So I'm writing a Bittorrent client in C++ and I can communicate with the tracker, however when I get the announce response my IP address is the only one I get in return. After looking at my traffic over wireshark and comparing it to the traffic to the same tracker in transmission I've concluded that I must be sending the info-hash of the torrent incorrectly.
So, I'm sending this as my info-hash of my test torrent (TPB AFK (totally legal to torrent!)):
99FEAE0A05C6A5DD9AF939FFCE5CA9B0D16F31B0
From reading a few other posts around the net I got the idea that I have to encode this somehow, and also that it needs to be 20 bytes (which I stupidly didn't realize it wasn't before...didn't count).
So there must be some sort of encoding that I must feed this hash into, but what is it?
Okay, so That string of 40 characters, is just 20 bytes...so the correct way to send the info_hash is:
0x99 0xFE 0xAE 0x0A 0x05 0xC6 0xA5 0xDD 0x9A 0xF9 0x39 0xFF 0xCE 0x5C 0xA9 0xB0 0xD1 0x6F 0x31 0xB0
Related
I have a device that I am communicating with by sending and receiving a particular binary packet structure. The device has a somewhat well defined API, but there are over 100 possible message types that it can return. What is a good design to use to handle the processing of these different message types?
Here is an example in pseudocode, I am ignoring framing, and checksum bytes to make it clearer.
// I receive this message, where 0x00 indicates the device status,
//and each other byte is a particular error or status
message = [0x00, 0x01, 0x01, 0x04]
// The next message I receive, where 0x10 indicates system time,
// and the rest of the fields are the integer clock seconds of the device.
message = [0x10, 0x00, 0x32, 0xFF, 0x8E]
// 100 other message types....
As you can see, each message I receive needs to be processed slightly different, has different meanings. I originally was going to use a gigantic switch statement case 0x00: process_errors() case 0x10: process_time() but I was curious if there a better design that I could use to increase flexibility of adding new message types, better useability, etc.
You can try using TLV (Tag Length Value) implementation. It is good for processing stream of data.
Tag - This will be a byte of data(as per your example) which identifies the type of message that follows. For this to be utilized, you should before hand be aware of which message type has how many data. For instance, in case of 0x00 (device status) you should now beforehand that the next 3 bytes are the data.
Length - The length of data bytes
Value - The actual data
Here is what you can do:
1) Prepare a map of the Tag and Length of different messages that your system supports.
2) Receive bytes of data continuously.
3) Read the 1st byte (this will be the tag) and determine what type of message it is. In your case this will give you 0x00, 0x10 etc.
4) Refer to your map of tag and length information. You will determine how many bytes of data you need to read further.
5) Once you read the data portion, your receiver should be ready to receive next message (ready to read next tag)
This is all about reading the messages. Once you have the message and its data with you, you can use it as you like. For instance, in addition to the length of message corresponding to a Tag, you can register a function also. This will let you call a particular function along with the parameters required by it.
Device Status
Data Tag = 00
Data Length = 03
Data Value = 01 01 04
System time
Data Tag = 10
Data Length = 04
Data Value = 00 32 FF 8E
I found a site where a lot of CRC values are listed, with configurations/setup. There is also a "check" value, which I believe is generated with some kind of default input (some dummy string or such).
Does anybody know what this is and/or how I can reproduce it?
Sample config: width=3 poly=0x3 init=0x7 refin=true refout=true xorout=0x0 check=0x6 name="CRC-3/ROHC"
Site: http://reveng.sourceforge.net/crc-catalogue/all.htm#crc.cat.arc
Thanks a lot.
sorry, found the solution.
HEX: 0x31 0x32 0x33 0x34 0x35 0x36 0x37 0x38 0x39
String: 123456789
I'm trying to make a Windows program that sends data to a microcontroller, through serial port (USB emulating COM port).
Until now, I made it with ASCII strings, but I have to do a job with a classmate, that told me that I don't have to do that; That I have to send to the serial port the actual bytes that he needs to use (he is programming the microcontroller I am programming the Windows interface).
