~mattyw/gomaasapi/fix_for_httptest_build_leak

// Copyright 2013 Canonical Ltd.  This software is licensed under the

// GNU Lesser General Public License version 3 (see the file COPYING).

package gomaasapi

import (

	"crypto/rand"

	"fmt"

	"math/big"

	"net/http"

	"net/url"

	"strconv"

	"strings"

	"time"

)

var nonceMax = big.NewInt(100000000)

func generateNonce() (string, error) {

	randInt, err := rand.Int(rand.Reader, nonceMax)

	if err != nil {

		return "", err

	}

	return strconv.Itoa(int(randInt.Int64())), nil

}

func generateTimestamp() string {

	return strconv.Itoa(int(time.Now().Unix()))

}

type OAuthSigner interface {

	OAuthSign(request *http.Request) error

}

type OAuthToken struct {

	ConsumerKey    string

	ConsumerSecret string

	TokenKey       string

	TokenSecret    string

}

// Trick to ensure *plainTextOAuthSigner implements the OAuthSigner interface.

var _ OAuthSigner = (*plainTextOAuthSigner)(nil)

type plainTextOAuthSigner struct {

	token *OAuthToken

	realm string

}

func NewPlainTestOAuthSigner(token *OAuthToken, realm string) (OAuthSigner, error) {

	return &plainTextOAuthSigner{token, realm}, nil

}

// OAuthSignPLAINTEXT signs the provided request using the OAuth PLAINTEXT

// method: http://oauth.net/core/1.0/#anchor22.

func (signer plainTextOAuthSigner) OAuthSign(request *http.Request) error {

	signature := signer.token.ConsumerSecret + `&` + signer.token.TokenSecret

	nonce, err := generateNonce()

	if err != nil {

		return err

	}

	authData := map[string]string{

		"realm":                  signer.realm,

		"oauth_consumer_key":     signer.token.ConsumerKey,

		"oauth_token":            signer.token.TokenKey,

		"oauth_signature_method": "PLAINTEXT",

		"oauth_signature":        signature,

		"oauth_timestamp":        generateTimestamp(),

		"oauth_nonce":            nonce,

		"oauth_version":          "1.0",

	}

	// Build OAuth header.

	var authHeader []string

	for key, value := range authData {

		authHeader = append(authHeader, fmt.Sprintf(`%s="%s"`, key, url.QueryEscape(value)))

	}

	strHeader := "OAuth " + strings.Join(authHeader, ", ")

	request.Header.Add("Authorization", strHeader)

	return nil

}