[DO NOT MERGE] Fix keychain key upgrade issueandroid-7.1.2_r39android-7.1.2_r38android-7.1.2_r37nougat-mr2-security-release

Fix issues in keystore where it didn't handle key upgrade for granted keys
or keys with effective uid (keys under WiFi uid)  correctly.

Test: manual
Bug: 66094261
Change-Id: I6709b7562d47ad6156bee88a9e2d961f8a4a797d
Merged-In: I6709b7562d47ad6156bee88a9e2d961f8a4a797d
(cherry picked from commit 58291e0ff3302d9502a13c0ff16bbcaa7c15f8bd)

3 files changed, 71 insertions, 54 deletions

diff --git a/keystore/key_store_service.cpp b/keystore/key_store_service.cpp
index 020bfe4c..8fef42f1 100644
--- a/keystore/key_store_service.cpp
+++ b/keystore/key_store_service.cpp
@@ -14,6 +14,8 @@
  * limitations under the License.
  */
 
+#define LOG_TAG "keystore"
+
 #include "key_store_service.h"
 
 #include <fcntl.h>
@@ -111,16 +113,21 @@ int32_t KeyStoreService::del(const String16& name, int targetUid) {
         return ::PERMISSION_DENIED;
     }
     String8 name8(name);
-    String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid, ::TYPE_ANY));
-    int32_t result = mKeyStore->del(filename.string(), ::TYPE_ANY, get_user_id(targetUid));
-    if (result != ::NO_ERROR) {
+    String8 filename = mKeyStore->getBlobFileNameIfExists(name8, targetUid, ::TYPE_ANY);
+    if (filename.isEmpty()) return ResponseCode::KEY_NOT_FOUND;
+
+    ResponseCode result = mKeyStore->del(filename.string(), ::TYPE_ANY,
+            get_user_id(targetUid));
+    if (result != ResponseCode::NO_ERROR) {
         return result;
     }
 
-    // Also delete any characteristics files
-    String8 chrFilename(mKeyStore->getKeyNameForUidWithDir(
-        name8, targetUid, ::TYPE_KEY_CHARACTERISTICS));
-    return mKeyStore->del(chrFilename.string(), ::TYPE_KEY_CHARACTERISTICS, get_user_id(targetUid));
+    filename = mKeyStore->getBlobFileNameIfExists(name8, targetUid, ::TYPE_KEY_CHARACTERISTICS);
+    if (!filename.isEmpty()) {
+        return mKeyStore->del(filename.string(), ::TYPE_KEY_CHARACTERISTICS,
+                get_user_id(targetUid));
+    }
+    return ResponseCode::NO_ERROR;
 }
 
 int32_t KeyStoreService::exist(const String16& name, int targetUid) {
@@ -129,13 +136,8 @@ int32_t KeyStoreService::exist(const String16& name, int targetUid) {
         return ::PERMISSION_DENIED;
     }
 
-    String8 name8(name);
-    String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid, ::TYPE_ANY));
-
-    if (access(filename.string(), R_OK) == -1) {
-        return (errno != ENOENT) ? ::SYSTEM_ERROR : ::KEY_NOT_FOUND;
-    }
-    return ::NO_ERROR;
+    String8 filename = mKeyStore->getBlobFileNameIfExists(String8(name), targetUid,  ::TYPE_ANY);
+    return (!filename.isEmpty()) ? ResponseCode::NO_ERROR : ResponseCode::KEY_NOT_FOUND;
 }
 
 int32_t KeyStoreService::list(const String16& prefix, int targetUid, Vector<String16>* matches) {
@@ -467,10 +469,9 @@ int64_t KeyStoreService::getmtime(const String16& name, int32_t uid) {
         return -1L;
     }
 
-    String8 name8(name);
-    String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, targetUid, ::TYPE_ANY));
+    String8 filename = mKeyStore->getBlobFileNameIfExists(String8(name), targetUid, ::TYPE_ANY);
 
