473,287 Members | 1,926 Online
Bytes | Software Development & Data Engineering Community
Post Job

Home Posts Topics Members FAQ

Join Bytes to post your question to a community of 473,287 software developers and data experts.

a problem with encryption

This is the problem: I do not get the output I need when encoding and
decoding data using rijndael alghoritm.
Look at the code and see what the problem is actually:

Please paste this code into your Visual Studio and compile it + run it; so
you can see what the actual problem is.

Thanks.

code:

using System;
using System.IO;
using System.Text;
using System.Security.Cryptography;
namespace ConsoleApplication1
{
class MyMainClass
{
public static void Main()
{
string original = "Original string";
string roundtrip;
ASCIIEncoding textConverter = new ASCIIEncoding();
RijndaelManaged myRijndael = new RijndaelManaged();
byte[] fromEncrypt;
byte[] encrypted;
byte[] toEncrypt;
byte[] key;
byte[] IV;
//Create a new key and initialization vector.
myRijndael.GenerateKey();
myRijndael.GenerateIV();
//Get the key and IV.
key = myRijndael.Key;
IV = myRijndael.IV;
//Get an encryptor.
ICryptoTransform encryptor = myRijndael.CreateEncryptor(key, IV);
//Encrypt the data.
MemoryStream msEncrypt = new MemoryStream();
CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor,
CryptoStreamMode.Write);
//Convert the data to a byte array.
toEncrypt = textConverter.GetBytes(original);
//Write all data to the crypto stream and flush it.
csEncrypt.Write(toEncrypt, 0, toEncrypt.Length);
csEncrypt.FlushFinalBlock();
//Get encrypted array of bytes.
encrypted = msEncrypt.ToArray();

//Here I send data trough network stream
//create byte array to be sent trough tcp network
byte[] finalized = new byte[key.Length+IV.Length+encrypted.Length];
//merge all values into single byte array
key.CopyTo(finalized,0);
IV.CopyTo(finalized,32);
encrypted.CopyTo(finalized,48);
//here goes tcp code with sending the array trough network. it works fine,
and is no problem.
//For simplicitiy's sake, here i'll just simulate a new application that
uses values it got from the first application.
//SIMULATED NEW APPLICATION
//Create values that will be used in decryption process and that are passed
trough network
byte[] key1 = new byte[32];
byte[] IV1 = new byte[16];
byte[] encrypted1 = new byte[finalized.Length-48];
//read all values from the passed byte array and divid those correctly.
for (int i=0; i<32; i++)
{
key1[i]=finalized[i];
}
for (int i=32; i<48; i++)
{
IV1[i-32]=finalized[i];
}
for (int i=48; i<finalized.Length; i++)
{
encrypted1[i-48]=finalized[i];
}
//now use values to get the result:
//Get a decryptor that uses the same key and IV as the encryptor.
ICryptoTransform decryptor = myRijndael.CreateDecryptor(key1, IV1);
//Now decrypt the previously encrypted message using the decryptor
MemoryStream msDecrypt = new MemoryStream(encrypted1);
CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor,
CryptoStreamMode.Read);
fromEncrypt = new byte[encrypted1.Length];
//Read the data out of the crypto stream.
csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the byte array back into a string.
roundtrip = textConverter.GetString(fromEncrypt);
//Display the original data and the decrypted data to see where the actual
problem is:
Console.WriteLine("Original string: {0}", original + "_");
Console.WriteLine("String I got to another application: {0}", roundtrip +
"_");
//Guess what! The result string has some dummy stuff at the end and it is
//just not the data I encoded. It is actually there, but I really don't want
//that sh*t at the end. I placed "_" sign just to see that there is a
problem with data I got.
}
}
}
Jul 21 '05 #1
10 2288
crawlerxp <ny******@email.htnet.hr> wrote:
This is the problem: I do not get the output I need when encoding and
decoding data using rijndael alghoritm.
Look at the code and see what the problem is actually:

Please paste this code into your Visual Studio and compile it + run it; so
you can see what the actual problem is.


