C / C++ / MFC

16-Jan-07 0:47

Hi,
I am new to VC++ and i am currently working on a project in VC++.
I keep getting the error LNK 2001:unresolved external symbol "double __cdecl ut_asin(double)"
I get this error only while linking..not during complilation!!
I have a declaration as:
double ut_asin( double a );
whose definition is given in math.h

Can anyone help me to resolve this error??

Thanks,
Shiva Priya.

prasad_som16-Jan-07 0:51

prasad_som

16-Jan-07 0:51

shivapriyak wrote:
double __cdecl ut_asin(double)"

Where it is defined ? Linked is not able to find it.

Prasad
Notifier using ATL | Operator new[],delete[][^]

shivapriyak16-Jan-07 0:59

16-Jan-07 0:59

Thnx for the immediate reply..
see i hav a file as ut_math.h in which the math.h file is included...
This file has macros like:
#define mqerASN ut_asin
#define fasin ut_asin

Now, I have included ut_math.h in a file called as Common_func.cpp where this method is used as:
DDIST_B = ut_asin( DDIST_SIN_ANG_SIN_RATIO * sin( DABS_ANG_B ) ) * FIXED_EARTH_RAD;

This is what I have done and I started getting the linking error.I hope you got my prob.

Thnx

Shiva Priya.

prasad_som16-Jan-07 1:02

prasad_som

16-Jan-07 1:02

You have not answered question , where is ut_asin is defined ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

shivapriyak16-Jan-07 1:20

16-Jan-07 1:20

double ut_asin( double a )
{
if( fabs(a) < 1.0 )
return asin(a);
else if( fabs(a) < 1.00001 )
return (double)(mqerSGN( asin((double)1.0), a));
}
this is the definition of ut_asin in a file called as ut_math_e.cpp

thnx,Priya

prasad_som16-Jan-07 1:23

prasad_som

16-Jan-07 1:23

shivapriyak wrote:
ut_math_e.cpp

Does this this file is included in project and compiling ?

Prasad
Notifier using ATL | Operator new[],delete[][^]

David Crow16-Jan-07 3:02

David Crow

16-Jan-07 3:02

shivapriyak wrote:
this is the definition of ut_asin in a file called as ut_math_e.cpp

Is ut_math_e.cpp being compiled?

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

Cedric Moonen16-Jan-07 0:52

Cedric Moonen

16-Jan-07 0:52

shivapriyak wrote:
I have a declaration as:
double ut_asin( double a );
whose definition is given in math.h

Can you explain more in detail what you mean by that ? I never heard about a function called ut_asin in the math library (I might be wrong this looks strange to me).

What did you do exactly ?
You probably provided yourself a function prototype and forgot to define the body of the function. Can you post some relevant code (and don't forget to use the pre tags)

Cédric Moonen
Software developer

Charting control [v1.1]

shivapriyak16-Jan-07 0:58

16-Jan-07 0:58

Hamid_RT16-Jan-07 1:16

Hamid_RT

16-Jan-07 1:16

Wheres ut_asin?

WhiteSky

KarstenK16-Jan-07 3:00

KarstenK

16-Jan-07 3:00

You got to understand that compiling and linking are different things and steps in building a program.

I think you got to include the lib, I guess the "math.lib" in your project settings.

Greetings from Germany

Converting encrypted data into string/decimal and vice versa

David Crow16-Jan-07 3:03

David Crow

16-Jan-07 3:03

KarstenK wrote:
I think you got to include the lib, I guess the "math.lib" in your project settings.

Doubtful, since ut_asin() is his own function.

"Approved Workmen Are Not Ashamed" - 2 Timothy 2:15

"Judge not by the eye but by the heart." - Native American Proverb

vgandhi16-Jan-07 0:17

Re: Converting encrypted data into string/decimal and vice versa

16-Jan-07 0:17

Hello,
I am creating a challenge response application and in that making a call to encrypt a buffer that looks like

PBYTE pBufPtr
if(!Encrypt(hKey, 0, TRUE, 0,(BYTE *)pBufPtr, &dwCount, dwBufferLen))

In this case I want to take the encrypted data pBufPtr and display it as a string to the user. So any suggestions on how I can convert the pBufPtr into a decimal number or string that can be displayed to the user for typing purposes.

