source-engine/thirdparty/cryptopp

Crypto++: free C++ Class Library of Cryptographic Schemes

Version 8.3 - TBD



Crypto++ Library is a free C++ class library of cryptographic schemes.

Currently the library contains the following algorithms:



                   algorithm type  name



 authenticated encryption schemes  GCM, CCM, EAX, ChaCha20Poly1305 and

                                   XChaCha20Poly1305



        high speed stream ciphers  ChaCha (8/12/20), ChaCha (IETF), Panama, Salsa20,

                                   Sosemanuk, XSalsa20, XChaCha20



           AES and AES candidates  AES (Rijndael), RC6, MARS, Twofish, Serpent,

                                   CAST-256



                                   ARIA, Blowfish, Camellia, CHAM, HIGHT, IDEA,

                                   Kalyna (128/256/512), LEA, SEED, RC5, SHACAL-2,

              other block ciphers  SIMON (64/128), Skipjack, SPECK (64/128),

                                   Simeck, SM4, Threefish (256/512/1024),

                                   Triple-DES (DES-EDE2 and DES-EDE3), TEA, XTEA



  block cipher modes of operation  ECB, CBC, CBC ciphertext stealing (CTS),

                                   CFB, OFB, counter mode (CTR), XTS



     message authentication codes  BLAKE2s, BLAKE2b, CMAC, CBC-MAC, DMAC, GMAC, HMAC,

                                   Poly1305, Poly1305 (IETF), SipHash, Two-Track-MAC,

                                   VMAC



                                   BLAKE2s, BLAKE2b, Keccack (F1600), SHA-1,

                   hash functions  SHA-2 (224/256/384/512), SHA-3 (224/256/384/512),

                                   SHAKE (128/256), SipHash, SM3, Tiger,

                                   RIPEMD (128/160/256/320), WHIRLPOOL



                                   RSA, DSA, Determinsitic DSA, ElGamal,

          public-key cryptography  Nyberg-Rueppel (NR), Rabin-Williams (RW), LUC,

                                   LUCELG, EC-based German Digital Signature (ECGDSA),

                                   DLIES (variants of DHAES), ESIGN



   padding schemes for public-key  PKCS#1 v2.0, OAEP, PSS, PSSR, IEEE P1363

                          systems  EMSA2 and EMSA5



                                   Diffie-Hellman (DH), Unified Diffie-Hellman (DH2),

            key agreement schemes  Menezes-Qu-Vanstone (MQV), Hashed MQV (HMQV),

                                   Fully Hashed MQV (FHMQV), LUCDIF, XTR-DH



      elliptic curve cryptography  ECDSA, Determinsitic ECDSA, ed25519, ECNR, ECIES,

                                   ECDH, ECMQV, x25519



          insecure or obsolescent  MD2, MD4, MD5, Panama Hash, DES, ARC4, SEAL

algorithms retained for backwards  3.0, WAKE-OFB, DESX (DES-XEX3), RC2,

     compatibility and historical  SAFER, 3-WAY, GOST, SHARK, CAST-128, Square

                            value



Other features include:



  * pseudo random number generators (PRNG): ANSI X9.17 appendix C, RandomPool,

    DARN, VIA Padlock, RDRAND, RDSEED, NIST Hash and HMAC DRBGs

  * password based key derivation functions: PBKDF1 and PBKDF2 from PKCS #5,

    PBKDF from PKCS #12 appendix B, HKDF from RFC 5869, Scrypt from RFC 7914

  * Shamir's secret sharing scheme and Rabin's information dispersal algorithm

    (IDA)

  * fast multi-precision integer (bignum) and polynomial operations

  * finite field arithmetics, including GF(p) and GF(2^n)

  * prime number generation and verification

  * useful non-cryptographic algorithms

      + DEFLATE (RFC 1951) compression/decompression with gzip (RFC 1952) and

        zlib (RFC 1950) format support

      + Hex, base-32, base-64, URL safe base-64 encoding and decoding

      + 32-bit CRC, CRC-C and Adler32 checksum

  * class wrappers for these platform and operating system features (optional):