<snip>

The problem is that you're assuming the decrypted size will be the same
as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is
a bad idea) but passing the encoding a buffer 16 bytes long.

*Always* use the return value of Stream.Read.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #2
crawlerxp <ny******@email.htnet.hr> wrote:
This is the problem: I do not get the output I need when encoding and
decoding data using rijndael alghoritm.
Look at the code and see what the problem is actually:

Please paste this code into your Visual Studio and compile it + run it; so
you can see what the actual problem is.


<snip>

The problem is that you're assuming the decrypted size will be the same
as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is
a bad idea) but passing the encoding a buffer 16 bytes long.

*Always* use the return value of Stream.Read.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #3
>The problem is that you're assuming the decrypted size will be the same
as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is a
bad idea) but passing the encoding a buffer 16 bytes long.
*Always* use the return value of Stream.Read.


Well, the problem was not in network operations and data send. It was in
decrypted data.
The problem was I did always get n to 16 bytes filled with zeros.

So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.

Thanks btw.

I have another question:
When I'm sending this data trough network stream from client to server,
I always create byte type array big enough to accept possible data from
the client application.
Do I have to always create it big enough to support any possible data
size, or I can read everything in blocks and then merge it to a single
byte array for example.

This is how it is done by now:

client code:
(this is a connection thread code cut from the main code:)

try
{
this.hostName = this.textBox2.Text;
TcpClient client = new TcpClient(hostName, portNum);

NetworkStream ns = client.GetStream();

//size of response buffer
byte[] bytes = new byte[1024];

//using custom encryption class to encrypt given data
bit256_RijndaelEnCryptorC enkripted = new bit256_RijndaelEnCryptorC();

//encrypt string from the textbox
encrypted.EnCrypt(this.textBox1.Text);

//create data-to-be-sent buffer
byte[] byteTime = new byte[encrypted.ReleaseEnCrypted).Length];

//fill it
byteTime = encrypted.ReleaseEnCrypted();

//write it trough stream
ns.Write(byteTime, 0, byteTime.Length);

//receive a response
int bytesRead = ns.Read(bytes, 0, bytes.Length);

client.Close();

}

server code:

TcpClient client = listener.AcceptTcpClient();

NetworkStream ns = client.GetStream();

//buffer for incoming data
byte[] bytes = new byte[4096];

//read data from the ns
int bytesRead = ns.Read(bytes, 0, bytes.Length);

//input data in a work buffer
byte[] returned = new byte[bytesRead];

for (int u=0; u<bytesRead; u++)
{
returned[u]=bytes[u];
}

//create data variables to be used in encryption process
byte[] key = new byte[32];
byte[] IV = new byte[16];
byte[] encrypted = new byte[returned.Length-48];

//strip usable data from the incoming stream
for (int i=0; i<32; i++)
{
key[i]=returned[i];
}
for (int i=32; i<48; i++)
{
IV[i-32]=returned[i];
}
for (int i=48; i<returned.Length; i++)
{
encrypted[i-48]=returned[i];
}

//create a custom encryption (this time decryption) class
bit256_RijndaelEnCryptorC dekripted = new
bit256_RijndaelEnCryptorC(key,IV,encrypted);
encrypted.DeCrypt();

string result = encrypted.ReleaseDeCrypted();

byte[] byteTime = Encoding.ASCII.GetBytes("server performed
operations!");

try
{
ns.Write(byteTime, 0, byteTime.Length);
ns.Close();
}
client.Close();

*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!
Jul 21 '05 #4
>The problem is that you're assuming the decrypted size will be the same
as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is a
bad idea) but passing the encoding a buffer 16 bytes long.
*Always* use the return value of Stream.Read.


Well, the problem was not in network operations and data send. It was in
decrypted data.
The problem was I did always get n to 16 bytes filled with zeros.

So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.

