Files
openthread/tests/unit/test_checksum.cpp
T
Abtin Keshavarzian 4de7bc578e [random] introduce template-based NonCrypto random APIs (#13142)
This commit introduces a new set of template-based APIs for
non-cryptographic random number generation in the `Random::NonCrypto`
namespace. These new methods provide a cleaner, type-safe, and more
robust interface compared to the previous methods.

Key additions:
- `Generate<UintType>()`: Returns a random value of the given
  unsigned integer type (`uint8_t`, `uint16_t`, or `uint32_t`).
- `GenerateUpToExcluding<UintType>(aMax)`: Returns a random value in
  the range `[0, aMax)`.
- `GenerateFromMinUpToExcluding<UintType>(aMin, aMax)`: Returns a
  random value in the range `[aMin, aMax)`.
- `GenerateInClosedRange<UintType>(aMin, aMax)`: Returns a random
  value in the closed range `[aMin, aMax]`.

The introduction of `GenerateInClosedRange` is an improvement as it
safely handles ranges up to the maximum value of the integer type
(e.g., `0xffff`) without the risk of overflow.

All call sites across the OpenThread core stack and tests have been
updated to adopt these new APIs. The public `otRandomNonCrypto`
functions are also updated to leverage the new internal methods.

Doxygen documentation is added for all new template methods,
detailing their behavior, including edge cases where the upper bound
is smaller than or equal to the lower bound.
2026-05-25 19:39:59 -07:00

545 lines
18 KiB
C++

/*
* 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.
*/
#include "common/encoding.hpp"
#include "common/message.hpp"
#include "common/numeric_limits.hpp"
#include "common/random.hpp"
#include "common/string.hpp"
#include "instance/instance.hpp"
#include "net/checksum.hpp"
#include "net/icmp6.hpp"
#include "net/ip4_types.hpp"
#include "net/udp6.hpp"
#include "utils/verhoeff_checksum.hpp"
#include "test_platform.h"
#include "test_util.hpp"
namespace ot {
uint16_t CalculateChecksum(const void *aBuffer, uint16_t aLength)
{
// Calculates checksum over a given buffer data. This implementation
// is inspired by the algorithm from RFC-1071.
uint32_t sum = 0;
const uint8_t *bytes = reinterpret_cast<const uint8_t *>(aBuffer);
while (aLength >= sizeof(uint16_t))
{
sum += BigEndian::ReadUint16(bytes);
bytes += sizeof(uint16_t);
aLength -= sizeof(uint16_t);
}
if (aLength > 0)
{
sum += (static_cast<uint32_t>(bytes[0]) << 8);
}
// Fold 32-bit sum to 16 bits.
while (sum >> 16)
{
sum = (sum & 0xffff) + (sum >> 16);
}
return static_cast<uint16_t>(sum & 0xffff);
}
uint16_t CalculateChecksum(const Ip6::Address &aSource,
const Ip6::Address &aDestination,
uint8_t aIpProto,
const Message &aMessage)
{
// This method calculates the checksum over an IPv6 message.
constexpr uint16_t kMaxPayload = 1024;
OT_TOOL_PACKED_BEGIN
struct PseudoHeader
{
Ip6::Address mSource;
Ip6::Address mDestination;
uint32_t mPayloadLength;
uint32_t mProtocol;
} OT_TOOL_PACKED_END;
OT_TOOL_PACKED_BEGIN
struct ChecksumData
{
PseudoHeader mPseudoHeader;
uint8_t mPayload[kMaxPayload];
} OT_TOOL_PACKED_END;
ChecksumData data;
uint16_t payloadLength;
payloadLength = aMessage.GetLength() - aMessage.GetOffset();
data.mPseudoHeader.mSource = aSource;
data.mPseudoHeader.mDestination = aDestination;
data.mPseudoHeader.mProtocol = BigEndian::HostSwap32(aIpProto);
data.mPseudoHeader.mPayloadLength = BigEndian::HostSwap32(payloadLength);
SuccessOrQuit(aMessage.Read(aMessage.GetOffset(), data.mPayload, payloadLength));
return CalculateChecksum(&data, sizeof(PseudoHeader) + payloadLength);
}
uint16_t CalculateChecksum(const Ip4::Address &aSource,
const Ip4::Address &aDestination,
uint8_t aIpProto,
const Message &aMessage)
{
// This method calculates the checksum over an IPv4 message.
