openssl evp RSA 加密解密

openssl evp RSA 加密解密

可以直接使用RSA.h 提供的接口

如下测试使用EVP提供的RSA接口

1. EVP提供的RSA 加密解密

  主要接口：

int EVP_PKEY_encrypt_init(EVP_PKEY_CTX *ctx);
int EVP_PKEY_encrypt(EVP_PKEY_CTX *ctx,
                     unsigned char *out, size_t *outlen,
                     const unsigned char *in, size_t inlen);
int EVP_PKEY_decrypt_init(EVP_PKEY_CTX *ctx);
int EVP_PKEY_decrypt(EVP_PKEY_CTX *ctx,
                     unsigned char *out, size_t *outlen,
                     const unsigned char *in, size_t inlen);

   测试代码

   先生成 EVP_KEY 

    //生成密钥对
    RSA *r = RSA_new();
    int bits = 512;
    BIGNUM *e = BN_new();
    BN_set_word(e, 65537);
    RSA_generate_key_ex(r, bits, e, NULL);

    EVP_PKEY *key;
    key = EVP_PKEY_new();
    EVP_PKEY_set1_RSA(key, r);

  测试加密解密 

    //默认使用的是 RSA_PKCS1_PADDING，即这里最大加密块为64-11=53,大量数组需要分组处理
    char *srcStr = "01234567890123456789012345678901234567890123456789123";
    //char *srcStr = "hello world";
    int enclen = 0;
    char encData[1024] = {0};
    char decData[1024] = {0};
    int declen = 0;
    printf("src=%s\n",srcStr);
    
    
    //加密
    EVP_PKEY_CTX *ectx;
    ectx = EVP_PKEY_CTX_new(key, NULL);
    EVP_PKEY_encrypt_init(ectx);
    EVP_PKEY_encrypt(ectx, encData, &enclen, srcStr, strlen(srcStr));
    
    
    //解密
    EVP_PKEY_CTX *dctx;
    dctx = EVP_PKEY_CTX_new(key, NULL);
    EVP_PKEY_decrypt_init(dctx);
    EVP_PKEY_decrypt(dctx, decData, &declen, encData, enclen);
    printf("dec=%s\n",decData);

    EVP_PKEY_CTX_free(ectx);
    EVP_PKEY_CTX_free(dctx);

    
    EVP_PKEY_free(key);
    BN_free(e);
    RSA_free(r);

 执行结果：

src=01234567890123456789012345678901234567890123456789123
dec=01234567890123456789012345678901234567890123456789123
Program ended with exit code: 0

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