feat(cred): 初步实现Cred (#846)

* 初步实现Cred

* 添加seteuid和setegid

* 添加cred测试程序

* 修改Cred::fscmp返回结果为CredFsCmp枚举

* 完善root用户相关信息

user/apps/test_cred/.gitignore

@@ -0,0 +1 @@
+test_cred

user/apps/test_cred/Makefile

@@ -0,0 +1,20 @@
+ifeq ($(ARCH), x86_64)
+	CROSS_COMPILE=x86_64-linux-musl-
+else ifeq ($(ARCH), riscv64)
+	CROSS_COMPILE=riscv64-linux-musl-
+endif
+
+CC=$(CROSS_COMPILE)gcc
+
+.PHONY: all
+all: main.c
+	$(CC) -static -o test_cred main.c
+
+.PHONY: install clean
+install: all
+	mv test_cred $(DADK_CURRENT_BUILD_DIR)/test_cred
+
+clean:
+	rm test_cred *.o
+
+fmt:

user/apps/test_cred/main.c

@@ -0,0 +1,42 @@
+#include <sys/types.h>
+#include <unistd.h>
+#include <stdio.h>
+#include <assert.h>
+
+int main()
+{
+    printf("Current uid: %d, euid: %d, gid: %d, egid: %d\n\n", getuid(), geteuid(), getgid(), getegid());
+
+    // 测试uid
+    printf("Set uid 1000\n");
+    setuid(1000);
+    int uid = getuid();
+    assert(uid == 1000);
+    printf("Current uid:%d\n\n", uid);
+
+    // 测试gid
+    printf("Set gid 1000\n");
+    setgid(1000);
+    int gid = getgid();
+    assert(gid == 1000);
+    printf("Current gid:%d\n\n", gid);
+
+    // 测试euid
+    printf("Setg euid 1000\n");
+    seteuid(1000);
+    int euid = geteuid();
+    assert(euid == 1000);
+    printf("Current euid:%d\n\n", euid);
+
+    // 测试egid
+    printf("Set egid 1000\n");
+    setegid(1000);
+    int egid = getegid();
+    assert(egid == 1000);
+    printf("Current egid:%d\n\n", egid);
+
+    // 测试uid在非root用户下无法修改
+    printf("Try to setuid for non_root.\n");
+    assert(setuid(0) < 0); // 非root用户无法修改uid
+    printf("Current uid: %d, euid: %d, gid: %d, egid: %d\n", getuid(), geteuid(), getgid(), getegid());
+}

user/dadk/config/test_cred-0.1.0.dadk

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+{
+  "name": "test_cred",
+  "version": "0.1.0",
+  "description": "测试cred",
+  "task_type": {
+    "BuildFromSource": {
+      "Local": {
+        "path": "apps/test_cred"
+      }
+    }
+  },
+  "depends": [],
+  "build": {
+    "build_command": "make install"
+  },
+  "clean": {
+    "clean_command": "make clean"
+  },
+  "install": {
+    "in_dragonos_path": "/bin"
+  },
+  "target_arch": ["x86_64"]
+}

user/sysconfig/etc/group

@@ -0,0 +1 @@
+root::0:

user/sysconfig/etc/gshadow

@@ -0,0 +1 @@
+root:::

user/sysconfig/etc/passwd

@@ -0,0 +1 @@
+root::0:0:root:/root:/bin/NovaShell

user/sysconfig/etc/shadow

@@ -0,0 +1 @@
+root:::0:99999:7:::