Merge lp:~vds/usso/better_interface into lp:usso

[Vincenzo Di Somma]

Refactoring the interface and handling errors a little better. There are no unit tests for the main interface, but the example shows that they work as expected. Tests will be added in a following branch, if we decide to spend more time on this project.

[lp:~vds/usso/better_interface]

18. By Vincenzo Di Somma on 2013-01-29

Fixing comments and little code style.

19. By Vincenzo Di Somma on 2013-01-29

Commented tests.

20. By Vincenzo Di Somma on 2013-01-29

Commented tests in a more reasonable way thanks to gmb.

Unmerged revisions

=== added file 'COPYING'
--- COPYING	1970-01-01 00:00:00 +0000
+++ COPYING	2013-01-25 16:44:31 +0000
@@ -0,0 +1,674 @@
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+APPLICABLE LAW.  EXCEPT WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT
+HOLDERS AND/OR OTHER PARTIES PROVIDE THE PROGRAM "AS IS" WITHOUT WARRANTY
+OF ANY KIND, EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO,
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+IS WITH YOU.  SHOULD THE PROGRAM PROVE DEFECTIVE, YOU ASSUME THE COST OF
+ALL NECESSARY SERVICING, REPAIR OR CORRECTION.
+
+  16. Limitation of Liability.
+
+  IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
+WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MODIFIES AND/OR CONVEYS
+THE PROGRAM AS PERMITTED ABOVE, BE LIABLE TO YOU FOR DAMAGES, INCLUDING ANY
+GENERAL, SPECIAL, INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING OUT OF THE
+USE OR INABILITY TO USE THE PROGRAM (INCLUDING BUT NOT LIMITED TO LOSS OF
+DATA OR DATA BEING RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD
+PARTIES OR A FAILURE OF THE PROGRAM TO OPERATE WITH ANY OTHER PROGRAMS),
+EVEN IF SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF
+SUCH DAMAGES.
+
+  17. Interpretation of Sections 15 and 16.
+
+  If the disclaimer of warranty and limitation of liability provided
+above cannot be given local legal effect according to their terms,
+reviewing courts shall apply local law that most closely approximates
+an absolute waiver of all civil liability in connection with the
+Program, unless a warranty or assumption of liability accompanies a
+copy of the Program in return for a fee.
+
+                     END OF TERMS AND CONDITIONS
+
+            How to Apply These Terms to Your New Programs
+
+  If you develop a new program, and you want it to be of the greatest
+possible use to the public, the best way to achieve this is to make it
+free software which everyone can redistribute and change under these terms.
+
+  To do so, attach the following notices to the program.  It is safest
+to attach them to the start of each source file to most effectively
+state the exclusion of warranty; and each file should have at least
+the "copyright" line and a pointer to where the full notice is found.
+
+    <one line to give the program's name and a brief idea of what it does.>
+    Copyright (C) <year>  <name of author>
+
+    This program is free software: you can redistribute it and/or modify
+    it under the terms of the GNU General Public License as published by
+    the Free Software Foundation, either version 3 of the License, or
+    (at your option) any later version.
+
+    This program is distributed in the hope that it will be useful,
+    but WITHOUT ANY WARRANTY; without even the implied warranty of
+    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+    GNU General Public License for more details.
+
+    You should have received a copy of the GNU General Public License
+    along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+Also add information on how to contact you by electronic and paper mail.
+
+  If the program does terminal interaction, make it output a short
+notice like this when it starts in an interactive mode:
+
+    <program>  Copyright (C) <year>  <name of author>
+    This program comes with ABSOLUTELY NO WARRANTY; for details type `show w'.
+    This is free software, and you are welcome to redistribute it
+    under certain conditions; type `show c' for details.
+
+The hypothetical commands `show w' and `show c' should show the appropriate
+parts of the General Public License.  Of course, your program's commands
+might be different; for a GUI interface, you would use an "about box".
+
+  You should also get your employer (if you work as a programmer) or school,
+if any, to sign a "copyright disclaimer" for the program, if necessary.
+For more information on this, and how to apply and follow the GNU GPL, see
+<http://www.gnu.org/licenses/>.
+
+  The GNU General Public License does not permit incorporating your program
+into proprietary programs.  If your program is a subroutine library, you
+may consider it more useful to permit linking proprietary applications with
+the library.  If this is what you want to do, use the GNU Lesser General
+Public License instead of this License.  But first, please read
+<http://www.gnu.org/philosophy/why-not-lgpl.html>.