I always used WriteFile() with ASCII strings, in the form:
WriteFile(handlePort, bufferPort, strlen(buffer_puerto), &nBytes, NULL);
I have to send a byte chain, like 10000001 10010001 0000000 10100001 11101101.
The problem is that when WriteFile() detects the third byte 00000000, it is interpreted like a null character '\0' and does not send more bytes.
Please, can anyone help me? Is there any way to send all of the bytes (after the third 00000000) without losing any information?
Is there another function apart from WriteFile() which can do that? How should I do it?
It's not WriteFile, it's strlen that's stopping at 0. You want:
...
int len = 5;
char bytes[] = {0x81, 0x91, 0x0, 0xa1, 0xed};
WriteFile(handlePort,bytes,len,&nBytes,NULL);
if (len != nBytes) {
error("Not all bytes written!");
}
...
The problem is you're using strlen which is designed to stop at a zero byte. WriteFile is fine; it just needs you to tell it the right number of bytes to write.
I am trying to read a file. The call is from VB to CPP dll.
Here is my sample code snippet
VB CALL
Private Sub ReadFile(...)
On Error GoTo Problem
Dim errorString As String
Sample.ReadFile basepath, filename, register, errorString
GoTo Completed
Problem:
WriteToLogFile basepath + filename + errorString //error string contains the formatted hresult message from cpp dll
My CPP function:
HRESULT ReadFile(...)
{
hr= actualread(...)
if(FAILED(hr)
{
return E_FAIL //
}
If I change E_FAIL to ERROR_FILE_NOT_FOUND VB is not logging the error message.
The E_FAIL message description is Unspecified error. Which does not help the user much.
It logs E_POINTER,E_HANDLE etc anything that starts with E_ not with ERROR_
COM specifies which values in a HRESULT are treated as errors, and which aren't. To quote from Structure of COM Error Codes:
The high-order bit in the HRESULT or SCODE indicates whether the return value represents success or failure. If set to 0, SEVERITY_SUCCESS, the value indicates success. If set to 1, SEVERITY_ERROR, it indicates failure.
The E_ constants are designed to be used this way, and have appropriate values to ensure they get treated as errors. The ERROR_ constants are not, they are meant for a different convention for reporting errors.
As WhozCraig pointed out in the comments, there is a HRESULT_FROM_WIN32 function you can use to convert a Win32 error code to a HRESULT.
Decoding Errors
-2147220978 style numbers are 32 bit signed integers, convert to hex with calculator.
Windows errors (smallish numbers) and COM HResults (typically, but with exceptions, start with an 8 as in 0x80040154) are defined in WinError.h, except 8007nnnn where you look up the Window error number that it contains.
As a general rule Windows errors are less than 65,535 (0xFFFF). Errors starting 0x80000001 are Component Object Model (COM) HResults. Errors starting 0xC0000001 are NTStatus results. Errors starting 0xD0000001 are also NTStatus values returned in a HResult.
WinError - Returned from Windows API Calls
HResult - Returned from COM calls
NTStatus - Returned from kernel and some API calls also return when
encountering a kernel error.
NTStatus errors (typically but not always start with an C as in 0xC0000022) are defined in NTStatus.h.
.h files are the best source because it includes the symbolic name of the error which can give clues such as the source of the error. FormatMessage doesn't give the symbolic name only the description.
You get these files by downloading the Platform SDK (it's gigabytes)
http://www.microsoft.com/en-us/download/details.aspx%3Fid%3D8279&sa=U&ei=w2IrULDDLsHFmAWbmIHoBg&ved=0CBwQFjAA&usg=AFQjCNHZn9-4f2NnuN9o3UWUsOF3wL7HBQ
If you just want the two files I have them on my skydrive so I can reference them anywhere I go.
https://skydrive.live.com/redir?resid=E2F0CE17A268A4FA!121
Note internet errors (12,000 - 12,999) are windows errors but are specified in wininet.h also available above.
There are errors defined in other .h files. But 99% are in the three above.
