OpenSSL 解析P12格式证书文件

1 解压openssl-0.9.8k_WIN32.zip 到 c:\根目录；解压文件夹如下；

2 打开控制台，并切换到OpenSSL可执行文件所在目录；

3 利用OpenSSL创建.p12测试文件(也就是证书制作过程)；详细创建步骤如下；
  3.1 生成ca私钥
  a) openssl dsaparam -out dsaparam 1024
  b) openssl gendsa -out dsakey dsaparam

  3.2 生成ca待签名证书
  openssl req -new -out ca-req.csr -key dsakey -config ..\openssl.cnf


  3.3用CA私钥进行自签名，得到自签名的CA根证书
  openssl x509 -req -in ca-req.csr -out ca-cert.cer -signkey dsakey -days 365

  3.4至此，自签名CA根证书制作完毕。当前目录下将产生四个文件，分别是：
    ca-cert.cer  
     ca-req.csr
     dsakey
     dsaparam

  3.5 利用OpenSSL把.cer转换为.p12格式；
openssl pkcs12 -export -clcerts -in ca-cert.cer -inkey dsakey -out ca.p12


  3.6 检查并确认.p12文件；

 
4 添加OpenSLL头文件和lib库文件；
VS2008->Tools->Options->Projects and Solutions->VC++ Directories


5创建一个”Win32 Console Application”空的工程，命名为”OpenSSLTester”, 然后添加main.cpp，把如下测试代码添加进去；并且把libeay32.dll，ssleay32.dll和ca.p12添加到此工程文件夹下；

#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#include <openssl/pkcs12.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/pem.h>

#pragma comment(lib, "libeay32.lib")
#pragma comment(lib, "ssleay32.lib")

static const char *mon[12]=
{
    "Jan","Feb","Mar","Apr","May","Jun",
    "Jul","Aug","Sep","Oct","Nov","Dec"
};

/* 转换时间并存储到一个缓存区中*/
int UTCTIME_print(char buf[], ASN1_UTCTIME *tm)
{
    char* v = NULL;
    int gmt = 0;
    int i = 0;
    int y = 0, M = 0,d = 0,h = 0, m = 0, s = 0;

    i = tm->length;
    v = (char*)tm->data;

    if (i < 10)
    {
        fprintf(stderr, "Bad time value\n");
    }

    if (v[i-1] == 'Z')
    {
        gmt=1;
    }

    for (i=0; i<10; i++)
    {
        if ((v[i] > '9') || (v[i] < '0'))
        {
            fprintf(stderr, "Bad time value\n");
        }

        y = (v[0]-'0')*10+(v[1]-'0');

        if (y < 50)
        { 
            y += 100;
        }

        M = (v[2]-'0')*10 + (v[3]-'0');

        if ((M > 12) || (M < 1))
        {
            fprintf(stderr, "Bad time value\n");
        }

        d = (v[4]-'0')*10 + (v[5]-'0');
        h = (v[6]-'0')*10 + (v[7]-'0');
        m = (v[8]-'0')*10 + (v[9]-'0');

        if ( i >= 12 
            && (v[10] >= '0')
            && (v[10] <= '9')
            && (v[11] >= '0') 
            && (v[11] <= '9'))
        {
            s = (v[10]-'0')*10 + (v[11]-'0');
        }
    }

    sprintf(buf, "%s %2d %02d:%02d:%02d %d%s", mon[M-1], d, h, m, s, y+1900, (gmt)?" GMT":"");
    return 0;
}

int main(void)
{
    PKCS12 *p12 = NULL;
    X509* usrCert = NULL;
    EVP_PKEY* pkey = NULL;
    STACK_OF(X509)* ca = NULL;
    BIO*bio = NULL;
    char pass[128] = "1234";
    //int i;
    char* p = NULL;
    char buf[1024] = {0};

    SSLeay_add_all_algorithms();
    ERR_load_crypto_strings();
    
    bio = BIO_new_file("ca.p12", "r");
    
    //P12
    p12 = d2i_PKCS12_bio(bio, NULL); //得到p12结构
    BIO_free_all(bio);
    PKCS12_parse(p12, pass, &pkey, &usrCert, &ca); //得到x509结构
    PKCS12_free(p12);

//     if (pkey)
//     {
//         fprintf(stdout, "***Private Key***\n");
//         PEM_write_PrivateKey(stdout, pkey, NULL, NULL, 0, NULL, NULL);
//     }

    if (usrCert)
    {
        fprintf(stdout, "***User Certificate***\n");
        //PEM_write_X509_AUX(stdout, usrCert);
        fprintf(stdout, "Subject:");
        p = X509_NAME_oneline(X509_get_subject_name(usrCert), NULL, 0);
        fprintf(stdout, "%s\n", p);

        fprintf(stdout, "Issuer:");
        p = X509_NAME_oneline(X509_get_issuer_name(usrCert), NULL, 0);
        fprintf(stdout, "%s\n", p);

        fprintf(stdout, "Not Before:");
        UTCTIME_print(buf, X509_get_notBefore(usrCert));
        fprintf(stdout, "%s\n", buf);

        fprintf(stdout, "Not After:");
        UTCTIME_print(buf, X509_get_notAfter(usrCert));
        fprintf(stdout, "%s\n", buf);
        //X509_print_fp(stdout, usrCert);   //add by slz token by openssl
    }

    //if (ca && sk_num(ca))
    //{
    //    fprintf(stdout, "***Other Certificates***\n");
    //    for (i = 0; i < sk_X509_num(ca); i++)
    //        PEM_write_X509_AUX(stdout, sk_X509_value(ca, i));
    //}

    EVP_PKEY_free(pkey);
    X509_free(usrCert);
    sk_X509_free(ca);

    return 0;
}

  这样.p12格式的信息就全部被解析出来了。

change:
  添加输出Key详细信息功能

void RSA_Printer(const RSA* rsa)
{
    int i = 0, line = 0;
    //modulus
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->n->dmax-1; i>=0; i--, line++)
    {
        if(i == rsa->n->dmax-1)
        {
            printf("n (modulus):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->n->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //publicExponent
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->e->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->e->dmax-1)
        {
            printf("e (publicExponent):\n");
        }
        printf("%.4X ",(unsigned long)*(rsa->e->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //privateExponent
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->d->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->d->dmax-1)
        {
            printf("d (privateExponent):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->d->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //prime1
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->p->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->p->dmax-1)
        {
            printf("p (prime1):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->p->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //prime2
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->q->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->q->dmax-1)
        {
            printf("q (prime2):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->q->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //exponent1
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->dmp1->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->dmp1->dmax-1)
        {
            printf("dmp1 (exponent1):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->dmp1->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //exponent2
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->dmq1->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->dmq1->dmax-1)
        {
            printf("dmq1 (exponent2):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->dmq1->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");

    //coefficient
    //////////////////////////////////////////////////////////////////////////
    line = 1;
    for(i=rsa->iqmp->dmax-1; i>=0; i--,line++)
    {
        if(i==rsa->iqmp->dmax-1)
        {
            printf("iqmp (coefficient):\n");
        }
        printf("%.8X ",(unsigned long)*(rsa->iqmp->d+i));
        if ( (line!=0)
            && (line%8==0) )
        {
            printf("\n");
        }
    }
    printf("\n\n");
}

int main()
{
...
     //P12
    p12 = d2i_PKCS12_bio(bio, NULL); //得到p12结构
    PKCS12_parse(p12, pass, &pkey, &usrCert, &ca); //得到x509结构

    RSA *rsa;
    int ret = 0;
    rsa = pkey->pkey.rsa;

    //Case 1
    //////////////////////////////////////////////////////////////////////////
    RSA_Printer(rsa);//自己写的RSA解析函数

    //Case 2
    //////////////////////////////////////////////////////////////////////////
    BIO* bioOpt;
    bioOpt = BIO_new_file("0000_MA2_20120207_0001_Private.key","w");//RSA key写到文件中
    RSA_print(bioOpt, rsa, 0);
    BIO_free(bioOpt);
...
}

参考：
1 OpenSSL证书制作过程.pdf