我正在尝试使用 C++ 中 rsa 的 openssl 实现来了解公钥加密。你能帮我吗？到目前为止，这些是我的想法（如有必要，请更正）
- Alice 通过网络连接到 Bob
- 爱丽丝和鲍勃想要安全的通信
- Alice 生成一个公钥/私钥对并将公钥发送给 Bob
- Bob 接收公钥并用公钥加密随机生成的对称密码密钥（例如河豚）并将结果发送给 Alice
- Alice 用最初生成的私钥解密密文，得到对称河豚密钥
- Alice 和 Bob 现在都知道对称河豚密钥，并且可以建立安全的通信通道
现在，我查看了 openssl/rsa.h rsa 实现（因为我已经有使用 openssl/blowfish.h 的实践经验），我看到了这两个函数：
int RSA_public_encrypt(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
int RSA_private_decrypt(int flen, unsigned char *from,
unsigned char *to, RSA *rsa, int padding);
如果 Alice 要生成 *rsa，如何生成 rsa 密钥对？是否有类似 rsa_public 和 rsa_private 的东西是从 rsa 派生的？*rsa 是否同时包含公钥和私钥，并且上述函数会根据它是否需要公钥或私钥自动删除必要的密钥？如果生成两个唯一的 *rsa 指针，那么实际上，我们有以下内容：
int RSA_public_encrypt(int flen, unsigned char *from,
unsigned char *to, RSA *rsa_public, int padding);
int RSA_private_decrypt(int flen, unsigned char *from,
unsigned char *to, RSA *rsa_private, int padding);
其次，*rsa 公钥应该以什么格式发送给 Bob？是否必须将其重新解释为字符数组，然后以标准方式发送？我听说过一些关于证书的事情——它们与它有什么关系吗？
对不起，所有的问题，最好的祝福，本。
编辑： Coe 我目前正在雇用：
/*
* theEncryptor.cpp
*
*
* Created by ben on 14/01/2010.
* Copyright 2010 __MyCompanyName__. All rights reserved.
*
*/
#include "theEncryptor.h"
#include <iostream>
#include <sys/socket.h>
#include <sstream>
theEncryptor::theEncryptor()
{
}
void
theEncryptor::blowfish(unsigned char *data, int data_len, unsigned char* key, int enc)
{
// hash the key first!
unsigned char obuf[20];
bzero(obuf,20);
SHA1((const unsigned char*)key, 64, obuf);
BF_KEY bfkey;
int keySize = 16;//strlen((char*)key);
BF_set_key(&bfkey, keySize, obuf);
unsigned char ivec[16];
memset(ivec, 0, 16);
unsigned char* out=(unsigned char*) malloc(data_len);
bzero(out,data_len);
int num = 0;
BF_cfb64_encrypt(data, out, data_len, &bfkey, ivec, &num, enc);
//for(int i = 0;i<data_len;i++)data[i]=out[i];
memcpy(data, out, data_len);
free(out);
}
void
theEncryptor::generateRSAKeyPair(int bits)
{
rsa = RSA_generate_key(bits, 65537, NULL, NULL);
}
int
theEncryptor::publicEncrypt(unsigned char* data, unsigned char* dataEncrypted,int dataLen)
{
return RSA_public_encrypt(dataLen, data, dataEncrypted, rsa, RSA_PKCS1_OAEP_PADDING);
}
int
theEncryptor::privateDecrypt(unsigned char* dataEncrypted,
unsigned char* dataDecrypted)
{
return RSA_private_decrypt(RSA_size(rsa), dataEncrypted,
dataDecrypted, rsa, RSA_PKCS1_OAEP_PADDING);
}
void
theEncryptor::receivePublicKeyAndSetRSA(int sock, int bits)
{
int max_hex_size = (bits / 4) + 1;
char keybufA[max_hex_size];
bzero(keybufA,max_hex_size);
char keybufB[max_hex_size];
bzero(keybufB,max_hex_size);
int n = recv(sock,keybufA,max_hex_size,0);
n = send(sock,"OK",2,0);
n = recv(sock,keybufB,max_hex_size,0);
n = send(sock,"OK",2,0);
rsa = RSA_new();
BN_hex2bn(&rsa->n, keybufA);
BN_hex2bn(&rsa->e, keybufB);
}
void
theEncryptor::transmitPublicKey(int sock, int bits)
{
const int max_hex_size = (bits / 4) + 1;
long size = max_hex_size;
char keyBufferA[size];
char keyBufferB[size];
bzero(keyBufferA,size);
bzero(keyBufferB,size);
sprintf(keyBufferA,"%s\r\n",BN_bn2hex(rsa->n));
sprintf(keyBufferB,"%s\r\n",BN_bn2hex(rsa->e));
int n = send(sock,keyBufferA,size,0);
char recBuf[2];
n = recv(sock,recBuf,2,0);
n = send(sock,keyBufferB,size,0);
n = recv(sock,recBuf,2,0);
}
void
theEncryptor::generateRandomBlowfishKey(unsigned char* key, int bytes)
{
/*
srand( (unsigned)time( NULL ) );
std::ostringstream stm;
for(int i = 0;i<bytes;i++){
int randomValue = 65 + rand()% 26;
stm << (char)((int)randomValue);
}
std::string str(stm.str());
const char* strs = str.c_str();
for(int i = 0;bytes;i++)key[i]=strs[i];
*/
int n = RAND_bytes(key, bytes);
if(n==0)std::cout<<"Warning key was generated with bad entropy. You should not consider communication to be secure"<<std::endl;
}
theEncryptor::~theEncryptor(){}