constexpr uint16_t kMaxPayload = 1024;
OT_TOOL_PACKED_BEGIN
struct PseudoHeader
{
Ip4::Address mSource;
Ip4::Address mDestination;
uint16_t mPayloadLength;
uint16_t mProtocol;
} OT_TOOL_PACKED_END;
OT_TOOL_PACKED_BEGIN
struct ChecksumData
{
PseudoHeader mPseudoHeader;
uint8_t mPayload[kMaxPayload];
} OT_TOOL_PACKED_END;
ChecksumData data;
uint16_t payloadLength;
payloadLength = aMessage.GetLength() - aMessage.GetOffset();
data.mPseudoHeader.mSource = aSource;
data.mPseudoHeader.mDestination = aDestination;
data.mPseudoHeader.mProtocol = BigEndian::HostSwap16(aIpProto);
data.mPseudoHeader.mPayloadLength = BigEndian::HostSwap16(payloadLength);
SuccessOrQuit(aMessage.Read(aMessage.GetOffset(), data.mPayload, payloadLength));
return CalculateChecksum(&data, sizeof(PseudoHeader) + payloadLength);
}
void CorruptMessage(Message &aMessage)
{
// Change a random bit in the message.
uint16_t byteOffset;
uint8_t bitOffset;
uint8_t byte;
byteOffset = Random::NonCrypto::GenerateUpToExcluding<uint16_t>(aMessage.GetLength());
SuccessOrQuit(aMessage.Read(byteOffset, byte));
bitOffset = Random::NonCrypto::GenerateUpToExcluding<uint8_t>(kBitsPerByte);
byte ^= (1 << bitOffset);
aMessage.Write(byteOffset, byte);
}
void TestUdpMessageChecksum(void)
{
constexpr uint16_t kMinSize = sizeof(Ip6::Udp::Header);
constexpr uint16_t kMaxSize = Buffer::kSize * 3 + 24;
const char *kSourceAddress = "fd00:1122:3344:5566:7788:99aa:bbcc:ddee";
const char *kDestAddress = "fd01:2345:6789:abcd:ef01:2345:6789:abcd";
Instance *instance = static_cast<Instance *>(testInitInstance());
VerifyOrQuit(instance != nullptr);
for (uint16_t size = kMinSize; size <= kMaxSize; size++)
{
Message *message = instance->Get<Ip6::Ip6>().NewMessage();
Ip6::Udp::Header udpHeader;
Ip6::MessageInfo messageInfo;
VerifyOrQuit(message != nullptr, "Ip6::NewMesssage() failed");
SuccessOrQuit(message->SetLength(size));
// Write UDP header with a random payload.
Random::NonCrypto::Fill(udpHeader);
udpHeader.SetChecksum(0);
message->Write(0, udpHeader);
if (size > sizeof(udpHeader))
{
uint8_t buffer[kMaxSize];
uint16_t payloadSize = size - sizeof(udpHeader);
Random::NonCrypto::FillBuffer(buffer, payloadSize);
message->WriteBytes(sizeof(udpHeader), &buffer[0], payloadSize);
}
SuccessOrQuit(messageInfo.GetSockAddr().FromString(kSourceAddress));
SuccessOrQuit(messageInfo.GetPeerAddr().FromString(kDestAddress));
// Verify that the `Checksum::UpdateMessageChecksum` correctly
// updates the checksum field in the UDP header on the message.
Checksum::UpdateMessageChecksum(*message, messageInfo.GetSockAddr(), messageInfo.GetPeerAddr(), Ip6::kProtoUdp);
SuccessOrQuit(message->Read(message->GetOffset(), udpHeader));
VerifyOrQuit(udpHeader.GetChecksum() != 0);
// Verify that the calculated UDP checksum is valid.
VerifyOrQuit(CalculateChecksum(messageInfo.GetSockAddr(), messageInfo.GetPeerAddr(), Ip6::kProtoUdp,
*message) == 0xffff);
// Verify that `Checksum::VerifyMessageChecksum()` accepts the
// message and its calculated checksum.
