mini-keyctl: use ParseInt to parse keys

- Valid ID format examples: 0x90a, 123
 - ID like 90a will not work now.

Bug: None
Test: mini-keyctl unlink 0x11d25c86 0x2873c96d

Change-Id: I057bce0a49a60f475d54b23e28dc18db25124466

libkeyutils/mini_keyctl.cpp

@@ -20,6 +20,7 @@
 
 #include "mini_keyctl_utils.h"
 
+#include <error.h>
 #include <stdio.h>
 #include <unistd.h>
 
@@ -36,6 +37,14 @@ static void Usage(int exit_code) {
   _exit(exit_code);
 }
 
+static key_serial_t parseKeyOrDie(const char* str) {
+  key_serial_t key;
+  if (!android::base::ParseInt(str, &key)) {
+    error(1 /* exit code */, 0 /* errno */, "Unparsable key: '%s'\n", str);
+  }
+  return key;
+}
+
 int main(int argc, const char** argv) {
   if (argc < 2) Usage(1);
   const std::string action = argv[1];
@@ -67,17 +76,13 @@ int main(int argc, const char** argv) {
     return RestrictKeyring(keyring);
   } else if (action == "unlink") {
     if (argc != 4) Usage(1);
-    key_serial_t key = std::stoi(argv[2], nullptr, 16);
+    key_serial_t key = parseKeyOrDie(argv[2]);
     const std::string keyring = argv[3];
     return Unlink(key, keyring);
   } else if (action == "security") {
     if (argc != 3) Usage(1);
     const char* key_str = argv[2];
-    key_serial_t key;
-    if (!android::base::ParseInt(key_str, &key)) {
-      fprintf(stderr, "Unparsable key: '%s'\n", key_str);
-      return 1;
-    }
+    key_serial_t key = parseKeyOrDie(key_str);
     std::string context = RetrieveSecurityContext(key);
     if (context.empty()) {
       perror(key_str);

libkeyutils/mini_keyctl_utils.cpp

@@ -30,6 +30,7 @@
 
 #include <android-base/file.h>
 #include <android-base/logging.h>
+#include <android-base/parseint.h>
 #include <android-base/properties.h>
 #include <android-base/strings.h>
 #include <keyutils.h>
@@ -53,12 +54,8 @@ static bool GetKeyringId(const std::string& keyring_desc, key_serial_t* keyring_
   }
 
   // If the keyring id is already a hex number, directly convert it to keyring id
-  try {
-    key_serial_t id = std::stoi(keyring_desc, nullptr, 16);
-    *keyring_id = id;
+  if (android::base::ParseInt(keyring_desc.c_str(), keyring_id)) {
     return true;
-  } catch (const std::exception& e) {
-    LOG(INFO) << "search /proc/keys for keyring id";
   }
 
   // Only keys allowed by SELinux rules will be shown here.