transport: create Client interface (#132)

* plumbing: move plumbing/client package to plumbing/transport.

* transport: create Client interface.

* A Client can instantiate any client transport service.
* InstallProtocol installs a Client for a given protocol,
  instead of just a UploadPackService.
* A Client can open a session for fetch-pack or send-pack
  for a specific Endpoint.
* Adapt ssh and http clients to the new client interface.

* updated doc

28 files changed, 1440 insertions, 1277 deletions

diff --git a/plumbing/client/common.go b/plumbing/client/common.go
deleted file mode 100644
index 1524753..0000000
--- a/plumbing/client/common.go
+++ /dev/null
@@ -1,46 +0,0 @@
-// Package clients includes the implementation for different transport protocols
-//
-// go-git needs the packfile and the refs of the repo. The
-// `NewGitUploadPackService` function returns an object that allows to
-// download them.
-//
-// go-git supports HTTP and SSH (see `Protocols`) for downloading the packfile
-// and the refs, but you can also install your own protocols (see
-// `InstallProtocol` below).
-//
-// Each protocol has its own implementation of
-// `NewGitUploadPackService`, but you should generally not use them
-// directly, use this package's `NewGitUploadPackService` instead.
-package clients
-
-import (
-	"fmt"
-
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/http"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/ssh"
-)
-
-// Protocols are the protocols supported by default.
-var Protocols = map[string]common.GitUploadPackServiceFactory{
-	"http":  http.NewGitUploadPackService,
-	"https": http.NewGitUploadPackService,
-	"ssh":   ssh.NewGitUploadPackService,
-}
-
-// InstallProtocol adds or modifies an existing protocol.
-func InstallProtocol(scheme string, f common.GitUploadPackServiceFactory) {
-	Protocols[scheme] = f
-}
-
-// NewGitUploadPackService returns the appropriate upload pack service
-// among of the set of known protocols: HTTP, SSH. See `InstallProtocol`
-// to add or modify protocols.
-func NewGitUploadPackService(endpoint common.Endpoint) (common.GitUploadPackService, error) {
-	f, ok := Protocols[endpoint.Scheme]
-	if !ok {
-		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Scheme)
-	}
-
-	return f(endpoint), nil
-}
diff --git a/plumbing/client/common/common_test.go b/plumbing/client/common/common_test.go
deleted file mode 100644
index cf4d871..0000000
--- a/plumbing/client/common/common_test.go
+++ /dev/null
@@ -1,126 +0,0 @@
-package common
-
-import (
-	"bytes"
-	"encoding/base64"
-	"testing"
-
-	"gopkg.in/src-d/go-git.v4/plumbing"
-	"gopkg.in/src-d/go-git.v4/plumbing/format/packp"
-
-	. "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { TestingT(t) }
-
-type SuiteCommon struct{}
-
-var _ = Suite(&SuiteCommon{})
-
-func (s *SuiteCommon) TestNewEndpoint(c *C) {
-	e, err := NewEndpoint("ssh://git@github.com/user/repository.git")
-	c.Assert(err, IsNil)
-	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
-}
-
-func (s *SuiteCommon) TestNewEndpointSCPLike(c *C) {
-	e, err := NewEndpoint("git@github.com:user/repository.git")
-	c.Assert(err, IsNil)
-	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
-}
-
-func (s *SuiteCommon) TestNewEndpointWrongForgat(c *C) {
-	e, err := NewEndpoint("foo")
-	c.Assert(err, Not(IsNil))
-	c.Assert(e.Host, Equals, "")
-}
-
-const CapabilitiesFixture = "6ecf0ef2c2dffb796033e5a02219af86ec6584e5 HEADmulti_ack thin-pack side-band side-band-64k ofs-delta shallow no-progress include-tag multi_ack_detailed no-done symref=HEAD:refs/heads/master agent=git/2:2.4.8~dbussink-fix-enterprise-tokens-compilation-1167-gc7006cf"
-
-func (s *SuiteCommon) TestCapabilitiesSymbolicReference(c *C) {
-	cap := packp.NewCapabilities()
-	cap.Decode(CapabilitiesFixture)
-	c.Assert(cap.SymbolicReference("HEAD"), Equals, "refs/heads/master")
-}
-
-const GitUploadPackInfoFixture = "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"
-
-func (s *SuiteCommon) TestGitUploadPackInfo(c *C) {
-	b, _ := base64.StdEncoding.DecodeString(GitUploadPackInfoFixture)
-
-	i := NewGitUploadPackInfo()
-	err := i.Decode(bytes.NewBuffer(b))
-	c.Assert(err, IsNil)
-
-	name := i.Capabilities.SymbolicReference("HEAD")
-	c.Assert(name, Equals, "refs/heads/master")
-	c.Assert(i.Refs, HasLen, 4)
-
-	ref := i.Refs[plumbing.ReferenceName(name)]
-	c.Assert(ref, NotNil)
-	c.Assert(ref.Hash().String(), Equals, "6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
-
-	ref = i.Refs[plumbing.HEAD]
-	c.Assert(ref, NotNil)
-	c.Assert(ref.Target(), Equals, plumbing.ReferenceName(name))
-}
-
-const GitUploadPackInfoNoHEADFixture = "MDAxZSMgc2VydmljZT1naXQtdXBsb2FkLXBhY2sKMDAwMDAwYmNkN2UxZmVlMjYxMjM0YmIzYTQzYzA5NmY1NTg3NDhhNTY5ZDc5ZWZmIHJlZnMvaGVhZHMvdjQAbXVsdGlfYWNrIHRoaW4tcGFjayBzaWRlLWJhbmQgc2lkZS1iYW5kLTY0ayBvZnMtZGVsdGEgc2hhbGxvdyBuby1wcm9ncmVzcyBpbmNsdWRlLXRhZyBtdWx0aV9hY2tfZGV0YWlsZWQgbm8tZG9uZSBhZ2VudD1naXQvMS45LjEKMDAwMA=="
-
-func (s *SuiteCommon) TestGitUploadPackInfoNoHEAD(c *C) {
-	b, _ := base64.StdEncoding.DecodeString(GitUploadPackInfoNoHEADFixture)
-
-	i := NewGitUploadPackInfo()
-	err := i.Decode(bytes.NewBuffer(b))
-	c.Assert(err, IsNil)
-
-	name := i.Capabilities.SymbolicReference("HEAD")
-	c.Assert(name, Equals, "")
-	c.Assert(i.Refs, HasLen, 1)
-
-	ref := i.Refs["refs/heads/v4"]
-	c.Assert(ref, NotNil)
-	c.Assert(ref.Hash().String(), Equals, "d7e1fee261234bb3a43c096f558748a569d79eff")
-}
-
-func (s *SuiteCommon) TestGitUploadPackInfoEmpty(c *C) {
-	b := bytes.NewBuffer(nil)
-
-	i := NewGitUploadPackInfo()
-	err := i.Decode(b)
-	c.Assert(err, ErrorMatches, "permanent.*empty.*")
-}
-
-func (s *SuiteCommon) TestGitUploadPackEncode(c *C) {
-	info := NewGitUploadPackInfo()
-	info.Capabilities.Add("symref", "HEAD:refs/heads/master")
-
-	ref := plumbing.ReferenceName("refs/heads/master")
-	hash := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
-	info.Refs = map[plumbing.ReferenceName]*plumbing.Reference{
-		plumbing.HEAD: plumbing.NewSymbolicReference(plumbing.HEAD, ref),
-		ref:           plumbing.NewHashReference(ref, hash),
-	}
-
-	c.Assert(info.Head(), NotNil)
-	c.Assert(info.String(), Equals,
-		"001e# service=git-upload-pack\n"+
-			"000000506ecf0ef2c2dffb796033e5a02219af86ec6584e5 HEAD\x00symref=HEAD:refs/heads/master\n"+
-			"003f6ecf0ef2c2dffb796033e5a02219af86ec6584e5 refs/heads/master\n"+
-			"0000",
-	)
-}
-
-func (s *SuiteCommon) TestGitUploadPackRequest(c *C) {
-	r := &GitUploadPackRequest{}
-	r.Want(plumbing.NewHash("d82f291cde9987322c8a0c81a325e1ba6159684c"))
-	r.Want(plumbing.NewHash("2b41ef280fdb67a9b250678686a0c3e03b0a9989"))
-	r.Have(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-
-	c.Assert(r.String(), Equals,
-		"0032want d82f291cde9987322c8a0c81a325e1ba6159684c\n"+
-			"0032want 2b41ef280fdb67a9b250678686a0c3e03b0a9989\n"+
-			"0032have 6ecf0ef2c2dffb796033e5a02219af86ec6584e5\n0000"+
-			"0009done\n",
-	)
-}
diff --git a/plumbing/client/common_test.go b/plumbing/client/common_test.go
deleted file mode 100644
index 058c4d3..0000000
--- a/plumbing/client/common_test.go
+++ /dev/null
@@ -1,85 +0,0 @@
-package clients
-
-import (
-	"fmt"
-	"io"
-	"testing"
-
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-
-	. "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { TestingT(t) }
-
-type SuiteCommon struct{}
-
-var _ = Suite(&SuiteCommon{})
-
-func (s *SuiteCommon) TestNewGitUploadPackServiceHTTP(c *C) {
-	e, err := common.NewEndpoint("http://github.com/src-d/go-git")
-	c.Assert(err, IsNil)
-
-	output, err := NewGitUploadPackService(e)
-	c.Assert(err, IsNil)
-	c.Assert(typeAsString(output), Equals, "*http.GitUploadPackService")
-
-	e, err = common.NewEndpoint("https://github.com/src-d/go-git")
-	c.Assert(err, IsNil)
-
-	output, err = NewGitUploadPackService(e)
-	c.Assert(err, IsNil)
-	c.Assert(typeAsString(output), Equals, "*http.GitUploadPackService")
-}
-
-func (s *SuiteCommon) TestNewGitUploadPackServiceSSH(c *C) {
-	e, err := common.NewEndpoint("ssh://github.com/src-d/go-git")
-	c.Assert(err, IsNil)
-
-	output, err := NewGitUploadPackService(e)
-	c.Assert(err, IsNil)
-	c.Assert(typeAsString(output), Equals, "*ssh.GitUploadPackService")
-}
-
-func (s *SuiteCommon) TestNewGitUploadPackServiceUnknown(c *C) {
-	e, err := common.NewEndpoint("unknown://github.com/src-d/go-git")
-	c.Assert(err, IsNil)
-
-	_, err = NewGitUploadPackService(e)
-	c.Assert(err, NotNil)
-}
-
-func (s *SuiteCommon) TestInstallProtocol(c *C) {
-	InstallProtocol("newscheme", newDummyProtocolService)
-	c.Assert(Protocols["newscheme"], NotNil)
-}
-
-type dummyProtocolService struct{}
-
-func newDummyProtocolService(common.Endpoint) common.GitUploadPackService {
-	return &dummyProtocolService{}
-}
-
-func (s *dummyProtocolService) Connect() error {
-	return nil
-}
-
-func (s *dummyProtocolService) SetAuth(auth common.AuthMethod) error {
-	return nil
-}
-
-func (s *dummyProtocolService) Info() (*common.GitUploadPackInfo, error) {
-	return nil, nil
-}
-
-func (s *dummyProtocolService) Fetch(r *common.GitUploadPackRequest) (io.ReadCloser, error) {
-	return nil, nil
-}
-
-func (s *dummyProtocolService) Disconnect() error {
-	return nil
-}
-
-func typeAsString(v interface{}) string {
-	return fmt.Sprintf("%T", v)
-}
diff --git a/plumbing/client/http/common.go b/plumbing/client/http/common.go
deleted file mode 100644
index 2447995..0000000
--- a/plumbing/client/http/common.go
+++ /dev/null
@@ -1,76 +0,0 @@
-// Package http implements a HTTP client for go-git.
-package http
-
-import (
-	"fmt"
-	"net/http"
-
-	"gopkg.in/src-d/go-git.v4/plumbing"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-)
-
-// AuthMethod is concrete implementation of common.AuthMethod for HTTP services
-type AuthMethod interface {
-	common.AuthMethod
-	setAuth(r *http.Request)
-}
-
-// BasicAuth represent a HTTP basic auth
-type BasicAuth struct {
-	username, password string
-}
-
-// NewBasicAuth returns a BasicAuth base on the given user and password
-func NewBasicAuth(username, password string) *BasicAuth {
-	return &BasicAuth{username, password}
-}
-
-func (a *BasicAuth) setAuth(r *http.Request) {
-	r.SetBasicAuth(a.username, a.password)
-}
-
-// Name is name of the auth
-func (a *BasicAuth) Name() string {
-	return "http-basic-auth"
-}
-
-func (a *BasicAuth) String() string {
-	masked := "*******"
-	if a.password == "" {
-		masked = "<empty>"
-	}
-
-	return fmt.Sprintf("%s - %s:%s", a.Name(), a.username, masked)
-}
-
-// Err is a dedicated error to return errors based on status code
-type Err struct {
-	Response *http.Response
-}
-
-// NewErr returns a new Err based on a http response
-func NewErr(r *http.Response) error {
-	if r.StatusCode >= http.StatusOK && r.StatusCode < http.StatusMultipleChoices {