Also the decimal or string value obtained by converting the pBufPtr needs to be converted back into the encrypted data for the response side of the application.

So I need to convert encrypted data into string/decimal/BCD and take that string/decimal/BCD and convert it back into the encrypted data buffer.

So please let me know how is this possible. Thank you.

vg

Rage16-Jan-07 1:32

Rage

16-Jan-07 1:32

Are you asking for a encryption/decription routine, or how to convert a byte pointer to something displayable ?

Re: Converting encrypted data into string/decimal and vice versa

vgandhi16-Jan-07 8:40

Re: Converting encrypted data into string/decimal and vice versa

16-Jan-07 8:40

I am asking to convert the encrypted byte data to something displayable. The encrypted data looks like
"Œ[Ü‹¼| £](%ÎÝ‡X/2A9›Žf˜Qvdýýýý««««««««îþîþ"

so it has symbols such as ««««««« %
how do I convert the this binary data into something displayable so that it can be displayed on the screen for the user to read it.
The idea is to create a challenge by encrypting the data.
2) This encrypted data user reads it out from the a dialog in some displayable form(this part I need help on)
3) That converted encrypted data is converted back to its binary form and used to create the response.

James R. Twine16-Jan-07 3:52

Re: Converting encrypted data into string/decimal and vice versa

16-Jan-07 3:52

vgandhi wrote:
In this case I want to take the encrypted data pBufPtr and display it as a string to the user. So any suggestions on how I can convert the pBufPtr into a decimal number or string that can be displayed to the user for typing purposes.

Also the decimal or string value obtained by converting the pBufPtr needs to be converted back into the encrypted data for the response side of the application

The simplest thing to do is to convert each byte of the encrypted data into two hexidecimal characters, so that a byte of the value of 'z' becomes the string of two characters: '7A', and you can extend this to each byte of encrypted data. I.e 'ijk123' becomes '696A6B313233'.

If the encrypted data is of fixed length, for example, it will always be 10 characters of encrypted data, you can render it to hexidecimal and back again using functions like sprintf(...) and sscanf(...).

::sprintf( "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
    btaEncData[ 0 ], btaEncData[ 1 ], btaEncData[ 2 ], btaEncData[ 3 ], 
    btaEncData[ 4 ], btaEncData[ 5 ], btaEncData[ 6 ], 
    btaEncData[ 7 ], btaEncData[ 8 ], btaEncData[ 9 ] );
 
// ....
 
::sscanf( cpHexData, "%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
    &btaEncData[ 0 ], &btaEncData[ 1 ], &btaEncData[ 2 ], &btaEncData[ 3 ], 
    &btaEncData[ 4 ], &btaEncData[ 5 ], &btaEncData[ 6 ], 
    &btaEncData[ 7 ], &btaEncData[ 8 ], &btaEncData[ 9 ] );

That is a simple example, and not the most optimal, but it should give you the general idea.

You can reduce the amount of data the user has to type by converting the encrypted data buffer into blocks of 32-bit values (DWORDs) or 64-bit values (hypers), and using a function like ultoa(...) or _ui64toa(...) with a higher radix to reduce number of characters but use a wider range of them, and use the corresponding ato*(...) functions to convert them back.

ultoa( 0xFFFFFFFF, caBuffer, 10 ); // = "<code>4294967295</code>"
ultoa( 0xFFFFFFFF, caBuffer, 16 ); // = "<code>ffffffff</code>"
ultoa( 0xFFFFFFFF, caBuffer, 36 ); // = "<code>1z141z3</code>"

Peace!

-=- James
Please rate this message - let me know if I helped or not!<HR>If you think it costs a lot to do it right, just wait until you find out how much it costs to do it wrong!
Avoid driving a vehicle taller than you and remember that Professional Driver on Closed Course does not mean your Dumb Ass on a Public Road!
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vgandhi16-Jan-07 9:15

Re: Converting encrypted data into string/decimal and vice versa

16-Jan-07 9:15

Dear James,
Say I use the following
ultoa( 0xFFFFFFFF, caBuffer, 10 ); and the value I get is "4294967295"

Now how would I conver the 429496... number back into the original caBuffer form after making the above call.

