Practical experience sharing: Use PyO3 to build your Python module

PyO3 is mainly used to create native Python extension modules. PyO3 also supports running and interacting with Python code from Rust binary files, which can realize the coexistence of rust and Python code. For some modules with higher performance requirements, you can consider using PyO3 to build the corresponding functional modules. The function of PyO3 is separated, so there is no need to worry too much about the coupling between the modules, and the speed can be improved to a certain extent.

github address: https://github.com/PyO3/pyo3

The version rules are as follows:

• Python 3.6+
• Rust 1.41+

Next, we use a small demo to understand the whole process from PyO3 compilation module to normal use in Python.

cargo new --lib string-sum

Create project

# lib.rs
[package]
name = "string-sum"
version = "0.1.0"
edition = "2018"

[lib]
name = "string_sum"
# "cdylib" is necessary to produce a shared library for Python to import from.
#
# Downstream Rust code (including code in `bin/`, `examples/`, and `tests/`) will not be able
# to `use string_sum;` unless the "rlib" or "lib" crate type is also included, e.g.:
# crate-type = ["cdylib", "rlib"]
crate-type = ["cdylib"]

[dependencies.pyo3]
version = "0.14.1"
features = ["extension-module"] // 扩展模块，像其他的还有auto-initialize

// src/lib.rs
use std::usize;

use  pyo3::prelude::*;

// like this
// def sum_as_string(a:str, b:str) -> str:
//      return a+b
#[pyfunction]
fn sum_as_string(a: usize, b: usize) -> PyResult<String>{
    Ok((a+b).to_string())
}

// Mount method to module 
#[pymodule]
fn string_sum(py: Python, m: &PyModule) -> PyResult<()>{
    m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
    Ok(())
}

Compile and use

After the compilation is complete, we will find a wheel file under the target folder. The file name combination is "module name + current Python version + current system model", for example: string_sum-0.1.0-cp39-cp39-macosx_10_7_x86_64.whl

pip3 install ./target/wheel/string_sum-0.1.0-cp39-cp39-macosx_10_7_x86_64.whl

Create a python file:

# example.py
from string_sum import sum_as_string
print(sum_as_string(1,2))
# echo 3

Compilation tool selection and use

The official provides two choices of compilation tools:

• maturin by rust
• The traditional setup.py way

Use maturin to compile

# 安装 
pip3 install maturin
# 编译
maturin build
# maturin publish 发布
# 虚拟环境中使用 会自动去寻找/target/wheel/ 下的 *.wheel文件然后安装
virtualenv venv
source ./venv/bin/activate
maturin develop

Use setup.py to compile

# 安装
pip3 install setuptools-rust

Write the setup.py file:

# setup.py


from setuptools import setup
from setuptools_rust import Binding, RustExtension

setup(
    # 包名称
    name="string_sum", 
    # 包版本 
    version="0.1",
    # rust扩展 其中"string_sum.string_sum"中
    # 第一个string_sum 指的是当前的包
    # 第二个指的是
    # #[pymodule]
    # fn string_sum(py: Python, m: &PyModule) -> PyResult<()>{
    #     m.add_function(wrap_pyfunction!(sum_as_string, m)?)?;
    #     Ok(())
    # }
    # 中的string_sum
    rust_extensions=[
        RustExtension(
            "string_sum.string_sum", 
            binding=Binding.PyO3,
            debug=False
            )
    ],
    # 需要创建一个文件夹 string_sum
    packages=["string_sum"],
    # rust extensions are not zip safe, just like C-extensions.
    zip_safe=False,
    # 标注
    classifiers=[
        "License :: OSI Approved :: MIT License",
        "Development Status :: 3 - Alpha",
        "Intended Audience :: Developers",
        "Programming Language :: Python",
        "Programming Language :: Rust",
        "Operating System :: POSIX",
        "Operating System :: MacOS :: MacOS X",
    ],
    include_package_data=True
)

# 打包
mkdir string_sum
touch string_sum/__init__.py
virtualenv venv && source venv/bin/activate
pip setup.py build && pip setup.py install && pip setup.py develop

Will quote local files:

Application in

Similarly, if the created App itself is running inside docker. Then the first step we need to install rust environment dockerfile. details as follows:

#!/bin/bash
curl https://sh.rustup.rs -sSf | bash -s -- -y
source $HOME/.cargo/env
rustc --version
python setup.py install

# ddockerfile 
FROM python:3.7
WORKDIR /app
ADD . /app
RUN pip install --upgrade pip \
    && pip install -r requirements.txt
RUN ./init.sh
CMD [python, xx.py]