-		return nil
-	}
-
-	switch r.StatusCode {
-	case http.StatusUnauthorized:
-		return common.ErrAuthorizationRequired
-	case http.StatusNotFound:
-		return common.ErrRepositoryNotFound
-	}
-
-	return plumbing.NewUnexpectedError(&Err{r})
-}
-
-// StatusCode returns the status code of the response
-func (e *Err) StatusCode() int {
-	return e.Response.StatusCode
-}
-
-func (e *Err) Error() string {
-	return fmt.Sprintf("unexpected requesting %q status code: %d",
-		e.Response.Request.URL, e.Response.StatusCode,
-	)
-}
diff --git a/plumbing/client/http/common_test.go b/plumbing/client/http/common_test.go
deleted file mode 100644
index 7503d84..0000000
--- a/plumbing/client/http/common_test.go
+++ /dev/null
@@ -1,51 +0,0 @@
-package http
-
-import (
-	"net/http"
-	"testing"
-
-	. "gopkg.in/check.v1"
-)
-
-func Test(t *testing.T) { TestingT(t) }
-
-type SuiteCommon struct{}
-
-var _ = Suite(&SuiteCommon{})
-
-func (s *SuiteCommon) TestNewBasicAuth(c *C) {
-	a := NewBasicAuth("foo", "qux")
-
-	c.Assert(a.Name(), Equals, "http-basic-auth")
-	c.Assert(a.String(), Equals, "http-basic-auth - foo:*******")
-}
-
-func (s *SuiteCommon) TestNewErrOK(c *C) {
-	res := &http.Response{StatusCode: http.StatusOK}
-	err := NewErr(res)
-	c.Assert(err, IsNil)
-}
-
-func (s *SuiteCommon) TestNewErrUnauthorized(c *C) {
-	s.testNewHTTPError(c, http.StatusUnauthorized, "authorization required")
-}
-
-func (s *SuiteCommon) TestNewErrNotFound(c *C) {
-	s.testNewHTTPError(c, http.StatusNotFound, "repository not found")
-}
-
-func (s *SuiteCommon) TestNewHTTPError40x(c *C) {
-	s.testNewHTTPError(c, http.StatusPaymentRequired, "unexpected client error.*")
-}
-
-func (s *SuiteCommon) testNewHTTPError(c *C, code int, msg string) {
-	req, _ := http.NewRequest("GET", "foo", nil)
-	res := &http.Response{
-		StatusCode: code,
-		Request:    req,
-	}
-
-	err := NewErr(res)
-	c.Assert(err, NotNil)
-	c.Assert(err, ErrorMatches, msg)
-}
diff --git a/plumbing/client/http/git_upload_pack.go b/plumbing/client/http/git_upload_pack.go
deleted file mode 100644
index 1ecf299..0000000
--- a/plumbing/client/http/git_upload_pack.go
+++ /dev/null
@@ -1,202 +0,0 @@
-package http
-
-import (
-	"bufio"
-	"bytes"
-	"fmt"
-	"io"
-	"net/http"
-	"strings"
-
-	"gopkg.in/src-d/go-git.v4/plumbing"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/pktline"
-)
-
-// GitUploadPackService git-upload-pack service over HTTP
-type GitUploadPackService struct {
-	client   *http.Client
-	endpoint common.Endpoint
-	auth     AuthMethod
-}
-
-// NewGitUploadPackService connects to a git-upload-pack service over HTTP, the
-// auth is extracted from the URL, or can be provided using the SetAuth method
-func NewGitUploadPackService(endpoint common.Endpoint) common.GitUploadPackService {
-	return newGitUploadPackService(endpoint, http.DefaultClient)
-}
-
-// NewGitUploadPackServiceFactory creates a http client factory with a customizable client
-// See `InstallProtocol` to install and override default http client.
-// Unless a properly initialized client is given, it will fall back into `http.DefaultClient`.
-func NewGitUploadPackServiceFactory(client *http.Client) common.GitUploadPackServiceFactory {
-	return func(endpoint common.Endpoint) common.GitUploadPackService {
-		return newGitUploadPackService(endpoint, client)
-	}
-}
-
-func newGitUploadPackService(endpoint common.Endpoint, client *http.Client) common.GitUploadPackService {
-	if client == nil {
-		client = http.DefaultClient
-	}
-	s := &GitUploadPackService{
-		client:   client,
-		endpoint: endpoint,
-	}
-	s.setBasicAuthFromEndpoint()
-	return s
-}
-
-// Connect has not any effect, is here to satisfy interface
-func (s *GitUploadPackService) Connect() error {
-	return nil
-}
-
-func (s *GitUploadPackService) setBasicAuthFromEndpoint() {
-	info := s.endpoint.User
-	if info == nil {
-		return
-	}
-
-	p, ok := info.Password()
-	if !ok {
-		return
-	}
-
-	u := info.Username()
-	s.auth = NewBasicAuth(u, p)
-}
-
-// SetAuth sets the AuthMethod
-func (s *GitUploadPackService) SetAuth(auth common.AuthMethod) error {
-	httpAuth, ok := auth.(AuthMethod)
-	if !ok {
-		return common.ErrInvalidAuthMethod
-	}
-
-	s.auth = httpAuth
-	return nil
-}
-
-// Info returns the references info and capabilities from the service
-func (s *GitUploadPackService) Info() (*common.GitUploadPackInfo, error) {
-	url := fmt.Sprintf(
-		"%s/info/refs?service=%s",
-		s.endpoint.String(), common.GitUploadPackServiceName,
-	)
-
-	res, err := s.doRequest("GET", url, nil)
-	if err != nil {
-		return nil, err
-	}
-
-	defer res.Body.Close()
-
-	i := common.NewGitUploadPackInfo()
-	return i, i.Decode(res.Body)
-}
-
-// Fetch request and returns a reader to a packfile
-func (s *GitUploadPackService) Fetch(r *common.GitUploadPackRequest) (io.ReadCloser, error) {
-	url := fmt.Sprintf(
-		"%s/%s",
-		s.endpoint.String(), common.GitUploadPackServiceName,
-	)
-
-	res, err := s.doRequest("POST", url, r.Reader())
-	if err != nil {
-		return nil, err
-	}
-
-	reader := newBufferedReadCloser(res.Body)
-	if _, err := reader.Peek(1); err != nil {
-		if err == io.ErrUnexpectedEOF {
-			return nil, common.ErrEmptyGitUploadPack
-		}
-
-		return nil, err
-	}
-
-	if err := discardResponseInfo(reader); err != nil {
-		return nil, err
-	}
-
-	return reader, nil
-}
-
-func discardResponseInfo(r io.Reader) error {
-	s := pktline.NewScanner(r)
-	for s.Scan() {
-		if bytes.Equal(s.Bytes(), []byte{'N', 'A', 'K', '\n'}) {
-			break
-		}
-	}
-
-	return s.Err()
-}
-
-func (s *GitUploadPackService) doRequest(method, url string, content *strings.Reader) (*http.Response, error) {
-	var body io.Reader
-	if content != nil {
-		body = content
-	}
-
-	req, err := http.NewRequest(method, url, body)
-	if err != nil {
-		return nil, plumbing.NewPermanentError(err)
-	}
-
-	s.applyHeadersToRequest(req, content)
-	s.applyAuthToRequest(req)
-
-	res, err := s.client.Do(req)
-	if err != nil {
-		return nil, plumbing.NewUnexpectedError(err)
-	}
-
-	if err := NewErr(res); err != nil {
-		_ = res.Body.Close()
-		return nil, err
-	}
-
-	return res, nil
-}
-
-func (s *GitUploadPackService) applyHeadersToRequest(req *http.Request, content *strings.Reader) {
-	req.Header.Add("User-Agent", "git/1.0")
-	req.Header.Add("Host", "github.com")
-
-	if content == nil {
-		req.Header.Add("Accept", "*/*")
-	} else {
-		req.Header.Add("Accept", "application/x-git-upload-pack-result")
-		req.Header.Add("Content-Type", "application/x-git-upload-pack-request")
-		req.Header.Add("Content-Length", string(content.Len()))
-	}
-}
-
-func (s *GitUploadPackService) applyAuthToRequest(req *http.Request) {
-	if s.auth == nil {
-		return
-	}
-
-	s.auth.setAuth(req)
-}
-
-// Disconnect do nothing
-func (s *GitUploadPackService) Disconnect() error {
-	return nil
-}
-
-type bufferedReadCloser struct {
-	*bufio.Reader
-	closer io.Closer
-}
-
-func newBufferedReadCloser(r io.ReadCloser) *bufferedReadCloser {
-	return &bufferedReadCloser{bufio.NewReader(r), r}
-}
-
-func (r *bufferedReadCloser) Close() error {
-	return r.closer.Close()
-}
diff --git a/plumbing/client/http/git_upload_pack_test.go b/plumbing/client/http/git_upload_pack_test.go
deleted file mode 100644
index 8010cea..0000000
--- a/plumbing/client/http/git_upload_pack_test.go
+++ /dev/null
@@ -1,149 +0,0 @@
-package http
-
-import (
-	"crypto/tls"
-	"io/ioutil"
-	"net/http"
-
-	. "gopkg.in/check.v1"
-	"gopkg.in/src-d/go-git.v4/plumbing"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-)
-
-type RemoteSuite struct {
-	Endpoint common.Endpoint
-}
-
-var _ = Suite(&RemoteSuite{})
-
-func (s *RemoteSuite) SetUpSuite(c *C) {
-	var err error
-	s.Endpoint, err = common.NewEndpoint("https://github.com/git-fixtures/basic")
-	c.Assert(err, IsNil)
-}
-
-func (s *RemoteSuite) TestNewGitUploadPackServiceAuth(c *C) {
-	e, err := common.NewEndpoint("https://foo:bar@github.com/git-fixtures/basic")
-	c.Assert(err, IsNil)
-
-	r := NewGitUploadPackService(e)
-	auth := r.(*GitUploadPackService).auth
-
-	c.Assert(auth.String(), Equals, "http-basic-auth - foo:*******")
-}
-
-func (s *RemoteSuite) TestNewGitUploadPackServiceFactory(c *C) {
-	e, err := common.NewEndpoint("https://foo:bar@github.com/git-fixtures/basic")
-	c.Assert(err, IsNil)
-
-	roundTripper := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}}
-	client := &http.Client{Transport: roundTripper}
-	r := NewGitUploadPackServiceFactory(client)(e).(*GitUploadPackService)
-
-	c.Assert(r.auth.String(), Equals, "http-basic-auth - foo:*******")
-	c.Assert(r.client.Transport, Equals, roundTripper)
-}
-
-func (s *RemoteSuite) TestConnect(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-}
-
-func (s *RemoteSuite) TestSetAuth(c *C) {
-	auth := &BasicAuth{}
-	r := NewGitUploadPackService(s.Endpoint)
-	r.SetAuth(auth)
-	c.Assert(auth, Equals, r.(*GitUploadPackService).auth)
-}
-
-type mockAuth struct{}
-
-func (*mockAuth) Name() string   { return "" }
-func (*mockAuth) String() string { return "" }
-
-func (s *RemoteSuite) TestSetAuthWrongType(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.SetAuth(&mockAuth{}), Equals, common.ErrInvalidAuthMethod)
-}
-
-func (s *RemoteSuite) TestInfoEmpty(c *C) {
-	endpoint, _ := common.NewEndpoint("https://github.com/git-fixture/empty")
-	r := NewGitUploadPackService(endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	info, err := r.Info()
-	c.Assert(err, Equals, common.ErrAuthorizationRequired)
-	c.Assert(info, IsNil)
-}
-
-func (s *RemoteSuite) TestInfoNotExists(c *C) {
-	endpoint, _ := common.NewEndpoint("https://github.com/git-fixture/not-exists")
-	r := NewGitUploadPackService(endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	info, err := r.Info()
-	c.Assert(err, Equals, common.ErrAuthorizationRequired)
-	c.Assert(info, IsNil)
-}
-
-func (s *RemoteSuite) TestDefaultBranch(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	info, err := r.Info()
-	c.Assert(err, IsNil)
-	c.Assert(info.Capabilities.SymbolicReference("HEAD"), Equals, "refs/heads/master")
-}
-
-func (s *RemoteSuite) TestCapabilities(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	info, err := r.Info()
-	c.Assert(err, IsNil)
-	c.Assert(info.Capabilities.Get("agent").Values, HasLen, 1)
-}
-
-func (s *RemoteSuite) TestFetch(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	req := &common.GitUploadPackRequest{}
-	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-
-	reader, err := r.Fetch(req)
-	c.Assert(err, IsNil)
-
-	b, err := ioutil.ReadAll(reader)
-	c.Assert(err, IsNil)
-	c.Assert(b, HasLen, 85374)
-}
-
-func (s *RemoteSuite) TestFetchNoChanges(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	req := &common.GitUploadPackRequest{}