=== added file 'COPYING.LESSER'
--- COPYING.LESSER	1970-01-01 00:00:00 +0000
+++ COPYING.LESSER	2013-01-25 16:44:31 +0000
@@ -0,0 +1,165 @@
+                   GNU LESSER GENERAL PUBLIC LICENSE
+                       Version 3, 29 June 2007
+
+ Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
+ Everyone is permitted to copy and distribute verbatim copies
+ of this license document, but changing it is not allowed.
+
+
+  This version of the GNU Lesser General Public License incorporates
+the terms and conditions of version 3 of the GNU General Public
+License, supplemented by the additional permissions listed below.
+
+  0. Additional Definitions.
+
+  As used herein, "this License" refers to version 3 of the GNU Lesser
+General Public License, and the "GNU GPL" refers to version 3 of the GNU
+General Public License.
+
+  "The Library" refers to a covered work governed by this License,
+other than an Application or a Combined Work as defined below.
+
+  An "Application" is any work that makes use of an interface provided
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+
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+
+  You may convey a covered work under sections 3 and 4 of this License
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+  2. Conveying Modified Versions.
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+  If you modify a copy of the Library, and, in your modifications, a
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+
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+   b) under the GNU GPL, with none of the additional permissions of
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+  The object code form of an Application may incorporate material from
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+
+   a) Give prominent notice with each copy of the object code that the
+   Library is used in it and that the Library and its use are
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+
+   b) Accompany the object code with a copy of the GNU GPL and this license
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+
+  4. Combined Works.
+
+  You may convey a Combined Work under terms of your choice that,
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+   c) For a Combined Work that displays copyright notices during
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+
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+   e) Provide Installation Information, but only if you would otherwise
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+   a) Accompany the combined library with a copy of the same work based
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+   b) Give prominent notice with the combined library that part of it
+   is a work based on the Library, and explaining where to find the
+   accompanying uncombined form of the same work.
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+  6. Revised Versions of the GNU Lesser General Public License.
+
+  The Free Software Foundation may publish revised and/or new versions
+of the GNU Lesser General Public License from time to time. Such new
+versions will be similar in spirit to the present version, but may
+differ in detail to address new problems or concerns.
+
+  Each version is given a distinguishing version number. If the
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+
+  If the Library as you received it specifies that a proxy can decide
+whether future versions of the GNU Lesser General Public License shall
+apply, that proxy's public statement of acceptance of any version is
+permanent authorization for you to choose that version for the
+Library.

=== removed file 'LICENSE'
--- LICENSE	2013-01-18 11:38:24 +0000
+++ LICENSE	1970-01-01 00:00:00 +0000
@@ -1,683 +0,0 @@
-USSO is Copyright 2013 Canonical Ltd.
-
-Canonical Ltd ("Canonical") distributes the source code for the
-USSO under the GNU Affero General Public
-License, version 3 ("AGPLv3").  The full text of this licence is
-given below.
-
-The image and icon files in USSO are copyright
-Canonical, and unlike the source code they are not licensed under the
-AGPLv3.  Canonical grants you the right to use them for testing and
-development purposes only, but not to use them in production (commercially or
-non-commercially).
-
-Third-party copyright in this distribution is noted where applicable.
-
-All rights not expressly granted are reserved.
-
-=========================================================================
-
-                   GNU AFFERO GENERAL PUBLIC LICENSE
-                       Version 3, 19 November 2007
-                 (http://www.gnu.org/licenses/agpl.html)
-
- Copyright (C) 2007 Free Software Foundation, Inc. <http://fsf.org/>
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=== modified file 'example/usso_example.go'
--- example/usso_example.go	2013-01-21 16:57:31 +0000
+++ example/usso_example.go	2013-01-25 16:44:31 +0000
@@ -1,23 +1,27 @@
 package main
 