      + high resolution timers on Windows, Unix, and Mac OS

      + /dev/random, /dev/urandom, /dev/srandom

      + Microsoft's CryptGenRandom or BCryptGenRandom on Windows

  * A high level interface for most of the above, using a filter/pipeline

    metaphor

  * benchmarks and validation testing

  * x86, x64 (x86-64), x32 (ILP32), ARM-32, Aarch32, Aarch64 and Power8 in-core code

    for the commonly used algorithms

      + run-time CPU feature detection and code selection

      + supports GCC-style and MSVC-style inline assembly, and MASM for x64

      + x86, x64 (x86-64), x32 provides MMX, SSE2, and SSE4 implementations

      + ARM-32, Aarch32 and Aarch64 provides NEON, ASIMD and ARMv8 implementations

      + Power8 provides in-core AES using NX Crypto Acceleration



The Crypto++ library was orginally written by Wei Dai. The library is now

maintained by several team members and the community. You are welcome to use it

for any purpose without paying anyone, but see License.txt for the fine print.



The following compilers are supported for this release. Please visit

http://www.cryptopp.com the most up to date build instructions and porting notes.



  * Visual Studio 2003 - 2019

  * GCC 3.3 - 10.1

  * Apple Clang 4.3 - 9.3

  * LLVM Clang 2.9 - 10.0

  * C++ Builder 2015

  * Intel C++ Compiler 9 - 16.0

  * Sun Studio 12u1 - 12.6

  * IBM XL C/C++ 10.0 - 13.3



*** Important Usage Notes ***



1. If a constructor for A takes a pointer to an object B (except primitive

types such as int and char), then A owns B and will delete B at A's

destruction.  If a constructor for A takes a reference to an object B,

then the caller retains ownership of B and should not destroy it until

A no longer needs it.



2. Crypto++ is thread safe at the class level. This means you can use

Crypto++ safely in a multithreaded application, but you must provide

synchronization when multiple threads access a common Crypto++ object.



*** MSVC-Specific Information ***



To compile Crypto++ with MSVC, open "cryptest.sln" (for MSVC 2003 - 2015)

and build one or more of the following projects:



cryptest Non-DLL-Import Configuration - This builds the full static library

  along with a full test driver.

cryptest DLL-Import Configuration - This builds a static library containing

  only algorithms not in the DLL, along with a full test driver that uses

  both the DLL and the static library.

cryptdll - This builds the DLL. Please note that if you wish to use Crypto++

  as a FIPS validated module, you must use a pre-built DLL that has undergone

  the FIPS validation process instead of building your own.

dlltest - This builds a sample application that only uses the DLL.



The DLL used to provide FIPS validated cryptography. The library was moved

to the CMVP's <A HREF=

"http://csrc.nist.gov/groups/STM/cmvp/documents/140-1/140val-historical.htm">

Historical Validation List</A>. The library and the DLL are no longer considered

validated. You should no longer use the DLL.



To use the Crypto++ DLL in your application, #include "dll.h" before including

any other Crypto++ header files, and place the DLL in the same directory as

your .exe file. dll.h includes the line #pragma comment(lib, "cryptopp")

so you don't have to explicitly list the import library in your project

settings. To use a static library form of Crypto++, make the "cryptlib"

project a dependency of your application project, or specify it as

an additional library to link with in your project settings.

In either case you should check the compiler options to

make sure that the library and your application are using the same C++

run-time libraries and calling conventions.



*** DLL Memory Management ***



Because it's possible for the Crypto++ DLL to delete objects allocated

by the calling application, they must use the same C++ memory heap. Three

methods are provided to achieve this.

1.  The calling application can tell Crypto++ what heap to use. This method

    is required when the calling application uses a non-standard heap.

2.  Crypto++ can tell the calling application what heap to use. This method

    is required when the calling application uses a statically linked C++ Run

    Time Library. (Method 1 does not work in this case because the Crypto++ DLL

    is initialized before the calling application's heap is initialized.)