Structure of HResults and NTStatus Codes
The most significant bit in HResults, and the two most significant bits in NTStatus are set on error. Hence Hresults start 8 on error and NTStatus starts C on Error. The next 14 or 15 bits are reserved and some specify the facility - what area the error is in. This is the third and fourth number when reading hex. EG 0xnn07nnnn - An HResult facility code 7 is a normal Windows' error (returned from a COM program - hence it's returned as a HResult). Facility codes are defined in Winerror.h for HResults and NTStatus.h for NTStatus codes. They are different.
To Decode 0x8003nnnn Errors
HResults with facility code 3 means the HResult contains OLE Structured Storage errors (0x0 to 0xff). These are the same as Dos error codes. These don't seem to be in Windows' header files and the list of codes is at the end of this post.
To Decode 0x8004nnnn Errors
HResults with facility code 4 means the HResult contains OLE errors (0x0 to 0x1ff) while the rest of the range (0x200 onwards) is component specific errors so 20e from one component will have a different meaning to 20e from another component.
This is why the source of the error is extra important for errors above 0x80040200.
To Decode 0x8007nnnn Errors
HResults with facility code 7 means the HResult contains a Windows' error code. You have to look up the Windows' error code not the HResult.
To decode 0x80070002. The 0x means it's a hexadecimal number, the 8 means error, the first 7 means it a windows error, and the rest of the number, 2, is the actual Windows error.
To look up the error we need it in decimal format. Start Calculator (Start - All Programs - Accessories - Calculator) and choose View menu - Scientific, then View menu - Hex. Enter 2. Then View menu - Decimal. It will say 2.
Start a Command Prompt (Start - All Programs - Accessories - Command Prompt) and type
net helpmsg 2
and it will say
The system cannot find the file specified.
or look it up in winerror.h
//
// MessageId: ERROR_FILE_NOT_FOUND
//
// MessageText:
//
// The system cannot find the file specified.
//
#define ERROR_FILE_NOT_FOUND 2L
To Decode 0x8019nnnn Errors
HResults with facility 0x19 are HTTP errors. Codes under 16,384 (0x4000) are the same as HTTP errors, eg HTTP status 404: The requested URL does not exist on the server is 0x80190194 (0x194 = 404). Codes 16,384 and higher are BITS specific.
To Decode 0xDnnnnnnn Errors
HResults starting 0xD are an HResult with a NTStatus value in it. Just cange the lead D to a C and treat as an NTStatus (Hresult = NTStatus OR 10000000).
Dos Error Codes (for 0x8003nnnn errors)
Code Message
01 Invalid function number
02 File not found
03 Path not found
04 Too many open files (no handles left)
05 Access denied
06 Invalid handle
07 Memory control blocks destroyed
08 Insufficient memory
09 Invalid memory block address
0A Invalid environment
0B Invalid format
0C Invalid access mode (open mode is invalid)
0D Invalid data
0E Reserved
0F Invalid drive specified
10 Attempt to remove current directory
11 Not same device
12 No more files
13 Attempt to write on a write-protected diskette
14 Unknown unit
15 Drive not ready
16 Unknown command
17 CRC error
18 Bad request structure length
19 Seek error
1A Unknown media type
1B Sector not found
1C Printer out of paper
1D Write fault
1E Read fault
1F General failure
20 Sharing violation
21 Lock violation
22 Invalid disk change
23 FCB unavailable
24 Sharing buffer overflow
25 Reserved
26 Unable to complete file operation (DOS 4.x)
27-31 Reserved
32 Network request not supported
33 Remote computer not listening
34 Duplicate name on network
35 Network name not found
36 Network busy
37 Network device no longer exists
38 NetBIOS command limit exceeded
39 Network adapter error
3A Incorrect network response
3B Unexpected network error
3C Incompatible remote adapter
3D Print queue full
3E No space for print file
3F Print file deleted