-    if (access(filename.string(), R_OK) == -1) {
+    if (filename.isEmpty()) {
         ALOGW("could not access %s for getmtime", filename.string());
         return -1L;
     }
@@ -1647,12 +1648,17 @@ int32_t KeyStoreService::upgradeKeyBlob(const String16& name, uid_t uid,
     UniquePtr<uint8_t, Malloc_Delete> upgraded_key_deleter(
         const_cast<uint8_t*>(upgraded_key.key_material));
 
-    rc = del(name, uid);
+    String8 filename = mKeyStore->getBlobFileNameIfExists(name8, uid, ::TYPE_KEYMASTER_10);
+    if (filename.isEmpty()) {
+        ALOGI("trying to upgrade a non existing blob");
+        return KEY_NOT_FOUND;
+    }
+    rc = mKeyStore->del(filename.string(), ::TYPE_ANY, get_user_id(uid));
     if (rc != ::NO_ERROR) {
+        ALOGI("upgradeKeyBlob keystore->del failed %d", rc);
         return rc;
     }
 
-    String8 filename(mKeyStore->getKeyNameForUidWithDir(name8, uid, ::TYPE_KEYMASTER_10));
     Blob newBlob(upgraded_key.key_material, upgraded_key.key_material_size, nullptr /* info */,
                  0 /* infoLength */, ::TYPE_KEYMASTER_10);
     newBlob.setFallback(blob->isFallback());
diff --git a/keystore/keystore.cpp b/keystore/keystore.cpp
index d0a61bf6..a7a81e87 100644
--- a/keystore/keystore.cpp
+++ b/keystore/keystore.cpp
@@ -150,6 +150,41 @@ android::String8 KeyStore::getKeyNameForUidWithDir(
     }
 }
 
+android::String8 KeyStore::getBlobFileNameIfExists(const android::String8& alias, uid_t uid,
+                                                  const BlobType type) {
+    android::String8 filepath8(getKeyNameForUidWithDir(alias, uid, type));
+
+    if (!access(filepath8.string(), R_OK | W_OK)) return filepath8;
+
+    // If this is one of the legacy UID->UID mappings, use it.
+    uid_t euid = get_keystore_euid(uid);
+    if (euid != uid) {
+        filepath8 = getKeyNameForUidWithDir(alias, euid, type);
+        if (!access(filepath8.string(), R_OK | W_OK)) return filepath8;
+    }
+
+    // They might be using a granted key (<uid>_<granted_alias>), try parsing the alias.
+    char* end;
+    uid_t granter_uid = strtoul(alias, &end, 10);
+    // Does the alias look like a granted key?
+    if (end[0] != '_' || end[1] == 0 || (!granter_uid)) {
+        return android::String8();
+    }
+    android::String8 granted_alias(end + 1);
+
+    // We might be asked to get a characteristics file, but still need to check grant
+    // on the key file itself.
+    android::String8 keyfilepath8 = getKeyNameForUidWithDir(granted_alias, granter_uid, ::TYPE_ANY);
+    if (!hasGrant(keyfilepath8.string(), uid)) {
+        return android::String8();
+    }
+    // Get the granted blob file path of the desired type
+    filepath8 = getKeyNameForUidWithDir(granted_alias, granter_uid, type);
+    if (!access(filepath8.string(), R_OK | W_OK)) return filepath8;
+
+    return android::String8();
+}
+
 void KeyStore::resetUser(uid_t userId, bool keepUnenryptedEntries) {
     android::String8 prefix("");
     android::Vector<android::String16> aliases;
@@ -508,39 +543,13 @@ bool KeyStore::isHardwareBacked(const android::String16& keyType) const {
 
 ResponseCode KeyStore::getKeyForName(Blob* keyBlob, const android::String8& keyName,
                                      const uid_t uid, const BlobType type) {
-    android::String8 filepath8(getKeyNameForUidWithDir(keyName, uid, type));
+    auto filepath8 = getBlobFileNameIfExists(keyName, uid, type);
     uid_t userId = get_user_id(uid);
 
