I want to parse a IPV6 packet that consists of extension headers. The "Hdr Ext Len" (second) field of extension headers such as Hop by Hop option, Routing, destination options and Authentication header, is defined as
8-bit unsigned integer. Length of the header in 8-octet units, not including the first 8 octets.
Consider the following IPV6 packet with authentication header (AH). The second byte of AH has a value 04 which signifies 24 bytes (got this information from hex packet decoder in https://hpd.gasmi.net/).
I would like to know how to decode the value of this field "Hdr Ext Len" to get the actual extension header size.
IPV6 Header
6E 00 00 00 00 34 33 01 FE 80 00 00 00 00 00 00 00 00 00 00 00 00 00 02 FE 80 00 00 00 00 00 00 00 00 00 00 00 00 00 01
Authentication extension header
59 04 00 00 00 00 01 00 00 00 00 15 8F 74 57 E3 C2 D4 13 EF 5E F1 FF 13
OSPF packet
03 02 00 1C 02 02 02 02 00 00 00 01 E9 DF 00 00 00 00 00 13 05 DC 00 01 00 00 0B 93
Related
I'm trying to decode a hex string to a datetime format from a BLE custom UUID. I don't have any information except the decoded value and datetime, that's why I put similar examples in milliseconds and minutes. It will be complicated to see the value of another year.
If you look closely, you will notice there are only 2 values repeated twice in each row (bold and italic). First starts with 0x01 (maybe a flag) and then 2 bytes and second 2 bytes too.
Similar minutes:
01 8E 6C 00 00 8E 6C 00 00 62 25 62 25 00 00 00 00 00 00 00 - 1669024172,5141 (Nov 21 2022 09:49:32,5387632)
01 9C 6C 00 00 9C 6C 00 00 62 49 62 49 00 00 00 00 00 00 00 - 1669024172,68598 (Nov 21 2022 09:49:32,7638451)
01 fd 6c 00 00 fd 6c 00 00 64 0f 64 0f 00 00 00 00 00 00 00 - 1669024174,23293 (Nov 21 2022 09:49:34,3170414)
01 0d 6d 00 00 0d 6d 00 00 6e 2f 6e 2f 00 00 00 00 00 00 00 - 1669024174,5767 (Nov 21 2022 09:49:34,5414078)
01 f0 6d 00 00 f0 6d 00 00 62 21 62 21 00 00 00 00 00 00 00 - 1669024178,01436 (Nov 21 2022 09:49:38,0746688)
01 00 6e 00 00 00 6e 00 00 67 81 67 81 00 00 00 00 00 00 00 - 1669024178,35812 (Nov 21 2022 09:49:38,2775026)
Similar milliseconds:
01 16 1d 00 00 16 1d 00 00 4d f4 4d f4 00 00 00 00 00 00 00 - 1669023854,70251 (Nov 21 2022 09:44:14,7728813)
01 1e 6e 00 00 1e 6e 00 00 67 c5 67 c5 00 00 00 00 00 00 00 - 1669024178,70189 (Nov 21 2022 09:49:38,7714679)
01 e2 6d 00 00 e2 6d 00 00 62 4d 62 4d 00 00 00 00 00 00 00 - 1669024177,84247 (2022-11-21 10:49:37,8263242)
01 5f dd 06 00 5f dd 06 00 cb 46 cb 46 00 00 00 00 00 00 00 - 1669110577,66758 (2022-11-22 10:49:37,8231004)
01 00 6e 00 00 00 6e 00 00 67 81 67 81 00 00 00 00 00 00 00 - 1669024178,35812 (2022-11-21 10:49:38,2775026)
01 7c dd 06 00 7c dd 06 00 c8 0c c8 0c 00 00 00 00 00 00 00 - 1669024178 (2022-11-22 10:49:38,2722736)
It's looks like:
It's not decoded in the unix epoch (JAN 1 1970)
The first value is increasing (0xXX6C, 0xXX6E, 0xXX6E), so maybe it's the int part.
I tried to decode like year, minutes, seconds but it seems it isn't.
