add iam system

add iam store

feat: add crypto crate

introduce decrypt_data and encrypt_data functions

Signed-off-by: bestgopher <84328409@qq.com>

iam/src/error.rs

@@ -0,0 +1,35 @@
+use core::error;
+
+use crate::policy;
+
+#[derive(thiserror::Error, Debug)]
+pub enum Error {
+    #[error(transparent)]
+    PolicyError(#[from] policy::Error),
+
+    #[error("ecsotre error: {0}")]
+    EcstoreError(ecstore::error::Error),
+
+    #[error("{0}")]
+    StringError(String),
+
+    #[error("crypto: {0}")]
+    CryptoError(#[from] crypto::Error),
+
+    #[error("user '{0}' does not exist")]
+    NoSuchUser(String),
+
+    #[error("invalid arguments specified")]
+    InvalidArgument,
+
+    #[error("not initialized")]
+    IamSysNotInitialized,
+
+    #[error("invalid service type: {0}")]
+    InvalidServiceType(String),
+
+    #[error("malformed credential")]
+    ErrCredMalformed,
+}
+
+pub type Result<T> = std::result::Result<T, Error>;