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
+}