Sometimes first value is bigger than 2 bytes (3 bytes):
01 DE 61 04 00 DE 61 04 00 4A C1 4A C1 00 00 00 00 00 00 00 - 1669104436 (Nov 22 2022 09:07:16,1902042)
I tried this solutions:
https://stackoverflow.com/questions/1389046/what-is-the-specification-of-hexadecimal-date-format-in-sql-server Error: System.ArgumentOutOfRangeException (trying one of my hex)
http://erbhavi.blogspot.com/search/label/Converting%20DateTime%20to%20Hex%20in%20C%23 DateTime yourDateTime = new DateTime( ticks1970 + gmt * 10000000L ); //Error CS0019: Operator '*' can't apply to types 'string' y 'long'
I'll update the question if I find more info.
I am trying to return hexadecimal string as response from my AWS Lambda function. When it reaches to the client the data seems to be modified.
Data :
47 49 46 38 39 61 01 00 01 00 80 00 00 00 00 00
ff ff ff 21 f9 04 01 00 00 01 00 2c 00 00 00 00
01 00 01 00 00 08 04 00 03 04 04 00 3b
Hexadecimal Excaped Data ( Sent Data ):
\x47\x49\x46\x38\x39\x61\x01\x00\x01\x00\x80\x00\x00\x00\x00\x00"
"\xff\xff\xff\x21\xf9\x04\x01\x00\x00\x01\x00\x2c\x00\x00\x00\x00"
"\x01\x00\x01\x00\x00\x08\x04\x00\x03\x04\x04\x00\x3b
Received Data
47 49 46 38 39 61 01 00 01 00 c2 80 00 00 00 00
00 c3 bf c3 bf c3 bf 21 c3 b9 04 01 00 00 01 00
2c 00 00 00 00 01 00 01 00 00 08 04 00 03 04 04
00 3b
How to fix this?
Last time I checked it was not very explicit in the doc, but API Gateway is really made for json (or similar) and support for binary is 'on the roadmap' but clearly doesn't seem to be a priority. It converts everything it sends to utf-8.
Comparing precisely your original data with the received one you can see it :
47 49 46 38 39 61 01 00 01 00 80 00 00 00 00 00 ff ff ff 21 f9 04 01 00 00 01 00 2c 00 00 00 00 01 00 01 00 00 08 04 00 03 04 04 00 3b
47 49 46 38 39 61 01 00 01 00 c2 80 00 00 00 00 00 c3 bf c3 bf c3 bf 21 c3 b9 04 01 00 00 01 00 2c 00 00 00 00 01 00 01 00 00 08 04 00 03 04 04 00 3b
Everything under 0x7f is OK because the unicode code point is the same as the encoded byte (U+0047 -> 47), but for 0x80 or more the problem arises : U+0080 -> c2 80, U+00FF -> c3 bf and so on.
We had a similar problem recently : binary data was corrupted and bigger when sent through Gateway than with direct access to our backend. It was because a lot of bytes get replaced by Unicode special 'replacement character' aka 'U+FFFD' aka '0xEF 0xBF 0xBD'.
How to fix ? We just stopped using Gateway but if you can afford your data to be bigger, you can base64 encode it.
In my application I'm using an amalgamated embeded version of SQLite v3.8.4. In the past I had compatibility issues with v3.7 regarding page_size > 32768. Now I'd like to keep backwards compatibility on database files with v3.6.20 (default on RHEL6), but when I try to open my DB file on my RHEL6 machine I see the error:
Error: file is encrypted or is not a database
I can dump the database to an SQL file and then again import it to v3.7. This seems to do the trick to be readable on v3.6.20 but my DB is 3 GB in size and is not feasible for me to wait 2 hours for each dump.
What options can I set on my v3.8 to generate v3.6 compatible databases?
