Thank you for your reply.
All test vector in https://github.com/weidai11/cryptopp/blob/master/TestVectors/xts.txt. are byte-aligned . I've tested these vectors locally, and they're all pass. But it doesn't have a non-byte-aligned vector like datalen=250bit in https://github.com/weidai11/cryptopp/blob/master/TestVectors/xts.txt. We can found non-byte-aligned vector in https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/CAVP-TESTING-BLOCK-CIPHER-MODES#XTS . All byte-aligned vector in https://csrc.nist.gov/Projects/Cryptographic-Algorithm-Validation-Program/CAVP-TESTING-BLOCK-CIPHER-MODES#XTS can pass， but all non-byte-aligned vector are fail. 在2021年5月20日星期四 UTC+8 下午1:07:48<Jeffrey Walton> 写道： > On Thursday, May 20, 2021 at 12:38:14 AM UTC-4 Jeffrey Walton wrote: > >> On Wednesday, May 19, 2021 at 11:53:54 PM UTC-4 yu...@nvidia.com wrote: >> >>> I intend to use Crypto++ XTS-AES for encrypting data. I tested XTS-AES >>> with the following NIST vector and got an unexpected >>> CT= 54a8629d76db46d0c516fca52c9c903baa3a635ddd56f09760f63252c8b46140 . >>> >>> I call the following function: >>> XTS_Mode< AES >::Encryption e; >>> e.SetKeyWithIV(in_key, KeySize, in_iv, IVSize); >>> StringSource(in_plain_txt,svSize(plain_txt, 1),true, >>> new StreamTransformationFilter(e, >>> new StringSink(cipher), >>> StreamTransformationFilter::NO_PADDING >>> ) // StreamTransformationFilter >>> ); // StringSource >>> >>> My questions: >>> >>> - Does Crypto++ XTS-AES not support non-byte aligned data >>> encryption and decryption >>> >>> >> XTS mode should support non-aligned data. For SSE, it uses _mm_loadu_si128 >> and _mm_storeu_si128, which are unaligned loads and stores. The class >> also uses 'GetWord<word64>(false, LITTLE_ENDIAN_ORDER, ...)' and >> 'PutWord<word64>(false, LITTLE_ENDIAN_ORDER, ...)'. The 'false' says the >> data is not aligned, so a memcpy is used. Also see >> https://github.com/weidai11/cryptopp/blob/master/xts.cpp. >> >> We've seen some trouble with bad code generation when two pointers happen >> to be the same in strcipher.cpp. But I don't believe XTS uses it. Also see >> https://github.com/weidai11/cryptopp/issues/1010. >> > > Something else that might be a factor... The head notes in xts.h ( > https://github.com/weidai11/cryptopp/blob/master/xts.h) says: > > /// \details XTS mode is a wide block mode defined by IEEE > P1619-2008. NIST > /// SP-800-38E approves the mode for storage devices citing IEEE > 1619-2007. > /// IEEE 1619-2007 provides both a reference implementation and test > vectors. > /// The IEEE reference implementation fails to arrive at the expected > result > /// for some test vectors. > > That's a bad sign :( > > I keep the programs that are used to generate test vectors so we can > always establish provenance if needed. The program is located in one of my > testing GitHubs. For XTS, it is located at > https://github.com/noloader/cryptopp-test. > > The test vectors we use are located at > https://github.com/weidai11/cryptopp/blob/master/TestVectors/xts.txt. > Looking through the test vector, it looks like we use both the XTS test > vectors, the XTS reference implementation and Botan. Botan is Jack Lloyd's > Botan (https://github.com/randombit/botan), and we use to to add > additional test vectors when we feel there are gaps. > > Jeff > -- You received this message because you are subscribed to the Google Groups "Crypto++ Users" group. To unsubscribe from this group and stop receiving emails from it, send an email to cryptopp-users+unsubscr...@googlegroups.com. To view this discussion on the web visit https://groups.google.com/d/msgid/cryptopp-users/2cdb34ba-208c-4de8-a9a5-dee081f8c836n%40googlegroups.com.