# requirements.txt
semantic-version==2.8.5
setuptools-rust==0.12.1
toml==0.10.2

# rust国内镜像源 config
# /root/.cargo/config
[source.crates-io]
registry = "https://github.com/rust-lang/crates.io-index"
replace-with = 'ustc'
[source.ustc]
registry = "git://mirrors.ustc.edu.cn/crates.io-index"
[term]
verbose = true
color = 'auto'

The specific directory is as follows:

-rw-r--r-- Cargo.lock
-rw-r--r-- Cargo.toml
-rw-r--r-- config           # 配置文件
-rw-r--r-- Dockerfile
-rwxrwxrwx init.sh          # 初始化rust环境脚本
-rw-r--r-- requirements.txt
-rw-r--r-- setup.py         # 打包脚本
drwxr-xr-x src              # rust项目
drwxr-xr-x string_sum 
-rw-r--r-- xx.py            # 可行性测试文件

Write a Python rsa encryption and decryption package with PyO3

who have read the previous article 1616e740500f1c "Soul Painter: Comic Graphic SSH" should have an understanding of the entire encryption and decryption process of rsa. Then we might as well use PyO3 to build a Python rsa encryption and decryption package. The usage scenarios are as follows:

The client locally generates a public and private key, and sends the public key to the server for storage through the pre-authentication process. In the later communication process, the client actively sends a message to the server. The client encrypts the information with the private key, and the server uses the corresponding public key. Key for decryption.

github address: https://github.com/hzjsea/pyo3-crypto

Later, some contents were expanded, such as MD5 encryption, signature and so on.

# 自动化脚本
#!/bin/bash

echo "init......"

# set python version 
# INSTALL_PYTHON_VERSION=python3.6

find_python() {
        set +e
        unset BEST_VERSION
        for V in 37 3.7 38 3.8 39 3.9 3; do
                if which python$V >/dev/null; then
                        if [ "$BEST_VERSION" = "" ]; then
                                BEST_VERSION=$V
                        fi
                fi
        done
        echo $BEST_VERSION
        set -e
}

if [ "$INSTALL_PYTHON_VERSION" = "" ]; then
        INSTALL_PYTHON_VERSION=$(find_python)
fi

# This fancy syntax sets INSTALL_PYTHON_PATH to "python3.7", unless
# INSTALL_PYTHON_VERSION is defined.
# If INSTALL_PYTHON_VERSION equals 3.8, then INSTALL_PYTHON_PATH becomes python3.8
# 找不到就python3.7
INSTALL_PYTHON_PATH=python${INSTALL_PYTHON_VERSION:-3.7}
echo $INSTALL_PYTHON_PATH

echo "Python version is $INSTALL_PYTHON_VERSION"
$INSTALL_PYTHON_PATH -m venv venv
if [ ! -f "activate" ]; then
        ln -s venv/bin/activate .
fi

. ./activate

python -m pip install --upgrade pip
python -m pip install wheel
python -m pip install -r ./requirements.txt
maturin build
maturin develop

current_shell=$(echo $SHELL)
if current_shell=/bin/bash; then
    echo  "PASS: source /venv/bin/activate >> ~/.bashrc"
elif current_shell=/bin/zsh;then
    echo "PASS: source /venv/bin/activate >> ~/.zshrc"
fi

//  src/lib.rs 文件
use std::u32;
use pyo3::prelude::*;
use openssl::rsa::{Padding,Rsa};

const SECRET: &'static str = "CHFfxQA3tqEZgKusgwZjmI5lFsoZxXGXnQLA97oYga2M33sLwREZyy1mWCM8GIIA";

mod crypto_utils {
    use hmac::{Hmac, Mac, NewMac};
    use sha2::Sha256;
    use std::fmt::Write;

    type Hmacsha256 = Hmac<Sha256>;
    fn encode_hex(bytes: &[u8]) -> String {
        let mut s = String::with_capacity(bytes.len() * 2);
        for &b in bytes {
            match write!(&mut s, "{:02x}", b) {
                Ok(_) => {},
                Err(_) => {}
            };
        }
        s
    }

    pub fn hash_hmac(secret: &str, msg: &str) -> String {
        let mut mac = Hmacsha256::new_from_slice(secret.as_bytes()).expect("HMAC can take key of any size");
        mac.update(msg.as_bytes());
        let result = mac.finalize();
        let code_bytes = result.into_bytes();
        encode_hex(&code_bytes)
    }

}

// create public/private key  create_key(1024)
fn create_key(len:u32) -> (String,String){
    let rsa = openssl::rsa::Rsa::generate(len).unwrap();
    let pubkey = String::from_utf8(rsa.public_key_to_pem().unwrap()).unwrap();
    let prikey  = String::from_utf8(rsa.private_key_to_pem().unwrap()).unwrap();