SuccessOrQuit(Checksum::VerifyMessageChecksum(*message, messageInfo, Ip6::kProtoUdp));
// Corrupt the message and verify that checksum is no longer accepted.
CorruptMessage(*message);
VerifyOrQuit(Checksum::VerifyMessageChecksum(*message, messageInfo, Ip6::kProtoUdp) != kErrorNone,
"Checksum passed on corrupted message");
message->Free();
}
}
void TestIcmp6MessageChecksum(void)
{
constexpr uint16_t kMinSize = sizeof(Ip6::Icmp::Header);
constexpr uint16_t kMaxSize = Buffer::kSize * 3 + 24;
const char *kSourceAddress = "fd00:feef:dccd:baab:9889:7667:5444:3223";
const char *kDestAddress = "fd01:abab:beef:cafe:1234:5678:9abc:0";
Instance *instance = static_cast<Instance *>(testInitInstance());
VerifyOrQuit(instance != nullptr, "Null OpenThread instance\n");
for (uint16_t size = kMinSize; size <= kMaxSize; size++)
{
Message *message = instance->Get<Ip6::Ip6>().NewMessage();
Ip6::Icmp::Header icmp6Header;
Ip6::MessageInfo messageInfo;
VerifyOrQuit(message != nullptr, "Ip6::NewMesssage() failed");
SuccessOrQuit(message->SetLength(size));
// Write ICMP6 header with a random payload.
Random::NonCrypto::Fill(icmp6Header);
icmp6Header.SetChecksum(0);
message->Write(0, icmp6Header);
if (size > sizeof(icmp6Header))
{
uint8_t buffer[kMaxSize];
uint16_t payloadSize = size - sizeof(icmp6Header);
Random::NonCrypto::FillBuffer(buffer, payloadSize);
message->WriteBytes(sizeof(icmp6Header), &buffer[0], payloadSize);
}
SuccessOrQuit(messageInfo.GetSockAddr().FromString(kSourceAddress));
SuccessOrQuit(messageInfo.GetPeerAddr().FromString(kDestAddress));
// Verify that the `Checksum::UpdateMessageChecksum` correctly
// updates the checksum field in the ICMP6 header on the message.
Checksum::UpdateMessageChecksum(*message, messageInfo.GetSockAddr(), messageInfo.GetPeerAddr(),
Ip6::kProtoIcmp6);
SuccessOrQuit(message->Read(message->GetOffset(), icmp6Header));
VerifyOrQuit(icmp6Header.GetChecksum() != 0, "Failed to update checksum");
// Verify that the calculated ICMP6 checksum is valid.
VerifyOrQuit(CalculateChecksum(messageInfo.GetSockAddr(), messageInfo.GetPeerAddr(), Ip6::kProtoIcmp6,
*message) == 0xffff);
// Verify that `Checksum::VerifyMessageChecksum()` accepts the
// message and its calculated checksum.
SuccessOrQuit(Checksum::VerifyMessageChecksum(*message, messageInfo, Ip6::kProtoIcmp6));
// Corrupt the message and verify that checksum is no longer accepted.
CorruptMessage(*message);
VerifyOrQuit(Checksum::VerifyMessageChecksum(*message, messageInfo, Ip6::kProtoIcmp6) != kErrorNone,
"Checksum passed on corrupted message");
message->Free();
}
}
void TestTcp4MessageChecksum(void)
{
constexpr size_t kMinSize = sizeof(Ip4::Tcp::Header);
constexpr size_t kMaxSize = Buffer::kSize * 3 + 24;
const char *kSourceAddress = "12.34.56.78";
const char *kDestAddress = "87.65.43.21";
Ip4::Address sourceAddress;
Ip4::Address destAddress;
Instance *instance = static_cast<Instance *>(testInitInstance());
VerifyOrQuit(instance != nullptr);
SuccessOrQuit(sourceAddress.FromString(kSourceAddress));
SuccessOrQuit(destAddress.FromString(kDestAddress));
for (uint16_t size = kMinSize; size <= kMaxSize; size++)
{
Message *message = instance->Get<Ip6::Ip6>().NewMessage();
Ip4::Tcp::Header tcpHeader;
VerifyOrQuit(message != nullptr, "Ip6::NewMesssage() failed");
SuccessOrQuit(message->SetLength(size));
// Write TCP header with a random payload.