 import (
+	"bytes"
 	"encoding/json"
 	"fmt"
+	"io/ioutil"
 	"launchpad.net/usso"
+	"net/http"
 )
 
-var email string
-var password string
-var tokenName string
+var email, password, tokenName, signature_method string
 
 func inputParams() {
-	fmt.Println("This application will query the staging Ubuntu SSO Server to fetch authorisation tokens.")
+	fmt.Println("This application will query the staging Ubuntu SSO Server" +
+		" to fetch authorisation tokens.")
 	fmt.Print("Enter email: ")
 	fmt.Scanf("%s", &email)
 	fmt.Print("Enter password: ")
 	fmt.Scanf("%s", &password)
 	fmt.Print("Enter token name: ")
 	fmt.Scanf("%s", &tokenName)
+	fmt.Print("Enter signature method (PLAINTEXT or HMAC-SHA1): ")
+	fmt.Scanf("%s", &signature_method)
 }
 
 func main() {
@@ -26,16 +30,46 @@
 	// Fetch the tokens using usso.GetToken.
 	fmt.Println("Fetching tokens from staging server...")
 	server := usso.StagingUbuntuSSOServer
-	// One would use server := usso.ProductionUbuntuSSOServer to use the production Ubuntu SSO Server.
-	token, err := server.GetToken(email, password, tokenName)
+	// One would use server := usso.ProductionUbuntuSSOServer 
+	// to use the production Ubuntu SSO Server.
+	ssodata, err := server.GetToken(email, password, tokenName)
 	if err != nil {
 		panic(err)
 	}
 	// Format the result as json for displaying it:
-	json_token, err := json.Marshal(token)
+	json_token, err := json.Marshal(ssodata)
 	if err != nil {
 		panic(err)
 	}
 	fmt.Printf("Got tokens: %s\n", json_token)
 
+	// This would be the easiest way to get the account data.
+	//accounts, _ := server.GetAccounts(ssodata)
+	//fmt.Printf("Got accounts info: %s\n", accounts)
+
+	// But this shows how to sign a generic request.
+	ssodata.BaseURL = fmt.Sprintf(
+		"https://login.staging.ubuntu.com/api/v2/accounts/%s",
+		ssodata.ConsumerKey)
+	ssodata.HTTPMethod = "GET"
+	ssodata.SignatureMethod = signature_method
+	request, _ := http.NewRequest(ssodata.HTTPMethod, ssodata.BaseURL, nil)
+	usso.SignRequest(ssodata, request)
+
+	if err != nil {
+		fmt.Printf("Error: %s\n", err)
+	}
+	// run the request
+	client := &http.Client{}
+	response, err := client.Do(request)
+	if err != nil {
+		fmt.Printf("Error: %s\n", err)
+	}
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		fmt.Println(err)
+	}
+	var b bytes.Buffer
+	b.Write(body)
+	fmt.Printf("response: %+v\n", b.String())
 }

