Generate and use access/secret keys properly (#3498)

cmd/credential.go

@@ -0,0 +1,74 @@
+/*
+ * Minio Cloud Storage, (C) 2015, 2016 Minio, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package cmd
+
+import (
+	"crypto/rand"
+	"encoding/base64"
+)
+
+const (
+	accessKeyMinLen = 5
+	accessKeyMaxLen = 20
+	secretKeyMinLen = 8
+	secretKeyMaxLen = 40
+
+	alphaNumericTable    = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+	alphaNumericTableLen = byte(len(alphaNumericTable))
+)
+
+func mustGetAccessKey() string {
+	keyBytes := make([]byte, accessKeyMaxLen)
+	if _, err := rand.Read(keyBytes); err != nil {
+		panic(err)
+	}
+
+	for i := 0; i < accessKeyMaxLen; i++ {
+		keyBytes[i] = alphaNumericTable[keyBytes[i]%alphaNumericTableLen]
+	}
+
+	return string(keyBytes)
+}
+
+func mustGetSecretKey() string {
+	keyBytes := make([]byte, secretKeyMaxLen)
+	if _, err := rand.Read(keyBytes); err != nil {
+		panic(err)
+	}
+
+	return string([]byte(base64.StdEncoding.EncodeToString(keyBytes))[:secretKeyMaxLen])
+}
+
+// isAccessKeyValid - validate access key for right length.
+func isAccessKeyValid(accessKey string) bool {
+	return len(accessKey) >= accessKeyMinLen && len(accessKey) <= accessKeyMaxLen
+}
+
+// isSecretKeyValid - validate secret key for right length.
+func isSecretKeyValid(secretKey string) bool {
+	return len(secretKey) >= secretKeyMinLen && len(secretKey) <= secretKeyMaxLen
+}
+
+// credential container for access and secret keys.
+type credential struct {
+	AccessKey string `json:"accessKey"`
+	SecretKey string `json:"secretKey"`
+}
+
+func newCredential() credential {
+	return credential{mustGetAccessKey(), mustGetSecretKey()}
+}