CryptUnProtectData() 在 Windows 7 嵌入式 COMPACT 上返回 ERROR_INSUFFICIENT_BUFFER(122) 錯誤

Question

當我如下執行 CryptUnProtectData() 時，它會出現 ERROR_INSUFFICIENT_BUFFER (122) 錯誤。 請注意，輸入字節數組（加密數據）和 output 字節數組（解密字節數據）的大小相同。 操作系統為Windows 7 嵌入式緊湊型。

BYTE encryptedValue[612] = // Get encrypted value using CryptProtectData
DATA_BLOB encryptedData;
encryptedData.cbData = 612;
encryptedData.pbData = encryptedValue;

BYTE unencryptedValue[612];
DATA_BLOB unencryptedData1;
unencryptedData1.cbData = 612;
unencryptedData1.pbData = unencryptedValue;

if (CryptUnprotectData( &(encryptedData),
NULL,
NULL,
NULL,
NULL,
CRYPTPROTECT_LOCAL_MACHINE, 
&(unencryptedData)  == FALSE)
{
// FAILS here.Get windows error
}

注意：如果我將 unencryptedData 的緩沖區大小增加到 950 左右，API 開始工作。 為什么會出現這種行為？ 上面的代碼在 Windows CE 5.0 中工作正常

完整代碼如下：

UINT32 ExecuteCryptDecrypt()
{
    const UINT32 unencryptedLength = 612;
    UINT32 cryptProtectError = 1;
    UINT32 cryptUnProtectError = 2;
    BYTE unencryptedValue[unencryptedLength] = {0xA3, 0x38, 0x2C, 0x5D, 0x5E, 0x13, 0xC7, 0xF3, 0x94, 0xA9, 0x3B, 0x0A, 0x57, 0xBA, 0x10, 0x9B, 0x0D, 0x3D, 0x31, 0x5A, 0x7C, 0xA4, 0x61, 0x78, 0xA8, 0x55, 0x37, 0x8E, 0xD4, 0x76, 0x0D, 0x24, 0xB4, 0x06, 0x67, 0xBA, 0xC4, 0xAD, 0xFC, 0x37, 0x12, 0x3F, 0x0D, 0xA1, 0xF3, 0x30, 0x35, 0xEC, 0x80, 0x3F, 0x35, 0xD3, 0x60, 0xA9, 0xEF, 0x30, 0x63, 0xE5, 0xFE, 0xEB, 0x5A, 0x2A, 0xFF, 0xA7, 0x4F, 0x92, 0x8B, 0xB0, 0xB0, 0xD7, 0x33, 0x06, 0x17, 0x9B, 0x35, 0xCB, 0xAA, 0x3F, 0x15, 0x26, 0x69, 0xB9, 0x9C, 0xEF, 0xA6, 0xB6, 0xC5, 0xB3, 0x0D, 0x16, 0x94, 0xEA, 0x18, 0x75, 0x93, 0x2F, 0x41, 0xD4, 0xB5, 0x67, 0xDB, 0x82, 0x52, 0xE4, 0xFB, 0xCC, 0x9A, 0xD4, 0x43, 0x75, 0x8F, 0x24, 0x5D, 0xA0, 0xDB, 0x9D, 0xFA, 0x68, 0x74, 0xB7, 0x2C, 0x3D, 0x89, 0xCD, 0xF2, 0x94, 0xEC, 0xD6, 0xF2, 0x25, 0x57, 0x8E, 0xB8, 0x4A, 0x8D, 0x65, 0x05, 0x70, 0xFD, 0x61, 0xB6, 0x1D, 0x02, 0x75, 0x78, 0xC6, 0xBC, 0x43, 0x43, 0x41, 0xEF, 0x4F, 0xCB, 0xA1, 0xFE, 0xE1, 0x33, 0x7C, 0xEE, 0xD5, 0x76, 0x4F, 0x2B, 0x77, 0xD8, 0x25, 0x4C, 0x2C, 0x62, 0x40, 0x07, 0x7E, 0x51, 0xBA, 0x9C, 0xB4, 0x68, 0xCD, 0x63, 0xFD, 0x9E, 0xBF, 0x03, 0x58, 0x8F, 0x58, 0xF9, 0x8B, 0x6A, 0xC7, 0xCF, 0x1E, 0xCD, 0x01, 0x09, 0x89, 0xFB, 0xE0, 0x85, 0xB4, 0x73, 0x20, 0xDE, 0xFE, 0x0D, 0xA6, 0x81, 0xCC, 0xB0, 0xD2, 0x8A, 0xF0, 0x80, 0x51, 0xCE, 0x77, 0x1C, 0xC7, 0xEF, 0x68, 0x86, 0x84, 0x94, 0xCA, 