=== added file 'oauth.go'
--- oauth.go	1970-01-01 00:00:00 +0000
+++ oauth.go	2013-01-25 16:44:31 +0000
@@ -0,0 +1,127 @@
+package usso
+
+import (
+	"crypto/hmac"
+	"crypto/sha1"
+	"encoding/base64"
+	"errors"
+	"fmt"
+	"math/rand"
+	"net/http"
+	"net/url"
+	"strconv"
+	"time"
+)
+
+func init() {
+	// Initialize the random generator.
+	rand.Seed(time.Now().UTC().UnixNano())
+}
+
+func timestamp() string {
+	// Create a timestamp used in authorization header.
+	return strconv.Itoa(int(time.Now().Unix()))
+}
+
+func nonce() string {
+	// Create a nonce used in authorization header.
+	return strconv.Itoa(rand.Intn(100000000))
+}
+
+type SSOData struct {
+	// Contains the oauth data to perform a request.
+	HTTPMethod      string     `json:"-"`
+	BaseURL         string     `json:"-"`
+	Params          url.Values `json:"-"`
+	Nonce           string     `json:"-"`
+	Timestamp       string     `json:"-"`
+	SignatureMethod string     `json:"-"`
+	ConsumerKey     string     `json:"consumer_key"`
+	ConsumerSecret  string     `json:"consumer_secret"`
+	TokenKey        string     `json:"token_key"`
+	TokenName       string     `json:"token_name"`
+	TokenSecret     string     `json:"token_secret"`
+}
+
+func (oauth *SSOData) signature() (string, error) {
+	// Depending on the signature method, create the signature from the 
+	// consumer secret, the token secret and, if required, the URL.
+	// Supported signature methods are PLAINTEXT and HMAC-SHA1.
+
+	switch oauth.SignatureMethod {
+	case "PLAINTEXT":
+		return fmt.Sprintf(
+			`%s%%26%s`,
+			oauth.ConsumerSecret,
+			oauth.TokenSecret), nil
+	case "HMAC-SHA1":
+		base_url, err := NormalizeURL(oauth.BaseURL)
+		if err != nil {
+			return "", err
+		}
+		params, err := NormalizeParameters(oauth.Params)
+		if err != nil {
+			return "", err
+		}
+		base_string := fmt.Sprintf(`%s&%s&%s%s%s%s%s%s%s`,
+			oauth.HTTPMethod,
+			url.QueryEscape(base_url),
+			url.QueryEscape(params),
+			url.QueryEscape("oauth_consumer_key="+oauth.ConsumerKey),
+			url.QueryEscape("&oauth_nonce="+oauth.Nonce),
+			url.QueryEscape("&oauth_signature_method="+oauth.SignatureMethod),
+			url.QueryEscape("&oauth_timestamp="+oauth.Timestamp),
+			url.QueryEscape("&oauth_token="+oauth.TokenKey),
+			url.QueryEscape("&oauth_version=1.0"))
+		hashfun := hmac.New(sha1.New, []byte(
+			oauth.ConsumerSecret+"&"+oauth.TokenSecret))
+		hashfun.Write([]byte(base_string))
+		rawsignature := hashfun.Sum(nil)
+		base64signature := make(
+			[]byte, base64.StdEncoding.EncodedLen(len(rawsignature)))
+		base64.StdEncoding.Encode(base64signature, rawsignature)
+		return string(base64signature), nil
+	default:
+		return "", errors.New(
+			"usso/oauth: Oauth Signature Method not supported.")
+	}
+	return "", nil
+}
+
+func (oauth *SSOData) GetAuthorizationHeader() (string, error) {
+	// Sign the provided request.
+	if oauth.Nonce == "" {
+		oauth.Nonce = nonce()
+	}
+	if oauth.Timestamp == "" {
+		oauth.Timestamp = timestamp()
+	}
+	signature, err := oauth.signature()
+	if err != nil {
+		return "", err
+	}
+	auth := fmt.Sprintf(
+		`OAuth realm="API", `+
+			`oauth_consumer_key="%s", `+
+			`oauth_token="%s", `+
+			`oauth_signature_method="%s", `+
+			`oauth_signature="%s", `+
+			`oauth_timestamp="%s", `+
+			`oauth_nonce="%s", `+
+			`oauth_version="1.0"`,
+		url.QueryEscape(oauth.ConsumerKey),
+		url.QueryEscape(oauth.TokenKey),
+		oauth.SignatureMethod,
+		signature,
+		url.QueryEscape(oauth.Timestamp),
+		url.QueryEscape(oauth.Nonce))
+
+	return auth, nil
+}
+
+func (oauth *SSOData) SignRequest(req *http.Request) error {
+	// Sign the provided request.
+	auth, error := oauth.GetAuthorizationHeader()
+	req.Header.Add("Authorization", auth)
+	return error
+}

