[string] add UTF-8 validation (#5810)

src/cli/cli_dataset.cpp

@@ -40,6 +40,7 @@
 #include <openthread/dataset_ftd.h>
 
 #include "cli/cli.hpp"
+#include "common/string.hpp"
 #include "utils/parse_cmdline.hpp"
 
 using ot::Utils::CmdLineParser::ParseAsHexString;
@@ -485,6 +486,7 @@ otError Dataset::ProcessNetworkName(uint8_t aArgsLength, char *aArgs[])
         size_t length;
 
         VerifyOrExit((length = strlen(aArgs[0])) <= OT_NETWORK_NAME_MAX_SIZE, error = OT_ERROR_INVALID_ARGS);
+        VerifyOrExit(IsValidUtf8String(aArgs[0]), error = OT_ERROR_INVALID_ARGS);
 
         memset(&sDataset.mNetworkName, 0, sizeof(sDataset.mNetworkName));
         memcpy(sDataset.mNetworkName.m8, aArgs[0], length);
@@ -865,29 +867,45 @@ exit:
 
 otError Dataset::ProcessSet(uint8_t aArgsLength, char *aArgs[])
 {
-    otError                  error = OT_ERROR_NONE;
-    otOperationalDatasetTlvs dataset;
-    uint16_t                 tlvsLength;
+    otError                error = OT_ERROR_NONE;
+    MeshCoP::Dataset::Type datasetType;
 
     VerifyOrExit(aArgsLength == 2, error = OT_ERROR_INVALID_ARGS);
 
-    tlvsLength = sizeof(dataset.mTlvs);
-    SuccessOrExit(error = ParseAsHexString(aArgs[1], tlvsLength, dataset.mTlvs));
-    dataset.mLength = static_cast<uint8_t>(tlvsLength);
-
     if (strcmp(aArgs[0], "active") == 0)
     {
-        SuccessOrExit(error = otDatasetSetActiveTlvs(mInterpreter.mInstance, &dataset));
+        datasetType = MeshCoP::Dataset::Type::kActive;
     }
     else if (strcmp(aArgs[0], "pending") == 0)
     {
-        SuccessOrExit(error = otDatasetSetPendingTlvs(mInterpreter.mInstance, &dataset));
+        datasetType = MeshCoP::Dataset::Type::kPending;
     }
     else
     {
         ExitNow(error = OT_ERROR_INVALID_ARGS);
     }
 
+    {
+        MeshCoP::Dataset       dataset(datasetType);
+        MeshCoP::Dataset::Info datasetInfo;
+        uint16_t               tlvsLength = MeshCoP::Dataset::kMaxSize;
+
+        SuccessOrExit(error = ParseAsHexString(aArgs[1], tlvsLength, dataset.GetBytes()));
+        dataset.SetSize(tlvsLength);
+        VerifyOrExit(dataset.IsValid(), error = OT_ERROR_INVALID_ARGS);
+        dataset.ConvertTo(datasetInfo);
+
+        switch (datasetType)
+        {
+        case MeshCoP::Dataset::Type::kActive:
+            SuccessOrExit(error = otDatasetSetActive(mInterpreter.mInstance, &datasetInfo));
+            break;
+        case MeshCoP::Dataset::Type::kPending:
+            SuccessOrExit(error = otDatasetSetPending(mInterpreter.mInstance, &datasetInfo));
+            break;
+        }
+    }
+
 exit:
     return error;
 }

src/core/common/string.cpp

@@ -33,6 +33,8 @@
 
 #include "string.hpp"
 
+#include <string.h>
+
 namespace ot {
 
 uint16_t StringLength(const char *aString, uint16_t aMaxLength)
@@ -73,4 +75,66 @@ otError StringBase::Write(char *aBuffer, uint16_t aSize, uint16_t &aLength, cons
     return error;
 }
 