Random::NonCrypto::Fill(tcpHeader);
message->Write(0, tcpHeader);
if (size > sizeof(tcpHeader))
{
uint8_t buffer[kMaxSize];
uint16_t payloadSize = size - sizeof(tcpHeader);
Random::NonCrypto::FillBuffer(buffer, payloadSize);
message->WriteBytes(sizeof(tcpHeader), &buffer[0], payloadSize);
}
// Verify that the `Checksum::UpdateMessageChecksum` correctly
// updates the checksum field in the UDP header on the message.
Checksum::UpdateMessageChecksum(*message, sourceAddress, destAddress, Ip4::kProtoTcp);
SuccessOrQuit(message->Read(message->GetOffset(), tcpHeader));
VerifyOrQuit(tcpHeader.GetChecksum() != 0);
// Verify that the calculated UDP checksum is valid.
VerifyOrQuit(CalculateChecksum(sourceAddress, destAddress, Ip4::kProtoTcp, *message) == 0xffff);
message->Free();
}
}
void TestUdp4MessageChecksum(void)
{
constexpr uint16_t kMinSize = sizeof(Ip4::Udp::Header);
constexpr uint16_t kMaxSize = Buffer::kSize * 3 + 24;
const char *kSourceAddress = "12.34.56.78";
const char *kDestAddress = "87.65.43.21";
Ip4::Address sourceAddress;
Ip4::Address destAddress;
Instance *instance = static_cast<Instance *>(testInitInstance());
SuccessOrQuit(sourceAddress.FromString(kSourceAddress));
SuccessOrQuit(destAddress.FromString(kDestAddress));
VerifyOrQuit(instance != nullptr);
for (uint16_t size = kMinSize; size <= kMaxSize; size++)
{
Message *message = instance->Get<Ip6::Ip6>().NewMessage();
Ip4::Udp::Header udpHeader;
VerifyOrQuit(message != nullptr, "Ip6::NewMesssage() failed");
SuccessOrQuit(message->SetLength(size));
// Write UDP header with a random payload.
Random::NonCrypto::Fill(udpHeader);
udpHeader.SetChecksum(0);
message->Write(0, udpHeader);
if (size > sizeof(udpHeader))
{
uint8_t buffer[kMaxSize];
uint16_t payloadSize = size - sizeof(udpHeader);
Random::NonCrypto::FillBuffer(buffer, payloadSize);
message->WriteBytes(sizeof(udpHeader), &buffer[0], payloadSize);
}
// Verify that the `Checksum::UpdateMessageChecksum` correctly
// updates the checksum field in the UDP header on the message.
Checksum::UpdateMessageChecksum(*message, sourceAddress, destAddress, Ip4::kProtoUdp);
SuccessOrQuit(message->Read(message->GetOffset(), udpHeader));
VerifyOrQuit(udpHeader.GetChecksum() != 0);
// Verify that the calculated UDP checksum is valid.
VerifyOrQuit(CalculateChecksum(sourceAddress, destAddress, Ip4::kProtoUdp, *message) == 0xffff);
message->Free();
}
}
void TestIcmp4MessageChecksum(void)
{
// A captured ICMP echo request (ping) message. Checksum field is set to zero.
const uint8_t kExampleIcmpMessage[] = "\x08\x00\x00\x00\x67\x2e\x00\x00\x62\xaf\xf1\x61\x00\x04\xfc\x24"
"\x08\x09\x0a\x0b\x0c\x0d\x0e\x0f\x10\x11\x12\x13\x14\x15\x16\x17"
"\x18\x19\x1a\x1b\x1c\x1d\x1e\x1f\x20\x21\x22\x23\x24\x25\x26\x27"
"\x28\x29\x2a\x2b\x2c\x2d\x2e\x2f\x30\x31\x32\x33\x34\x35\x36\x37";
uint16_t kChecksumForExampleMessage = 0x5594;
Instance *instance = static_cast<Instance *>(testInitInstance());
Message *message = instance->Get<Ip6::Ip6>().NewMessage();
Ip4::Address source;
Ip4::Address dest;
uint8_t mPayload[sizeof(kExampleIcmpMessage)];
Ip4::Icmp::Header icmpHeader;
SuccessOrQuit(message->AppendBytes(kExampleIcmpMessage, sizeof(kExampleIcmpMessage)));
// Random IPv4 address, ICMP message checksum does not include a presudo header like TCP and UDP.