40 Network name deleted
41 Access denied
42 Network device type incorrect
43 Network name not found
44 Network name limit exceeded
45 NetBIOS session limit exceeded
46 Temporarily paused
47 Network request not accepted
48 Print or disk redirection is paused
49-4F Reserved
50 File already exists
51 Reserved
52 Cannot make directory entry
53 Fail on INT 24
54 Too many redirections
55 Duplicate redirection
56 Invalid password
57 Invalid parameter
58 Network device fault
59 Function not supported by network (DOS 4.x)
5A Required system component not installed (DOS 4.x)
Facility Codes
NTStatus Facilities HResults Facilities
Common status values
0x0 Null 0x0
Debugger 0x1 Rpc 0x1
Rpc_runtime 0x2 Dispatch 0x2
Rpc_stubs 0x3 Storage 0x3
Io_error_code 0x4 Itf 0x4
Various drivers 0x5-0xf Win32 0x7
Ntwin32 0x7 Windows 0x8
Ntsspi 0x9 Sspi 0x9
Terminal_server 0xa Security 0x9
Faciltiy_mui_error_code 0xb Control 0xa
Usb_error_code 0x10 Cert 0xb
Hid_error_code 0x11 Internet 0xc
Firewire_error_code 0x12 Mediaserver 0xd
Cluster_error_code 0x13 Msmq 0xe
Acpi_error_code 0x14 Setupapi 0xf
Sxs_error_code 0x15 Scard 0x10
Transaction 0x19 Complus 0x11
Commonlog 0x1a Aaf 0x12
Video 0x1b Urt 0x13
Filter_manager 0x1c Acs 0x14
Monitor 0x1d Dplay 0x15
Graphics_kernel 0x1e Umi 0x16
Driver_framework 0x20 Sxs 0x17
Fve_error_code 0x21 Windows_ce 0x18
Fwp_error_code 0x22 Http 0x19
Ndis_error_code 0x23 Usermode_commonlog 0x1a
Hypervisor 0x35 Usermode_filter_manager 0x1f
Ipsec 0x36 Backgroundcopy 0x20
Maximum_value 0x37 Configuration 0x21
State_management 0x22
Metadirectory 0x23
Windowsupdate 0x24
Directoryservice 0x25
Graphics 0x26
Shell 0x27
Tpm_services 0x28
Tpm_software 0x29
Pla 0x30
Fve 0x31
Fwp 0x32
Winrm 0x33
Ndis 0x34
Usermode_hypervisor 0x35
Cmi 0x36
Windows_defender 0x50
In a Windows Application I created I am attempting to run a batch file that points to a .vbs. It runs the vbs script but it does not modify the registry as needed. However, if I run the batch file manually it functions properly. Does anyone have any insight as to what could be the issue? I thought it was permissions but why would it matter if I manually click on the batch file or if my program opens it? Regardless, I have modified the batch file to try to run as admin but nothing online seems to work.
It says nowhere that CreateProcess can run batch files. As batch files aren't programs CreateProcess can't do anything with it. CMD.exe executes batch files.
YOU WOULD HAVE KNOWN THIS BY TESTING THE RETURN VALUE and by reading the Docs
From Help
Return Value
If the function succeeds, the return value is nonzero.
If the function fails, the return value is zero. To get extended error information, call GetLastError.
Also from Help
To run a batch file, you must start the command interpreter; set lpApplicationName to cmd.exe and set lpCommandLine to the name of the batch file.
This is What You are Doing Wrong
1. You have a bizzare program design.
Any program can prompt for user input and write to the registry. You are writing a program that will have at least four different ways of writing the registry (.NET, WSH, WMI, API). Then you run a batch that has two ways of writing the registry (WMI and reg.exe). Then a vbs file with two ways (WMI, WSH).
2. You do not test for errors.
You must test for errors. The only person with access to the error is YOU. Errors say what happened. You must fix the error or crash. And there is no point asking without the error number, error source, what it was trying to do, and the parameters.
Errors are to be expected. Users do delete or move files for example.
3. You must read the documentation
It has to be open while you program. It explains what you need to tell it for it to behave in certain ways. Just typing random commands (as many here do - they are invalid of course) OR typing random parameters (as you are) doesn't work. If you don't read them you don't know what they mean.
