader, userAgent)
	r.Header.Add("Content-Type", "application/x-www-form-urlencoded")
	r.Header.Add("Content-Length", strconv.Itoa(len(datac)))

	var exchange *http.Response
	if exchange, err = client.Do(r); err != nil {
	return "", fmt.Errorf("Www-Authenticate: failed to reach auth url %s", authEndpoint)
	}

	defer exchange.Body.Close()
	if exchange.StatusCode != 200 {
	return "", fmt.Errorf("Www-Authenticate: auth url %s responded with status code %d", authEndpoint, exchange.StatusCode)
	}

	var content []byte
	if content, err = ioutil.ReadAll(exchange.Body); err != nil {
	return "", fmt.Errorf("Www-Authenticate: error reading response from %s", authEndpoint)
	}

	var authResp acrAuthResponse
	if err = json.Unmarshal(content, &authResp); err != nil {
	return "", fmt.Errorf("Www-Authenticate: unable to read response %s", content)
	}

	return authResp.RefreshToken, nil
	}

	// Try and parse a string of assignments in the form of:
	// key1 = value1, key2 = "value 2", key3 = ""
	// Note: this method and handle quotes but does not handle escaping of quotes
	func parseAssignments(statements string) (*map[string]string, error) {
	var cursor int
	result := make(map[string]string)
	var errorMsg = fmt.Errorf("malformed header value: %s", statements)
	for {
	// parse key
	equalIndex := nextOccurrence(statements, cursor, "=")
	if equalIndex == -1 {
	return nil, errorMsg
	}
	key := strings.TrimSpace(statements[cursor:equalIndex])

	// parse value
	cursor = nextNoneSpace(statements, equalIndex+1)
	if cursor == -1 {
	return nil, errorMsg
	}
	// case: value is quoted
	if statements[cursor] == '"' {
	cursor = cursor + 1
	// like I said, not handling escapes, but this will skip any comma that's
	// within the quotes which is somewhat more likely
	closeQuoteIndex := nextOccurrence(statements, cursor, "\"")
	if closeQuoteIndex == -1 {
	return nil, errorMsg
	}
	value := statements[cursor:closeQuoteIndex]
	result[key] = value

	commaIndex := nextNoneSpace(statements, closeQuoteIndex+1)
	if commaIndex == -1 {
	// no more comma, done
	return &result, nil
	} else if statements[commaIndex] != ',' {
	// expect comma immediately after close quote
	return nil, errorMsg
	} else {
	cursor = commaIndex + 1
	}
	} else {
	commaIndex := nextOccurrence(statements, cursor, ",")
	endStatements := commaIndex == -1
	var untrimmed string
	if endStatements {
	untrimmed = statements[cursor:commaIndex]
	} else {
	untrimmed = statements[cursor:]
	}
	value := strings.TrimSpace(untrimmed)

	if len(value) == 0 {
	// disallow empty value without quote
	return nil, errorMsg
	}

	result[key] = value

	if endStatements {
	return &result, nil
	}
	cursor = commaIndex + 1
	}
	}
	}

	func nextOccurrence(str string, start int, sep string) int {
	if start >= len(str) {
	return -1
	}
	offset := strings.Index(str[start:], sep)
	if offset == -1 {
	return -1
	}
	return offset + start
	}

	func nextNoneSpace(str string, start int) int {
	if start >= len(str) {
	return -1
	}
	offset := strings.IndexFunc(str[start:], func(c rune) bool { return !unicode.IsSpace(c) })
	if offset == -1 {
	return -1
	}
	return offset + start
	}