Thanks btw.

I have another question:
When I'm sending this data trough network stream from client to server,
I always create byte type array big enough to accept possible data from
the client application.
Do I have to always create it big enough to support any possible data
size, or I can read everything in blocks and then merge it to a single
byte array for example.

This is how it is done by now:

client code:
(this is a connection thread code cut from the main code:)

try
{
this.hostName = this.textBox2.Text;
TcpClient client = new TcpClient(hostName, portNum);

NetworkStream ns = client.GetStream();

//size of response buffer
byte[] bytes = new byte[1024];

//using custom encryption class to encrypt given data
bit256_RijndaelEnCryptorC enkripted = new bit256_RijndaelEnCryptorC();

//encrypt string from the textbox
encrypted.EnCrypt(this.textBox1.Text);

//create data-to-be-sent buffer
byte[] byteTime = new byte[encrypted.ReleaseEnCrypted).Length];

//fill it
byteTime = encrypted.ReleaseEnCrypted();

//write it trough stream
ns.Write(byteTime, 0, byteTime.Length);

//receive a response
int bytesRead = ns.Read(bytes, 0, bytes.Length);

client.Close();

}

server code:

TcpClient client = listener.AcceptTcpClient();

NetworkStream ns = client.GetStream();

//buffer for incoming data
byte[] bytes = new byte[4096];

//read data from the ns
int bytesRead = ns.Read(bytes, 0, bytes.Length);

//input data in a work buffer
byte[] returned = new byte[bytesRead];

for (int u=0; u<bytesRead; u++)
{
returned[u]=bytes[u];
}

//create data variables to be used in encryption process
byte[] key = new byte[32];
byte[] IV = new byte[16];
byte[] encrypted = new byte[returned.Length-48];

//strip usable data from the incoming stream
for (int i=0; i<32; i++)
{
key[i]=returned[i];
}
for (int i=32; i<48; i++)
{
IV[i-32]=returned[i];
}
for (int i=48; i<returned.Length; i++)
{
encrypted[i-48]=returned[i];
}

//create a custom encryption (this time decryption) class
bit256_RijndaelEnCryptorC dekripted = new
bit256_RijndaelEnCryptorC(key,IV,encrypted);
encrypted.DeCrypt();

string result = encrypted.ReleaseDeCrypted();

byte[] byteTime = Encoding.ASCII.GetBytes("server performed
operations!");

try
{
ns.Write(byteTime, 0, byteTime.Length);
ns.Close();
}
client.Close();

*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!
Jul 21 '05 #5
Tonci Jukic <ny******@email.htnet.hr> wrote:
The problem is that you're assuming the decrypted size will be the same as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is a
bad idea) but passing the encoding a buffer 16 bytes long.
*Always* use the return value of Stream.Read.


Well, the problem was not in network operations and data send. It was in
decrypted data.


I didn't say it *was* in the network operations.
The problem was I did always get n to 16 bytes filled with zeros.
That's because you ignored the fact that Read wasn't returning 16
bytes.
So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.
That's a bad way of doing things. Just use the return value of Read to
find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.
Thanks btw.

I have another question:
When I'm sending this data trough network stream from client to server,
I always create byte type array big enough to accept possible data from
the client application.
Do I have to always create it big enough to support any possible data
size, or I can read everything in blocks and then merge it to a single
byte array for example.
Yes. That's much more robust - relying on a single call to Read as you
are at the moment is a very bad idea.

See http://www.pobox.com/~skeet/csharp/readbinary.html
This is how it is done by now:
<snip>
byte[] encrypted = new byte[returned.Length-48];
<snip>
encrypted.DeCrypt();


That's not your actual code, is it? Byte arrays don't have a DeCrypt
method. Please always post your *actual* code.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #6
Tonci Jukic <ny******@email.htnet.hr> wrote:
The problem is that you're assuming the decrypted size will be the same as the encrypted size - it's not. You're only actually reading 15 bytes
(and moreover, you're assuming they'll all be read in one go, which is a
bad idea) but passing the encoding a buffer 16 bytes long.
*Always* use the return value of Stream.Read.


Well, the problem was not in network operations and data send. It was in
decrypted data.


I didn't say it *was* in the network operations.
The problem was I did always get n to 16 bytes filled with zeros.
That's because you ignored the fact that Read wasn't returning 16
bytes.
So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.
That's a bad way of doing things. Just use the return value of Read to
find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.
Thanks btw.

I have another question:
When I'm sending this data trough network stream from client to server,
I always create byte type array big enough to accept possible data from
the client application.
Do I have to always create it big enough to support any possible data
size, or I can read everything in blocks and then merge it to a single
byte array for example.
Yes. That's much more robust - relying on a single call to Read as you
are at the moment is a very bad idea.

See http://www.pobox.com/~skeet/csharp/readbinary.html
This is how it is done by now:
<snip>
byte[] encrypted = new byte[returned.Length-48];
<snip>
encrypted.DeCrypt();


That's not your actual code, is it? Byte arrays don't have a DeCrypt
method. Please always post your *actual* code.

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #7
> So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted. That's a bad way of doing things. Just use the return value of Read to find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.

Well. I really don't know a way to know how long the string I send to
the server app can be. As you could see in the code, I send key, IV and
encrypted data in a byte array trough network stream. I really don't
know how to send the length of the string I encrypted to the server by
which the server would know how much to decrypt.
The only way I could think of was to trim encrypted byte array at the
very start before sending data trough network.
Yes. That's much more robust - relying on a single call to Read as you are at the moment is a very bad idea.

How could I possible use multiple read calls? What would it give to me?
That's not your actual code, is it? Byte arrays don't have a DeCrypt

method. Please always post your *actual* code.

Well. We've got a slight problem here:)

I tried to cut\paste and edit my code here. I've translated variables
into english as I thought it would be easier for you to understand the
code.

Too bad attachments are not possible here, but here is almost the
complete code I've been using.

(I'm totally green in C# and .NET (although I've been using C++ till
now) so please don't laugh at my code. I woul appreciate any comments
and suggestions about it.)

http://www.dg.disorange.com/download/code.zip
*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!
Jul 21 '05 #8
> So I've just swapped line:

roundtrip = textConverter.GetString(fromEncrypt);

with:

roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted. That's a bad way of doing things. Just use the return value of Read to find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.

Well. I really don't know a way to know how long the string I send to
the server app can be. As you could see in the code, I send key, IV and
encrypted data in a byte array trough network stream. I really don't
know how to send the length of the string I encrypted to the server by
which the server would know how much to decrypt.
The only way I could think of was to trim encrypted byte array at the
very start before sending data trough network.
Yes. That's much more robust - relying on a single call to Read as you are at the moment is a very bad idea.

How could I possible use multiple read calls? What would it give to me?
That's not your actual code, is it? Byte arrays don't have a DeCrypt

method. Please always post your *actual* code.

Well. We've got a slight problem here:)

I tried to cut\paste and edit my code here. I've translated variables
into english as I thought it would be easier for you to understand the
code.

Too bad attachments are not possible here, but here is almost the
complete code I've been using.

(I'm totally green in C# and .NET (although I've been using C++ till
now) so please don't laugh at my code. I woul appreciate any comments
and suggestions about it.)

http://www.dg.disorange.com/download/code.zip
*** Sent via Developersdex http://www.developersdex.com ***
Don't just participate in USENET...get rewarded for it!
Jul 21 '05 #9
Tonci Jukic <ny******@email.htnet.hr> wrote:
roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.

That's a bad way of doing things. Just use the return value of Read to

find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.

Well. I really don't know a way to know how long the string I send to
the server app can be. As you could see in the code, I send key, IV and
encrypted data in a byte array trough network stream. I really don't
know how to send the length of the string I encrypted to the server by
which the server would know how much to decrypt.
The only way I could think of was to trim encrypted byte array at the
very start before sending data trough network.


You don't need to trim anything. Just take note of how much decrypted
data you're actually receiving. From your original sample, all you've
got to change is:

csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the byte array back into a string.
roundtrip = textConverter.GetString(fromEncrypt);

to

int bytesRead = csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the byte array back into a string.
roundtrip = textConverter.GetString(fromEncrypt, 0, bytesRead);

(It doesn't deal with the situation where there's more data to read
than you expect, or a single call to Read doesn't return all the data.)
Yes. That's much more robust - relying on a single call to Read as you

are at the moment is a very bad idea.

How could I possible use multiple read calls? What would it give to me?


It would mean that if you send more data than the decrypting code wants
to decrypt in one call, your code would still work.
That's not your actual code, is it? Byte arrays don't have a DeCrypt

method. Please always post your *actual* code.

Well. We've got a slight problem here:)

I tried to cut\paste and edit my code here. I've translated variables
into english as I thought it would be easier for you to understand the
code.

Too bad attachments are not possible here, but here is almost the
complete code I've been using.

(I'm totally green in C# and .NET (although I've been using C++ till
now) so please don't laugh at my code. I woul appreciate any comments
and suggestions about it.)

http://www.dg.disorange.com/download/code.zip


Ah. The problem is that you changed variable names half way through -
you wrote (in your previous message) encrypted.DeCrypt() instead of
dekripted.DeCrypt(). It's always worth trying to compile the code
you're about to post. It's also worth posting short and complete code -
see http://www.pobox.com/~skeet/csharp/complete.html

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #10
Tonci Jukic <ny******@email.htnet.hr> wrote:
roundtrip =
textConverter.GetString(fromEncrypt).TrimEnd(Conve rt.ToChar(0));

That way I always get the original data I've encrypted.

That's a bad way of doing things. Just use the return value of Read to

find out how much real data you've got, and use the form of GetString
that lets you specify how much to decode.

Well. I really don't know a way to know how long the string I send to
the server app can be. As you could see in the code, I send key, IV and
encrypted data in a byte array trough network stream. I really don't
know how to send the length of the string I encrypted to the server by
which the server would know how much to decrypt.
The only way I could think of was to trim encrypted byte array at the
very start before sending data trough network.


You don't need to trim anything. Just take note of how much decrypted
data you're actually receiving. From your original sample, all you've
got to change is:

csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the byte array back into a string.
roundtrip = textConverter.GetString(fromEncrypt);

to

int bytesRead = csDecrypt.Read(fromEncrypt, 0, fromEncrypt.Length);
//Convert the byte array back into a string.
roundtrip = textConverter.GetString(fromEncrypt, 0, bytesRead);

(It doesn't deal with the situation where there's more data to read
than you expect, or a single call to Read doesn't return all the data.)
Yes. That's much more robust - relying on a single call to Read as you

are at the moment is a very bad idea.

How could I possible use multiple read calls? What would it give to me?


It would mean that if you send more data than the decrypting code wants
to decrypt in one call, your code would still work.
That's not your actual code, is it? Byte arrays don't have a DeCrypt

method. Please always post your *actual* code.

Well. We've got a slight problem here:)

I tried to cut\paste and edit my code here. I've translated variables
into english as I thought it would be easier for you to understand the
code.

Too bad attachments are not possible here, but here is almost the
complete code I've been using.

(I'm totally green in C# and .NET (although I've been using C++ till
now) so please don't laugh at my code. I woul appreciate any comments
and suggestions about it.)

http://www.dg.disorange.com/download/code.zip


Ah. The problem is that you changed variable names half way through -
you wrote (in your previous message) encrypted.DeCrypt() instead of
dekripted.DeCrypt(). It's always worth trying to compile the code
you're about to post. It's also worth posting short and complete code -
see http://www.pobox.com/~skeet/csharp/complete.html

--
Jon Skeet - <sk***@pobox.com>
http://www.pobox.com/~skeet
If replying to the group, please do not mail me too
Jul 21 '05 #11

This thread has been closed and replies have been disabled. Please start a new discussion.

Similar topics

8
by: Joshua Beall | last post by:
Hi All, Up until now I have been storing passwords in the database as an sha1 hash. I like doing it this way, but a problem arises with people who forget their passwords - I cannot retrieve it...
34
by: Blake T. Garretson | last post by:
I want to save some sensitive data (passwords, PIN numbers, etc.) to disk in a secure manner in one of my programs. What is the easiest/best way to accomplish strong file encryption in Python? ...
1
by: Marshall Dudley | last post by:
I have an application where I need to encrypt a bit of text, and then I need to be able to decrypt it using a customer's key. I want to make sure that the key to decrypt is NOT on the server...
1
by: Cliff | last post by:
We are trying to connect to 3 different Oracle databases using MS Access as the front-end and ODBC as the connection. The problem that we are having is that 1 of the databases requires a...
7
by: helmut woess | last post by:
Hi, has anybody knowledge about the safetyness of encrypting stored procs in SQL-Server 2005 using WITH ENCRYPTION? Or can they be hacked with the same old tools which exists for SQL 2000? ...
3
by: Todd Gruben | last post by:
I am trying to send some encrypted data from a php application to be decoded in a .Net application. Both apps encode/decode a given string but generate different encrypted results. Anyone have...
3
by: Chuck P | last post by:
I need to deploy and asp.net 2.0 application that has dpapi/machine encrypted connection strings. I tried using the VS Build Publish menu selection and then putting the encryption in the...
11
by: John Williams | last post by:
I've written a simple program to do XOR encryption as my first foray into understanding how encryption works. The code compiles fine, however it segmentation faults on every run. using gdb to...
8
by: manmit.walia | last post by:
Hello Everyone, Long time ago, I posted a small problem I had about converting a VB6 program to C#. Well with the help with everyone I got it converted. But I overlooked something and don't...
22
by: j1mb0jay | last post by:
I have had to create a simple string encryption program for coursework, I have completed the task and now have to do a write up on how it could be improved at a later date. If you could look...
2
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 7 Feb 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:30 (7.30PM). In this month's session, the creator of the excellent VBE...
0
by: Aftab Ahmad | last post by:
Hello Experts! I have written a code in MS Access for a cmd called "WhatsApp Message" to open WhatsApp using that very code but the problem is that it gives a popup message everytime I clicked on...
0
by: ryjfgjl | last post by:
ExcelToDatabase: batch import excel into database automatically...
0
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 6 Mar 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, we are pleased to welcome back...
0
by: marcoviolo | last post by:
Dear all, I would like to implement on my worksheet an vlookup dynamic , that consider a change of pivot excel via win32com, from an external excel (without open it) and save the new file into a...
1
isladogs
by: isladogs | last post by:
The next Access Europe meeting will be on Wednesday 6 Mar 2024 starting at 18:00 UK time (6PM UTC) and finishing at about 19:15 (7.15PM). In this month's session, we are pleased to welcome back...
0
by: Vimpel783 | last post by:
Hello! Guys, I found this code on the Internet, but I need to modify it a little. It works well, the problem is this: Data is sent from only one cell, in this case B5, but it is necessary that data...
0
by: ArrayDB | last post by:
The error message I've encountered is; ERROR:root:Error generating model response: exception: access violation writing 0x0000000000005140, which seems to be indicative of an access violation...
1
by: PapaRatzi | last post by:
Hello, I am teaching myself MS Access forms design and Visual Basic. I've created a table to capture a list of Top 30 singles and forms to capture new entries. The final step is a form (unbound)...

By using Bytes.com and it's services, you agree to our Privacy Policy and Terms of Use.

To disable or enable advertisements and analytics tracking please visit the manage ads & tracking page.