-    ResponseCode responseCode = get(filepath8.string(), keyBlob, type, userId);
-    if (responseCode == NO_ERROR) {
-        return responseCode;
-    }
-
-    // If this is one of the legacy UID->UID mappings, use it.
-    uid_t euid = get_keystore_euid(uid);
-    if (euid != uid) {
-        filepath8 = getKeyNameForUidWithDir(keyName, euid, type);
-        responseCode = get(filepath8.string(), keyBlob, type, userId);
-        if (responseCode == NO_ERROR) {
-            return responseCode;
-        }
-    }
-
-    // They might be using a granted key.
-    android::String8 filename8 = getKeyName(keyName, type);
-    char* end;
-    strtoul(filename8.string(), &end, 10);
-    if (end[0] != '_' || end[1] == 0) {
-        return KEY_NOT_FOUND;
-    }
-    filepath8 = android::String8::format("%s/%s", getUserState(userId)->getUserDirName(),
-                                         filename8.string());
-    if (!hasGrant(filepath8.string(), uid)) {
-        return responseCode;
-    }
+    if (!filepath8.isEmpty())
+        return get(filepath8.string(), keyBlob, type, userId);
 
-    // It is a granted key. Try to load it.
-    return get(filepath8.string(), keyBlob, type, userId);
+    return ResponseCode::KEY_NOT_FOUND;
 }
 
 UserState* KeyStore::getUserState(uid_t userId) {
@@ -598,7 +607,7 @@ const grant_t* KeyStore::getGrant(const char* filename, uid_t uid) const {
 }
 
 bool KeyStore::upgradeBlob(const char* filename, Blob* blob, const uint8_t oldVersion,
-                           const BlobType type, uid_t uid) {
+                           const BlobType type, uid_t userId) {
     bool updated = false;
     uint8_t version = oldVersion;
 
@@ -608,7 +617,7 @@ bool KeyStore::upgradeBlob(const char* filename, Blob* blob, const uint8_t oldVe
 
         blob->setType(type);
         if (type == TYPE_KEY_PAIR) {
-            importBlobAsKey(blob, filename, uid);
+            importBlobAsKey(blob, filename, userId);
         }
         version = 1;
         updated = true;
@@ -640,7 +649,7 @@ struct BIO_Delete {
 };
 typedef UniquePtr<BIO, BIO_Delete> Unique_BIO;
 
-ResponseCode KeyStore::importBlobAsKey(Blob* blob, const char* filename, uid_t uid) {
+ResponseCode KeyStore::importBlobAsKey(Blob* blob, const char* filename, uid_t userId) {
     // We won't even write to the blob directly with this BIO, so const_cast is okay.
     Unique_BIO b(BIO_new_mem_buf(const_cast<uint8_t*>(blob->getValue()), blob->getLength()));
     if (b.get() == NULL) {
@@ -668,13 +677,13 @@ ResponseCode KeyStore::importBlobAsKey(Blob* blob, const char* filename, uid_t u
         return SYSTEM_ERROR;
     }
 
-    ResponseCode rc = importKey(pkcs8key.get(), len, filename, get_user_id(uid),
+    ResponseCode rc = importKey(pkcs8key.get(), len, filename, userId,
                                 blob->isEncrypted() ? KEYSTORE_FLAG_ENCRYPTED : KEYSTORE_FLAG_NONE);
     if (rc != NO_ERROR) {
         return rc;
     }
 
-    return get(filename, blob, TYPE_KEY_PAIR, uid);
+    return get(filename, blob, TYPE_KEY_PAIR, userId);
 }
 
 void KeyStore::readMetaData() {
diff --git a/keystore/keystore.h b/keystore/keystore.h
index 278a0a0d..fee4527f 100644
--- a/keystore/keystore.h
+++ b/keystore/keystore.h
@@ -58,6 +58,8 @@ class KeyStore {
                                       const BlobType type);
     android::String8 getKeyNameForUidWithDir(const android::String8& keyName, uid_t uid,
                                              const BlobType type);
+    android::String8 getBlobFileNameIfExists(const android::String8& alias, uid_t uid,
+                                            const BlobType type);
 
     /*
      * Delete entries owned by userId. If keepUnencryptedEntries is true