=== added file 'oauth_test.go'
--- oauth_test.go	1970-01-01 00:00:00 +0000
+++ oauth_test.go	2013-01-25 16:44:31 +0000
@@ -0,0 +1,52 @@
+package usso
+
+import (
+	. "launchpad.net/gocheck"
+	"net/http"
+	"net/url"
+)
+
+func (suite *USSOTestSuite) TestSignRequestPlainText(c *C) {
+	baseUrl := "https://localhost"
+	ssodata := SSOData{BaseURL: baseUrl, ConsumerKey: consumerKey,
+		ConsumerSecret: consumerSecret, TokenKey: tokenKey,
+		TokenName: tokenName, TokenSecret: tokenSecret}
+	request, _ := http.NewRequest("GET", baseUrl, nil)
+	ssodata.HTTPMethod = "GET"
+	ssodata.SignatureMethod = "PLAINTEXT"
+	err := ssodata.SignRequest(request)
+	c.Assert(err, IsNil)
+	authHeader := request.Header["Authorization"][0]
+	c.Assert(authHeader, Matches, `^OAuth.*`)
+	c.Assert(authHeader, Matches, `.*realm="API".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_consumer_key="`+url.QueryEscape(ssodata.ConsumerKey)+`".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_token="`+url.QueryEscape(ssodata.TokenKey)+`".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_signature="`+url.QueryEscape(
+			ssodata.ConsumerSecret+`&`+ssodata.TokenSecret)+`.*`)
+}
+
+func (suite *USSOTestSuite) TestSignRequestSHA1(c *C) {
+	// Test the request signing with oauth_signature_method = SHA1
+	baseUrl := "https://localhost"
+	ssodata := SSOData{BaseURL: baseUrl, ConsumerKey: consumerKey,
+		ConsumerSecret: consumerSecret, TokenKey: tokenKey,
+		TokenName: tokenName, TokenSecret: tokenSecret,
+		Nonce: "10888885", Timestamp: "1358853126"}
+	request, _ := http.NewRequest("GET", baseUrl, nil)
+	ssodata.HTTPMethod = "GET"
+	ssodata.SignatureMethod = "HMAC-SHA1"
+	err := ssodata.SignRequest(request)
+	c.Assert(err, IsNil)
+	authHeader := request.Header["Authorization"][0]
+	c.Assert(authHeader, Matches, `^OAuth.*`)
+	c.Assert(authHeader, Matches, `.*realm="API".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_consumer_key="`+url.QueryEscape(ssodata.ConsumerKey)+`".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_token="`+url.QueryEscape(ssodata.TokenKey)+`".*`)
+	c.Assert(authHeader, Matches,
+		`.*oauth_signature="`+"amJnYeek4G9ObTgTiE2y6cwTyPg="+`.*`)
+}

=== added file 'url.go'
--- url.go	1970-01-01 00:00:00 +0000
+++ url.go	2013-01-25 16:44:31 +0000
@@ -0,0 +1,41 @@
+package usso
+
+import (
+	"fmt"
+	"net/url"
+	"strings"
+)
+
+func normalizeHost(scheme, host_spec string) string {
+	standard_ports := map[string]string{
+		"http":  "80",
+		"https": "443",
+	}
+	host_parts := strings.Split(host_spec, ":")
+	if len(host_parts) == 2 && host_parts[1] == standard_ports[scheme] {
+		// There's a port, but it's the default one.  Leave it out.
+		return host_parts[0]
+	}
+	return host_spec
+}
+
+func NormalizeURL(input_url string) (string, error) {
+	parsed_url, err := url.Parse(input_url)
+	if err != nil {
+		return "", err
+	}
+
+	host := normalizeHost(parsed_url.Scheme, parsed_url.Host)
+	normalized_url := fmt.Sprintf("%v://%v%v", parsed_url.Scheme, host, parsed_url.Path)
+	return normalized_url, nil
+}
+
+func NormalizeParameters(parameters url.Values) (string, error) {
+	filtered_map := make(url.Values, len(parameters))
+	for param, value := range parameters {
+		if param != "oauth_signature" {
+			filtered_map[param] = value
+		}
+	}
+	return filtered_map.Encode(), nil
+}

