Add KeyLine stuct

This is responsible for creating the key line to be returned
by checkers.

6 files changed, 159 insertions, 43 deletions

diff --git a/go/internal/checker/authorizedkeys/authorized_keys.go b/go/internal/checker/authorizedkeys/authorized_keys.go
index 769892e..0f392dd 100644
--- a/go/internal/checker/authorizedkeys/authorized_keys.go
+++ b/go/internal/checker/authorizedkeys/authorized_keys.go
@@ -3,8 +3,9 @@ package authorizedkeys
 import (
 	"errors"
 	"fmt"
-	"path"
+	"strconv"
 
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/checker/keyline"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/readwriter"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/config"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/gitlabnet/authorizedkeys"
@@ -28,35 +29,13 @@ func (c *Checker) Execute() error {
 
 	if expectedUsername == actualUsername {
 		if err := c.printKeyLine(key); err != nil {
-			return fmt.Errorf("Failed to print key line: %v", err)
+			return err
 		}
 	}
 
 	return nil
 }
 
-func (c *Checker) printKeyLine(key string) error {
-	client, err := authorizedkeys.NewClient(c.Config)
-	if err != nil {
-		return err
-	}
-
-	response, err := client.GetByKey(key)
-	if err != nil {
-		fmt.Fprintln(c.ReadWriter.Out, fmt.Sprintf("# No key was found for %s", key))
-	} else {
-		fmt.Fprintln(c.ReadWriter.Out, c.formatKeyLine(response.Id, response.Key))
-	}
-
-	return nil
-}
-
-func (c *Checker) formatKeyLine(id int64, key string) string {
-	command := fmt.Sprintf("%s key-%d", path.Join(c.Config.RootDir, "bin", "gitlab-shell"), id)
-
-	return fmt.Sprintf(`command="%s",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s`, command, key)
-}
-
 func (c *Checker) validateArguments() error {
 	args := c.Args
 	argsSize := len(args)
@@ -79,3 +58,31 @@ func (c *Checker) validateArguments() error {
 
 	return nil
 }
+
+func (c *Checker) printKeyLine(key string) error {
+	client, err := authorizedkeys.NewClient(c.Config)
+	if err != nil {
+		return err
+	}
+
+	response, err := client.GetByKey(key)
+	if err != nil {
+		fmt.Fprintln(c.ReadWriter.Out, fmt.Sprintf("# No key was found for %s", key))
+	} else {
+		keyLine := &keyline.KeyLine{
+			Id:      strconv.FormatInt(response.Id, 10),
+			Value:   response.Key,
+			Prefix:  "key",
+			RootDir: c.Config.RootDir,
+		}
+
+		line, err := keyLine.ToString()
+		if err != nil {
+			return err
+		}
+
+		fmt.Fprintln(c.ReadWriter.Out, line)
+	}
+
+	return nil
+}
diff --git a/go/internal/checker/authorizedkeys/authorized_keys_test.go b/go/internal/checker/authorizedkeys/authorized_keys_test.go
index e70e06e..4c21092 100644
--- a/go/internal/checker/authorizedkeys/authorized_keys_test.go
+++ b/go/internal/checker/authorizedkeys/authorized_keys_test.go
@@ -55,18 +55,18 @@ func TestExecute(t *testing.T) {
 			expectedOutput: "command=\"/tmp/bin/gitlab-shell key-1\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty public-key\n",
 		},
 		{
-			desc:          "When key doesn't match any existing key",
-			arguments:     []string{"user", "user", "not-found"},
+			desc:           "When key doesn't match any existing key",
+			arguments:      []string{"user", "user", "not-found"},
 			expectedOutput: "# No key was found for not-found\n",
 		},
 		{
-			desc:          "When the API returns an error",
-			arguments:     []string{"user", "user", "broken-message"},
+			desc:           "When the API returns an error",
+			arguments:      []string{"user", "user", "broken-message"},
 			expectedOutput: "# No key was found for broken-message\n",
 		},
 		{
-			desc:          "When the API fails",
-			arguments:     []string{"user", "user", "broken"},
+			desc:           "When the API fails",
+			arguments:      []string{"user", "user", "broken"},
 			expectedOutput: "# No key was found for broken\n",
 		},
 	}
diff --git a/go/internal/checker/authorizedprincipals/authorized_principals.go b/go/internal/checker/authorizedprincipals/authorized_principals.go
index 029bedc..3cd3387 100644
--- a/go/internal/checker/authorizedprincipals/authorized_principals.go
+++ b/go/internal/checker/authorizedprincipals/authorized_principals.go
@@ -3,8 +3,8 @@ package authorizedprincipals
 import (
 	"errors"
 	"fmt"
-	"path"
 
+	"gitlab.com/gitlab-org/gitlab-shell/go/internal/checker/keyline"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/command/readwriter"
 	"gitlab.com/gitlab-org/gitlab-shell/go/internal/config"
 )
@@ -24,21 +24,13 @@ func (c *Checker) Execute() error {
 	keyId := args[0]
 	principals := args[1:]
 
