I'm trying to parse some text information from within project files of an Adobe program (Adobe Premiere Pro). The project files are gzip compressed XML files. These then contain fields which have base64 encoded fields which contain further information about a component of the project. I'm trying to look at the information within these fields.
I can't for the life of me identify the compression scheme used here. It doesn't look like GZip as it doesn't have the appropriate headers. Can anyone help?
An example of a base64 encoded field is:
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
It's a Zlib-compressed string with a 32-byte uncompressed header.
var encoding = #"";
byte[] data = Convert.FromBase64String(encoding);
var compressedArray = new byte[data.Length - 32];
Array.Copy(data, 32, compressedArray, 0, data.Length - 32);
var decompressed = ZlibStream.UncompressBuffer(compressedArray);
var str = Encoding.Unicode.GetString(decompressed);
The header contains the uncompressed length of the data in little-endian order at offset 8: a5 d5 or 0xd5a4, which equals 54692. It is hard to tell from this example if the uncompressed length is stored as a5 d5, a5 d5 00 00, or a5 d5 00 00 00 00 00 00.
Related
I stuck in python while developing security access python script using HMAC-SHA1 algorithm key.
I have python version 2.7 which already includes HMAC-SHA1 libraries. Using library I tried to write script in the below mentioned way. But unfortunately when I execute the script the key calculated is different from the expected key given to me.
---------------Code Start--------------------------
from hashlib import sha1
import hmac
import base64
import hashlib, binascii
SecurityConst_key = "121a3ace5827a3b6" #(0x12 1A 3A CE 58 27 A3 B6)
msg = "4272696C6C69616E63655F6175746F21" # Brilliance_auto!
key = hmac.new(SecurityConst_key, msg, sha1).digest()
key = base64.b64encode(key)
print binascii.hexlify(key)
----------------Code End----------------------
Key calculated is : 4d416963747a41737a546f774530464373536e4d646b6c323972673d
Which is different from the leftmost 128 bits.
Expected key is: 0x15 4A ED 59 CF B3 2E DC 37 8D 30 6B 0F 02 AB 6B
(Truncate the 160 bits result. Output the leftmost 128 bits of the HMAC, it is the Key)
Can some one please help me to fix the possible issue.
So,what you need to be really careful of is understanding whether something is a byte-string or a hex-string. In python, most crypto and mac and sha's take binary strings. So your line:
SecurityConst_key = "121a3ace5827a3b6" #(0x12 1A 3A CE 58 27 A3 B6)
is not true. Thats actually 0x31 32 31 ... You need to get your data right first. Try hex decoding your key and your data before passing it in. "121a3ace5827a3b6".decode("hex").
On the other hand, for the data, you could just use the raw string.
Secondly you are also base64 encoding your output of the mac before printing that off as hex. That seems - wrong. You either base64 it and look at that, or you hex-encode it, and look at that. Base64 by design is ascii-printable (for hashes you traditionally print in hex)
I have a executable for an embedded device.
It does not have header information that gdb recognizes, but instead uses a proprietary header specified by the vendor.
I can analyse the file just fine using IDA-pro, but I'd like to run some code to see what it does.
The executable is loaded at address 0x52000000
However if I just load the file using
exec-file myfile
I get
"myfile": not in executable format: File format not recognized
And if I restore the memory at the correct location using:
restore myfile 52000000
I get:
You can't do that without a process to debug.
How do I get out of this chicken-and-egg problem?
I just want to jump in the middle of the code, set some registers to predetermined values and run some code to see what happens.
Note that I'm using the gdb ARM toolchain from ARM itself.
As per #artless_noise suggestion I did the following:
objcopy.exe
--output-target=elf32-bigarm
--input-target=binary
--change-start=0x52000000
INPUTFILE OUTPUTFILE
This adds an elf header to the file.
However it does not fix the whole problem.
The output of
readelf.exe -a OUTPUTFILE
gives:
ELF Header:
Magic: 7f 45 4c 46 01 02 01 61 00 00 00 00 00 00 00 00
Class: ELF32
Data: 2's complement, big endian
Version: 1 (current)
OS/ABI: ARM
ABI Version: 0
Type: REL (Relocatable file)
Machine: ARM
Version: 0x1
Entry point address: 0x52000000
Start of program headers: 0 (bytes into file)
Start of section headers: 57316 (bytes into file)
Flags: 0x0
Size of this header: 52 (bytes)
Size of program headers: 0 (bytes)
Number of program headers: 0
Size of section headers: 40 (bytes)
Number of section headers: 5
Section header string table index: 2
Section Headers:
[Nr] Name Type Addr Off Size ES Flg Lk Inf Al
[ 0] NULL 00000000 000000 000000 00 0 0 0
[ 1] .data PROGBITS 00000000 000034 00df8c 00 WA 0 0 1
.....
Note that the .data section still has an address of 0x00000000. This should be 0x52000000.
To fix this I opened up a hex editor at address 0xdf8c.
This is close the where the section headers are.
The structure of the section headers is as follows, along with the data I expect to be there.
typedef struct {
Elf32_Word sh_name;
Elf32_Word sh_type; = 1 {.data}
Elf32_Word sh_flags; = ?
