RSA

RSA属于不对称加密算法
特点: 加密和解密使用完全不同又完全匹配的一对公钥和私钥


-- RSA密钥产生
RSA * RSA_generate_key(int bits, unsigned long e, void (*callback) (int,int,void *),void *cb_arg);

-- RSA加密和解密
int RSA_public_encrypt(int flen, const unsigned char *from,unsigned char *to, RSA *rsa,int padding);
int RSA_private_decrypt(int flen, const unsigned char *from,unsigned char *to, RSA *rsa,int padding);

-- RSA签名和验证
RSA签名操作是把被签署消息的散列值编码后用私钥加密
int RSA_sign(int type, const unsigned char *m, unsigned int m_length, unsigned char *sigret, unsigned int *siglen, RSA *rsa);
int RSA_verify(int type, const unsigned char *m, unsigned int m_length, unsigned char *sigbuf, unsigned int siglen, RSA *rsa);