3.  Crypto++ can automatically use the heap provided by the calling application's

    dynamically linked C++ Run Time Library. The calling application must

    make sure that the dynamically linked C++ Run Time Library is initialized

    before Crypto++ is loaded. (At this time it is not clear if it is possible

    to control the order in which DLLs are initialized on Windows 9x machines,

    so it might be best to avoid using this method.)



When Crypto++ attaches to a new process, it searches all modules loaded

into the process space for exported functions "GetNewAndDeleteForCryptoPP"

and "SetNewAndDeleteFromCryptoPP". If one of these functions is found,

Crypto++ uses methods 1 or 2, respectively, by calling the function.

Otherwise, method 3 is used.



*** Linux and Unix-like Specific Information ***



A makefile is included for you to compile Crypto++ with GCC and compatibles.

Make sure you are using GNU Make and GNU ld. The make process will produce

two files, libcryptopp.a and cryptest.exe. Run "cryptest.exe v" for the

validation suite and "cryptest.exe tv all" for additional test vectors.



The makefile uses '-DNDEBUG -g2 -O2' CXXFLAGS by default. If you use an

alternate build system, like Autotools or CMake, then ensure the build system

includes '-DNDEBUG' for production or release builds. The Crypto++ library uses

asserts for debugging and diagnostics during development; it does not

rely on them to crash a program at runtime.



If an assert triggers in production software, then unprotected sensitive

information could be egressed from the program to the filesystem or the

platform's error reporting program, like Apport on Ubuntu or CrashReporter

on Apple.



The makefile orders object files to help remediate problems associated with

C++ static initialization order. The library does not use custom linker scripts.

If you use an alternate build system, like Autotools or CMake, and collect source

files into a list, then ensure these three are at the head of the list: 'cryptlib.cpp

cpu.cpp integer.cpp <other sources>'. They should be linked in the same order:

'cryptlib.o cpu.o integer.o <other objects>'.



If your linker supports initialization attributes, like init_priority, then you can

define CRYPTOPP_INIT_PRIORITY to control object initialization order. Set it to a

value like 250. User programs can use CRYPTOPP_USER_PRIORITY to avoid conflicts with

library values. Initialization attributes are more reliable than object file ordering,

but its not ubiquitously supported by linkers.



The makefile links to the static version of the Crypto++ library to avoid binary

planting and other LD_PRELOAD tricks. You should use the static version of the

library in your programs to help avoid unwanted redirections.



*** Side Channel Attacks ***



Crypto++ attempts to resist side channel attacks using various remediations.

The remdiations are applied as a best effort but are probably incomplete. They

are incomplete due to cpu speculation bugs like Spectre, Meltdown, Foreshadow.

The attacks target both cpu caches and internal buffers. Intel generally refers

to internal buffer attacks as "Microarchitectural Data Sampling" (MDS).



The library uses hardware instructions when possible for block ciphers, hashes

and other operations. The hardware acceleration remediates some timing

attacks. The library also uses cache-aware algoirthms and access patterns

to minimize leakage cache evictions.



Some of the public key algorithms have branches and some of the branches depend

on data that can be private or secret. The branching occurs in some field

operations like exponentiation over integers and elliptic curves. The branching

has been minimized but not completely eliminated.



Crypto++ does not enagage Specter remediations at this time. The GCC options

for Specter are -mfunction-return=thunk and -mindirect-branch=thunk, and the

library uses them during testing. If you want the Specter workarounds then add

the GCC options to your CXXFLAGS when building the library.



To help resist attacks you should disable hyperthreading on cpus. If you

suspect or find an information leak then please report it.



*** Documentation and Support ***



Crypto++ is documented through inline comments in header files, which are

processed through Doxygen to produce an HTML reference manual. You can find

a link to the manual from http://www.cryptopp.com. Also at that site is

the Crypto++ FAQ, which you should browse through before attempting to

use this library, because it will likely answer many of questions that

may come up. Finally, the site provide the wiki which has many topics

and code examples.



If you run into any problems, please try the Crypto++ mailing list.