=== added file 'url_test.go'
--- url_test.go	1970-01-01 00:00:00 +0000
+++ url_test.go	2013-01-25 16:44:31 +0000
@@ -0,0 +1,84 @@
+package usso
+
+import (
+	"launchpad.net/gocheck"
+	"net/url"
+)
+
+func (suite *USSOTestSuite) TestNormalizeURLReturnsBasicURL(c *gocheck.C) {
+	output, err := NormalizeURL("http://example.com/path")
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "http://example.com/path")
+}
+
+func (suite *USSOTestSuite) TestNormalizeURLStripsStandardHTTPPort(
+	c *gocheck.C) {
+	output, err := NormalizeURL("http://example.com:80/path")
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "http://example.com/path")
+}
+
+func (suite *USSOTestSuite) TestNormalizeURLStripsStandardHTTPSPort(
+	c *gocheck.C) {
+	output, err := NormalizeURL("https://example.com:443/path")
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "https://example.com/path")
+}
+
+func (suite *USSOTestSuite) TestNormalizeURLLeavesNonstandardPort(
+	c *gocheck.C) {
+	output, err := NormalizeURL("http://example.com:8080/")
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "http://example.com:8080/")
+}
+
+func (suite *USSOTestSuite) TestNormalizeURLStripsParameters(c *gocheck.C) {
+	output, err := NormalizeURL("http://example.com/path?query=value&param=arg")
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "http://example.com/path")
+}
+
+func (suite *USSOTestSuite) TestNormalizeParametersReturnsParameters(
+	c *gocheck.C) {
+	output, err := NormalizeParameters(url.Values{"param": []string{"value"}})
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "param=value")
+}
+
+func (suite *USSOTestSuite) TestNormalizeParametersConcatenatesParameters(
+	c *gocheck.C) {
+	output, err := NormalizeParameters(
+		url.Values{"a": []string{"1"}, "b": []string{"2"}})
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Matches, "(a=1&b=2|b=2&a=1)")
+}
+
+func (suite *USSOTestSuite) TestNormalizeParametersSortsParameters(
+	c *gocheck.C) {
+	params := url.Values{
+		"b": []string{"x"},
+		"a": []string{"y"},
+	}
+	output, err := NormalizeParameters(params)
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Matches, "(a=y&b=x|b=x&a=y)")
+}
+
+func (suite *USSOTestSuite) TestNormalizeParametersEscapesParameters(
+	c *gocheck.C) {
+	output, err := NormalizeParameters(url.Values{"a&b": []string{"1"}})
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Equals, "a%26b=1")
+}
+
+func (suite *USSOTestSuite) TestNormalizeParametersOmitsOAuthSignature(
+	c *gocheck.C) {
+	params := url.Values{
+		"a":               []string{"1"},
+		"oauth_signature": []string{"foobarsplatszot"},
+		"z":               []string{"26"},
+	}
+	output, err := NormalizeParameters(params)
+	c.Check(err, gocheck.Equals, nil)
+	c.Check(output, gocheck.Matches, "(a=1&z=26|z=26&a=1)")
+}