-	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-	req.Have(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-
-	reader, err := r.Fetch(req)
-	c.Assert(err, Equals, common.ErrEmptyGitUploadPack)
-	c.Assert(reader, IsNil)
-}
-
-func (s *RemoteSuite) TestFetchMulti(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-
-	req := &common.GitUploadPackRequest{}
-	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-	req.Want(plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
-
-	reader, err := r.Fetch(req)
-	c.Assert(err, IsNil)
-
-	b, err := ioutil.ReadAll(reader)
-	c.Assert(err, IsNil)
-	c.Assert(b, HasLen, 85585)
-}
diff --git a/plumbing/client/ssh/git_upload_pack.go b/plumbing/client/ssh/git_upload_pack.go
deleted file mode 100644
index db7fa93..0000000
--- a/plumbing/client/ssh/git_upload_pack.go
+++ /dev/null
@@ -1,311 +0,0 @@
-// Package ssh implements a ssh client for go-git.
-package ssh
-
-import (
-	"bytes"
-	"errors"
-	"fmt"
-	"io"
-	"strings"
-
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/advrefs"
-	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/pktline"
-	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/ulreq"
-
-	"golang.org/x/crypto/ssh"
-)
-
-// New errors introduced by this package.
-var (
-	ErrInvalidAuthMethod      = errors.New("invalid ssh auth method")
-	ErrAuthRequired           = errors.New("cannot connect: auth required")
-	ErrNotConnected           = errors.New("not connected")
-	ErrAlreadyConnected       = errors.New("already connected")
-	ErrUploadPackAnswerFormat = errors.New("git-upload-pack bad answer format")
-	ErrUnsupportedVCS         = errors.New("only git is supported")
-	ErrUnsupportedRepo        = errors.New("only github.com is supported")
-
-	nak = []byte("NAK")
-	eol = []byte("\n")
-)
-
-// GitUploadPackService holds the service information.
-// The zero value is safe to use.
-type GitUploadPackService struct {
-	connected bool
-	endpoint  common.Endpoint
-	client    *ssh.Client
-	auth      AuthMethod
-}
-
-// NewGitUploadPackService initialises a GitUploadPackService,
-func NewGitUploadPackService(endpoint common.Endpoint) common.GitUploadPackService {
-	return &GitUploadPackService{endpoint: endpoint}
-}
-
-// Connect connects to the SSH server, unless a AuthMethod was set with SetAuth
-// method, by default uses an auth method based on PublicKeysCallback, it
-// connects to a SSH agent, using the address stored in the SSH_AUTH_SOCK
-// environment var
-func (s *GitUploadPackService) Connect() error {
-	if s.connected {
-		return ErrAlreadyConnected
-	}
-
-	if err := s.setAuthFromEndpoint(); err != nil {
-		return err
-	}
-
-	var err error
-	s.client, err = ssh.Dial("tcp", s.getHostWithPort(), s.auth.clientConfig())
-	if err != nil {
-		return err
-	}
-
-	s.connected = true
-	return nil
-}
-
-func (s *GitUploadPackService) getHostWithPort() string {
-	host := s.endpoint.Host
-	if strings.Index(s.endpoint.Host, ":") == -1 {
-		host += ":22"
-	}
-
-	return host
-}
-
-func (s *GitUploadPackService) setAuthFromEndpoint() error {
-	var u string
-	if info := s.endpoint.User; info != nil {
-		u = info.Username()
-	}
-
-	var err error
-	s.auth, err = NewSSHAgentAuth(u)
-	return err
-}
-
-// SetAuth sets the AuthMethod
-func (s *GitUploadPackService) SetAuth(auth common.AuthMethod) error {
-	var ok bool
-	s.auth, ok = auth.(AuthMethod)
-	if !ok {
-		return ErrInvalidAuthMethod
-	}
-
-	return nil
-}
-
-// Info returns the GitUploadPackInfo of the repository. The client must be
-// connected with the repository (using the ConnectWithAuth() method) before
-// using this method.
-func (s *GitUploadPackService) Info() (*common.GitUploadPackInfo, error) {
-	if !s.connected {
-		return nil, ErrNotConnected
-	}
-
-	session, err := s.client.NewSession()
-	if err != nil {
-		return nil, err
-	}
-	defer func() {
-		// the session can be closed by the other endpoint,
-		// therefore we must ignore a close error.
-		_ = session.Close()
-	}()
-
-	out, err := session.Output(s.getCommand())
-	if err != nil {
-		return nil, err
-	}
-
-	i := common.NewGitUploadPackInfo()
-	return i, i.Decode(bytes.NewReader(out))
-}
-
-// Disconnect the SSH client.
-func (s *GitUploadPackService) Disconnect() error {
-	if !s.connected {
-		return ErrNotConnected
-	}
-	s.connected = false
-	return s.client.Close()
-}
-
-// Fetch returns a packfile for a given upload request.  It opens a new
-// SSH session on a connected GitUploadPackService, sends the given
-// upload request to the server and returns a reader for the received
-// packfile.  Closing the returned reader will close the SSH session.
-func (s *GitUploadPackService) Fetch(req *common.GitUploadPackRequest) (io.ReadCloser, error) {
-	if !s.connected {
-		return nil, ErrNotConnected
-	}
-
-	session, i, o, done, err := openSSHSession(s.client, s.getCommand())
-	if err != nil {
-		return nil, fmt.Errorf("cannot open SSH session: %s", err)
-	}
-
-	if err := talkPackProtocol(i, o, req); err != nil {
-		return nil, err
-	}
-
-	return &fetchSession{
-		Reader:  o,
-		session: session,
-		done:    done,
-	}, nil
-}
-
-func openSSHSession(c *ssh.Client, cmd string) (
-	*ssh.Session, io.WriteCloser, io.Reader, <-chan error, error) {
-
-	session, err := c.NewSession()
-	if err != nil {
-		return nil, nil, nil, nil, fmt.Errorf("cannot open SSH session: %s", err)
-	}
-
-	i, err := session.StdinPipe()
-	if err != nil {
-		return nil, nil, nil, nil, fmt.Errorf("cannot pipe remote stdin: %s", err)
-	}
-
-	o, err := session.StdoutPipe()
-	if err != nil {
-		return nil, nil, nil, nil, fmt.Errorf("cannot pipe remote stdout: %s", err)
-	}
-
-	done := make(chan error)
-	go func() {
-		done <- session.Run(cmd)
-	}()
-
-	return session, i, o, done, nil
-}
-
-// TODO support multi_ack mode
-// TODO support multi_ack_detailed mode
-// TODO support acks for common objects
-// TODO build a proper state machine for all these processing options
-func talkPackProtocol(w io.WriteCloser, r io.Reader,
-	req *common.GitUploadPackRequest) error {
-
-	if err := skipAdvRef(r); err != nil {
-		return fmt.Errorf("skipping advertised-refs: %s", err)
-	}
-
-	if err := sendUlReq(w, req); err != nil {
-		return fmt.Errorf("sending upload-req message: %s", err)
-	}
-
-	if err := sendHaves(w, req); err != nil {
-		return fmt.Errorf("sending haves message: %s", err)
-	}
-
-	if err := sendDone(w); err != nil {
-		return fmt.Errorf("sending done message: %s", err)
-	}
-
-	if err := w.Close(); err != nil {
-		return fmt.Errorf("closing input: %s", err)
-	}
-
-	if err := readNAK(r); err != nil {
-		return fmt.Errorf("reading NAK: %s", err)
-	}
-
-	return nil
-}
-
-func skipAdvRef(r io.Reader) error {
-	d := advrefs.NewDecoder(r)
-	ar := advrefs.New()
-
-	return d.Decode(ar)
-}
-
-func sendUlReq(w io.Writer, req *common.GitUploadPackRequest) error {
-	ur := ulreq.New()
-	ur.Wants = req.Wants
-	ur.Depth = ulreq.DepthCommits(req.Depth)
-	e := ulreq.NewEncoder(w)
-
-	return e.Encode(ur)
-}
-
-func sendHaves(w io.Writer, req *common.GitUploadPackRequest) error {
-	e := pktline.NewEncoder(w)
-	for _, have := range req.Haves {
-		if err := e.Encodef("have %s\n", have); err != nil {
-			return fmt.Errorf("sending haves for %q: %s", have, err)
-		}
-	}
-
-	if len(req.Haves) != 0 {
-		if err := e.Flush(); err != nil {
-			return fmt.Errorf("sending flush-pkt after haves: %s", err)
-		}
-	}
-
-	return nil
-}
-
-func sendDone(w io.Writer) error {
-	e := pktline.NewEncoder(w)
-
-	return e.Encodef("done\n")
-}
-
-func readNAK(r io.Reader) error {
-	s := pktline.NewScanner(r)
-	if !s.Scan() {
-		return s.Err()
-	}
-
-	b := s.Bytes()
-	b = bytes.TrimSuffix(b, eol)
-	if !bytes.Equal(b, nak) {
-		return fmt.Errorf("expecting NAK, found %q instead", string(b))
-	}
-
-	return nil
-}
-
-type fetchSession struct {
-	io.Reader
-	session *ssh.Session
-	done    <-chan error
-}
-
-// Close closes the session and collects the output state of the remote
-// SSH command.
-//
-// If both the remote command and the closing of the session completes
-// susccessfully it returns nil.
-//
-// If the remote command completes unsuccessfully or is interrupted by a
-// signal, it returns the corresponding *ExitError.
-//
-// Otherwise, if clossing the SSH session fails it returns the close
-// error.  Closing the session when the other has already close it is
-// not cosidered an error.
-func (f *fetchSession) Close() (err error) {
-	if err := <-f.done; err != nil {
-		return err
-	}
-
-	if err := f.session.Close(); err != nil && err != io.EOF {
-		return err
-	}
-
-	return nil
-}
-
-func (s *GitUploadPackService) getCommand() string {
-	directory := s.endpoint.Path
-	directory = directory[1:]
-
-	return fmt.Sprintf("git-upload-pack '%s'", directory)
-}
diff --git a/plumbing/client/ssh/git_upload_pack_test.go b/plumbing/client/ssh/git_upload_pack_test.go
deleted file mode 100644
index 4d5b2b1..0000000
--- a/plumbing/client/ssh/git_upload_pack_test.go
+++ /dev/null
@@ -1,144 +0,0 @@
-package ssh
-
-import (
-	"io/ioutil"
-	"os"
-
-	. "gopkg.in/check.v1"
-	"gopkg.in/src-d/go-git.v4/plumbing"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
-)
-
-type RemoteSuite struct {
-	Endpoint common.Endpoint
-}
-
-var _ = Suite(&RemoteSuite{})
-
-func (s *RemoteSuite) SetUpSuite(c *C) {
-	var err error
-	s.Endpoint, err = common.NewEndpoint("git@github.com:git-fixtures/basic.git")
-	c.Assert(err, IsNil)
-
-	if os.Getenv("SSH_AUTH_SOCK") == "" {
-		c.Skip("SSH_AUTH_SOCK is not set")
-	}
-}
-
-// A mock implementation of client.common.AuthMethod
-// to test non ssh auth method detection.
-type mockAuth struct{}
-
-func (*mockAuth) Name() string   { return "" }
-func (*mockAuth) String() string { return "" }
-
-func (s *RemoteSuite) TestSetAuthWrongType(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.SetAuth(&mockAuth{}), Equals, ErrInvalidAuthMethod)
-}
-
-func (s *RemoteSuite) TestAlreadyConnected(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	defer func() {
-		c.Assert(r.Disconnect(), IsNil)
-	}()
-
-	c.Assert(r.Connect(), Equals, ErrAlreadyConnected)
-}
-
-func (s *RemoteSuite) TestDisconnect(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	c.Assert(r.Disconnect(), IsNil)
-}
-
-func (s *RemoteSuite) TestDisconnectedWhenNonConnected(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Disconnect(), Equals, ErrNotConnected)
-}
-
-func (s *RemoteSuite) TestAlreadyDisconnected(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	c.Assert(r.Disconnect(), IsNil)
-	c.Assert(r.Disconnect(), Equals, ErrNotConnected)
-}
-
-func (s *RemoteSuite) TestServeralConnections(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	c.Assert(r.Disconnect(), IsNil)
-
-	c.Assert(r.Connect(), IsNil)
-	c.Assert(r.Disconnect(), IsNil)