The subscription information and the list archive are available on

http://www.cryptopp.com.



*** Source Code and Contributing ***



The source code and its planned changes are available at the following locations.



  * The Crypto++ GitHub repository allows you to view the latest (unreleased)

    Crypto++ source code via the Linux kernel's git beginning around June 2015.

    Its also serves as an incubator to nuture and grow the library.

  * The former Crypto++ SourceForge repository allows you to view the Crypto++

    source code via Apache's subversion until about July 2015. At that time,

    SourceForge had infrastructure problems and a cutover to GutHub was performed.

  * The Roadmap on the wiki provides the general direction the library is heading.

    It includes planned features and releases, and even some wishlist items.



Contributions of all types are welcomed. Contributions include the following.



  * Bug finding and fixes

  * Features and enhancements

  * Test scripts and test cases

  * Branch and release testing

  * Documentation and updates



If you think you have found a bug in the library, then you should discuss it on the

Users mailing list. Discussing it will help bring the issue to the attention of folks

who can help resolve the issue. If you want to contribute a bug fix to the library,

then make a Pull Request or make a Diff available somewhere. Also see Bug Reports on

the wiki.



Features and enhancements are welcomend additions to the library. This category tends

to be time consuming because algorithms and their test cases need to be reviewed and

merged. Please be mindful of the test cases, and attempt to procure them from an

independent source.



The library cherishes test scripts and test cases. They ensure the library is fit and

they help uncover issues with the library before users experience them. If you have

some time, then write some test cases, especially the ones that are intended to break

things.



Branch and release testing is your chance to ensure Master (and planned merges) meets

your expectations and perform as expected. If you have a few spare cycles, then please

test Master on your favorite platform. We need more testing on MinGW, Windows Phone,

Windows Store, Solaris 10 (and below), and modern iOS and OS X (including TV and

Watch builds).



Documentation and updates includes both the inline source code annotations using

Doxygen, and the online information provided in the wiki. The wiki is more verbose and

usually provides more contextual information than the API reference. Besides testing,

documentation is one of the highest returns on investment.



*** History ***



The items in this section comprise the most recent history. Please see History.txt

for the record back to Crypto++ 1.0.