=== modified file 'usso.go'
--- usso.go	2013-01-22 10:39:12 +0000
+++ usso.go	2013-01-25 16:44:31 +0000
@@ -1,16 +1,13 @@
-// Copyright 2013 Canonical Ltd.  This software is licensed under the
-// GNU Affero General Public License version 3 (see the file LICENSE).
-
 package usso
 
 import (
+	"bytes"
 	"encoding/json"
+	"fmt"
 	"io/ioutil"
 	"log"
 	"math/rand"
 	"net/http"
-	"net/url"
-	"strconv"
 	"strings"
 	"time"
 )
@@ -29,6 +26,12 @@
 	return server.baseUrl + "/api/v2/tokens"
 }
 
+// AccountURL returns the URL where the Ubuntu SSO account information can be 
+// requested.
+func (server UbuntuSSOServer) AccountsURL() string {
+	return server.baseUrl + "/api/v2/accounts/"
+}
+
 // ProductionUbuntuSSOServer represents the production Ubuntu SSO server
 // located at https://login.ubuntu.com.
 var ProductionUbuntuSSOServer = UbuntuSSOServer{"https://login.ubuntu.com"}
@@ -37,16 +40,10 @@
 // at https://login.staging.ubuntu.com. Use it for testing.
 var StagingUbuntuSSOServer = UbuntuSSOServer{"https://login.staging.ubuntu.com"}
 
-type SSOData struct {
-	BaseURL        string
-	ConsumerKey    string `json:"consumer_key"`
-	ConsumerSecret string `json:"consumer_secret"`
-	TokenKey       string `json:"token_key"`
-	TokenName      string `json:"token_name"`
-	TokenSecret    string `json:"token_secret"`
-}
-
-func (server UbuntuSSOServer) GetToken(email string, password string, tokenName string) (*SSOData, error) {
+func (server UbuntuSSOServer) GetToken(
+	// Giving user credentials and token name, retrieves oauth credentials
+	// for the users, the oauth credentials can be used later to sign requests.
+	email string, password string, tokenName string) (*SSOData, error) {
 	credentials := map[string]string{
 		"email":      email,
 		"password":   password,
@@ -78,17 +75,40 @@
 	return &ssodata, nil
 }
 
-func (oauth *SSOData) Sign(req *http.Request) error {
-	// Sign the provided request.
-	auth := `OAuth realm="API", ` +
-		`oauth_consumer_key="` + url.QueryEscape(oauth.ConsumerKey) + `", ` +
-		`oauth_token="` + url.QueryEscape(oauth.TokenKey) + `", ` +
-		`oauth_signature_method="PLAINTEXT", ` +
-		`oauth_signature="` + url.QueryEscape(
-		oauth.ConsumerSecret+`&`+oauth.TokenSecret) + `", ` +
-		`oauth_timestamp="` + strconv.FormatInt(time.Now().Unix(), 10) + `", ` +
-		`oauth_nonce="` + strconv.Itoa(int(rand.Intn(99999999))) + `", ` +
-		`oauth_version="1.0"`
-	req.Header.Add("Authorization", auth)
-	return nil
+func (server UbuntuSSOServer) GetAccounts(ssodata *SSOData) (string, error) {
+	// Returns all the Ubuntu SSO information related to this account.
+	ssodata.BaseURL = server.AccountsURL() + ssodata.ConsumerKey
+	ssodata.HTTPMethod = "GET"
+	ssodata.SignatureMethod = "HMAC-SHA1"
+	request, err := http.NewRequest(ssodata.HTTPMethod, ssodata.BaseURL, nil)
+	if err != nil {
+		return "", err
+	}
+	err = SignRequest(ssodata, request)
+	if err != nil {
+		return "", err
+	}
+	client := &http.Client{}
+	response, err := client.Do(request)
+	if err != nil {
+		fmt.Printf("Error: %s\n", err)
+	}
+	body, err := ioutil.ReadAll(response.Body)
+	if err != nil {
+		fmt.Println(err)
+	}
+	var b bytes.Buffer
+	b.Write(body)
+	return fmt.Sprint(b.String()), nil
+}
+
+func SignRequest(ssodata *SSOData, request *http.Request) error {
+	// Given oauth credentials and a request, return it signed.
+	return ssodata.SignRequest(request)
+}
+
+func GetAuthorizationHeader(ssodata *SSOData) (string, error) {
+	// Given oauth credentials return a valid http authorization header.
+	header, err := ssodata.GetAuthorizationHeader()
+	return header, err
 }

