Qt利用OpenSSl实现RSA数字签名

#include "mainwindow.h" #include "ui_mainwindow.h" MainWindow::MainWindow(QWidget *parent) : QMainWindow(parent), ui(new Ui::MainWindow) { ui->setupUi(this); m_prsa = NULL; } MainWindow::~MainWindow() { delete ui; } void MainWindow::on_pushButton_2_clicked() { createRSAKey(); } void MainWindow::createRSAKey() { //创建目录 QString strPath = "./key"; QDir dir; if(dir.exists(strPath) == false) { dir.mkpath(strPath);//创建目录 } BIGNUM *bne = BN_new(); int ret = BN_set_word(bne,RSA_F4);/* 设置随机数的长度 */ RSA *rsa = RSA_new(); ret = RSA_generate_key_ex(rsa,1024,bne,NULL);/*设置密钥的长度1024，生成RSA密钥对 */ if(ret != 1) { QMessageBox::information(this,"错误提示","生成RSA密钥错误！无法实现后续数字签名！",QMessageBox::Yes); return; } /* 提取私钥 */ FILE *filename = NULL; filename = fopen("./key/privateKey.pem", "wb"); PEM_write_RSAPrivateKey(filename, rsa, NULL, NULL, 0, NULL, NULL); fclose(filename); filename = NULL; /* 提取公钥 */ unsigned char *n_b = (unsigned char *)calloc(RSA_size(rsa), sizeof(unsigned char)); unsigned char *e_b = (unsigned char *)calloc(RSA_size(rsa), sizeof(unsigned char)); int n_size = BN_bn2bin(rsa->n, n_b); int b_size = BN_bn2bin(rsa->e, e_b); RSA *pubrsa = RSA_new(); pubrsa->n = BN_bin2bn(n_b, n_size, NULL); pubrsa->e = BN_bin2bn(e_b, b_size, NULL); // //另一种格式的公钥输出 // filename = fopen("./key/publicKeyRSA.pem", "wb"); // PEM_write_RSAPublicKey(filename, pubrsa); // fclose(filename); // filename = NULL; filename = fopen("./key/publicKey.pem", "wb"); PEM_write_RSA_PUBKEY(filename, pubrsa); fclose(filename); filename = NULL; RSA_free(pubrsa); RSA_free(rsa); } void MainWindow::CreateSignature(QByteArray const &strxml,unsigned char *bSign,size_t *iSignlen) { unsigned char *bData = NULL;//报文 bData = (unsigned char*)(strxml.data()); size_t iDatalen = strxml.size(); LoadRSA();//这里可以放在构造函数执行一次加载进来就可以了 unsigned char szTmp[20]={0}; SHA1(bData, iDatalen, szTmp);//一定先生成摘要 int ret = RSA_sign(NID_sha1,szTmp,20,bSign,iSignlen,m_prsa); if(ret!=1) { QMessageBox::information(this,"错误提示","生成签名失败！",QMessageBox::Yes); } } void MainWindow::on_pushButton_clicked() { unsigned char bsign[128]={0};// 保存数字签名 size_t sign_len = 0; //数字签名的长度 QString strXml; strXml = ui->lineEdit->text(); // 先utf8编码 CreateSignature(strXml.toUtf8(), bsign, &sign_len); // 十六进制输出，不是RSA签名的一部分 QByteArray signByteArray(reinterpret_cast<char*>(&bsign),sign_len); QString strShow(signByteArray.toHex()); ui->textEdit->setText(strShow); } void MainWindow::LoadRSA() { if(m_prsa != NULL) return; FILE *file; if((file=fopen(".//key//privateKey.pem","r"))==NULL) { QMessageBox::information(this,"错误提示","打开RSA密钥错误！",QMessageBox::Yes); return; } //奇怪的是p_rsa指针放到外面作为成员时，初始化一次，打算反复使用，指针失效了，变为空了 m_prsa = PEM_read_RSAPrivateKey(file,NULL,NULL,NULL); fclose(file); if(m_prsa == NULL) { QMessageBox::information(this,"错误提示","读取RSA密钥错误！",QMessageBox::Yes); return; } }