CryptProtectData 执行失败返回 87

在wince中使用CryptProtectData参照下面的代码

 

#include <stdio.h>
#include <windows.h>
#include <Wincrypt.h>
#define MY_ENCODING_TYPE  (PKCS_7_ASN_ENCODING | X509_ASN_ENCODING)
void MyHandleError(char *s);

void main()
{

DATA_BLOB DataIn;
DATA_BLOB DataOut;
DATA_BLOB DataVerify;
BYTE *pbDataInput =(BYTE *)"Hello world of data protection.";
DWORD cbDataInput = strlen((char *)pbDataInput)+1;
DataIn.pbData = pbDataInput;    
DataIn.cbData = cbDataInput;
CRYPTPROTECT_PROMPTSTRUCT PromptStruct;
LPWSTR pDescrOut = NULL;

//-------------------------------------------------------------------
//  Begin processing.

printf("The data to be encrypted is: %s/n",pbDataInput);

//-------------------------------------------------------------------
//  Initialize PromptStruct.

ZeroMemory(&PromptStruct, sizeof(PromptStruct));
PromptStruct.cbSize = sizeof(PromptStruct);
PromptStruct.dwPromptFlags = CRYPTPROTECT_PROMPT_ON_PROTECT;
PromptStruct.szPrompt = L"This is a user prompt.";

//-------------------------------------------------------------------
//  Begin protect phase.

if(CryptProtectData(
     &DataIn,
     L"This is the description string.", // A description string. 
     NULL,                               // Optional entropy
	                                     // not used.
     NULL,                               // Reserved.
     &PromptStruct,                      // Pass a PromptStruct.
     0,
     &DataOut))
{
     printf("The encryption phase worked. /n");
}
else
{
    MyHandleError("Encryption error!");
}
//-------------------------------------------------------------------
//   Begin unprotect phase.

if (CryptUnprotectData(
        &DataOut,
        &pDescrOut,
        NULL,                 // Optional entropy
        NULL,                 // Reserved
        &PromptStruct,        // Optional PromptStruct
        0,
        &DataVerify))
{
     printf("The decrypted data is: %s/n", DataVerify.pbData);
     printf("The description of the data was: %S/n",pDescrOut);
}
else
{
    MyHandleError("Decryption error!");
}
//-------------------------------------------------------------------
// At this point, memcmp could be used to compare DataIn.pbData and 
// DataVerify.pbDate for equality. If the two functions worked
// correctly, the two byte strings are identical. 

//-------------------------------------------------------------------
//  Clean up.

LocalFree(pDescrOut);
LocalFree(DataOut.pbData);
LocalFree(DataVerify.pbData);
} // End of main

//-------------------------------------------------------------------
//  This example uses the function MyHandleError, a simple error
//  handling function, to print an error message to the  
//  standard error (stderr) file and exit the program. 
//  For most applications, replace this function with one 
//  that does more extensive error reporting.

void MyHandleError(char *s)
{
    fprintf(stderr,"An error occurred in running the program. /n");
    fprintf(stderr,"%s/n",s);
    fprintf(stderr, "Error number %x./n", GetLastError());
    fprintf(stderr, "Program terminating. /n");
    exit(1);
} // End of MyHandleError
在ce下居然返回失败,GetLastError() = 87
上网查了很多资料都是这么调用了,没有办法有看了msdn87的含义是参数错误
分析只有DataOut这个参数可能有问题,因为没有被初始化为零。
添加上ZeroMemory(&DataOut,sizeof(DataOut))后ok,无语.....注意这是在windows ce 5.0中调用出错在windows xp并没有出错

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