-
-	c.Assert(r.Connect(), IsNil)
-	c.Assert(r.Disconnect(), IsNil)
-}
-
-func (s *RemoteSuite) TestInfoNotConnected(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	_, err := r.Info()
-	c.Assert(err, Equals, ErrNotConnected)
-}
-
-func (s *RemoteSuite) TestDefaultBranch(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	defer func() { c.Assert(r.Disconnect(), IsNil) }()
-
-	info, err := r.Info()
-	c.Assert(err, IsNil)
-	c.Assert(info.Capabilities.SymbolicReference("HEAD"), Equals, "refs/heads/master")
-}
-
-func (s *RemoteSuite) TestCapabilities(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	defer func() { c.Assert(r.Disconnect(), IsNil) }()
-
-	info, err := r.Info()
-	c.Assert(err, IsNil)
-	c.Assert(info.Capabilities.Get("agent").Values, HasLen, 1)
-}
-
-func (s *RemoteSuite) TestFetchNotConnected(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	pr := &common.GitUploadPackRequest{}
-	pr.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-	_, err := r.Fetch(pr)
-	c.Assert(err, Equals, ErrNotConnected)
-}
-
-func (s *RemoteSuite) TestFetch(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	defer func() { c.Assert(r.Disconnect(), IsNil) }()
-
-	req := &common.GitUploadPackRequest{}
-	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
-	req.Want(plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
-	reader, err := r.Fetch(req)
-	c.Assert(err, IsNil)
-	defer func() { c.Assert(reader.Close(), IsNil) }()
-
-	b, err := ioutil.ReadAll(reader)
-	c.Assert(err, IsNil)
-	c.Check(len(b), Equals, 85585)
-}
-
-func (s *RemoteSuite) TestFetchError(c *C) {
-	r := NewGitUploadPackService(s.Endpoint)
-	c.Assert(r.Connect(), IsNil)
-	defer func() { c.Assert(r.Disconnect(), IsNil) }()
-
-	req := &common.GitUploadPackRequest{}
-	req.Want(plumbing.NewHash("1111111111111111111111111111111111111111"))
-
-	reader, err := r.Fetch(req)
-	c.Assert(err, IsNil)
-
-	err = reader.Close()
-	c.Assert(err, Not(IsNil))
-}
diff --git a/plumbing/transport/client/client.go b/plumbing/transport/client/client.go
new file mode 100644
index 0000000..5c6da05
--- /dev/null
+++ b/plumbing/transport/client/client.go
@@ -0,0 +1,32 @@
+package client
+
+import (
+	"fmt"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport/http"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport/ssh"
+)
+
+// Protocols are the protocols supported by default.
+var Protocols = map[string]transport.Client{
+	"http":  http.DefaultClient,
+	"https": http.DefaultClient,
+	"ssh":   ssh.DefaultClient,
+}
+
+// InstallProtocol adds or modifies an existing protocol.
+func InstallProtocol(scheme string, c transport.Client) {
+	Protocols[scheme] = c
+}
+
+// NewClient returns the appropriate client among of the set of known protocols:
+// HTTP, SSH. See `InstallProtocol` to add or modify protocols.
+func NewClient(endpoint transport.Endpoint) (transport.Client, error) {
+	f, ok := Protocols[endpoint.Scheme]
+	if !ok {
+		return nil, fmt.Errorf("unsupported scheme %q", endpoint.Scheme)
+	}
+
+	return f, nil
+}
diff --git a/plumbing/transport/client/client_test.go b/plumbing/transport/client/client_test.go
new file mode 100644
index 0000000..90bad57
--- /dev/null
+++ b/plumbing/transport/client/client_test.go
@@ -0,0 +1,73 @@
+package client
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type ClientSuite struct{}
+
+var _ = Suite(&ClientSuite{})
+
+func (s *ClientSuite) TestNewClientHTTP(c *C) {
+	e, err := transport.NewEndpoint("http://github.com/src-d/go-git")
+	c.Assert(err, IsNil)
+
+	output, err := NewClient(e)
+	c.Assert(err, IsNil)
+	c.Assert(typeAsString(output), Equals, "*http.Client")
+
+	e, err = transport.NewEndpoint("https://github.com/src-d/go-git")
+	c.Assert(err, IsNil)
+
+	output, err = NewClient(e)
+	c.Assert(err, IsNil)
+	c.Assert(typeAsString(output), Equals, "*http.Client")
+}
+
+func (s *ClientSuite) TestNewClientSSH(c *C) {
+	e, err := transport.NewEndpoint("ssh://github.com/src-d/go-git")
+	c.Assert(err, IsNil)
+
+	output, err := NewClient(e)
+	c.Assert(err, IsNil)
+	c.Assert(typeAsString(output), Equals, "*ssh.Client")
+}
+
+func (s *ClientSuite) TestNewClientUnknown(c *C) {
+	e, err := transport.NewEndpoint("unknown://github.com/src-d/go-git")
+	c.Assert(err, IsNil)
+
+	_, err = NewClient(e)
+	c.Assert(err, NotNil)
+}
+
+func (s *ClientSuite) TestInstallProtocol(c *C) {
+	InstallProtocol("newscheme", &dummyClient{})
+	c.Assert(Protocols["newscheme"], NotNil)
+}
+
+type dummyClient struct {
+	*http.Client
+}
+
+func (*dummyClient) NewFetchPackSession(transport.Endpoint) (
+	transport.FetchPackSession, error) {
+	return nil, nil
+}
+
+func (*dummyClient) NewSendPackSession(transport.Endpoint) (
+	transport.SendPackSession, error) {
+	return nil, nil
+}
+
+func typeAsString(v interface{}) string {
+	return fmt.Sprintf("%T", v)
+}
diff --git a/plumbing/transport/client/example_test.go b/plumbing/transport/client/example_test.go
new file mode 100644
index 0000000..3e7a4f0
--- /dev/null
+++ b/plumbing/transport/client/example_test.go
@@ -0,0 +1,21 @@
+package client_test
+
+import (
+	"crypto/tls"
+	"net/http"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport/client"
+	githttp "gopkg.in/src-d/go-git.v4/plumbing/transport/http"
+)
+
+func ExampleInstallProtocol() {
+	// Create custom net/http client that.
+	httpClient := &http.Client{
+		Transport: &http.Transport{
+			TLSClientConfig: &tls.Config{InsecureSkipVerify: true},
+		},
+	}
+
+	// Install it as default client for https URLs.
+	client.InstallProtocol("https", githttp.NewClient(httpClient))
+}
diff --git a/plumbing/transport/common.go b/plumbing/transport/common.go
new file mode 100644
index 0000000..cc30564
--- /dev/null
+++ b/plumbing/transport/common.go
@@ -0,0 +1,121 @@
+// Package transport includes the implementation for different transport
+// protocols.
+//
+// `Client` can be used to fetch and send packfiles to a git server.
+// The `client` package provides higher level functions to instantiate the
+// appropiate `Client` based on the repository URL.
+//
+// Go-git supports HTTP and SSH (see `Protocols`), but you can also install
+// your own protocols (see the `client` package).
+//
+// Each protocol has its own implementation of `Client`, but you should
+// generally not use them directly, use `client.NewClient` instead.
+package transport
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"net/url"
+	"regexp"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+)
+
+var (
+	ErrRepositoryNotFound     = errors.New("repository not found")
+	ErrAuthorizationRequired  = errors.New("authorization required")
+	ErrEmptyUploadPackRequest = errors.New("empty git-upload-pack given")
+	ErrInvalidAuthMethod      = errors.New("invalid auth method")
+)
+
+const (
+	UploadPackServiceName = "git-upload-pack"
+)
+
+// Client can initiate git-fetch-pack and git-send-pack processes.
+type Client interface {
+	// NewFetchPackSession starts a git-fetch-pack session for an endpoint.
+	NewFetchPackSession(Endpoint) (FetchPackSession, error)
+	// NewSendPackSession starts a git-send-pack session for an endpoint.
+	NewSendPackSession(Endpoint) (SendPackSession, error)
+}
+
+type Session interface {
+	SetAuth(auth AuthMethod) error
+	io.Closer
+}
+
+type AuthMethod interface {
+	fmt.Stringer
+	Name() string
+}
+
+// FetchPackSession represents a git-fetch-pack session.
+// A git-fetch-pack session has two steps: reference discovery
+// (`AdvertisedReferences` function) and fetching pack (`FetchPack` function).
+// In that order.
+type FetchPackSession interface {
+	Session
+	// AdvertisedReferences retrieves the advertised references for a
+	// repository. It should be called before FetchPack, and it cannot be
+	// called after FetchPack.
+	AdvertisedReferences() (*UploadPackInfo, error)
+	// FetchPack takes a request and returns a reader for the packfile
+	// received from the server.
+	FetchPack(req *UploadPackRequest) (io.ReadCloser, error)
+}
+
+// FetchPackSession represents a git-send-pack session.
+// A git-send-pack session has two steps: reference discovery
+// (`AdvertisedReferences` function) and sending pack (`SendPack` function).
+// In that order.
+type SendPackSession interface {
+	Session
+	// AdvertisedReferences retrieves the advertised references for a
+	// repository. It should be called before FetchPack, and it cannot be
+	// called after FetchPack.
+	AdvertisedReferences() (*UploadPackInfo, error)
+	// UpdateReferences sends an update references request and returns a
+	// writer to be used for packfile writing.
+	//TODO: Complete signature.
+	SendPack() (io.WriteCloser, error)
+}
+
+type Endpoint url.URL
+
+var (
+	isSchemeRegExp   = regexp.MustCompile("^[^:]+://")
+	scpLikeUrlRegExp = regexp.MustCompile("^(?P<user>[^@]+@)?(?P<host>[^:]+):/?(?P<path>.+)$")
+)
+
+func NewEndpoint(endpoint string) (Endpoint, error) {
+	endpoint = transformSCPLikeIfNeeded(endpoint)
+
+	u, err := url.Parse(endpoint)
+	if err != nil {
+		return Endpoint{}, plumbing.NewPermanentError(err)
+	}
+
+	if !u.IsAbs() {
+		return Endpoint{}, plumbing.NewPermanentError(fmt.Errorf(
+			"invalid endpoint: %s", endpoint,
+		))
+	}
+
+	return Endpoint(*u), nil
+}
+
+func (e *Endpoint) String() string {
+	u := url.URL(*e)
+	return u.String()
+}
+
+func transformSCPLikeIfNeeded(endpoint string) string {
+	if !isSchemeRegExp.MatchString(endpoint) && scpLikeUrlRegExp.MatchString(endpoint) {
+		m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
+		return fmt.Sprintf("ssh://%s%s/%s", m[1], m[2], m[3])
+	}
+
+	return endpoint
+}
diff --git a/plumbing/transport/common_test.go b/plumbing/transport/common_test.go
new file mode 100644
index 0000000..9ca4459
--- /dev/null
+++ b/plumbing/transport/common_test.go
@@ -0,0 +1,31 @@
+package transport
+
+import (
+	"testing"
+
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type SuiteCommon struct{}
+
+var _ = Suite(&SuiteCommon{})
+
+func (s *SuiteCommon) TestNewEndpoint(c *C) {
+	e, err := NewEndpoint("ssh://git@github.com/user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointSCPLike(c *C) {
+	e, err := NewEndpoint("git@github.com:user/repository.git")
+	c.Assert(err, IsNil)
+	c.Assert(e.String(), Equals, "ssh://git@github.com/user/repository.git")
+}
+
+func (s *SuiteCommon) TestNewEndpointWrongForgat(c *C) {
+	e, err := NewEndpoint("foo")
+	c.Assert(err, Not(IsNil))
+	c.Assert(e.Host, Equals, "")
+}
diff --git a/plumbing/client/common/common.go b/plumbing/transport/fetch_pack.go
index b2d52e8..3b2a39c 100644
--- a/plumbing/client/common/common.go
+++ b/plumbing/transport/fetch_pack.go
@@ -1,14 +1,10 @@
-// Package common contains interfaces and non-specific protocol entities
-package common
+package transport
 