    (pubkey, prikey)
}



#[pyclass]
struct Crypto {
    // #[pyo3(get, set)]
    // pubkey: String,
    // #[pyo3(get,set)]
    // prikey: String,
    pub_key: Rsa<openssl::pkey::Public>,
    pri_key: Rsa<openssl::pkey::Private>
}

#[pyfunction]
fn generate_key(len:u32) -> (String, String){
    create_key(len)
}

#[pymethods]
impl Crypto {
    #[new]
    pub fn __new__(pubkey: &str,prikey: &str) -> Self {
        Crypto {
            // pubkey: pubkey.to_owned(),
            // prikey: prikey.to_owned(),
            pub_key: Rsa::public_key_from_pem(pubkey.as_bytes()).unwrap(),
            pri_key: Rsa::private_key_from_pem(prikey.as_bytes()).unwrap(),
        }
    }

    // public decrypt 
    pub fn public_decrypt(&self, msg:&str) -> String {
        let mut out: [u8; 4096] = [0;4096];
        let decoded = openssl::base64::decode_block(msg).unwrap();
        if let Ok(size) = self.pub_key.public_decrypt(&decoded, &mut out, Padding::PKCS1) {
            let real_size = if size > 4096 {4096} else {size};
            // openssl::base64::encode_block(&out[..real_size])
            String::from_utf8(out[..real_size].to_vec()).unwrap()
        } else {
            String::default()
        }
    }

    // public encrypt 
    pub fn public_encrypt(&self, msg:&str) -> String {
        let mut out: [u8; 4096] = [0;4096];
        if let Ok(size) = self.pub_key.public_encrypt(msg.as_bytes(), &mut out, Padding::PKCS1) {
            let real_size = if size > 4096 {4096}else{size};
            openssl::base64::encode_block(&out[..real_size])
        } else {
            String::default()
        }
    }

    // private encrypt
    pub fn private_encrypt(&self, msg:&str) -> String{
        let mut out: [u8; 4096] = [0;4096];
        if let Ok(size) = self.pri_key.private_encrypt(msg.as_bytes(), &mut out, Padding::PKCS1) {
            let real_size = if size > 4096 {4096}else{size};
            openssl::base64::encode_block(&out[..real_size])
        } else {
            String::default()
        }
    }

    // private decrypt
    pub fn private_decrypt(&self, msg: &str) -> String{
        let mut out: [u8; 4096] = [0;4096];
        let decoded = openssl::base64::decode_block(msg).unwrap();
        if let Ok(size) = self.pri_key.private_decrypt(&decoded, &mut out, Padding::PKCS1) {
            let real_size = if size > 4096 {4096} else {size};
            // openssl::base64::encode_block(&out[..real_size])
            String::from_utf8(out[..real_size].to_vec()).unwrap()
        } else {
            String::default()
        } 
    }

    // sign
    pub fn sign(&self, msg: &str) ->String {
        crypto_utils::hash_hmac(SECRET, msg)
    }
}

#[pymodule]
fn yacrypto(_py: Python, m: &PyModule) -> PyResult<()> {
    m.add_class::<Crypto>()?;
    m.add_function(wrap_pyfunction!(generate_key, m)?).unwrap();
    Ok(())
}


#[cfg(test)]
mod tests {
    use base64;
    #[test]
    fn works(){

        // create rsa
        let rsa = openssl::rsa::Rsa::generate(1024).unwrap();
        // create public key 
        let public_key = rsa.public_key_to_pem().unwrap();
        println!("{:?}", String::from_utf8(public_key.clone()));
        let private_key = rsa.private_key_to_pem().unwrap();


        let data = "hellowo\n\t\rrld";
        // public encrypt 
        let mut buf:Vec<u8> = vec![0;rsa.size() as usize];
        let rsa_pub = openssl::rsa::Rsa::public_key_from_pem(&public_key).unwrap();
        let _ = rsa_pub.public_encrypt(data.as_bytes(), &mut buf , openssl::rsa::Padding::PKCS1);

        // private decrypt => 
        let data = buf;
        let mut buf:Vec<u8> = vec![0;rsa.size() as usize];
        let rsa_pri  = openssl::rsa::Rsa::private_key_from_pem(&private_key).unwrap();
        if let Ok(size) = rsa_pri.private_decrypt(&data, &mut buf, openssl::rsa::Padding::PKCS1){
            let real_size = if size > 1024 {1024} else {size};
            let buf = &buf[..real_size];
            let base64_string = openssl::base64::encode_block(&buf);
            let result = base64::decode(base64_string);
            println!("{:?}",result);
            // println!("buf => {:?}",openssl::base64::encode_block(&buf))

            let echo_str = String::from_utf8((&buf).to_vec()).unwrap();
            println!("{:?}",echo_str);

        }
    }
}

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