0x91, 0x67, 0x2D, 0xAB, 0xB9, 0xE0, 0x7A, 0xC7, 0x98, 0x15, 0xA5, 0x08, 0x19, 0xD1, 0x82, 0x48, 0xDC, 0xC7, 0xC9, 0xBD, 0x7F, 0xCA, 0xB4, 0x6E, 0xD4, 0x3D, 0xF3, 0x0F, 0x8B, 0x9D, 0x7E, 0x56, 0xF3, 0x8B, 0xD1, 0xA1, 0xFC, 0x9B, 0xFA, 0xFA, 0x14, 0x51, 0x6A, 0xD4, 0xFC, 0x4C, 0xEE, 0x6D, 0x4E, 0x80, 0x00, 0x7F, 0xB9, 0x46, 0xB0, 0x46, 0xE6, 0xC9, 0x98, 0x7A, 0xEC, 0xF7, 0x82, 0x39, 0xA5, 0x1E, 0x65, 0xB1, 0x8F, 0x84, 0xB6, 0x23, 0x2F, 0xD0, 0x03, 0x04, 0xF7, 0x86, 0x9C, 0xEC, 0xD2, 0x14, 0xBD, 0xDB, 0x52, 0xFB, 0x7A, 0xD5, 0x67, 0x70, 0xA9, 0x3F, 0xD2, 0x84, 0xAC, 0xEC, 0xC4, 0x02, 0x18, 0x96, 0xC2, 0xBB, 0xB4, 0xF9, 0xD9, 0xE7, 0x3D, 0x32, 0x17, 0x16, 0x56, 0x7B, 0x68, 0x9A, 0xE9, 0x41, 0xE2, 0xDB, 0x2C, 0xC6, 0x91, 0x06, 0x64, 0x3E, 0x21, 0x56, 0x90, 0x61, 0xDF, 0xCF, 0xD0, 0x08, 0xF6, 0xBA, 0x99, 0x4C, 0xA2, 0x90, 0x82, 0xA6, 0x9F, 0x5C, 0x45, 0x54, 0xC6, 0xBA, 0xAD, 0xF9, 0x7B, 0x13, 0x96, 0x5D, 0x61, 0xA1, 0xB8, 0xBB, 0xC5, 0x7A, 0x71, 0xD4, 0x16, 0x37, 0xCD, 0x85, 0x2C, 0x7B, 0xD8, 0x16, 0x52, 0x02, 0x0A, 0x20, 0x2D, 0x05, 0xE9, 0xE3, 0x29, 0xAF, 0xB4, 0x34, 0x20, 0x07, 0x57, 0xD2, 0xB2, 0x8E, 0xE9, 0x1B, 0x28, 0x66, 0x04, 0xF3, 0xE0, 0x70, 0x8F, 0xA6, 0x5A, 0x45, 0xE8, 0xE8, 0xEA, 0x7F, 0x0F, 0xA4, 0x5A, 0xE5, 0x6C, 0x6C, 0x59, 0x92, 0x95, 0x25, 0x09, 0xD5, 0x7F, 0x5A, 0x29, 0xCF, 0x24, 0x5D, 0xC4, 0xFC, 0x2D, 0xA3, 0xC1, 0xC9, 0x59, 0x46, 0x6A, 0x5D, 0x24, 0xFA, 0x12, 0xF4, 0x19, 0x80, 0x87, 0x7E, 0xB1, 0x10, 0xFF, 0xF1, 0xC5, 0x47, 0xBF, 0x9A, 0x9F, 0xF2, 0xED, 0x93, 0xAC, 0xAC, 0xAF, 0x97, 0x6E, 0xD0, 0x1C, 0x96, 0xDA, 0xAE, 0x93, 0x4C, 0xAF, 0x11, 0xF6, 0x63, 0xF0, 0x1E, 0xD8, 0x34, 0x01, 0x28, 0xE4, 0x91, 0x79, 0x7F, 0xBC, 0x43, 0x43, 0x41, 0xEF, 0x4F, 0xCB, 0xA1, 0xFE, 0xE1, 0x33, 0x7C, 0xEE, 0xD5, 0x76, 0x4F, 0x2B, 0x77, 0xD8, 0x25, 0x4C, 0x2C, 0x62, 0x40, 0x07, 0x7E, 0x51, 0xBA, 0x9C, 0xB4, 0x68, 0xCD, 0x63, 0xFD, 0x9E, 0xBF, 0x03, 0x58, 0x8F, 0x58, 0xF9, 0x8B, 0x6A, 0xC7, 0xCF, 0x1E, 0xCD, 0x01, 0x09, 0x89, 0xFB, 0xE0, 0x85, 0xB4, 0x73, 0x20, 0xDE, 0xFE, 0x0D, 0xA6, 0x81, 0xCC, 0xB0, 0xD2, 0x8A, 0xF0, 0x80, 0x51, 0xCE, 0x77, 0x1C, 0xC7, 0xEF, 0x68, 0x86, 0x84, 0x94, 0xCA, 0x91, 0x67, 0x2D, 0xAB, 0xB9, 0xE0, 0x7A, 0xC7, 0x98, 0x15, 0xA5, 0x08, 0x19, 0xD1, 0x82, 0x48, 0xDC, 0xC7, 0xC9, 0xBD, 0x7F, 0xCA, 0xB4, 0x6E, 0xD4, 0x3D, 0xF3, 0x0F, 0x8B, 0x9D, 0x7E, 0x56, 0xF3, 0x8B};    