4. Playing helpless
When you get told the answer, you go and look everything up in the documentation, and then google it.
You not reply with a pathetic "it didn't work". You post the error number, error source, what it was trying to do, and the parameters.
This is how to decode errors
Decoding Errors
-2147220978 style numbers are 32 bit signed integers, convert to hex with calculator.
Windows errors (smallish numbers) and COM HResults (typically, but with exceptions, start with an 8 as in 0x80040154) are defined in WinError.h, except 8007nnnn where you look up the Window error number that it contains.
As a general rule Windows errors are less than 65,535 (0xFFFF). Errors starting 0x80000001 are Component Object Model (COM) HResults. Errors starting 0xC0000001 are NTStatus results. Errors starting 0xD0000001 are also NTStatus values returned in a HResult.
NTStatus errors (typically but not always start with an C as in 0xC0000022) are defined in NTStatus.h.
.h files are the best source because it includes the symbolic name of the error which can give clues such as the source of the error. FormatMessage doesn't give the symbolic name only the description.
You get these files by downloading the Platform SDK (it's gigabytes)
http://www.microsoft.com/en-us/download/details.aspx%3Fid%3D8279&sa=U&ei=w2IrULDDLsHFmAWbmIHoBg&ved=0CBwQFjAA&usg=AFQjCNHZn9-4f2NnuN9o3UWUsOF3wL7HBQ
If you just want the two files I have them on my skydrive so I can reference them anywhere I go.
https://skydrive.live.com/redir?resid=E2F0CE17A268A4FA!121
Note internet errors (12,000 - 12,999) are windows errors but are specified in wininet.h also available above.
There are errors defined in other .h files. But 99% are in the three above.
Structure of HResults and NTStatus Codes
The most significant bit in HResults, and the two most significant bits in NTStatus are set on error. Hence Hresults start 8 on error and NTStatus starts C on Error. The next 14 or 15 bits are reserved and some specify the facility - what area the error is in. This is the third and fourth number when reading hex. EG 0xnn07nnnn - An HResult facility code 7 is a normal Windows' error (returned from a COM program - hence it's returned as a HResult). Facility codes are defined in Winerror.h for HResults and NTStatus.h for NTStatus codes. They are different.
To Decode 0x8003nnnn Errors
HResults with facility code 3 means the HResult contains OLE Structured Storage errors (0x0 to 0xff). These are the same as Dos error codes. These don't seem to be in Windows' header files and the list of codes is at the end of this post.
To Decode 0x8004nnnn Errors
HResults with facility code 4 means the HResult contains OLE errors (0x0 to 0x1ff) while the rest of the range (0x200 onwards) is component specific errors so 20e from one component will have a different meaning to 20e from another component.
This is why the source of the error is extra important for errors above 0x80040200.
To Decode 0x8007nnnn Errors
HResults with facility code 7 means the HResult contains a Windows' error code. You have to look up the Windows' error code not the HResult.
To decode 0x80070002. The 0x means it's a hexadecimal number, the 8 means error, the first 7 means it a windows error, and the rest of the number, 2, is the actual Windows error.
To look up the error we need it in decimal format. Start Calculator (Start - All Programs - Accessories - Calculator) and choose View menu - Scientific, then View menu - Hex. Enter 2. Then View menu - Decimal. It will say 2.
Start a Command Prompt (Start - All Programs - Accessories - Command Prompt) and type
net helpmsg 2
and it will say
The system cannot find the file specified.
or look it up in winerror.h
//
// MessageId: ERROR_FILE_NOT_FOUND
//
// MessageText:
//
// The system cannot find the file specified.
//
#define ERROR_FILE_NOT_FOUND 2L
To Decode 0x8019nnnn Errors
HResults with facility 0x19 are HTTP errors. Codes under 16,384 (0x4000) are the same as HTTP errors, eg HTTP status 404: The requested URL does not exist on the server is 0x80190194 (0x194 = 404). Codes 16,384 and higher are BITS specific.
