MSDN HMAC-SHA1 example not working - c++

Question

Creating an HMAC steps by using CryptoAPI found here: http://msdn.microsoft.com/en-us/library/Aa379863
To compute an HMAC
Get a pointer to the Microsoft Cryptographic Service Provider
(CSP) by calling CryptAcquireContext.
Create a handle to an HMAChash object by calling
CryptCreateHash. Pass CALG_HMAC in the Algid parameter. Pass the
handle of a symmetric key in the hKey parameter. This symmetric key
is the key used to compute the HMAC.
Specify the type of hash to be used by calling
CryptSetHashParam with the dwParam parameter set to the value
HP_HMAC_INFO. The pbData parameter must point to an initialized
HMAC_INFO structure.
Call CryptHashData to begin computing the HMAC of the data. The
first call to CryptHashData causes the key value to be combined using
the XOR operator with the inner string and the data. The result of
the XOR operation is hashed, and then the target data for the HMAC
(pointed to by the pbData parameter passed in the call to
CryptHashData) is hashed. If necessary, subsequent calls to
CryptHashData may then be made to finish the hashing of the target
data.
Call CryptGetHashParam with the dwParam parameter set to
HP_HASHVAL. This call causes the inner hash to be finished and the
outer string to be combined using XOR with the key. The result of the
XOR operation is hashed, and then the result of the inner hash
(completed in the previous step) is hashed. The outer hash is then
finished and returned in the pbData parameter and the length in the
dwDataLen parameter.
I can not, for the life of me get this working. I have all the steps in order, and still can not even run my program. Errors while running:
Error in CryptImportKey 0x8009007
Error in CryptCreatHash 0x8009003
Error in CryptSetHashParam 0x00000057
Error in CryptHashData 0x00000057
Error in CryptGetHashParam 0x00000057
Can anyone help?
#include <iostream>
#include <windows.h>
#include <wincrypt.h>
using namespace std;
#define CALG_HMAC CALG_SHA1
int main()
{
//--------------------------------------------------------------------
// Declare variables.
HCRYPTPROV hProv = NULL;
HCRYPTHASH hHash = NULL;
HCRYPTKEY hKey = NULL;
BYTE DesKeyBlob[] = { 0x70,0x61,0x73,0x73,0x77,0x6F,0x72,0x64 };
HCRYPTHASH hHmacHash = NULL;
PBYTE pbHash = NULL;
DWORD dwDataLen = 20;
BYTE Data[] = {0x6D,0x65,0x73,0x73,0x61,0x67,0x65};
HMAC_INFO HmacInfo;
//--------------------------------------------------------------------
// Zero the HMAC_INFO structure
ZeroMemory(&HmacInfo, sizeof(HmacInfo));
HmacInfo.HashAlgid = CALG_HMAC;
HmacInfo.pbInnerString = (BYTE*)0x36;
HmacInfo.cbInnerString = 0;
HmacInfo.pbOuterString = (BYTE*)0x5C;
HmacInfo.cbOuterString = 0;
// Step 1
if (!CryptAcquireContext(
&hProv, // handle of the CSP
NULL, // key container name
NULL, // CSP name
PROV_RSA_FULL, // provider type
CRYPT_VERIFYCONTEXT)) // no key access is requested
{
printf(" Error in AcquireContext 0x%08x \n",
GetLastError());
}
//--------------------------------------------------------------------
//Step 2
//in step two, we need the hash key used to be imported?
//imports the key used... as hKey1
if(!CryptImportKey(
hProv,
DesKeyBlob,
sizeof(DesKeyBlob),
0,
CRYPT_EXPORTABLE,
&hKey ))
{
printf("Error in !CryptImportKey 0x%08x \n",
GetLastError());
}
if (!CryptCreateHash(
hProv, // handle of the CSP
CALG_HMAC, // hash algorithm to use
hKey, // hash key this shoudl point to a key used to compute the HMAC?
0, // reserved
&hHmacHash // address of hash object handle
)){
printf("Error in CryptCreateHash 0x%08x \n",
GetLastError());
}
// Step 3
if (!CryptSetHashParam(
hHmacHash,//hProv,//hHash,//hHmacHash, // handle of the HMAC hash object
HP_HMAC_INFO, // setting an HMAC_INFO object
(BYTE*)&HmacInfo, // the HMAC_INFO object
0)) // reserved
{
printf("Error in CryptSetHashParam 0x%08x \n",
GetLastError());
}
//Step 4
if (!CryptHashData(
hHmacHash, // handle of the HMAC hash object
Data, // message to hash
sizeof(Data), // number of bytes of data to add
0)) // flags
{
printf("Error in CryptHashData 0x%08x \n",
GetLastError());
}
//Step 5
if (!CryptGetHashParam(
hHmacHash, // handle of the HMAC hash object
HP_HASHVAL, // query on the hash value
pbHash, // pointer to the HMAC hash value
&dwDataLen, // length, in bytes, of the hash
0))
{
printf("Error in CryptGetHashParam 0x%08x \n", GetLastError());
}
// Print the hash to the console.
printf("The hash is: ");
for(DWORD i = 0 ; i < dwDataLen ; i++)
{
printf("%2.2x ",pbHash[i]);
}
printf("\n");
int a;
std::cin >> a;
return 0;
}

Answer 1

You might (?1) need to specify what hash algorithm you want to use.
#define CALG_HMAC CALG_SHA1 // or CALG_MD5 etc
Edit
Why do you initialize dwDataLen = 20 (instead of 0)?
Why did you change the hash algorithm from SHA1
Why do you not exit on ErrorExit anymore (that alone will prevent the crash instead of proper error message)
You use CryptImportKey instead of CryptDeriveKey -- no such thing even exists in the sample on MSDN. It can't be a coincidence that CryptImportKey is the call failing with 0x80090005 (NTE_BAD_DATA). The key is not supported by your CSP!
For that to work, you need key access so you'd at least need to change CRYPT_VERIFY_CONTEXT into something else (don't know what); I tried using
.
if (!CryptAcquireContext(
&hProv,
NULL,
MS_STRONG_PROV, // allow 2048 bit keys, in case you need it
PROV_RSA_FULL,
CRYPT_MACHINE_KEYSET)) // just a guess
Now my program results in 0x80090016: Keyset does not exist. This might simply be because I don't have that keyset, or because I'm running on Linux under Wine.
Hope this helps.
1 Compiled on Linux using:
i586-mingw32msvc-g++ -m32 -O2 -g test.cpp -o test.exe
It did crash when run (without parameters) but that might be wine incompatibility (or the fact that I haven't read the source to see what it does :))