 import (
 	"bytes"
-	"errors"
 	"fmt"
 	"io"
 	"io/ioutil"
-	"net/url"
-	"regexp"
 	"strings"
 
 	"gopkg.in/src-d/go-git.v4/plumbing"
@@ -19,82 +15,20 @@ import (
 	"gopkg.in/src-d/go-git.v4/storage/memory"
 )
 
-var (
-	ErrRepositoryNotFound    = errors.New("repository not found")
-	ErrAuthorizationRequired = errors.New("authorization required")
-	ErrEmptyGitUploadPack    = errors.New("empty git-upload-pack given")
-	ErrInvalidAuthMethod     = errors.New("invalid auth method")
-)
-
-const GitUploadPackServiceName = "git-upload-pack"
-
-type GitUploadPackService interface {
-	Connect() error
-	SetAuth(AuthMethod) error
-	Info() (*GitUploadPackInfo, error)
-	Fetch(*GitUploadPackRequest) (io.ReadCloser, error)
-	Disconnect() error
-}
-
-// GitUploadPackServiceFactory is capable of instantiating GitUploadPackService with given endpoint
-type GitUploadPackServiceFactory func(Endpoint) GitUploadPackService
-
-type AuthMethod interface {
-	Name() string
-	String() string
-}
-
-type Endpoint url.URL
-
-var (
-	isSchemeRegExp   = regexp.MustCompile("^[^:]+://")
-	scpLikeUrlRegExp = regexp.MustCompile("^(?P<user>[^@]+@)?(?P<host>[^:]+):/?(?P<path>.+)$")
-)
-
-func NewEndpoint(endpoint string) (Endpoint, error) {
-	endpoint = transformSCPLikeIfNeeded(endpoint)
-
-	u, err := url.Parse(endpoint)
-	if err != nil {
-		return Endpoint{}, plumbing.NewPermanentError(err)
-	}
-
-	if !u.IsAbs() {
-		return Endpoint{}, plumbing.NewPermanentError(fmt.Errorf(
-			"invalid endpoint: %s", endpoint,
-		))
-	}
-
-	return Endpoint(*u), nil
-}
-
-func transformSCPLikeIfNeeded(endpoint string) string {
-	if !isSchemeRegExp.MatchString(endpoint) && scpLikeUrlRegExp.MatchString(endpoint) {
-		m := scpLikeUrlRegExp.FindStringSubmatch(endpoint)
-		return fmt.Sprintf("ssh://%s%s/%s", m[1], m[2], m[3])
-	}
-
-	return endpoint
-}
-
-func (e *Endpoint) String() string {
-	u := url.URL(*e)
-	return u.String()
-}
-
-type GitUploadPackInfo struct {
+//TODO: Replace this by advrefs.AdvRefs.
+type UploadPackInfo struct {
 	Capabilities *packp.Capabilities
 	Refs         memory.ReferenceStorage
 }
 
-func NewGitUploadPackInfo() *GitUploadPackInfo {
-	return &GitUploadPackInfo{
+func NewUploadPackInfo() *UploadPackInfo {
+	return &UploadPackInfo{
 		Capabilities: packp.NewCapabilities(),
 		Refs:         make(memory.ReferenceStorage, 0),
 	}
 }
 
-func (i *GitUploadPackInfo) Decode(r io.Reader) error {
+func (i *UploadPackInfo) Decode(r io.Reader) error {
 	d := advrefs.NewDecoder(r)
 	ar := advrefs.New()
 	if err := d.Decode(ar); err != nil {
@@ -113,7 +47,7 @@ func (i *GitUploadPackInfo) Decode(r io.Reader) error {
 	return nil
 }
 
-func (i *GitUploadPackInfo) addRefs(ar *advrefs.AdvRefs) error {
+func (i *UploadPackInfo) addRefs(ar *advrefs.AdvRefs) error {
 	for name, hash := range ar.References {
 		ref := plumbing.NewReferenceFromStrings(name, hash.String())
 		i.Refs.SetReference(ref)
@@ -122,7 +56,7 @@ func (i *GitUploadPackInfo) addRefs(ar *advrefs.AdvRefs) error {
 	return i.addSymbolicRefs(ar)
 }
 
-func (i *GitUploadPackInfo) addSymbolicRefs(ar *advrefs.AdvRefs) error {
+func (i *UploadPackInfo) addSymbolicRefs(ar *advrefs.AdvRefs) error {
 	if !hasSymrefs(ar) {
 		return nil
 	}
@@ -146,16 +80,16 @@ func hasSymrefs(ar *advrefs.AdvRefs) bool {
 	return ar.Capabilities.Supports("symref")
 }
 
-func (i *GitUploadPackInfo) Head() *plumbing.Reference {
+func (i *UploadPackInfo) Head() *plumbing.Reference {
 	ref, _ := storer.ResolveReference(i.Refs, plumbing.HEAD)
 	return ref
 }
 
-func (i *GitUploadPackInfo) String() string {
+func (i *UploadPackInfo) String() string {
 	return string(i.Bytes())
 }
 
-func (i *GitUploadPackInfo) Bytes() []byte {
+func (i *UploadPackInfo) Bytes() []byte {
 	var buf bytes.Buffer
 	e := pktline.NewEncoder(&buf)
 
@@ -180,26 +114,26 @@ func (i *GitUploadPackInfo) Bytes() []byte {
 	return buf.Bytes()
 }
 
-type GitUploadPackRequest struct {
+type UploadPackRequest struct {
 	Wants []plumbing.Hash
 	Haves []plumbing.Hash
 	Depth int
 }
 
-func (r *GitUploadPackRequest) Want(h ...plumbing.Hash) {
+func (r *UploadPackRequest) Want(h ...plumbing.Hash) {
 	r.Wants = append(r.Wants, h...)
 }
 
-func (r *GitUploadPackRequest) Have(h ...plumbing.Hash) {
+func (r *UploadPackRequest) Have(h ...plumbing.Hash) {
 	r.Haves = append(r.Haves, h...)
 }
 
-func (r *GitUploadPackRequest) String() string {
+func (r *UploadPackRequest) String() string {
 	b, _ := ioutil.ReadAll(r.Reader())
 	return string(b)
 }
 
