1 files changed, 56 insertions, 0 deletions
diff --git a/internal/options/options.go b/internal/options/options.go
new file mode 100644
index 0000000..da63fc2
--- /dev/null
+++ b/internal/options/options.go
@@ -0,0 +1,56 @@
+// Package options provides parsing of user-provided onion-csr options
+package options
+
+import (
+	"encoding/hex"
+	"flag"
+	"fmt"
+	"os"
+)
+
+const usage = `Usage:
+
+  onion-csr -h
+  onion-csr -d HS_DIR -n NONCE
+
+Options:
+
+  -h, --help:      Output usage message and exit
+  -d, --hs-dir:    Path to hidden service directory
+  -n, --ca-nonce:  Nonce provided by a certificate authority in hex
+`
+
+// Options is a collection of onion-csr options
+type Options struct {
+	HSDir   string
+	CANonce []byte
+
+	caNonce string
+}
+
+// New parses user-supplied onion-csr options
+func New(cmd string, args []string) (opts Options, err error) {
+	fs := flag.NewFlagSet(cmd, flag.ContinueOnError)
+	fs.Usage = func() { fmt.Fprintf(os.Stderr, "%s", usage) }
+	stringOpt(fs, &opts.HSDir, "hs-dir", "d", "")
+	stringOpt(fs, &opts.caNonce, "ca-nonce", "n", "")
+	if err = fs.Parse(args); err != nil {
+		return opts, err
+	}
+
+	if opts.HSDir == "" {
+		return opts, fmt.Errorf("-d, --hs-dir: must not be an empty string")
+	}
+	if opts.CANonce, err = hex.DecodeString(opts.caNonce); err != nil {
+		return opts, fmt.Errorf("-n, --ca-nonce: %v", err)
+	}
+	if len(opts.CANonce) == 0 {
+		return opts, fmt.Errorf("-n, --ca-nonce: must not be empty string")
+	}
+	return opts, err
+}
+
+func stringOpt(fs *flag.FlagSet, opt *string, short, long, value string) {
+	fs.StringVar(opt, short, value, "")
+	fs.StringVar(opt, long, value, "")
+}