What's the equivalent of fopen(..) in API's CreateFile

I have this code in C:

Code:

file = fopen (filename, "rb");

What would be the euivalent in Win32 API?
Thanks?

The binary is default, so you need to open in read mode. Pass GENERIC_READ for dwDesiredAccess, FILE_SHARE_READ for dwShareMode, OPEN_EXISTING for dwCreationDisposition and 0 for dwFlagsAndAttributes.

FYI - The Platform SDK contains the MSCRT 6.0 source code (with bug fixes and 64bit support).
So you could look at the source for fopen() and see how it uses CreateFile() etc.

gg

You could - but the CRT source is rather horrible.

Yeah, I noticed that is default binary...thanks to all

I have another question, this is the C-style code:

Code:

for (i = 0; i < 16; i++) {
     printf("&#37;02x", digest[i]); 
     // this returns something like 0a44a522a8349e6ed4fd1b71e8745759
}

Now, when I ported to API

Code:

for (i = 0; i < 16; i++, szBuff++) {
     wsprintf(szBuff, "%02x", digest[i]);
     // this returns something like 04a2a396df17e7559
}
szBuff = '\0';

Any ideas

Since you seem to have only gotten the MSB of each hex digit pair, I'd say you've probably messed up the types somewhere.

Try posting more code next time, at least enough for us to establish some context for the question.

The last line of your 'new' code makes no sense at all.

Originally Posted by Joelito

Yeah, I noticed that is default binary...thanks to all

I have another question, this is the C-style code:

Code:

for (i = 0; i < 16; i++) {
     printf("%02x", digest[i]); 
     // this returns something like 0a44a522a8349e6ed4fd1b71e8745759
}

Now, when I ported to API

Code:

for (i = 0; i < 16; i++, szBuff++) {
     wsprintf(szBuff, "%02x", digest[i]);
     // this returns something like 04a2a396df17e7559
}
szBuff = '\0';

Any ideas

Maybe you should increment szBuff by two, since each hex number is two digits long?

--
Mats

Ok, I think I'm understanding:

Code:

void MDPrint (unsigned char digest[16], char *szBuff) {
	unsigned int i;
	for (i = 0; i < 16; i++, szBuff++) {
		wsprintf(szBuff++, "&#37;02x", digest[i]);
	}
	//szBuff = '\0';
}

//
char dump[17];
MD5File("dummy.txt", dump);
MessageBox(hWnd, dump, 0, 0);

Now, displays correctly the hashed string, but after that it crashes... ???

You need at least 33 bytes to cover a 16 byte string as hex - 16 * 2 bytes for the actual hex characters, and one for the NUL indicating end of string.

--
Mats

God, that loop is awful! Why use such stupid tricks? Just increment the stupid thing by two, once.

It crashes after displaying the string? Then why don't you show us the code that comes after?

Is this clearer?

Code:

void MDPrint (unsigned char digest[16], char *szBuff) {
	unsigned int i;
	for (i = 0; i < 16; i++) {
		wsprintf( &szBuff[i*2], "%02x", digest[i]);
	}
	szBuff[i*2] = '\0';
}

What are you passing to this function, as szBuff ?
Is it 33 wchar_t's ?

First, the code ain't mine
2nd, I don't know that much of C to API
@Salem: Thanks
Final code:

Code:

void MDPrint (unsigned char digest[16], char *szBuff) {
	unsigned int i;
	for (i = 0; i < 16; i++) {
		wsprintf(&szBuff[i*2], "&#37;02x", digest[i]);
	}
	szBuff[i*2] = '\0';
}

int MD5File(const char *pszFilename, char *szBuff) {
	MD5_CTX context = {0};
	HANDLE hFile;
	int len;
	unsigned char buffer[1024], digest[16];

	hFile = CreateFile(pszFilename, GENERIC_READ, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
	if (hFile == INVALID_HANDLE_VALUE) return 0;
	MD5Init(&context);
	while(len) {
		ReadFile(hFile, buffer, 1, &len, NULL);
		MD5Update (&context, buffer, len);
	}
	MD5Final(digest, &context);
	CloseHandle(hFile);
	MDPrint(digest, szBuff);
	return 1;
}

int main(int argc, char *argv[])
{
	char dump[128];
	MD5File(argv[1], dump);
	MessageBox(0, dump, 0, 0);
    return 0;
}

Originally Posted by matsp

Maybe you should increment szBuff by two, since each hex number is two digits long?

Even easier, don't think about the length at all:

Code:

for (i = 0; i < 16; i++) {
     szBuff += wsprintf(szBuff, "%02x", digest[i]);
}
szBuff = '\0'; /* This isn't necessary, because wsprintf() already makes sure it's there */

Now the loop is immune to any changes in the actual format string.