-func (r *GitUploadPackRequest) Reader() *strings.Reader {
+func (r *UploadPackRequest) Reader() *strings.Reader {
 	var buf bytes.Buffer
 	e := pktline.NewEncoder(&buf)
 
diff --git a/plumbing/transport/fetch_pack_test.go b/plumbing/transport/fetch_pack_test.go
new file mode 100644
index 0000000..7a7f86f
--- /dev/null
+++ b/plumbing/transport/fetch_pack_test.go
@@ -0,0 +1,96 @@
+package transport
+
+import (
+	"bytes"
+	"encoding/base64"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+
+	. "gopkg.in/check.v1"
+)
+
+type UploadPackSuite struct{}
+
+var _ = Suite(&UploadPackSuite{})
+
+const UploadPackInfoFixture = "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"
+
+func (s *UploadPackSuite) TestUploadPackInfo(c *C) {
+	b, _ := base64.StdEncoding.DecodeString(UploadPackInfoFixture)
+
+	i := NewUploadPackInfo()
+	err := i.Decode(bytes.NewBuffer(b))
+	c.Assert(err, IsNil)
+
+	name := i.Capabilities.SymbolicReference("HEAD")
+	c.Assert(name, Equals, "refs/heads/master")
+	c.Assert(i.Refs, HasLen, 4)
+
+	ref := i.Refs[plumbing.ReferenceName(name)]
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+
+	ref = i.Refs[plumbing.HEAD]
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Target(), Equals, plumbing.ReferenceName(name))
+}
+
+const UploadPackInfoNoHEADFixture = "MDAxZSMgc2VydmljZT1naXQtdXBsb2FkLXBhY2sKMDAwMDAwYmNkN2UxZmVlMjYxMjM0YmIzYTQzYzA5NmY1NTg3NDhhNTY5ZDc5ZWZmIHJlZnMvaGVhZHMvdjQAbXVsdGlfYWNrIHRoaW4tcGFjayBzaWRlLWJhbmQgc2lkZS1iYW5kLTY0ayBvZnMtZGVsdGEgc2hhbGxvdyBuby1wcm9ncmVzcyBpbmNsdWRlLXRhZyBtdWx0aV9hY2tfZGV0YWlsZWQgbm8tZG9uZSBhZ2VudD1naXQvMS45LjEKMDAwMA=="
+
+func (s *UploadPackSuite) TestUploadPackInfoNoHEAD(c *C) {
+	b, _ := base64.StdEncoding.DecodeString(UploadPackInfoNoHEADFixture)
+
+	i := NewUploadPackInfo()
+	err := i.Decode(bytes.NewBuffer(b))
+	c.Assert(err, IsNil)
+
+	name := i.Capabilities.SymbolicReference("HEAD")
+	c.Assert(name, Equals, "")
+	c.Assert(i.Refs, HasLen, 1)
+
+	ref := i.Refs["refs/heads/v4"]
+	c.Assert(ref, NotNil)
+	c.Assert(ref.Hash().String(), Equals, "d7e1fee261234bb3a43c096f558748a569d79eff")
+}
+
+func (s *UploadPackSuite) TestUploadPackInfoEmpty(c *C) {
+	b := bytes.NewBuffer(nil)
+
+	i := NewUploadPackInfo()
+	err := i.Decode(b)
+	c.Assert(err, ErrorMatches, "permanent.*empty.*")
+}
+
+func (s *UploadPackSuite) TestUploadPackEncode(c *C) {
+	info := NewUploadPackInfo()
+	info.Capabilities.Add("symref", "HEAD:refs/heads/master")
+
+	ref := plumbing.ReferenceName("refs/heads/master")
+	hash := plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5")
+	info.Refs = map[plumbing.ReferenceName]*plumbing.Reference{
+		plumbing.HEAD: plumbing.NewSymbolicReference(plumbing.HEAD, ref),
+		ref:           plumbing.NewHashReference(ref, hash),
+	}
+
+	c.Assert(info.Head(), NotNil)
+	c.Assert(info.String(), Equals,
+		"001e# service=git-upload-pack\n"+
+			"000000506ecf0ef2c2dffb796033e5a02219af86ec6584e5 HEAD\x00symref=HEAD:refs/heads/master\n"+
+			"003f6ecf0ef2c2dffb796033e5a02219af86ec6584e5 refs/heads/master\n"+
+			"0000",
+	)
+}
+
+func (s *UploadPackSuite) TestUploadPackRequest(c *C) {
+	r := &UploadPackRequest{}
+	r.Want(plumbing.NewHash("d82f291cde9987322c8a0c81a325e1ba6159684c"))
+	r.Want(plumbing.NewHash("2b41ef280fdb67a9b250678686a0c3e03b0a9989"))
+	r.Have(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	c.Assert(r.String(), Equals,
+		"0032want d82f291cde9987322c8a0c81a325e1ba6159684c\n"+
+			"0032want 2b41ef280fdb67a9b250678686a0c3e03b0a9989\n"+
+			"0032have 6ecf0ef2c2dffb796033e5a02219af86ec6584e5\n0000"+
+			"0009done\n",
+	)
+}
diff --git a/plumbing/transport/http/common.go b/plumbing/transport/http/common.go
new file mode 100644
index 0000000..038c469
--- /dev/null
+++ b/plumbing/transport/http/common.go
@@ -0,0 +1,155 @@
+// Package http implements a HTTP client for go-git.
+package http
+
+import (
+	"fmt"
+	"net/http"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+)
+
+type Client struct {
+	c *http.Client
+}
+
+var DefaultClient = NewClient(nil)
+
+// NewClient creates a new client with a custom net/http client.
+// See `InstallProtocol` to install and override default http client.
+// Unless a properly initialized client is given, it will fall back into
+// `http.DefaultClient`.
+func NewClient(c *http.Client) transport.Client {
+	if c == nil {
+		return &Client{http.DefaultClient}
+	}
+
+	return &Client{
+		c: c,
+	}
+}
+
+func (c *Client) NewFetchPackSession(ep transport.Endpoint) (
+	transport.FetchPackSession, error) {
+
+	return newFetchPackSession(c.c, ep), nil
+}
+
+func (c *Client) NewSendPackSession(ep transport.Endpoint) (
+	transport.SendPackSession, error) {
+
+	return newSendPackSession(c.c, ep), nil
+}
+
+type session struct {
+	auth     AuthMethod
+	client   *http.Client
+	endpoint transport.Endpoint
+}
+
+func (s *session) SetAuth(auth transport.AuthMethod) error {
+	a, ok := auth.(AuthMethod)
+	if !ok {
+		return transport.ErrInvalidAuthMethod
+	}
+
+	s.auth = a
+	return nil
+}
+
+func (*session) Close() error {
+	return nil
+}
+
+func (s *session) applyAuthToRequest(req *http.Request) {
+	if s.auth == nil {
+		return
+	}
+
+	s.auth.setAuth(req)
+}
+
+// AuthMethod is concrete implementation of common.AuthMethod for HTTP services
+type AuthMethod interface {
+	transport.AuthMethod
+	setAuth(r *http.Request)
+}
+
+func basicAuthFromEndpoint(ep transport.Endpoint) *BasicAuth {
+	info := ep.User
+	if info == nil {
+		return nil
+	}
+
+	p, ok := info.Password()
+	if !ok {
+		return nil
+	}
+
+	u := info.Username()
+	return NewBasicAuth(u, p)
+}
+
+// BasicAuth represent a HTTP basic auth
+type BasicAuth struct {
+	username, password string
+}
+
+// NewBasicAuth returns a basicAuth base on the given user and password
+func NewBasicAuth(username, password string) *BasicAuth {
+	return &BasicAuth{username, password}
+}
+
+func (a *BasicAuth) setAuth(r *http.Request) {
+	if a == nil {
+		return
+	}
+
+	r.SetBasicAuth(a.username, a.password)
+}
+
+// Name is name of the auth
+func (a *BasicAuth) Name() string {
+	return "http-basic-auth"
+}
+
+func (a *BasicAuth) String() string {
+	masked := "*******"
+	if a.password == "" {
+		masked = "<empty>"
+	}
+
+	return fmt.Sprintf("%s - %s:%s", a.Name(), a.username, masked)
+}
+
+// Err is a dedicated error to return errors based on status code
+type Err struct {
+	Response *http.Response
+}
+
+// NewErr returns a new Err based on a http response
+func NewErr(r *http.Response) error {
+	if r.StatusCode >= http.StatusOK && r.StatusCode < http.StatusMultipleChoices {
+		return nil
+	}
+
+	switch r.StatusCode {
+	case http.StatusUnauthorized:
+		return transport.ErrAuthorizationRequired
+	case http.StatusNotFound:
+		return transport.ErrRepositoryNotFound
+	}
+
+	return plumbing.NewUnexpectedError(&Err{r})
+}
+
+// StatusCode returns the status code of the response
+func (e *Err) StatusCode() int {
+	return e.Response.StatusCode
+}
+
+func (e *Err) Error() string {
+	return fmt.Sprintf("unexpected requesting %q status code: %d",
+		e.Response.Request.URL, e.Response.StatusCode,
+	)
+}
diff --git a/plumbing/transport/http/common_test.go b/plumbing/transport/http/common_test.go
new file mode 100644
index 0000000..1d09fba
--- /dev/null
+++ b/plumbing/transport/http/common_test.go
@@ -0,0 +1,89 @@
+package http
+
+import (
+	"crypto/tls"
+	"net/http"
+	"testing"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type ClientSuite struct {
+	Endpoint transport.Endpoint
+}
+
+var _ = Suite(&ClientSuite{})
+
+func (s *ClientSuite) SetUpSuite(c *C) {
+	var err error
+	s.Endpoint, err = transport.NewEndpoint("https://github.com/git-fixtures/basic")
+	c.Assert(err, IsNil)
+}
+
+func (s *FetchPackSuite) TestNewClient(c *C) {
+	roundTripper := &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: true}}
+	client := &http.Client{Transport: roundTripper}
+	r := NewClient(client).(*Client)
+
+	c.Assert(r.c, Equals, client)
+}
+
+func (s *ClientSuite) TestNewBasicAuth(c *C) {
+	a := NewBasicAuth("foo", "qux")
+
+	c.Assert(a.Name(), Equals, "http-basic-auth")
+	c.Assert(a.String(), Equals, "http-basic-auth - foo:*******")
+}
+
+func (s *ClientSuite) TestNewErrOK(c *C) {
+	res := &http.Response{StatusCode: http.StatusOK}
+	err := NewErr(res)
+	c.Assert(err, IsNil)
+}
+
+func (s *ClientSuite) TestNewErrUnauthorized(c *C) {
+	s.testNewHTTPError(c, http.StatusUnauthorized, "authorization required")
