libcrypton

A cryptography library on C++ for Neo blockchain ecosystem

This project is part of the neopt macro project, a C++ implementation of Neo Blockchain components, focused on portability.

Try it! (for developers interested in using crypdev tool)

There's an amazing tool here, called crypdev, specially made for crypto developers.

To build it (on linux):

• Get submodules: git submodule update --init --recursive (specially gets openssl)
• to build openssl engine: make vendor
• to build libcrypton and crypdev: just type make (this will add it to bin/crypdev).

If you open ./bin/crypdev you get a simple user terminal:

===============================================
Welcome to crypdev: a lib CryptoN tool for devs
===============================================
Type 'exit' to finish program (or 'help')

>help
crypdev command: 'help'

'help' command options: [ ]
existing commands are: 
set [ ecc hash ] [ secp256r1 | sha256 ]
gen [ ECC_TYPE ] [ keypair pubkey privkey ] [ compressed uncompressed ] [ PRIVATE_KEY ]
hash [ hash160 hash256 sha256 ripemd160 none ] [ TEXT_OR_BYTES ]
bytes [ reverse length ] [ TEXT_OR_BYTES ]
sign [ ECC_TYPE ] [ PRIVATE_KEY ] [ HASH_TYPE ] [ TEXT_OR_BYTES ] 
verify [ ECC_TYPE ] [ PUBLIC_KEY ] [ SIGNATURE ] [ HASH_TYPE ] [ TEXT_OR_BYTES ]  
rand [ BYTE_COUNT ] 
show [ engine ]

One simple example is, hashing an empty string on SHA256 (or other hashes: hash160,hash256,ripemd160):

>hash sha256 ""
hash: e3b0c44298fc1c149afbf4c8996fb92427ae41e4649b934ca495991b7852b855

Or hashing byte 0x00:

>hash sha256 0x00
hash: 6e340b9cffb37a989ca544e6bb780a2c78901d3fb33738768511a30617afa01d

Reversing and counting bytes:

>bytes reverse 0x010203
reversed bytes: 030201
>bytes length 0x010203
length: 3

Other nice example is generating a random keypair for elliptic curve secp256r1:

>set ecc secp256r1
CURVE SET TO 'secp256r1'

>gen ecc keypair
public key (compressed format): 037c50d797720fefe9194ecd5b4ef3c25b3791abb45639aa8453d110bae08a945a
private key: 13043155bf3e00b6e6352ffafba9f7fa96704de08c7db2fe810a92d644199258

Or even better, manually generating private key (randomly) and attached public key:

>gen ecc privkey
private key: 914083f84a7550d7ed21da047f7cfa60c5fddad98d1156b068c48b26fbe60831

>gen ecc pubkey compressed 914083f84a7550d7ed21da047f7cfa60c5fddad98d1156b068c48b26fbe60831
public key: 023115c1e143a8f05dddceb0c6adc687c6fa942ec73122f757db811d236ef72fc0

>gen ecc pubkey uncompressed 914083f84a7550d7ed21da047f7cfa60c5fddad98d1156b068c48b26fbe60831
public key: 043115c1e143a8f05dddceb0c6adc687c6fa942ec73122f757db811d236ef72fc05a0a78e2b2278e0ca244383caf09f7a69e5f288b3b632e6466f23da71c5afc22

gen ecc privkey is equivalent to rand 32, for curve secp256r1:

>rand 32
generated bytes (32): 914083f84a7550d7ed21da047f7cfa60c5fddad98d1156b068c48b26fbe60831

Signing a payload of 50 bytes:

>rand 50
generated bytes (50): 9ec1171a37169a9e4b38726127730d64bed872f7840afeaf54028834e531e2d89a8d269f78eb426628f6cc3dc3ad99a2a43b

>gen ecc keypair
public key (compressed format): 02bff10e1aa6b544fd9fc07b28488425931e6a0d9c44b5f3fd6b7c2f489a9987ad
private key: 4f7f56c979e2fafbe26c5d9164066ea581b4e08a52805ca377d573a853f0aa5e

>sign ecc 4f7f56c979e2fafbe26c5d9164066ea581b4e08a52805ca377d573a853f0aa5e hash 9ec1171a37169a9e4b38726127730d64bed872f7840afeaf54028834e531e2d89a8d269f78eb426628f6cc3dc3ad99a2a43b
signature: 7b6d7a7b0738f98bfcb7f94bcc7f5e4c4dd3469d321235d52117711096360e8eb133d42831f01a603d94574b626eb68b2d3686d7e75433b8d69874bc4f3948ce

>verify ecc 02bff10e1aa6b544fd9fc07b28488425931e6a0d9c44b5f3fd6b7c2f489a9987ad 7b6d7a7b0738f98bfcb7f94bcc7f5e4c4dd3469d321235d52117711096360e8eb133d42831f01a603d94574b626eb68b2d3686d7e75433b8d69874bc4f3948ce hash 9ec1171a37169a9e4b38726127730d64bed872f7840afeaf54028834e531e2d89a8d269f78eb426628f6cc3dc3ad99a2a43b 
verification result: 1

Since libcrypton can be implemented in multiple engines, you can check underlying engine:

>show engine
libcrypton engine: openssl

directly executing on file or command-line (silent mode)

If you want to embed crypdev on any script, you can use command mode -c, separating commands by semi-colon:

./bin/crypdev -c "rand 5 ; rand 10 ; rand 1"
d070440077
a313e92ddb08a706b23a
9b

Some commands often require reading until end of line, so it's good to protect by adding a line break before semi-colon:

./bin/crypdev -c "rand 5 ; hash none 0x0001 `echo $'\n;'` rand 10"
1e52f7557c
0001
afeaec7e0dac88ecfc51

Finally, it's even easier when reading from script file on disk (see scriptttest.txt):

cat scripttest.txt 
rand 5
hash sha256 0x0001
rand 10

./bin/crypdev -f scripttest.txt 
b2c6db7ab4
b413f47d13ee2fe6c845b2ee141af81de858df4ec549a58b7970bb96645bc8d2
635c59ca7d16aab29eb6

Why chosing C/C++ language for that?

Existing frameworks use high-level languages that may not be suitable for very lightweight architectures, such as microcontrollers with very limited computing capabilities.

C/C++ is interoperable with nearly all existing languages, so the idea is to provide modules that can be reused on other projects (on other languages too).

Note: this project is still being ported out of neopt, since other community projects have interest in using this special component in a very separate manner. In a few days, much more things should be here ;)

Build Instructions

There are three intended implementations for libcrypton: native (using csBigInteger++ library), using cryptopp and libopenssl.

C++ Native implementation

This implementation depends on csBigInteger C++ implementation. On debian-based systems (or ubuntu), just type make vendor (it will install libgmp-dev package).

OpenSSL implementation

This will depend on libopenssl installed. Type make vendor to get it.

tests

It will also configure test library (as long as you cloned this project with --submodules too). To test, just run make test.

C++ Standard

Currently, C++11 is adopted, in order to keep the best compatibility between conversors and compilers. However, it is recommended to migrate to C++17 as soon as possible, if this does not break compatibility with any existing modules and tools.

Let's please follow the CppCoreGuidelines.

vscode IDE

If using vscode IDE, it is recommended to install the following extensions:

• C/C++ (currently 0.23.0-insiders2)
• C++ Intellisense (currently 0.2.2)
• GoogleTest Adapter (currently 1.8.3)

C++ Format Style

The currently adopted style for C++ is Mozilla, with indentation level set to 3. Recommended configuration for vscode:

{
    "[cpp]": {
        "editor.tabSize" : 3,
        "editor.detectIndentation": false
    },
    "C_Cpp.clang_format_fallbackStyle": "{ BasedOnStyle : Mozilla , ColumnLimit : 0, IndentWidth: 3, AccessModifierOffset: -3}"
}

Variable Naming Style

The naming style for variables and methods is based on C# language. So, CamelCase is used and public variables start with upper-case letters, while private and local variables start with lower-case. The idea is to preseve maximum compatibility with reference project (which is on C#).

Anything that is beyond the scope of the reference project can use classic CamelCase C++ naming (for example, starting variables with lower-case).

License

Code follows MIT License.

Implementation BigIntegerGMP.cpp (class implementation of standard BigInteger.h) is LGPLv3. The reason is that this implementation depends on GNU MP Bignum Library (licensed LGPLv3 since version 6), what means that all modifications of BigIntegerGMP.cpp, or usage of its code (even partially) on other projects should also adopt LGPLv3 (not MIT License).

Implementation BigIntegerMono.cpp depends on Mono license, which is also MIT License.

The binaries generated by this project (nvm3_native.so or nvm3_mono.so) can be freely used on other projects, regardless of license.