+bool IsValidUtf8String(const char *aString)
+{
+    return IsValidUtf8String(aString, strlen(aString));
+}
+
+bool IsValidUtf8String(const char *aString, size_t aLength)
+{
+    bool    ret = true;
+    uint8_t byte;
+    uint8_t continuationBytes = 0;
+    size_t  position          = 0;
+
+    while (position < aLength)
+    {
+        byte = *reinterpret_cast<const uint8_t *>(aString + position);
+        ++position;
+
+        if ((byte & 0x80) == 0)
+        {
+            continue;
+        }
+
+        // This is a leading byte 1xxx-xxxx.
+
+        if ((byte & 0x40) == 0) // 10xx-xxxx
+        {
+            // We got a continuation byte pattern without seeing a leading byte earlier.
+            ExitNow(ret = false);
+        }
+        else if ((byte & 0x20) == 0) // 110x-xxxx
+        {
+            continuationBytes = 1;
+        }
+        else if ((byte & 0x10) == 0) // 1110-xxxx
+        {
+            continuationBytes = 2;
+        }
+        else if ((byte & 0x08) == 0) // 1111-0xxx
+        {
+            continuationBytes = 3;
+        }
+        else // 1111-1xxx  (invalid pattern).
+        {
+            ExitNow(ret = false);
+        }
+
+        while (continuationBytes-- != 0)
+        {
+            VerifyOrExit(position < aLength, ret = false);
+
+            byte = *reinterpret_cast<const uint8_t *>(aString + position);
+            ++position;
+
+            // Verify the continuation byte pattern 10xx-xxxx
+            VerifyOrExit((byte & 0xc0) == 0x80, ret = false);
+        }
+    }
+
+exit:
+    return ret;
+}
+
 } // namespace ot

src/core/common/string.hpp

@@ -258,6 +258,29 @@ private:
  *
  */
 
+/**
+ * This function validates whether a given byte sequence (string) follows UTF-8 encoding.
+ *
+ * @param[in]  aString  A null-terminated byte sequence.
+ *
+ * @retval TRUE   The sequence is a valid UTF-8 string.
+ * @retval FALSE  The sequence is not a valid UTF-8 string.
+ *
+ */
+bool IsValidUtf8String(const char *aString);
+
+/**
+ * This function validates whether a given byte sequence (string) follows UTF-8 encoding.
+ *
+ * @param[in]  aString  A byte sequence.
+ * @param[in]  aLength  Length of the sequence.
+ *
+ * @retval TRUE   The sequence is a valid UTF-8 string.
+ * @retval FALSE  The sequence is not a valid UTF-8 string.
+ *
+ */
+bool IsValidUtf8String(const char *aString, size_t aLength);
+
 } // namespace ot
 
 #endif // STRING_HPP_

src/core/mac/mac.cpp

@@ -42,6 +42,7 @@
 #include "common/locator-getters.hpp"
 #include "common/logging.hpp"
 #include "common/random.hpp"
+#include "common/string.hpp"
 #include "crypto/aes_ccm.hpp"
 #include "crypto/sha256.hpp"
 #include "mac/mac_frame.hpp"
@@ -261,6 +262,7 @@ otError Mac::ConvertBeaconToActiveScanResult(const RxFrame *aBeaconFrame, Active
         aResult.mIsJoinable = beaconPayload->IsJoiningPermitted();
         aResult.mIsNative   = beaconPayload->IsNative();
         IgnoreError(static_cast<NetworkName &>(aResult.mNetworkName).Set(beaconPayload->GetNetworkName()));
+        VerifyOrExit(IsValidUtf8String(aResult.mNetworkName.m8), error = OT_ERROR_PARSE);
         aResult.mExtendedPanId = beaconPayload->GetExtendedPanId();
     }
 
@@ -475,9 +477,15 @@ otError Mac::SetNetworkName(const char *aNameString)
     // longer than `kMaxSize` is correctly rejected (returning error
     // `OT_ERROR_INVALID_ARGS`).
 
+    otError  error;
     NameData data(aNameString, NetworkName::kMaxSize + 1);
 
-    return SetNetworkName(data);
+    VerifyOrExit(IsValidUtf8String(aNameString), error = OT_ERROR_INVALID_ARGS);
+
+    error = SetNetworkName(data);
+
+exit:
+    return error;
 }
 
 otError Mac::SetNetworkName(const NameData &aNameData)
@@ -509,9 +517,15 @@ otError Mac::SetDomainName(const char *aNameString)
     // longer than `kMaxSize` is correctly rejected (returning error
     // `OT_ERROR_INVALID_ARGS`).
 
+    otError  error;
     NameData data(aNameString, DomainName::kMaxSize + 1);
 
-    return SetDomainName(data);
+    VerifyOrExit(IsValidUtf8String(aNameString), error = OT_ERROR_INVALID_ARGS);
+
+    error = SetDomainName(data);
+
+exit:
+    return error;
 }
 
 otError Mac::SetDomainName(const NameData &aNameData)

src/core/meshcop/commissioner.cpp

@@ -590,6 +590,8 @@ otError Commissioner::SetProvisioningUrl(const char *aProvisioningUrl)
         ExitNow();
     }
 
+    VerifyOrExit(IsValidUtf8String(aProvisioningUrl), error = OT_ERROR_INVALID_ARGS);
+
     len = static_cast<uint8_t>(StringLength(aProvisioningUrl, sizeof(mProvisioningUrl)));
 