source.mFields.m32 = 0x12345678;
dest.mFields.m32 = 0x87654321;
Checksum::UpdateMessageChecksum(*message, source, dest, Ip4::kProtoIcmp);
SuccessOrQuit(message->Read(0, icmpHeader));
VerifyOrQuit(icmpHeader.GetChecksum() == kChecksumForExampleMessage);
SuccessOrQuit(message->Read(message->GetOffset(), mPayload, sizeof(mPayload)));
VerifyOrQuit(CalculateChecksum(mPayload, sizeof(mPayload)) == 0xffff);
}
class ChecksumTester
{
public:
static void TestExampleVector(void)
{
// Example from RFC 1071
const uint8_t kTestVector[] = {0x00, 0x01, 0xf2, 0x03, 0xf4, 0xf5, 0xf6, 0xf7};
const uint16_t kTestVectorChecksum = 0xddf2;
Checksum checksum;
VerifyOrQuit(checksum.GetValue() == 0, "Incorrect initial checksum value");
checksum.AddData(kTestVector, sizeof(kTestVector));
VerifyOrQuit(checksum.GetValue() == kTestVectorChecksum);
VerifyOrQuit(checksum.GetValue() == CalculateChecksum(kTestVector, sizeof(kTestVector)), );
}
};
#if OPENTHREAD_CONFIG_VERHOEFF_CHECKSUM_ENABLE
void TestVerhoeffChecksum(void)
{
static constexpr uint16_t kMaxStringSize = 50;
const char *kExamples[] = {"307318421", "487300178", "123455672", "0", "15",
"999999994", "000000001", "100000000", "2363"};
const char *kInvalidFormats[] = {
"307 318421",
"307318421 ",
" 307318421",
"ABCDE",
};
char string[kMaxStringSize];
char checksum;
char expectedChecksum;
printf("\nVerhoeffChecksum\n");
for (const char *example : kExamples)
{
uint16_t length = StringLength(example, kMaxStringSize - 1);
memcpy(string, example, length + 1);
printf("- \"%s\"\n", string);
SuccessOrQuit(Utils::VerhoeffChecksum::Validate(string));
expectedChecksum = string[length - 1];
string[length - 1] = (expectedChecksum == '0') ? '9' : (expectedChecksum - 1);
VerifyOrQuit(Utils::VerhoeffChecksum::Validate(string) == kErrorFailed);
string[length - 1] = '\0';
SuccessOrQuit(Utils::VerhoeffChecksum::Calculate(string, checksum));
VerifyOrQuit(checksum == expectedChecksum);
string[length - 1] = expectedChecksum == '0' ? '9' : (expectedChecksum - 1);
}
printf("\nInvalid format:\n");
for (const char *example : kInvalidFormats)
{
printf("- \"%s\"\n", example);
VerifyOrQuit(Utils::VerhoeffChecksum::Validate(example) == kErrorInvalidArgs);
VerifyOrQuit(Utils::VerhoeffChecksum::Calculate(example, checksum) == kErrorInvalidArgs);
}
}
#endif // OPENTHREAD_CONFIG_VERHOEFF_CHECKSUM_ENABLE
} // namespace ot
int main(void)
{
ot::ChecksumTester::TestExampleVector();
ot::TestUdpMessageChecksum();
ot::TestIcmp6MessageChecksum();
ot::TestTcp4MessageChecksum();
ot::TestUdp4MessageChecksum();
ot::TestIcmp4MessageChecksum();
#if OPENTHREAD_CONFIG_VERHOEFF_CHECKSUM_ENABLE
ot::TestVerhoeffChecksum();
#endif
printf("All tests passed\n");
return 0;
}