Please let me know.
Thanks

James R. Twine16-Jan-07 11:34

Re: Converting encrypted data into string/decimal and vice versa

16-Jan-07 11:34

vgandhi wrote:
Now how would I conver the 429496... number back into the original caBuffer form after making the above call.

   As i said, the ato*(...) functions - for example, if you use ultoa(...) to convert to string (ltoa == long to ascii/ANSI), you can use the atol(...) to get it back to a number (atol == ASCII/ANSI to long).

   If you look up those functions, you will see that there is no atoul(...) function - but you will find the strto*(...) functions. In this example, strotul(...) will convert it back.

   Peace!

vgandhi17-Jan-07 20:38

Re: Converting encrypted data into string/decimal and vice versa

17-Jan-07 20:38

Hey guys,
I am using this code to convert the data into string
CryptBinaryToString((BYTE *)pBufPtr,len,1,msg2,&lul_buflen);
The msg2 looks like
"KBeMW9yLvHwMow5dKCXO3ddKLzIGQTmbtNVmmFF2FmT9/f39q6urq6urq6vu/u7+"

and I am using the following functions to convert the string to long so that I can reduce the size to be displayed on the string
char *p;
long l = strtol(msg2, &p, 10);
long temp1 = atoi(msg2);
But both of them return 0 as the value.

Please help. Thanks.

vgandhi17-Jan-07 19:19

Re: Converting encrypted data into string/decimal and vice versa

17-Jan-07 19:19

Dear James,
In the message above you said we can reduce the buffer by using the function ultoa. But my question is I have to first convert the buffer into ulong and then use the function ultoa. So how do I convert the buffer to ulong because the function ultoa takes in a ulong as its first parameter. So please let me know.

Thanks.

James R. Twine18-Jan-07 12:51

Re: Converting encrypted data into string/decimal and vice versa

18-Jan-07 12:51

   The way to do that is to pad the data buffer (if required) to a 4-byte boundary, and then take 4 byte "chunks" of them, cast the address of the chunk to an unsigned long* (or DWORD*), and then dereference the pointer to get a DWORD value to convert.

   But since you are already converting the binary data to a string (as shown in a later example you posted), you will gain little if nothing by using my suggestion - your converting the binary data to a Base64 encoded string actually expands it (each three binary bytes becomes 4 ASCII characters using Base64 encoding).

   You may reduce the raw binary data a bit, but the worst case you can get using my idea is 7 alphanumeric digits per 4 binary bytes, as opposed to hexidecimal's which is 8 alphanumeric per 4 bytes of raw data.

   You can see an example of this here:

TCHAR   caBuffer[ 32 + 1 ];
BYTE    btaBinary[] = { 0x00, 0x04, 0xE4, 0xF0 };
BYTE    btaBinary2[] = { 'A', 'b', '1', '2' };
BYTE    btaBinary3[] = { 0xFF, 0xFF, 0xFF, 0xFF };

::_ultot( *(DWORD*)btaBinary, caBuffer, 36 );
::_ultot( *(DWORD*)btaBinary2, caBuffer, 36 );
::_ultot( *(DWORD*)btaBinary3, caBuffer, 36 );

   - And by reading the contents of caBuffer after each call to ::_ultot(...)

   If you can somehow compress the data, or reduce the encryption such that the length of the cyphertext is closer to the length of the plaintext, that will also go a long way.

   Peace!

vgandhi22-Jan-07 18:56

Re: Converting encrypted data into string/decimal and vice versa

22-Jan-07 18:56

Dear James,
In your above example how would I convert the encrypted data if it is not of fixed length using your solution above.
Also once everything is converted to hexidecimal now how would I convert that back into the encrypted data again?
Please let me know.

Thanks.

James R. Twine23-Jan-07 14:45