-	c.printPrincipalLines(keyId, principals)
+	if err := c.printPrincipalLines(keyId, principals); err != nil {
+		return err
+	}
 
 	return nil
 }
 
-func (c *Checker) printPrincipalLines(keyId string, principals []string) {
-	command := fmt.Sprintf("%s username-%s", path.Join(c.Config.RootDir, "bin", "gitlab-shell"), keyId)
-
-	for _, principal := range principals {
-		principalLine := fmt.Sprintf(`command="%s",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s`, command, principal)
-
-		fmt.Fprintln(c.ReadWriter.Out, principalLine)
-	}
-}
-
 func (c *Checker) validateArguments() error {
 	args := c.Args
 	argsSize := len(args)
@@ -62,3 +54,23 @@ func (c *Checker) validateArguments() error {
 
 	return nil
 }
+
+func (c *Checker) printPrincipalLines(keyId string, principals []string) error {
+	for _, principal := range principals {
+		principalKeyLine := &keyline.KeyLine{
+			Id:      keyId,
+			Value:   principal,
+			Prefix:  "username",
+			RootDir: c.Config.RootDir,
+		}
+
+		line, err := principalKeyLine.ToString()
+		if err != nil {
+			return err
+		}
+
+		fmt.Fprintln(c.ReadWriter.Out, line)
+	}
+
+	return nil
+}
diff --git a/go/internal/checker/authorizedprincipals/authorized_principals_test.go b/go/internal/checker/authorizedprincipals/authorized_principals_test.go
index 269059a..1339bd5 100644
--- a/go/internal/checker/authorizedprincipals/authorized_principals_test.go
+++ b/go/internal/checker/authorizedprincipals/authorized_principals_test.go
@@ -22,7 +22,7 @@ func TestExecute(t *testing.T) {
 			expectedOutput: "command=\"/tmp/bin/gitlab-shell username-key\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty principal\n",
 		},
 		{
-			desc:          "With mulitple principals",
+			desc:           "With mulitple principals",
 			arguments:      []string{"key", "principal-1", "principal-2"},
 			expectedOutput: "command=\"/tmp/bin/gitlab-shell username-key\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty principal-1\ncommand=\"/tmp/bin/gitlab-shell username-key\",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty principal-2\n",
 		},
diff --git a/go/internal/checker/keyline/key_line.go b/go/internal/checker/keyline/key_line.go
new file mode 100644
index 0000000..28280ae
--- /dev/null
+++ b/go/internal/checker/keyline/key_line.go
@@ -0,0 +1,48 @@
+package keyline
+
+import (
+	"errors"
+	"fmt"
+	"path"
+	"regexp"
+	"strings"
+)
+
+type KeyLine struct {
+	Id      string
+	Value   string
+	Prefix  string
+	RootDir string
+}
+
+const (
+	GitlabShellDir     = "bin"
+	GitlabShellProgram = "gitlab-shell"
+)
+
+func (k *KeyLine) ToString() (string, error) {
+	if err := k.validate(); err != nil {
+		return "", err
+	}
+
+	command := fmt.Sprintf("%s %s-%s", path.Join(k.RootDir, GitlabShellDir, GitlabShellProgram), k.Prefix, k.Id)
+
+	return fmt.Sprintf(`command="%s",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty %s`, command, k.Value), nil
+}
+
+func (k *KeyLine) validate() error {
+	isMatched, err := regexp.MatchString(`\A[a-z0-9-]+\z`, k.Id)
+	if err != nil {
+		return err
+	}
+
+	if !isMatched {
+		return errors.New(fmt.Sprintf("Invalid key_id: %s", k.Id))
+	}
+
+	if strings.Contains(k.Value, "\n") {
+		return errors.New(fmt.Sprintf("Invalid value: %s", k.Value))
+	}
+
+	return nil
+}
diff --git a/go/internal/checker/keyline/key_line_test.go b/go/internal/checker/keyline/key_line_test.go
new file mode 100644
index 0000000..6c90c22
--- /dev/null
+++ b/go/internal/checker/keyline/key_line_test.go
@@ -0,0 +1,49 @@
+package keyline
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/require"
+)
+
+func TestToString(t *testing.T) {
+	keyLine := &KeyLine{
+		Id:      "1",
+		Value:   "public-key",
+		Prefix:  "key",
+		RootDir: "/tmp",
+	}
+
+	result, err := keyLine.ToString()
+
+	require.NoError(t, err)
+	require.Equal(t, `command="/tmp/bin/gitlab-shell key-1",no-port-forwarding,no-X11-forwarding,no-agent-forwarding,no-pty public-key`, result)
+}
+
+func TestFailingToString(t *testing.T) {
+	testCases := []struct {
+		desc          string
+		keyLine       *KeyLine
+		expectedError string
+	}{
+		{
+			desc:          "When Id has non-alphanumeric and non-dash characters in it",
+			keyLine:       &KeyLine{Id: "key\n1"},
+			expectedError: "Invalid key_id: key\n1",
+		},
+		{
+			desc:          "When Value has newline in it",
+			keyLine:       &KeyLine{Id: "key", Value: "public\nkey"},
+			expectedError: "Invalid value: public\nkey",
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.desc, func(t *testing.T) {
+			result, err := tc.keyLine.ToString()
+
+			require.Empty(t, result)
+			require.EqualError(t, err, tc.expectedError)
+		})
+	}
+}