    DATA_BLOB unencryptedData;
    unencryptedData.cbData = unencryptedLength;
    unencryptedData.pbData = unencryptedValue;

    DATA_BLOB encryptedData;
    encryptedData.cbData = 0;
    encryptedData.pbData = NULL;
    
    BOOL isProtectSuccessful = FALSE;
    isProtectSuccessful = CryptProtectData( &(unencryptedData),
    NULL,   
    NULL,   
    NULL,   
    NULL,   
    CRYPTPROTECT_LOCAL_MACHINE, 
    &(encryptedData) );
    if ( isProtectSuccessful == FALSE ) 
    {
        return cryptProtectError;
    }

    DATA_BLOB encryptedData1;
    encryptedData1.cbData = encryptedData.cbData;
    encryptedData1.pbData = encryptedData.pbData;

    const UINT32 unencryptedLength1 = 612;
    BYTE unencryptedValue1[unencryptedLength1];
    DATA_BLOB unencryptedData1;
    unencryptedData1.cbData = unencryptedLength1;
    unencryptedData1.pbData = unencryptedValue1;

    BOOL isUnprotectSuccessful = FALSE;
    isUnprotectSuccessful = CryptUnprotectData( &(encryptedData),
        NULL,   // optional pointer to readable description of encrypted data
        NULL,   // optional pointer to additional entropy
        NULL,   // reserved, must be NULL
        NULL,   // pPromptStruct, must be NULL (not used)
        CRYPTPROTECT_LOCAL_MACHINE, 
        &(unencryptedData) );
    if ( isUnprotectSuccessful == FALSE ) 
    {
        return cryptUnProtectError;
    }

    return 0;
}

Answer 1

CryptUnprotectData() 為您分配目標緩沖區，然后在完成后將其刪除。 此示例顯示模式https://docs.microsoft.com/en-us/windows/win32/seccrypto/example-c-program-using-cryptprotectdata

無需初始化 DATA_BLOB 輸出緩沖區 - 讓 Windows 為您完成。