+}
+
+func (s *ClientSuite) TestNewErrNotFound(c *C) {
+	s.testNewHTTPError(c, http.StatusNotFound, "repository not found")
+}
+
+func (s *ClientSuite) TestNewHTTPError40x(c *C) {
+	s.testNewHTTPError(c, http.StatusPaymentRequired, "unexpected client error.*")
+}
+
+func (s *ClientSuite) testNewHTTPError(c *C, code int, msg string) {
+	req, _ := http.NewRequest("GET", "foo", nil)
+	res := &http.Response{
+		StatusCode: code,
+		Request:    req,
+	}
+
+	err := NewErr(res)
+	c.Assert(err, NotNil)
+	c.Assert(err, ErrorMatches, msg)
+}
+
+func (s *ClientSuite) TestSetAuth(c *C) {
+	auth := &BasicAuth{}
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	r.SetAuth(auth)
+	c.Assert(auth, Equals, r.(*fetchPackSession).auth)
+}
+
+type mockAuth struct{}
+
+func (*mockAuth) Name() string   { return "" }
+func (*mockAuth) String() string { return "" }
+
+func (s *ClientSuite) TestSetAuthWrongType(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	c.Assert(r.SetAuth(&mockAuth{}), Equals, transport.ErrInvalidAuthMethod)
+}
diff --git a/plumbing/transport/http/fetch_pack.go b/plumbing/transport/http/fetch_pack.go
new file mode 100644
index 0000000..0c32672
--- /dev/null
+++ b/plumbing/transport/http/fetch_pack.go
@@ -0,0 +1,155 @@
+package http
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"io"
+	"net/http"
+	"strings"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/pktline"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+)
+
+type fetchPackSession struct {
+	*session
+}
+
+func newFetchPackSession(c *http.Client,
+	ep transport.Endpoint) transport.FetchPackSession {
+
+	return &fetchPackSession{
+		session: &session{
+			auth:     basicAuthFromEndpoint(ep),
+			client:   c,
+			endpoint: ep,
+		},
+	}
+}
+
+func (s *fetchPackSession) AdvertisedReferences() (*transport.UploadPackInfo,
+	error) {
+
+	url := fmt.Sprintf(
+		"%s/info/refs?service=%s",
+		s.endpoint.String(), transport.UploadPackServiceName,
+	)
+
+	req, err := http.NewRequest(http.MethodGet, url, nil)
+	if err != nil {
+		return nil, err
+	}
+
+	s.applyAuthToRequest(req)
+	s.applyHeadersToRequest(req, nil)
+	res, err := s.client.Do(req)
+	if err != nil {
+		return nil, err
+	}
+
+	defer res.Body.Close()
+	if res.StatusCode == http.StatusUnauthorized {
+		return nil, transport.ErrAuthorizationRequired
+	}
+
+	i := transport.NewUploadPackInfo()
+	return i, i.Decode(res.Body)
+}
+
+func (s *fetchPackSession) FetchPack(r *transport.UploadPackRequest) (io.ReadCloser, error) {
+	url := fmt.Sprintf(
+		"%s/%s",
+		s.endpoint.String(), transport.UploadPackServiceName,
+	)
+
+	res, err := s.doRequest("POST", url, r.Reader())
+	if err != nil {
+		return nil, err
+	}
+
+	reader := newBufferedReadCloser(res.Body)
+	if _, err := reader.Peek(1); err != nil {
+		if err == io.ErrUnexpectedEOF {
+			return nil, transport.ErrEmptyUploadPackRequest
+		}
+
+		return nil, err
+	}
+
+	if err := discardResponseInfo(reader); err != nil {
+		return nil, err
+	}
+
+	return reader, nil
+}
+
+// Close does nothing.
+func (s *fetchPackSession) Close() error {
+	return nil
+}
+
+func discardResponseInfo(r io.Reader) error {
+	s := pktline.NewScanner(r)
+	for s.Scan() {
+		if bytes.Equal(s.Bytes(), []byte{'N', 'A', 'K', '\n'}) {
+			break
+		}
+	}
+
+	return s.Err()
+}
+
+func (s *fetchPackSession) doRequest(method, url string, content *strings.Reader) (*http.Response, error) {
+	var body io.Reader
+	if content != nil {
+		body = content
+	}
+
+	req, err := http.NewRequest(method, url, body)
+	if err != nil {
+		return nil, plumbing.NewPermanentError(err)
+	}
+
+	s.applyHeadersToRequest(req, content)
+	s.applyAuthToRequest(req)
+
+	res, err := s.client.Do(req)
+	if err != nil {
+		return nil, plumbing.NewUnexpectedError(err)
+	}
+
+	if err := NewErr(res); err != nil {
+		_ = res.Body.Close()
+		return nil, err
+	}
+
+	return res, nil
+}
+
+func (s *fetchPackSession) applyHeadersToRequest(req *http.Request, content *strings.Reader) {
+	req.Header.Add("User-Agent", "git/1.0")
+	req.Header.Add("Host", "github.com")
+
+	if content == nil {
+		req.Header.Add("Accept", "*/*")
+	} else {
+		req.Header.Add("Accept", "application/x-git-upload-pack-result")
+		req.Header.Add("Content-Type", "application/x-git-upload-pack-request")
+		req.Header.Add("Content-Length", string(content.Len()))
+	}
+}
+
+type bufferedReadCloser struct {
+	*bufio.Reader
+	closer io.Closer
+}
+
+func newBufferedReadCloser(r io.ReadCloser) *bufferedReadCloser {
+	return &bufferedReadCloser{bufio.NewReader(r), r}
+}
+
+func (r *bufferedReadCloser) Close() error {
+	return r.closer.Close()
+}
diff --git a/plumbing/transport/http/fetch_pack_test.go b/plumbing/transport/http/fetch_pack_test.go
new file mode 100644
index 0000000..5ec9991
--- /dev/null
+++ b/plumbing/transport/http/fetch_pack_test.go
@@ -0,0 +1,122 @@
+package http
+
+import (
+	"fmt"
+	"io/ioutil"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	. "gopkg.in/check.v1"
+)
+
+type FetchPackSuite struct {
+	Endpoint transport.Endpoint
+}
+
+var _ = Suite(&FetchPackSuite{})
+
+func (s *FetchPackSuite) SetUpSuite(c *C) {
+	fmt.Println("SetUpSuite\n")
+	var err error
+	s.Endpoint, err = transport.NewEndpoint("https://github.com/git-fixtures/basic")
+	c.Assert(err, IsNil)
+}
+
+func (s *FetchPackSuite) TestInfoEmpty(c *C) {
+	endpoint, _ := transport.NewEndpoint("https://github.com/git-fixture/empty")
+	r, err := DefaultClient.NewFetchPackSession(endpoint)
+	c.Assert(err, IsNil)
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, Equals, transport.ErrAuthorizationRequired)
+	c.Assert(info, IsNil)
+}
+
+//TODO: Test this error with HTTP BasicAuth too.
+func (s *FetchPackSuite) TestInfoNotExists(c *C) {
+	endpoint, _ := transport.NewEndpoint("https://github.com/git-fixture/not-exists")
+	r, err := DefaultClient.NewFetchPackSession(endpoint)
+	c.Assert(err, IsNil)
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, Equals, transport.ErrAuthorizationRequired)
+	c.Assert(info, IsNil)
+}
+
+func (s *FetchPackSuite) TestDefaultBranch(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.SymbolicReference("HEAD"), Equals, "refs/heads/master")
+}
+
+func (s *FetchPackSuite) TestCapabilities(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.Get("agent").Values, HasLen, 1)
+}
+
+func (s *FetchPackSuite) TestFullFetchPack(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info, NotNil)
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+
+	b, err := ioutil.ReadAll(reader)
+	c.Assert(err, IsNil)
+	c.Assert(b, HasLen, 85374)
+}
+
+func (s *FetchPackSuite) TestFetchPack(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+
+	b, err := ioutil.ReadAll(reader)
+	c.Assert(err, IsNil)
+	c.Assert(b, HasLen, 85374)
+}
+
+func (s *FetchPackSuite) TestFetchPackNoChanges(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Have(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+
+	reader, err := r.FetchPack(req)
+	c.Assert(err, Equals, transport.ErrEmptyUploadPackRequest)
+	c.Assert(reader, IsNil)
+}
+
+func (s *FetchPackSuite) TestFetchPackMulti(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Want(plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
+
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+
+	b, err := ioutil.ReadAll(reader)
+	c.Assert(err, IsNil)
+	c.Assert(b, HasLen, 85585)
+}
diff --git a/plumbing/transport/http/send_pack.go b/plumbing/transport/http/send_pack.go
new file mode 100644
index 0000000..39be95c
--- /dev/null
+++ b/plumbing/transport/http/send_pack.go
@@ -0,0 +1,29 @@
+package http
+
+import (
+	"errors"
+	"io"
+	"net/http"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+)
+
+var errSendPackNotSupported = errors.New("send-pack not supported yet")
+
+type sendPackSession struct{
+	*session
+}
+
+func newSendPackSession(c *http.Client, ep transport.Endpoint) transport.SendPackSession {
+	return &sendPackSession{&session{}}
+}
+
+func (s *sendPackSession) AdvertisedReferences() (*transport.UploadPackInfo,
+	error) {
+
+	return nil, errSendPackNotSupported
+}
+
+func (s *sendPackSession) SendPack() (io.WriteCloser, error) {
+	return nil, errSendPackNotSupported
+}
diff --git a/plumbing/client/ssh/auth_method.go b/plumbing/transport/ssh/auth_method.go
index 587f59a..9c3d6f3 100644
--- a/plumbing/client/ssh/auth_method.go
+++ b/plumbing/transport/ssh/auth_method.go
@@ -7,14 +7,12 @@ import (
 