     VerifyOrExit(len < sizeof(mProvisioningUrl), error = OT_ERROR_INVALID_ARGS);

src/core/meshcop/joiner.cpp

@@ -140,6 +140,10 @@ otError Joiner::Start(const char *     aPskd,
 
     otLogInfoMeshCoP("Joiner starting");
 
+    VerifyOrExit(aProvisioningUrl == nullptr || IsValidUtf8String(aProvisioningUrl), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aVendorName == nullptr || IsValidUtf8String(aVendorName), error = OT_ERROR_INVALID_ARGS);
+    VerifyOrExit(aVendorSwVersion == nullptr || IsValidUtf8String(aVendorSwVersion), error = OT_ERROR_INVALID_ARGS);
+
     VerifyOrExit(mState == kStateIdle, error = OT_ERROR_BUSY);
     VerifyOrExit(Get<ThreadNetif>().IsUp() && Get<Mle::Mle>().GetRole() == Mle::kRoleDisabled,
                  error = OT_ERROR_INVALID_STATE);

src/core/meshcop/meshcop.cpp

@@ -37,6 +37,7 @@
 #include "common/debug.hpp"
 #include "common/locator-getters.hpp"
 #include "common/logging.hpp"
+#include "common/string.hpp"
 #include "crypto/pbkdf2_cmac.h"
 #include "crypto/sha256.hpp"
 #include "mac/mac_types.hpp"
@@ -325,6 +326,8 @@ otError GeneratePskc(const char *              aPassPhrase,
     uint16_t   passphraseLen;
     uint8_t    networkNameLen;
 
+    VerifyOrExit(IsValidUtf8String(aPassPhrase), error = OT_ERROR_INVALID_ARGS);
+
     passphraseLen  = static_cast<uint16_t>(StringLength(aPassPhrase, OT_COMMISSIONING_PASSPHRASE_MAX_SIZE + 1));
     networkNameLen = static_cast<uint8_t>(StringLength(aNetworkName.GetAsCString(), OT_NETWORK_NAME_MAX_SIZE + 1));
 

src/core/meshcop/meshcop_tlvs.cpp

@@ -34,6 +34,7 @@
 #include "meshcop_tlvs.hpp"
 
 #include "common/debug.hpp"
+#include "common/string.hpp"
 #include "meshcop/meshcop.hpp"
 
 namespace ot {
@@ -129,6 +130,11 @@ void NetworkNameTlv::SetNetworkName(const Mac::NameData &aNameData)
     SetLength(len);
 }
 
+bool NetworkNameTlv::IsValid(void) const
+{
+    return IsValidUtf8String(mNetworkName, GetLength());
+}
+
 void SteeringDataTlv::CopyTo(SteeringData &aSteeringData) const
 {
     aSteeringData.Init(GetSteeringDataLength());

src/core/meshcop/meshcop_tlvs.hpp

@@ -511,7 +511,7 @@ public:
      * @retval FALSE  If the TLV does not appear to be well-formed.
      *
      */
-    bool IsValid(void) const { return true; }
+    bool IsValid(void) const;
 
     /**
      * This method gets the Network Name value.

src/core/thread/discover_scanner.cpp

@@ -336,7 +336,10 @@ void DiscoverScanner::HandleDiscoveryResponse(const Message &aMessage, const Ip6
 
         case MeshCoP::Tlv::kNetworkName:
             IgnoreError(aMessage.Read(offset, networkName));
-            IgnoreError(static_cast<Mac::NetworkName &>(result.mNetworkName).Set(networkName.GetNetworkName()));
+            if (networkName.IsValid())
+            {
+                IgnoreError(static_cast<Mac::NetworkName &>(result.mNetworkName).Set(networkName.GetNetworkName()));
+            }
             break;
 
         case MeshCoP::Tlv::kSteeringData:

tests/scripts/expect/cli-dataset.exp

@@ -204,18 +204,47 @@ address $addr\n"
 expect "Done"
 