Databases dump
$ hexdump -C works-on-3.6.20.sqlite | head -n 8
00000000 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00 |SQLite format 3.|
00000010 04 00 01 01 00 40 20 20 00 00 00 01 00 2d 8c 51 |.....# .....-.Q|
00000020 00 00 00 00 00 00 00 00 00 00 00 12 00 00 00 01 |................|
00000030 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 |................|
00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 01 |................|
00000060 00 2d e2 21 05 00 00 00 02 03 f6 00 00 22 fd 07 |.-.!........."..|
00000070 03 fb 03 f6 01 8f 02 38 00 7c 01 61 81 62 07 07 |.......8.|.a.b..|
$ hexdump -C fails-on-3.6.20.sqlite | head -n 8
00000000 53 51 4c 69 74 65 20 66 6f 72 6d 61 74 20 33 00 |SQLite format 3.|
00000010 80 00 02 02 00 40 20 20 00 00 00 04 00 00 00 2b |.....# .......+|
00000020 00 00 00 00 00 00 00 00 00 00 00 14 00 00 00 01 |................|
00000030 00 00 00 00 00 00 00 00 00 00 00 01 00 00 00 00 |................|
00000040 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 |................|
00000050 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 04 |................|
00000060 00 2d e6 04 0d 7f fc 00 18 75 a4 00 7f 36 7f c9 |.-.......u...6..|
00000070 7e 6b 7f 0b 7d 8f 7e 38 7c 7e 7d 62 7b ab 7c 47 |~k..}.~8|~}b{.|G|
The non-working database has enabled WAL mode, which was introduced in version 3.7.0. Disable it.
There is one audio input device on my PC.
QAudioDeviceInfo::availableDevices returns empty list.
calling waveInGetDevCaps(0) returns next:
FF FF - Mid
FF FF - Pid
10 00 00 00 version
1C 04 38 04 3A 04 40 04 -name
3E 04 44 04 3E 04 3D 04
20 00 28 00 57 00 65 00
62 00 63 00 61 00 6D 00
20 00 43 00 32 00 31 00
30 00 29 00 00 00 00 00
00 00 00 00 00 00 00 00
00 00 00 00 00 00 00 00
FF FF 0F 00 - formats
02 00 - channels
00 00 - reserved
I propose the reason is Cyrillic device name.
Any ideas?
Thanks for all!
UPD:
QList<QAudioDeviceInfo> devices = QAudioDeviceInfo::availableDevices(QAudio::AudioInput);
foreach(QAudioDeviceInfo deviceInfo, devices)
{
printList(deviceInfo.supportedByteOrders(), "Orders: ");
printList(deviceInfo.supportedChannelCounts(),"Channs: ");
printList(deviceInfo.supportedCodecs(), "Codecs: ");
printList(deviceInfo.supportedSampleRates(), "Rates : ");
printList(deviceInfo.supportedSampleSizes(), "Sizes : ");
printList(deviceInfo.supportedSampleTypes(), "Types : ");
printFormat(deviceInfo.preferredFormat(), "preferred");
}
Is there a way to see, via hex editor or otherwise, if data in a binary file is aligned or packed, specifically for an HPUX system?
If you know what you are looking for and can recognize it in a hex dump, then you can make informed estimates about whether the data is aligned or not, or packed. But in many ways, your question is unanswerable. Where did the data come from? Why can't you ask the person (driving a program, presumably) how it was created?
If you are asking 'what tools could I use to view the data', then you can consider:
od (octal dump - probably with the -c option too)
hd (hex dump - not always available, and seems to be absent on HP-UX)
sed l (that's a lower-case ell - it means list the data; not a good option unless the majority of the data is plain text)
Or you could do it in Perl. Once upon a long time ago (1987 or so), I wrote a program odx (octal dump in hex - weird) that I continue to use - it gives me a hex dump, 16 bytes per line, plus an image of the printable characters. This example isn't very exciting (odx run on itself - on a Sun Sparc):
Black JL: odx odx | sed 10q
0x0000: 7F 45 4C 46 01 02 01 00 00 00 00 00 00 00 00 00 .ELF............
0x0010: 00 02 00 12 00 00 00 01 00 01 0D 84 00 00 00 34 ...............4
0x0020: 00 00 77 9C 00 00 01 00 00 34 00 20 00 05 00 28 ..w......4. ...(
0x0030: 00 24 00 23 00 00 00 06 00 00 00 34 00 01 00 34 .$.#.......4...4
0x0040: 00 00 00 00 00 00 00 A0 00 00 00 A0 00 00 00 05 ................
0x0050: 00 00 00 00 00 00 00 03 00 00 00 D4 00 00 00 00 ................
0x0060: 00 00 00 00 00 00 00 11 00 00 00 00 00 00 00 04 ................
0x0070: 00 00 00 00 00 00 00 01 00 00 00 00 00 01 00 00 ................
0x0080: 00 00 00 00 00 00 22 86 00 00 22 86 00 00 00 05 ......"...".....
0x0090: 00 01 00 00 00 00 00 01 00 00 22 88 00 02 22 88 .........."...".
Black JL: