关于openssl pkcs7 数字信封的问题

发布于 2021-11-24 09:17:22 字数 4085 浏览 838 评论 5

以下是我生成PKCS7 数字信封的一个例子，我想进行数字信封的生成和解析。可是无法正确的解析，运用 openssl 0.9.8.d 请哪位专家帮忙看下。，谢谢啦！

注：EVP_PKEY *priKey 之前与对应公钥证书已经进行过RSA 的加解密，运行正常。

char* ssl_PKCS7_get_Enveloped_data (EVP_PKEY *priKey)
{
    //读取公钥证书

    char buf[4096];
    unsigned char *p;
    char *DerPathCharp = "/Users/ipc/Desktop/openssl/rsa_encode_decode/CryptoDemo/yaclifecert.der";

    FILE* fp=fopen(DerPathCharp,"rb");

    if(!fp) return NO;

    int len=fread(buf,1,5000,fp);

    fclose(fp);


    p=buf;

    X509 *x509_Cert=X509_new();

    d2i_X509(&x509_Cert,(const unsigned char **)&p,len);


    //调用openssl的代码如下：

    PKCS7* p7 = PKCS7_new();


    //设置类型为NID_pkcs7_enveloped

    PKCS7_set_type(p7, NID_pkcs7_enveloped);

    //DES算法，用于加密内容“How are you!”

    EVP_CIPHER *evp_cipher = EVP_des_cbc();

    PKCS7_set_cipher(p7,evp_cipher);



    //设置接收者证书，获取公钥用于加密对称密钥

    PKCS7_RECIP_INFO *p7recipinfo = PKCS7_add_recipient(p7,x509_Cert);

    BIO *p7bio = PKCS7_dataInit(p7, NULL);
    char *instr = "How Are You!";
    BIO_write(p7bio,instr,strlen(instr));
    printf("instr = %s",instr);
    //完成数字信封的运算

    PKCS7_dataFinal(p7, p7bio);

    //转换PKCS7结构体为DER编码
    X509* derTmp,*der;

    int derLen = i2d_PKCS7(p7,NULL);
    der = (unsigned char*)malloc(derLen);
    derTmp = der;
    //转换为der编码输出
    derLen = i2d_PKCS7(p7,&derTmp);


    BIO_free(p7bio);

    PKCS7_free(p7);



    //解P7数字信封的代码：

    //der编码转换为PKCS7结构体
    int derP7EnvelopedDataLen = derLen;
    PKCS7* v_p7 = NULL;

    PKCS7* v_p7_tmp = d2i_PKCS7(&v_p7,&der,derP7EnvelopedDataLen);

    //解析出原始数据, evp_key:接收者私钥，x509_cert:接收者证书
    BIO * v_p7bio_tmp = BIO_new(BIO_s_file());
    BIO * v_p7bio = PKCS7_dataDecode(v_p7,priKey,NULL,x509_Cert);

    //从BIO中读取原始数据,将得到"How are you!"
    unsigned char src[4096];
    int srcLen = BIO_read(v_p7bio,src,4096);

    printf("nsrc = %s",src);
    if (!strcmp(instr,src))
    {
        printf(" n ssl_PKCS7_get_Enveloped_data ok !!n");
    }

    BIO_free(v_p7bio);

    PKCS7_free(v_p7);

}