 switch_node 1
+send "dataset init active\n"
+expect "Done"
+send "dataset networkname Thread\\ 网络\n"
+expect "Done"
+send "dataset commit active\n"
+expect "Done"
+send "dataset active -x\n"
+expect "54687265616420e7bd91e7bb9c" ;# UTF-8 of "Thread 网络"
+expect "Done"
 send "dataset active -x\n"
 expect "dataset active -x"
-expect -re {([0-9a-f]+)}
+expect -re {([0-9a-f]+)[\r\n]+Done}
 set binary $expect_out(1,string)
-expect "Done"
 send "dataset set pending $binary\n"
 expect "Done"
 send "dataset pending -x\n"
 expect $binary
 expect "Done"
+send "dataset pending\n"
+expect "Network Name: Thread 网络"
+expect "Done"
 send "dataset set active $binary\n"
 expect "Done"
+send "dataset mgmtsetcommand active activetimestamp 200 -x 030d54687265616420e7bd91e7bb9c\n"
+expect "Done"
+send "dataset active\n"
+expect "Network Name: Thread 网络"
+expect "Done"
+send "dataset mgmtsetcommand active activetimestamp 210 -x 0301ff\n"
+expect "Done"
+send "dataset active\n"
+expect "Active Timestamp: 200"
+expect "Network Name: Thread 网络"
+expect "Done"
+send "dataset set active 03023432\n"
+expect "Done"
+send "dataset active\n"
+expect "Network Name: 42"
+expect "Done"
+send "dataset set active 0301bf\n"
+expect "Error 7: InvalidArgs"
 send "dataset help\n"
 expect "Done"
 send "dataset\n"

tests/scripts/expect/cli-networkname.exp

@@ -0,0 +1,80 @@
+#!/usr/bin/expect -f
+#
+#  Copyright (c) 2020, The OpenThread Authors.
+#  All rights reserved.
+#
+#  Redistribution and use in source and binary forms, with or without
+#  modification, are permitted provided that the following conditions are met:
+#  1. Redistributions of source code must retain the above copyright
+#     notice, this list of conditions and the following disclaimer.
+#  2. Redistributions in binary form must reproduce the above copyright
+#     notice, this list of conditions and the following disclaimer in the
+#     documentation and/or other materials provided with the distribution.
+#  3. Neither the name of the copyright holder nor the
+#     names of its contributors may be used to endorse or promote products
+#     derived from this software without specific prior written permission.
+#
+#  THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+#  AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+#  IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+#  ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+#  LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+#  CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+#  SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+#  INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+#  CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+#  ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+#  POSSIBILITY OF SUCH DAMAGE.
+#
+
+source "tests/scripts/expect/_common.exp"
+
+spawn_node 1
+spawn_node 2
+
+switch_node 1
+send "networkname Thread\\ Network\n"
+expect "Done"
+send "ifconfig up\n"
+expect "Done"
+send "thread start\n"
+expect "Done"
+wait_for "state" "leader"
+expect "Done"
+
+switch_node 2
+send "scan\n"
+expect "Thread Network"
+expect "Done"
+
+switch_node 1
+send "thread stop\n"
+expect "Done"
+send "networkname Thread\\ 网络\n"
+expect "Done"
+send "thread start\n"
+expect "Done"
+wait_for "state" "leader"
+expect "Done"
+
+switch_node 2
+send "scan\n"
+expect "Thread 网络"
+expect "Done"
+
+switch_node 1
+send "thread stop\n"
+expect "Done"
+send "networkname スレッド\n"
+expect "Done"
+send "thread start\n"
+expect "Done"
+wait_for "state" "leader"
+expect "Done"
+
+switch_node 2
+send "scan\n"
+expect "スレッド"
+expect "Done"
+
+dispose_all

tests/unit/test_string.cpp

@@ -139,12 +139,28 @@ void TestStringLength(void)
     printf(" -- PASS\n");
 }
 
+void TestUtf8(void)
+{
+    printf("\nTest 5: IsValidUtf8String() function\n");
+
+    VerifyOrQuit(IsValidUtf8String("An ASCII string"), "IsValidUtf8String() ASCII string fails");
+    VerifyOrQuit(IsValidUtf8String(u8"Строка UTF-8"), "IsValidUtf8String() UTF-8 string fails");
+    VerifyOrQuit(!IsValidUtf8String("\xbf"), "IsValidUtf8String() illegal string fails");
+    VerifyOrQuit(!IsValidUtf8String("\xdf"), "IsValidUtf8String() illegal string fails");
+    VerifyOrQuit(!IsValidUtf8String("\xef\x80"), "IsValidUtf8String() illegal string fails");
+    VerifyOrQuit(!IsValidUtf8String("\xf7\x80\x80"), "IsValidUtf8String() illegal string fails");
+    VerifyOrQuit(!IsValidUtf8String("\xff"), "IsValidUtf8String() illegal string fails");
+
+    printf(" -- PASS\n");
+}
+
 } // namespace ot
 
 int main(void)
 {
     ot::TestString();
     ot::TestStringLength();
+    ot::TestUtf8();
     printf("\nAll tests passed.\n");
     return 0;
 }