initial commit

internal/key/key.go

@@ -0,0 +1,38 @@
+package key
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/base64"
+	"errors"
+	"strings"
+)
+
+const Prefix = "gl_"
+
+func Generate() (plain, displayPrefix string, hash []byte, err error) {
+	return GenerateToken(Prefix)
+}
+
+func GenerateToken(prefix string) (plain, displayPrefix string, hash []byte, err error) {
+	random := make([]byte, 32)
+	if _, err = rand.Read(random); err != nil {
+		return "", "", nil, err
+	}
+	plain = prefix + base64.RawURLEncoding.EncodeToString(random)
+	displayPrefix = plain[:min(len(plain), 11)]
+	hash = Hash(plain)
+	return plain, displayPrefix, hash, nil
+}
+
+func Hash(plain string) []byte {
+	sum := sha256.Sum256([]byte(plain))
+	return sum[:]
+}
+
+func ValidateFormat(plain string) error {
+	if !strings.HasPrefix(plain, Prefix) || len(plain) < 40 {
+		return errors.New("invalid API key format")
+	}
+	return nil
+}

internal/key/key_test.go

@@ -0,0 +1,22 @@
+package key
+
+import (
+	"bytes"
+	"testing"
+)
+
+func TestGenerate(t *testing.T) {
+	plain, prefix, hash, err := Generate()
+	if err != nil {
+		t.Fatalf("Generate() error = %v", err)
+	}
+	if err := ValidateFormat(plain); err != nil {
+		t.Fatalf("generated key is invalid: %v", err)
+	}
+	if prefix != plain[:11] {
+		t.Fatalf("prefix = %q", prefix)
+	}
+	if !bytes.Equal(hash, Hash(plain)) {
+		t.Fatal("hash mismatch")
+	}
+}