使用openssl编码实现一本自签名证书的示例

 

#include <openssl/conf.h>
#include <openssl/bio.h>
#include <openssl/err.h>
#include <openssl/bn.h>
#include <openssl/txt_db.h>
#include <openssl/evp.h>
#include <openssl/x509.h>
#include <openssl/x509v3.h>
#include <openssl/objects.h>
#include <openssl/pem.h>
#include <openssl/engine.h>
#include <openssl/pkcs12.h>
#include <memory.h>
#include <malloc.h>

/**//*版本号*/
#define MA_X509_V1 0
#define MA_X509_V2 1
#define MA_X509_V3 2

/**//*序列号*/
#define MA_SN 1111

X509_REQ *req = NULL;
X509_NAME *pSubjectName=NULL;
X509_NAME_ENTRY *ent=NULL;
EVP_PKEY *pNewRsaKey = NULL;
EVP_MD *digest=NULL;

void add_subject_entity(char *key, char *value)
...{
    int nid;
    X509_NAME_ENTRY *ent;
    if( (nid =OBJ_txt2nid(key)) == NID_undef )
    ...{
        printf("add_subject_entity:concert nid error");
        return ;
    }

    ent = X509_NAME_ENTRY_create_by_NID(NULL,nid,MBSTRING_UTF8,
        (unsigned char*)value,-1);
    if(ent == NULL)
    ...{
        printf("add_subject_entity:create ent error");
        return;
    }

    if(X509_NAME_add_entry(pSubjectName,ent,-1,0) != 1)
    ...{
        printf("add_subject_entity:add to subjectname error");
        return;
    }
    return;
}

void create_req_demo()
...{
    req = X509_REQ_new();

    pNewRsaKey = EVP_PKEY_new();
    EVP_PKEY_assign_RSA(pNewRsaKey, RSA_generate_key(512,0x10001,NULL,NULL));
    X509_REQ_set_pubkey(req,pNewRsaKey);

    pSubjectName = X509_NAME_new();
    if(pSubjectName == NULL)
    ...{
        printf("create_req_demo:create subjectname error ");
        return;
    }

    add_subject_entity("countryName", "CN");
    add_subject_entity("stateOrProvinceName", "ZJ");
    add_subject_entity("localityName", "HZ");
    add_subject_entity("organizationName", "zhijiang");
    add_subject_entity("commonName", "piky");

    if(1 != X509_REQ_set_subject_name(req,pSubjectName))
    ...{
        printf("create_req_demo:add subjectname to req error");
    }

}

void create_cert_demo()
...{
  int ret = 0;
  X509 *certTmp =NULL;

  create_req_demo();

  /**//*申请内存*/
  certTmp = X509_new();
  if (NULL == certTmp)
  ...{
    printf("内存申请失败");
    return;
  }

  /**//*设置版本号:V3*/
  ret = X509_set_version(certTmp, MA_X509_V3);
  if (ret != 1)
  ...{
    printf("设置证书版本错误:0x%x",ret);
    return;
  }

  /**//*设置序列号*/
  ret = ASN1_INTEGER_set(X509_get_serialNumber(certTmp),MA_SN);
  if (ret != 1)
  ...{
      printf("设置序列号错误:0x%x", ret);
      return;
  }

  /**//*设置开始时间*/
  if(!X509_gmtime_adj(X509_get_notBefore(certTmp),0))
  ...{
    printf("设置开始时间失败:0x%x", ret);
    return;
  }

  if (!X509_gmtime_adj(X509_get_notAfter(certTmp), (long)60*60*24*10))
  ...{
    printf("设置结束时间失败");
  }

  if (!X509_set_subject_name(certTmp, X509_REQ_get_subject_name(req)))
  ...{
    printf("设置请求失败");
  }

  EVP_PKEY *tmppkey = X509_REQ_get_pubkey(req);
  if (!tmppkey || !X509_set_pubkey(certTmp,tmppkey))
  ...{
      EVP_PKEY_free(tmppkey);
      printf("设置公钥失败");
  }
  EVP_PKEY_free(tmppkey);

  X509_NAME *pName=X509_NAME_new();
  pName = X509_REQ_get_subject_name(req);

  if (!X509_set_issuer_name(certTmp, pName))
  ...{
      printf("设置签发者名字失败");
  }


  //digest = EVP_sha1();
  X509_sign(certTmp, pNewRsaKey, EVP_sha1());

  BIO *pbio;
  pbio = BIO_new(BIO_s_mem());
  PEM_write_bio_X509(pbio,certTmp);
  BUF_MEM * bptr;
  BIO_get_mem_ptr(pbio,&bptr);
  
  char *buf = (char *)malloc(bptr->length);
  if(NULL == buf)
  ...{
      printf("malloc error");
      return;
  }

  memcpy(buf, bptr->data, bptr->length);
  printf("%s ", buf);

}

int main(int argc, char* argv[])
...{
    create_cert_demo();
    return 0;
}