Implement tree/save/delete requests (#99)

helpers/helpers.go

@@ -0,0 +1,114 @@
+package helpers
+
+import (
+	"bytes"
+	"fmt"
+	"io"
+	"io/ioutil"
+	"os"
+	"os/exec"
+	"path/filepath"
+	"strings"
+)
+
+func DetectGpgBinary() (string, error) {
+	// Look in $PATH first, then check common locations - the first successful result wins
+	gpgBinaryPriorityList := []string{
+		"gpg2", "gpg",
+		"/bin/gpg2", "/usr/bin/gpg2", "/usr/local/bin/gpg2",
+		"/bin/gpg", "/usr/bin/gpg", "/usr/local/bin/gpg",
+	}
+
+	for _, binary := range gpgBinaryPriorityList {
+		err := ValidateGpgBinary(binary)
+		if err == nil {
+			return binary, nil
+		}
+	}
+	return "", fmt.Errorf("Unable to detect the location of the gpg binary to use")
+}
+
+func ValidateGpgBinary(gpgPath string) error {
+	return exec.Command(gpgPath, "--version").Run()
+}
+
+func GpgDecryptFile(filePath string, gpgPath string) (string, error) {
+	passwordFile, err := os.Open(filePath)
+	if err != nil {
+		return "", err
+	}
+
+	var stdout, stderr bytes.Buffer
+	gpgOptions := []string{"--decrypt", "--yes", "--quiet", "--batch", "-"}
+
+	cmd := exec.Command(gpgPath, gpgOptions...)
+	cmd.Stdin = passwordFile
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err := cmd.Run(); err != nil {
+		return "", fmt.Errorf("Error: %s, Stderr: %s", err.Error(), stderr.String())
+	}
+
+	return stdout.String(), nil
+}
+
+func GpgEncryptFile(filePath string, contents string, recipients []string, gpgPath string) error {
+	err := os.MkdirAll(filepath.Dir(filePath), 0755)
+	if err != nil {
+		return fmt.Errorf("Unable to create directory structure: %s", err.Error())
+	}
+
+	var stdout, stderr bytes.Buffer
+	gpgOptions := []string{"--encrypt", "--yes", "--quiet", "--batch", "--output", filePath}
+	for _, recipient := range recipients {
+		gpgOptions = append(gpgOptions, "--recipient", recipient)
+	}
+
+	cmd := exec.Command(gpgPath, gpgOptions...)
+	cmd.Stdin = strings.NewReader(contents)
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	if err = cmd.Run(); err != nil {
+		return fmt.Errorf("Error: %s, Stderr: %s", err.Error(), stderr.String())
+	}
+
+	return nil
+}
+
+func DetectGpgRecipients(filePath string) ([]string, error) {
+	dir := filepath.Dir(filePath)
+	for {
+		file, err := ioutil.ReadFile(filepath.Join(dir, ".gpg-id"))
+		if err == nil {
+			return strings.Split(strings.ReplaceAll(strings.TrimSpace(string(file)), "\r\n", "\n"), "\n"), nil
+		}
+
+		if !os.IsNotExist(err) {
+			return nil, fmt.Errorf("Unable to open `.gpg-id` file: %s", err.Error())
+		}
+
+		parentDir := filepath.Dir(dir)
+		if parentDir == dir {
+			return nil, fmt.Errorf("Unable to find '.gpg-id' file")
+		}
+
+		dir = parentDir
+	}
+}
+
+func IsDirectoryEmpty(dirPath string) (bool, error) {
+	f, err := os.Open(dirPath)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	_, err = f.Readdirnames(1)
+	if err == io.EOF {
+		return true, nil
+	}
+
+	return false, err
+}