 	"golang.org/x/crypto/ssh"
 	"golang.org/x/crypto/ssh/agent"
-	"gopkg.in/src-d/go-git.v4/plumbing/client/common"
 )
 
 // AuthMethod is the interface all auth methods for the ssh client
 // must implement. The clientConfig method returns the ssh client
 // configuration needed to establish an ssh connection.
 type AuthMethod interface {
-	common.AuthMethod
 	clientConfig() *ssh.ClientConfig
 }
 
diff --git a/plumbing/client/ssh/auth_method_test.go b/plumbing/transport/ssh/auth_method_test.go
index a87c950..f9e7dec 100644
--- a/plumbing/client/ssh/auth_method_test.go
+++ b/plumbing/transport/ssh/auth_method_test.go
@@ -2,13 +2,10 @@ package ssh
 
 import (
 	"fmt"
-	"testing"
 
 	. "gopkg.in/check.v1"
 )
 
-func Test(t *testing.T) { TestingT(t) }
-
 type SuiteCommon struct{}
 
 var _ = Suite(&SuiteCommon{})
diff --git a/plumbing/transport/ssh/common.go b/plumbing/transport/ssh/common.go
new file mode 100644
index 0000000..6f0f3d4
--- /dev/null
+++ b/plumbing/transport/ssh/common.go
@@ -0,0 +1,151 @@
+package ssh
+
+import (
+	"errors"
+	"fmt"
+	"io"
+	"strings"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	"golang.org/x/crypto/ssh"
+)
+
+// New errors introduced by this package.
+var (
+	ErrAdvertistedReferencesAlreadyCalled = errors.New("cannot call AdvertisedReference twice")
+	ErrAlreadyConnected                   = errors.New("ssh session already created")
+	ErrAuthRequired                       = errors.New("cannot connect: auth required")
+	ErrNotConnected                       = errors.New("not connected")
+	ErrUploadPackAnswerFormat             = errors.New("git-upload-pack bad answer format")
+	ErrUnsupportedVCS                     = errors.New("only git is supported")
+	ErrUnsupportedRepo                    = errors.New("only github.com is supported")
+)
+
+type Client struct{}
+
+var DefaultClient = NewClient()
+
+func NewClient() transport.Client {
+	return &Client{}
+}
+
+func (c *Client) NewFetchPackSession(ep transport.Endpoint) (
+	transport.FetchPackSession, error) {
+
+	return newFetchPackSession(ep)
+}
+
+func (c *Client) NewSendPackSession(ep transport.Endpoint) (
+	transport.SendPackSession, error) {
+
+	return newSendPackSession(ep)
+}
+
+type session struct {
+	connected   bool
+	endpoint    transport.Endpoint
+	client      *ssh.Client
+	session     *ssh.Session
+	stdin       io.WriteCloser
+	stdout      io.Reader
+	sessionDone chan error
+	auth        AuthMethod
+}
+
+func (s *session) SetAuth(auth transport.AuthMethod) error {
+	a, ok := auth.(AuthMethod)
+	if !ok {
+		return transport.ErrInvalidAuthMethod
+	}
+
+	s.auth = a
+	return nil
+}
+
+// Close closes the SSH session.
+func (s *session) Close() error {
+	if !s.connected {
+		return nil
+	}
+
+	s.connected = false
+	return s.client.Close()
+}
+
+// ensureConnected connects to the SSH server, unless a AuthMethod was set with
+// SetAuth method, by default uses an auth method based on PublicKeysCallback,
+// it connects to a SSH agent, using the address stored in the SSH_AUTH_SOCK
+// environment var.
+func (s *session) connect() error {
+	if s.connected {
+		return ErrAlreadyConnected
+	}
+
+	if err := s.setAuthFromEndpoint(); err != nil {
+		return err
+	}
+
+	var err error
+	s.client, err = ssh.Dial("tcp", s.getHostWithPort(), s.auth.clientConfig())
+	if err != nil {
+		return err
+	}
+
+	if err := s.openSSHSession(); err != nil {
+		_ = s.client.Close()
+		return err
+	}
+
+	s.connected = true
+	return nil
+}
+
+func (s *session) getHostWithPort() string {
+	host := s.endpoint.Host
+	if strings.Index(s.endpoint.Host, ":") == -1 {
+		host += ":22"
+	}
+
+	return host
+}
+
+func (s *session) setAuthFromEndpoint() error {
+	var u string
+	if info := s.endpoint.User; info != nil {
+		u = info.Username()
+	}
+
+	var err error
+	s.auth, err = NewSSHAgentAuth(u)
+	return err
+}
+
+func (s *session) openSSHSession() error {
+	var err error
+	s.session, err = s.client.NewSession()
+	if err != nil {
+		return fmt.Errorf("cannot open SSH session: %s", err)
+	}
+
+	s.stdin, err = s.session.StdinPipe()
+	if err != nil {
+		return fmt.Errorf("cannot pipe remote stdin: %s", err)
+	}
+
+	s.stdout, err = s.session.StdoutPipe()
+	if err != nil {
+		return fmt.Errorf("cannot pipe remote stdout: %s", err)
+	}
+
+	return nil
+}
+
+func (s *session) runCommand(cmd string) chan error {
+	done := make(chan error)
+	go func() {
+		done <- s.session.Run(cmd)
+	}()
+
+	return done
+}
diff --git a/plumbing/transport/ssh/common_test.go b/plumbing/transport/ssh/common_test.go
new file mode 100644
index 0000000..ac4d03e
--- /dev/null
+++ b/plumbing/transport/ssh/common_test.go
@@ -0,0 +1,17 @@
+package ssh
+
+import (
+	"testing"
+
+	. "gopkg.in/check.v1"
+)
+
+func Test(t *testing.T) { TestingT(t) }
+
+type ClientSuite struct{}
+
+var _ = Suite(&ClientSuite{})
+
+func (s *ClientSuite) TestNewClient(c *C) {
+	c.Assert(DefaultClient, DeepEquals, NewClient())
+}
diff --git a/plumbing/transport/ssh/fetch_pack.go b/plumbing/transport/ssh/fetch_pack.go
new file mode 100644
index 0000000..bda4edf
--- /dev/null
+++ b/plumbing/transport/ssh/fetch_pack.go
@@ -0,0 +1,202 @@
+// Package ssh implements a ssh client for go-git.
+package ssh
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/pktline"
+	"gopkg.in/src-d/go-git.v4/plumbing/format/packp/ulreq"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	"golang.org/x/crypto/ssh"
+)
+
+type fetchPackSession struct {
+	*session
+	cmdRun     bool
+	advRefsRun bool
+	done       chan error
+}
+
+func newFetchPackSession(ep transport.Endpoint) (*fetchPackSession, error) {
+	s := &fetchPackSession{
+		session: &session{
+			endpoint: ep,
+		},
+	}
+	if err := s.connect(); err != nil {
+		return nil, err
+	}
+
+	return s, nil
+}
+
+func (s *fetchPackSession) AdvertisedReferences() (*transport.UploadPackInfo, error) {
+	if s.advRefsRun {
+		return nil, ErrAdvertistedReferencesAlreadyCalled
+	}
+
+	if err := s.ensureRunCommand(); err != nil {
+		return nil, err
+	}
+
+	defer func() { s.advRefsRun = true }()
+
+	i := transport.NewUploadPackInfo()
+	return i, i.Decode(s.stdout)
+}
+
+// FetchPack returns a packfile for a given upload request.
+// Closing the returned reader will close the SSH session.
+func (s *fetchPackSession) FetchPack(req *transport.UploadPackRequest) (
+	io.ReadCloser, error) {
+
+	if !s.advRefsRun {
+		if _, err := s.AdvertisedReferences(); err != nil {
+			return nil, err
+		}
+	}
+
+	if err := fetchPack(s.stdin, s.stdout, req); err != nil {
+		return nil, err
+	}
+
+	return &fetchSession{
+		Reader:  s.stdout,
+		session: s.session.session,
+		done:    s.done,
+	}, nil
+}
+
+func (s *fetchPackSession) ensureRunCommand() error {
+	if s.cmdRun {
+		return nil
+	}
+
+	s.cmdRun = true
+	s.done = s.runCommand(s.getCommand())
+	return nil
+}
+
+type fetchSession struct {
+	io.Reader
+	session *ssh.Session
+	done    <-chan error
+}
+
+// Close closes the session and collects the output state of the remote
+// SSH command.
+//
+// If both the remote command and the closing of the session completes
+// susccessfully it returns nil.
+//
+// If the remote command completes unsuccessfully or is interrupted by a
+// signal, it returns the corresponding *ExitError.
+//
+// Otherwise, if clossing the SSH session fails it returns the close
+// error.  Closing the session when the other has already close it is
+// not cosidered an error.
+func (f *fetchSession) Close() (err error) {
+	if err := <-f.done; err != nil {
+		return err
+	}
+
+	if err := f.session.Close(); err != nil && err != io.EOF {
+		return err
+	}
+
+	return nil
+}
+
+func (s *fetchPackSession) getCommand() string {
+	directory := s.endpoint.Path
+	directory = directory[1:]
+
+	return fmt.Sprintf("git-upload-pack '%s'", directory)
+}
+
+var (
+	nak = []byte("NAK")
+	eol = []byte("\n")
+)
+
+// FetchPack implements the git-fetch-pack protocol.
+//
+// TODO support multi_ack mode
+// TODO support multi_ack_detailed mode
+// TODO support acks for common objects
+// TODO build a proper state machine for all these processing options
+func fetchPack(w io.WriteCloser, r io.Reader,
+	req *transport.UploadPackRequest) error {
+
+	if err := sendUlReq(w, req); err != nil {
+		return fmt.Errorf("sending upload-req message: %s", err)
+	}
+
+	if err := sendHaves(w, req); err != nil {
+		return fmt.Errorf("sending haves message: %s", err)
+	}
+
+	if err := sendDone(w); err != nil {
+		return fmt.Errorf("sending done message: %s", err)
+	}
+
+	if err := w.Close(); err != nil {
+		return fmt.Errorf("closing input: %s", err)
+	}
+
+	if err := readNAK(r); err != nil {
+		return fmt.Errorf("reading NAK: %s", err)
+	}
+
+	return nil
+}
+
+func sendUlReq(w io.Writer, req *transport.UploadPackRequest) error {
+	ur := ulreq.New()
+	ur.Wants = req.Wants
+	ur.Depth = ulreq.DepthCommits(req.Depth)
+	e := ulreq.NewEncoder(w)
+
+	return e.Encode(ur)
+}
+
+func sendHaves(w io.Writer, req *transport.UploadPackRequest) error {
+	e := pktline.NewEncoder(w)
+	for _, have := range req.Haves {
+		if err := e.Encodef("have %s\n", have); err != nil {
+			return fmt.Errorf("sending haves for %q: %s", have, err)
+		}
+	}
+
+	if len(req.Haves) != 0 {
+		if err := e.Flush(); err != nil {
+			return fmt.Errorf("sending flush-pkt after haves: %s", err)
+		}
+	}
+
+	return nil
+}
+
+func sendDone(w io.Writer) error {
+	e := pktline.NewEncoder(w)
+
+	return e.Encodef("done\n")
+}
+
+func readNAK(r io.Reader) error {
+	s := pktline.NewScanner(r)
+	if !s.Scan() {
+		return s.Err()
+	}
+
+	b := s.Bytes()
+	b = bytes.TrimSuffix(b, eol)
+	if !bytes.Equal(b, nak) {
+		return fmt.Errorf("expecting NAK, found %q instead", string(b))
+	}
+
+	return nil
+}
diff --git a/plumbing/transport/ssh/fetch_pack_test.go b/plumbing/transport/ssh/fetch_pack_test.go
new file mode 100644
index 0000000..3d62e57
--- /dev/null
+++ b/plumbing/transport/ssh/fetch_pack_test.go
@@ -0,0 +1,100 @@
+package ssh
+
+import (
+	"io/ioutil"
+	"os"
+
+	"gopkg.in/src-d/go-git.v4/plumbing"
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+
+	. "gopkg.in/check.v1"
+)
+
+type FetchPackSuite struct {
+	Endpoint transport.Endpoint
+}
+
+var _ = Suite(&FetchPackSuite{})
+
+func (s *FetchPackSuite) SetUpSuite(c *C) {
+	var err error
+	s.Endpoint, err = transport.NewEndpoint("git@github.com:git-fixtures/basic.git")
+	c.Assert(err, IsNil)
+
+	if os.Getenv("SSH_AUTH_SOCK") == "" {
+		c.Skip("SSH_AUTH_SOCK is not set")
+	}
+}
+
+func (s *FetchPackSuite) TestDefaultBranch(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.SymbolicReference("HEAD"), Equals, "refs/heads/master")
+}
+
+func (s *FetchPackSuite) TestCapabilities(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	info, err := r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+	c.Assert(info.Capabilities.Get("agent").Values, HasLen, 1)
+}
+
+func (s *FetchPackSuite) TestFullFetchPack(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	_, err = r.AdvertisedReferences()
+	c.Assert(err, IsNil)
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Want(plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+
+	defer func() { c.Assert(reader.Close(), IsNil) }()
+
+	b, err := ioutil.ReadAll(reader)
+	c.Assert(err, IsNil)
+	c.Check(len(b), Equals, 85585)
+}
+
+func (s *FetchPackSuite) TestFetchPack(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("6ecf0ef2c2dffb796033e5a02219af86ec6584e5"))
+	req.Want(plumbing.NewHash("e8d3ffab552895c19b9fcf7aa264d277cde33881"))
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(reader.Close(), IsNil) }()
+
+	b, err := ioutil.ReadAll(reader)
+	c.Assert(err, IsNil)
+	c.Check(len(b), Equals, 85585)
+}
+
+func (s *FetchPackSuite) TestFetchError(c *C) {
+	r, err := DefaultClient.NewFetchPackSession(s.Endpoint)
+	c.Assert(err, IsNil)
+	defer func() { c.Assert(r.Close(), IsNil) }()
+
+	req := &transport.UploadPackRequest{}
+	req.Want(plumbing.NewHash("1111111111111111111111111111111111111111"))
+
+	reader, err := r.FetchPack(req)
+	c.Assert(err, IsNil)
+
+	err = reader.Close()
+	c.Assert(err, Not(IsNil))
+}
diff --git a/plumbing/transport/ssh/send_pack.go b/plumbing/transport/ssh/send_pack.go
new file mode 100644
index 0000000..afe7510
--- /dev/null
+++ b/plumbing/transport/ssh/send_pack.go
@@ -0,0 +1,30 @@
+package ssh
+
+import (
+	"errors"
+	"io"
+
+	"gopkg.in/src-d/go-git.v4/plumbing/transport"
+)
+
+var errSendPackNotSupported = errors.New("send-pack not supported yet")
+
+type sendPackSession struct {
+	*session
+}
+
+func newSendPackSession(ep transport.Endpoint) (transport.SendPackSession,
+	error) {
+
+	return &sendPackSession{&session{}}, nil
+}
+
+func (s *sendPackSession) AdvertisedReferences() (*transport.UploadPackInfo,
+	error) {
+
+	return nil, errSendPackNotSupported
+}
+
+func (s *sendPackSession) SendPack() (io.WriteCloser, error) {
+	return nil, errSendPackNotSupported
+}