c++ openssl rsa从字符串中读取公私钥加解密 示例代码

在C++中，使用OpenSSL库处理RSA加密解密操作通常涉及`openssl PEM_read_bio_*`系列函数来读取PEM格式的公钥和私钥，以及`RSA_public_encrypt`和`RSA_private_decrypt`函数来进行数据的加解密。下面是一个简单的示例代码片段，展示如何从字符串中读取公钥和私钥，并进行加解密：

#include <openssl/pem.h>
#include <openssl/rsa.h>

std::string privateKeyPEM = "-----BEGIN RSA PRIVATE KEY-----\n"
"MIIEowIBAAKCAQEAwJH6V7q4+... (私钥内容省略)\n"
"-----END RSA PRIVATE KEY-----";

std::string publicKeyPEM = "-----BEGIN PUBLIC KEY-----\n"
"MIICIjANBgkqhkiG9w0BAQEFAAOCAg8AMIICCgKCAgEAtiFhj... (公钥内容省略)\n"
"-----END PUBLIC KEY-----";

// 解析私钥
RSA *pkeyPrivate;
BIO *bioPrivKey = BIO_new_mem_buf((unsigned char*)privateKeyPEM.c_str(), -1);
if (!pkeyPrivate = PEM_read_bio_RSAPrivateKey(bioPrivKey, NULL, NULL, NULL)) {
    // 错误处理...
}

// 解析公钥
RSA *pkeyPublic;
BIO *bioPubKey = BIO_new_mem_buf((unsigned char*)publicKeyPEM.c_str(), -1);
if (!pkeyPublic = PEM_read_bio_RSA_PUBKEY(bioPubKey, NULL, NULL, NULL)) {
    // 错误处理...
}

// 加密示例（使用公钥）
const unsigned char plaintext[] = "Hello, world!";
size_t plaintextLen = strlen(plaintext);
unsigned char ciphertext[1024];
size_t ciphertextLen = 0;
int result = RSA_public_encrypt(plaintextLen, plaintext, ciphertext, pkeyPublic, RSA_PKCS1_OAEP_PADDING);
if (result > 0) {
    std::cout << "Encrypted message: ";
    for (size_t i = 0; i < ciphertextLen; ++i) {
        printf("%02X ", ciphertext[i]);
    }
    std::cout << std::endl;
} else {
    // 错误处理...
}

// 解密示例（使用私钥）
unsigned char decryptedData[ciphertextLen + 1]; // 加1是为了容纳额外的null终止符
result = RSA_private_decrypt(ciphertextLen, ciphertext, decryptedData, pkeyPrivate, RSA_PKCS1_OAEP_PADDING);
if (result >= 0 && decryptedData[result] == '\0') { // 检查解密是否成功且有正确的终止符
    std::cout << "Decrypted message: " << decryptedData << std::endl;
} else {
    // 错误处理...
}

// 清理资源
BIO_free_all(bioPrivKey);
BIO_free_all(bioPubKey);
RSA_free(pkeyPrivate);
RSA_free(pkeyPublic);