Go implementation for LFS authenticate

1 files changed, 104 insertions, 0 deletions

diff --git a/go/internal/command/lfsauthenticate/lfsauthenticate.go b/go/internal/command/lfsauthenticate/lfsauthenticate.go
new file mode 100644
index 0000000..c1dc45f
--- /dev/null
+++ b/go/internal/command/lfsauthenticate/lfsauthenticate.go
@@ -0,0 +1,104 @@
+package lfsauthenticate
+
+import (
+	"encoding/base64"
+	"encoding/json"
+	"fmt"
+
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/commandargs"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/readwriter"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/shared/accessverifier"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/shared/disallowedcommand"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/config"
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/gitlabnet/lfsauthenticate"
+)
+
+const (
+	downloadAction = "download"
+	uploadAction   = "upload"
+)
+
+type Command struct {
+	Config     *config.Config
+	Args       *commandargs.CommandArgs
+	ReadWriter *readwriter.ReadWriter
+}
+
+type PayloadHeader struct {
+	Auth string `json:"Authorization"`
+}
+
+type Payload struct {
+	Header    PayloadHeader `json:"header"`
+	Href      string        `json:"href"`
+	ExpiresIn int           `json:"expires_in,omitempty"`
+}
+
+func (c *Command) Execute() error {
+	args := c.Args.SshArgs
+	if len(args) < 3 {
+		return disallowedcommand.Error
+	}
+
+	repo := args[1]
+	action, err := actionToCommandType(args[2])
+	if err != nil {
+		return err
+	}
+
+	accessResponse, err := c.verifyAccess(action, repo)
+	if err != nil {
+		return err
+	}
+
+	payload, err := c.authenticate(action, repo, accessResponse.UserId)
+	if err != nil {
+		// return nothing just like Ruby's GitlabShell#lfs_authenticate does
+		return nil
+	}
+
+	fmt.Fprintf(c.ReadWriter.Out, "%s\n", payload)
+
+	return nil
+}
+
+func actionToCommandType(action string) (commandargs.CommandType, error) {
+	var accessAction commandargs.CommandType
+	switch action {
+	case downloadAction:
+		accessAction = commandargs.UploadPack
+	case uploadAction:
+		accessAction = commandargs.ReceivePack
+	default:
+		return "", disallowedcommand.Error
+	}
+
+	return accessAction, nil
+}
+
+func (c *Command) verifyAccess(action commandargs.CommandType, repo string) (*accessverifier.Response, error) {
+	cmd := accessverifier.Command{c.Config, c.Args, c.ReadWriter}
+
+	return cmd.Verify(action, repo)
+}
+
+func (c *Command) authenticate(action commandargs.CommandType, repo, userId string) ([]byte, error) {
+	client, err := lfsauthenticate.NewClient(c.Config, c.Args)
+	if err != nil {
+		return nil, err
+	}
+
+	response, err := client.Authenticate(action, repo, userId)
+	if err != nil {
+		return nil, err
+	}
+
+	basicAuth := base64.StdEncoding.EncodeToString([]byte(response.Username + ":" + response.LfsToken))
+	payload := &Payload{
+		Header:    PayloadHeader{Auth: "Basic " + basicAuth},
+		Href:      response.RepoPath + "/info/lfs",
+		ExpiresIn: response.ExpiresIn,
+	}
+
+	return json.Marshal(payload)
+}