commit 05cd3f86167e7a55fbcf9727ce07297fad59b12d
author Peter Cai <peter@typeblog.net> Sat May 25 21:12:29 2019 +0800
committer big biff <bigbiff@teamw.in> Sun Sep 01 19:34:09 2019 +0200
tree 616eec72cb914c039653ccfc1741ec1c5c9bf339
parent 90edd2e867b238e71ee198e3460e289cd7dee54c

ext4crypt: change to upgrade key if export fails

Add support to upgrade key when export fails with KEY_REQUIRES_UPGRADE.

Ported from
https://source.codeaurora.org/quic/la/platform/system/vold/commit/?h=LA.UM.7.9.r1-06100-sm6150.0&id=85c46eaacc60290db5e71380d89eb4d99ed67995

Change-Id: Ic64be8ade00c0b0d014370ecc9341b1ecc9b0d7a

crypto/ext4crypt/KeyStorage4.cpp

diff --git a/crypto/ext4crypt/KeyStorage4.cpp b/crypto/ext4crypt/KeyStorage4.cpp
index cab88a1..b91d6e4 100644
--- a/crypto/ext4crypt/KeyStorage4.cpp
+++ b/crypto/ext4crypt/KeyStorage4.cpp
@@ -165,10 +165,28 @@
     std::string key_temp;
     Keymaster keymaster;
     if (!keymaster) return false;
-    if (!keymaster.exportKey(format, kmKey, "!", "!", &key_temp)) return false;
-    *key = KeyBuffer(key_temp.size());
-    memcpy(reinterpret_cast<void*>(key->data()), key_temp.c_str(), key->size());
-    return true;
+
+    //Export once, if upgrade needed, upgrade and export again
+    bool export_again = true;
+    while (export_again) {
+        export_again = false;
+        auto ret = keymaster.exportKey(format, kmKey, "!", "!", &key_temp);
+        if (ret == km::ErrorCode::OK) {
+            *key = KeyBuffer(key_temp.size());
+            memcpy(reinterpret_cast<void*>(key->data()), key_temp.c_str(), key->size());
+            return true;
+        }
+        if (ret != km::ErrorCode::KEY_REQUIRES_UPGRADE) return false;
+        LOG(DEBUG) << "Upgrading key";
+        std::string kmKeyStr(reinterpret_cast<const char*>(kmKey.data()), kmKey.size());
+        std::string newKey;
+        if (!keymaster.upgradeKey(kmKeyStr, km::AuthorizationSet(), &newKey)) return false;
+        memcpy(reinterpret_cast<void*>(kmKey.data()), newKey.c_str(), kmKey.size());
+        LOG(INFO) << "Key upgraded";
+        export_again = true;
+    }
+    //Should never come here
+    return false;
 }
 
 static std::pair<km::AuthorizationSet, km::HardwareAuthToken> beginParams(