=== modified file 'usso_test.go'
--- usso_test.go	2013-01-22 10:39:12 +0000
+++ usso_test.go	2013-01-25 16:44:31 +0000
@@ -1,6 +1,3 @@
-// Copyright 2013 Canonical Ltd.  This software is licensed under the
-// GNU Affero General Public License version 3 (see the file LICENSE).
-
 package usso
 
 import (
@@ -10,7 +7,6 @@
 	. "launchpad.net/gocheck"
 	"net/http"
 	"net/http/httptest"
-	"net/url"
 	"testing"
 )
 
@@ -49,7 +45,8 @@
 
 // newSingleServingServer create a single-serving test http server which will
 // return only one response as defined by the passed arguments.
-func newSingleServingServer(uri string, response string, code int) *SingleServingServer {
+func newSingleServingServer(
+	uri string, response string, code int) *SingleServingServer {
 	var requestContent string
 	var requested bool
 	handler := func(w http.ResponseWriter, r *http.Request) {
@@ -89,16 +86,19 @@
 	if err != nil {
 		panic(err)
 	}
-	server := newSingleServingServer("/api/v2/tokens", string(jsonServerResponseData), 200)
+	server := newSingleServingServer("/api/v2/tokens",
+		string(jsonServerResponseData), 200)
 	var testSSOServer = &UbuntuSSOServer{server.URL}
 	defer server.Close()
 
 	// The returned information is correct.
 	ssodata, err := testSSOServer.GetToken(email, password, tokenName)
 	c.Assert(err, IsNil)
-	expectedSSOData := &SSOData{ConsumerKey: consumerKey, ConsumerSecret: consumerSecret, TokenKey: tokenKey, TokenSecret: tokenSecret, TokenName: tokenName}
+	expectedSSOData := &SSOData{ConsumerKey: consumerKey,
+		ConsumerSecret: consumerSecret, TokenKey: tokenKey,
+		TokenSecret: tokenSecret, TokenName: tokenName}
 	c.Assert(ssodata, DeepEquals, expectedSSOData)
-	// The request that the fake Ubuntu SSO Server got contained the credentials.
+	//The request that the fake Ubuntu SSO Server got contained the credentials.
 	credentials := map[string]string{
 		"email":      email,
 		"password":   password,
@@ -110,18 +110,3 @@
 	}
 	c.Assert(*server.requestContent, Equals, string(expectedRequestContent))
 }
-
-func (suite *USSOTestSuite) TestSignRequestPlainText(c *C) {
-	baseUrl := "https://localhost"
-	ssoData := SSOData{BaseURL: baseUrl, ConsumerKey: consumerKey, ConsumerSecret: consumerSecret, TokenKey: tokenKey, TokenName: tokenName, TokenSecret: tokenSecret}
-	request, _ := http.NewRequest("GET", baseUrl, nil)
-
-	err := ssoData.Sign(request)
-
-	c.Assert(err, IsNil)
-	authHeader := request.Header["Authorization"][0]
-	c.Assert(authHeader, Matches, `.*OAuth realm="API".*`)
-	c.Assert(authHeader, Matches, `.*oauth_consumer_key="`+url.QueryEscape(ssoData.ConsumerKey)+`".*`)
-	c.Assert(authHeader, Matches, `.*oauth_token="`+url.QueryEscape(ssoData.TokenKey)+`".*`)
-	c.Assert(authHeader, Matches, `.*oauth_signature="`+url.QueryEscape(ssoData.ConsumerSecret+`&`+ssoData.TokenSecret)+`.*`)
-}