To Decode 0xDnnnnnnn Errors
HResults starting 0xD are an HResult with a NTStatus value in it. Just change the lead D to a C and treat as an NTStatus (Hresult = NTStatus OR 0x10000000).
Dos Error Codes (for 0x8003nnnn errors)
Code Message
01 Invalid function number
02 File not found
03 Path not found
04 Too many open files (no handles left)
05 Access denied
06 Invalid handle
07 Memory control blocks destroyed
08 Insufficient memory
09 Invalid memory block address
0A Invalid environment
0B Invalid format
0C Invalid access mode (open mode is invalid)
0D Invalid data
0E Reserved
0F Invalid drive specified
10 Attempt to remove current directory
11 Not same device
12 No more files
13 Attempt to write on a write-protected diskette
14 Unknown unit
15 Drive not ready
16 Unknown command
17 CRC error
18 Bad request structure length
19 Seek error
1A Unknown media type
1B Sector not found
1C Printer out of paper
1D Write fault
1E Read fault
1F General failure
20 Sharing violation
21 Lock violation
22 Invalid disk change
23 FCB unavailable
24 Sharing buffer overflow
25 Reserved
26 Unable to complete file operation (DOS 4.x)
27-31 Reserved
32 Network request not supported
33 Remote computer not listening
34 Duplicate name on network
35 Network name not found
36 Network busy
37 Network device no longer exists
38 NetBIOS command limit exceeded
39 Network adapter error
3A Incorrect network response
3B Unexpected network error
3C Incompatible remote adapter
3D Print queue full
3E No space for print file
3F Print file deleted
40 Network name deleted
41 Access denied
42 Network device type incorrect
43 Network name not found
44 Network name limit exceeded
45 NetBIOS session limit exceeded
46 Temporarily paused
47 Network request not accepted
48 Print or disk redirection is paused
49-4F Reserved
50 File already exists
51 Reserved
52 Cannot make directory entry
53 Fail on INT 24
54 Too many redirections
55 Duplicate redirection
56 Invalid password
57 Invalid parameter
58 Network device fault
59 Function not supported by network (DOS 4.x)
5A Required system component not installed (DOS 4.x)
Facility Codes
NTStatus Facilities HResults Facilities
Common status values 0x0 Null 0x0
Debugger 0x1 Rpc 0x1
Rpc_runtime 0x2 Dispatch 0x2
Rpc_stubs 0x3 Storage 0x3
Io_error_code 0x4 Itf 0x4
Various drivers 0x5-0xf Win32 0x7
Ntwin32 0x7 Windows 0x8
Ntsspi 0x9 Sspi 0x9
Terminal_server 0xa Security 0x9
Faciltiy_mui_error_code 0xb Control 0xa
Usb_error_code 0x10 Cert 0xb
Hid_error_code 0x11 Internet 0xc
Firewire_error_code 0x12 Mediaserver 0xd
Cluster_error_code 0x13 Msmq 0xe
Acpi_error_code 0x14 Setupapi 0xf
Sxs_error_code 0x15 Scard 0x10
Transaction 0x19 Complus 0x11
Commonlog 0x1a Aaf 0x12
Video 0x1b Urt 0x13
Filter_manager 0x1c Acs 0x14
Monitor 0x1d Dplay 0x15
Graphics_kernel 0x1e Umi 0x16
Driver_framework 0x20 Sxs 0x17
Fve_error_code 0x21 Windows_ce 0x18
Fwp_error_code 0x22 Http 0x19
Ndis_error_code 0x23 Usermode_commonlog 0x1a
Hypervisor 0x35 Usermode_filter_manager 0x1f
Ipsec 0x36 Backgroundcopy 0x20
Maximum_value 0x37 Configuration 0x21
State_management 0x22
Metadirectory 0x23
Windowsupdate 0x24
Directoryservice 0x25
Graphics 0x26
Shell 0x27
Tpm_services 0x28
Tpm_software 0x29
Pla 0x30
Fve 0x31
Fwp 0x32
Winrm 0x33
Ndis 0x34
Usermode_hypervisor 0x35
Cmi 0x36
Windows_defender 0x50