活化填料和盐

Question

我正在尝试实现函数来使用OpenSSL对文件进行签名，我需要激活填充和。我的签名功能如下：

unsigned char * sign( EVP_PKEY * pkey, const EVP_MD * htype, char * data, int data_len, int * sig_len ) 
{ 
   EVP_MD_CTX     md_ctx; 
   unsigned char *sig = malloc( EVP_PKEY_size(pkey) ); 


   *sig_len = EVP_PKEY_size(pkey); 

   EVP_SignInit   (&md_ctx, htype); 
   EVP_SignUpdate (&md_ctx, data, data_len); 

   if (EVP_SignFinal (&md_ctx, sig, sig_len, pkey) != 1) 
   { 
      free(sig); 
      sig = 0; 
      *sig_len = 0; 

      ERR_print_errors_fp(stderr); 
   } 

   return sig; 
} 

有没有添加填充物和盐的例子？有谁知道能帮助解决这个问题吗？

Answer 1

我刚刚在OpenSSL论坛上找到了解决方案：

unsigned char * signData( EVP_PKEY * pkey, const EVP_MD * htype, char * data, int data_len, int * sig_len, int padding, int salt ) 
{
    unsigned int signature_l;
    unsigned char signature[512]; 
    int res;
    EVP_MD_CTX* verif_ctx = EVP_MD_CTX_create(); 
    EVP_MD_CTX* md_ctx = EVP_MD_CTX_create(); 
    EVP_PKEY_CTX* keygen_ctx = EVP_PKEY_CTX_new(pkey, NULL); 
    /* signing */ 
    if (EVP_DigestSignInit(md_ctx, &keygen_ctx, EVP_sha512(), NULL, pkey)<1) 
        return 0;
    if (EVP_PKEY_CTX_set_rsa_padding(keygen_ctx, padding)<1) 
        return 0; 
    if (EVP_PKEY_CTX_set_rsa_pss_saltlen(keygen_ctx, salt)<1) 
        return 0; 
    signature_l = EVP_PKEY_size(pkey); 

    if (EVP_DigestSignUpdate(md_ctx, data, data_len)<1) return 0;
    if (EVP_DigestSignFinal(md_ctx, signature, &signature_l)<1) return 0; 
    /* verifying */     
    if (EVP_DigestVerifyInit(verif_ctx, &keygen_ctx, EVP_sha512(), NULL, pkey)<1) 
        return 0;
    if (EVP_PKEY_CTX_set_rsa_padding(verif_ctx->pctx, padding)<1) 
        return 0;
    if (EVP_PKEY_CTX_set_rsa_pss_saltlen(verif_ctx->pctx, salt)<1) 
        return 0;
    if (EVP_DigestVerifyUpdate(verif_ctx, data, data_len)<1) 
        return 0;
    res = EVP_DigestVerifyFinal(verif_ctx, signature, signature_l); 
    switch(res) 
    { 
    case 1:printf("sig checks out!\n"); 
        break; 
    case 0:printf("nope nope nope.\n"); break; 
    default: return 0;
    }
    return signature; 
}

希望这能对未来的人有所帮助！