8.2.0 - April 28, 2019

      - minor release, no recompile of programs required

      - expanded community input and support

        * 56 unique contributors as of this release

      - use PowerPC unaligned loads and stores with Power8

      - add SKIPJACK test vectors

      - fix SHAKE-128 and SHAKE-256 compile

      - removed IS_NEON from Makefile

      - fix Aarch64 build on Fedora 29

      - fix missing GF2NT_233_Multiply_Reduce_CLMUL in FIPS DLL

      - add missing BLAKE2 constructors

      - fix missing BlockSize() in BLAKE2 classes



8.1.0 - February 22, 2019

      - minor release, no recompile of programs required

      - expanded community input and support

        * 56 unique contributors as of this release

      - fix OS X PowerPC builds with Clang

      - add Microsoft ARM64 support

      - fix iPhone Simulator build due to missing symbols

      - add CRYPTOPP_BUGGY_SIMD_LOAD_AND_STORE

      - add carryless multiplies for NIST b233 and k233 curves

      - fix OpenMP build due to use of OpenMP 4 with down-level compilers

      - add SignStream and VerifyStream for ed25519 and large files

      - fix missing AlgorithmProvider in PanamaHash

      - add SHAKE-128 and SHAKE-256

      - fix AVX2 build due to _mm256_broadcastsi128_si256

      - add IETF ChaCha, XChaCha, ChaChaPoly1305 and XChaChaPoly1305



8.0.0 - December 28, 2018

      - major release, recompile of programs required

      - expanded community input and support

         * 54 unique contributors as of this release

      - add x25519 key exchange and ed25519 signature scheme

      - add limited Asymmetric Key Package support from RFC 5958

      - add Power9 DARN random number generator support

      - add CHAM, HC-128, HC-256, Hight, LEA, Rabbit, Simeck

      - fix FixedSizeAllocatorWithCleanup may be unaligned on some platforms

      - cutover to GNU Make-based cpu feature tests

      - rename files with dashes to underscores

      - fix LegacyDecryptor and LegacyDecryptorWithMAC use wrong MAC

      - fix incorrect AES/CBC decryption on Windows

      - avoid Singleton<T> when possible, avoid std::call_once completely

      - fix SPARC alignment problems due to GetAlignmentOf<T>() on word64

      - add ARM AES asm implementation from Cryptogams

      - remove CRYPTOPP_ALLOW_UNALIGNED_DATA_ACCESS support



7.0.0 - April 8, 2018

      - major release, recompile of programs required

      - expanded community input and support

         * 48 unique contributors as of this release

      - fix incorrect result when using Integer::ModInverse

         * may be CVE worthy, but request was not submitted

      - fix ARIA/CTR bus error on Sparc64

      - fix incorrect result when using a_exp_b_mod_c

      - fix undeclared identifier uint32_t on early Visual Studio

      - fix iPhoneSimulator build on i386

      - fix incorrect adler32 in ZlibDecompressor

      - fix Power7 test using PPC_FEATURE_ARCH_2_06

      - workaround incorrect Glibc sysconf return value on ppc64-le

      - add KeyDerivationFunction interface

      - add scrypt key derivation function

      - add Salsa20_Core transform callable from outside class

      - add sbyte, sword16, sword32 and sword64

      - remove s_nullNameValuePairs from unnamed namespace

      - ported to MSVC 2017, Xcode 9.3, Sun Studio 12.5, GCC 8.0.1,

        MacPorts GCC 7.0, Clang 4.0, Intel C++ 17.00, IBM XL C/C++ 13.1



6.1.0 - February 22, 2018

      - minor release, maintenance items

      - expanded community input and support

         * 46 unique contributors as of this release

      - use 2048-bit modulus default for DSA

      - fix build under Linuxbrew

      - use /bin/sh in GNUmakefile

      - fix missing flags for SIMON and SPECK in GNUMakefile-cross

      - fix ARM and MinGW misdetection

      - port setenv-android.sh to latest NDK

      - fix Clang check for C++11 lambdas

      - Simon and Speck to little-endian implementation

      - use LIB_MAJOR for ABI compatibility

      - fix ODR violation in AdvancedProcessBlocks_{ARCH} templates

      - handle C++17 std::uncaught_exceptions

      - ported to MSVC 2017, Xcode 8.1, Sun Studio 12.5, GCC 8.0.1,

        MacPorts GCC 7.0, Clang 4.0, Intel C++ 17.00, IBM XL C/C++ 13.1



6.0.0 - January 22, 2018

      - major release, recompile of programs required

      - expanded community input and support

         * 43 unique contributors as of this release

      - fixed CVE-2016-9939 (Issue 346, transient DoS)

      - fixed CVE-2017-9434 (Issue 414, misidentified memory error)

      - converted to BASE+SIMD implementation

         * BASE provides an architecture neutral C++ implementation

         * SIMD provides architecture specific hardware acceleration

      - improved PowerPC Power4, Power7 and Power8 support

      - added ARIA, EC German DSA, Deterministic signatures (RFC 6979),

        Kalyna, NIST Hash and HMAC DRBG, Padlock RNG, Poly1305, SipHash,

        Simon, Speck, SM3, SM4, Threefish algorithms

      - added NaCl interface from the compact library

         * x25519 key exhange and ed25519 signing provided through NaCl interface

      - improved Testing and QA

      - ported to MSVC 2017, Xcode 8.1, Sun Studio 12.5, GCC 7.3,

        MacPorts GCC 7.0, Clang 4.0, Intel C++ 17.00, IBM XL C/C++ 13.1



June 2015 - Changing of the guard. Wei Dai turned the library over to the

        community. The first community release was Crypto++ 5.6.3. Wei is

        no longer involved with the daily operations of the project. Wei

        still provides guidance when we have questions.



Originally written by Wei Dai, maintained by the Crypto++ Project