Elf32_Addr sh_addr; = 0x00000000
Elf32_Off sh_offset; = 0x00000034
Elf32_Word sh_size; = 0x0000df8c
Elf32_Word sh_link;
Elf32_Word sh_info;
Elf32_Word sh_addralign;
Elf32_Word sh_entsize;
} Elf32_Shdr;
The first header is always all zeros, the second header is the .data section.
So I look for the magic numbers and fill in the starting address, save the file and reload it into gdb.
Now it works
I have a log file and a table name entered by user as input. Now this table name entered by user will be searched in log file and if any data corresponding to that table is found it should be mapped into a more non technical language which the end user can understand.
Can anyonyone suggest how to do this mapping and then print the equivalent mapped string as output.
For example the data to be mapped is:
!!!!!! Diff004: record 0 differs in content for fields 'pid'
!!!!!! Diff005: record 1 differs in content for fields 'pid'
!!!!!! Diff006: record 2 differs in content for fields 'pid'
This data to be mapped into more non-technical statement and then those mapped statemennt to be shown to user instead of these.
real data on request of #TLP
Checking table CTusr000...
!!!!!! Diff004: record 0 differs in content for fields 'pid'
!!!!!!
uexpday,uexphr,uexpmin,uexpsec
db1 [Rec 000000] 30 00 00 00 00 00 00 00,00 00,53 55 50 45 52 55 53 45 52 00 00,77
It is really hard for me to figure out what mapped into a more non-technical language means, since that's not technical language, but it is.. english.
So, have a look at the following example that shows you how to get record no and field name, from a generic $line.
#!/usr/bin/perl -w
use strict;
use warnings;
my $line = "!!!!!! Diff004: record 0 differs in content for fields 'pid'";
$line =~ /^!{6}\s+.*record\s+(\d+)\s+differs.*fields\s+'(\w+)'$/;
print "record no: $1\n";
print "field name: $2\n";
Combine those informations in the better non-technical manner you intent.
The example is for a single $line only.
I'm leaving to you reading lines from file task and iterative processing task.
I'm testing how some of my code handles bad data, and I need a few series of bytes that are invalid UTF-8.
Can you post some, and ideally, an explanation of why they are bad/where you got them?
Take a look at Markus Kuhn's UTF-8 decoder capability and stress test file
You'll find examples of many UTF-8 irregularities, including lonely start bytes, continuation bytes missing, overlong sequences, etc.
In PHP:
$examples = array(
'Valid ASCII' => "a",
'Valid 2 Octet Sequence' => "\xc3\xb1",
'Invalid 2 Octet Sequence' => "\xc3\x28",
'Invalid Sequence Identifier' => "\xa0\xa1",
'Valid 3 Octet Sequence' => "\xe2\x82\xa1",
'Invalid 3 Octet Sequence (in 2nd Octet)' => "\xe2\x28\xa1",
'Invalid 3 Octet Sequence (in 3rd Octet)' => "\xe2\x82\x28",
'Valid 4 Octet Sequence' => "\xf0\x90\x8c\xbc",
'Invalid 4 Octet Sequence (in 2nd Octet)' => "\xf0\x28\x8c\xbc",
'Invalid 4 Octet Sequence (in 3rd Octet)' => "\xf0\x90\x28\xbc",
'Invalid 4 Octet Sequence (in 4th Octet)' => "\xf0\x28\x8c\x28",
'Valid 5 Octet Sequence (but not Unicode!)' => "\xf8\xa1\xa1\xa1\xa1",
'Valid 6 Octet Sequence (but not Unicode!)' => "\xfc\xa1\xa1\xa1\xa1\xa1",
);
From http://www.php.net/manual/en/reference.pcre.pattern.modifiers.php#54805
The idea of patterns of ill-formed byte-sequences can be gotten from the table of well-formed byte sequences. See "Table 3-7. Well-Formed UTF-8 Byte Sequences" in the Unicode Standard 6.2.
Code Points First Byte Second Byte Third Byte Fourth Byte
U+0000 - U+007F 00 - 7F
U+0080 - U+07FF C2 - DF 80 - BF
U+0800 - U+0FFF E0 A0 - BF 80 - BF
U+1000 - U+CFFF E1 - EC 80 - BF 80 - BF
U+D000 - U+D7FF ED 80 - 9F 80 - BF
U+E000 - U+FFFF EE - EF 80 - BF 80 - BF
U+10000 - U+3FFFF F0 90 - BF 80 - BF 80 - BF
U+40000 - U+FFFFF F1 - F3 80 - BF 80 - BF 80 - BF
U+100000 - U+10FFFF F4 80 - 8F 80 - BF 80 - BF
Here are the examples generated from U+24B62. I used them for a bug report: Bug #65045 mb_convert_encoding breaks well-formed character
// U+24B62: "\xF0\xA4\xAD\xA2"
"\xF0\xA4\xAD" ."\xF0\xA4\xAD\xA2"."\xF0\xA4\xAD\xA2"
"\xF0\xA4\xAD\xA2"."\xF0\xA4\xAD\xA2"."\xF0\xA4\xAD"
The oversimplification of range of trailing bytes([0x80, 0xBF]) can be seen in the various libraries.
// U+0800 - U+0FFF
\xE0\x80\x80
// U+D000 - U+D7FF
\xED\xBF\xBF
// U+10000 - U+3FFFF
\xF0\x80\x80\x80
// U+100000 - U+10FFFF
\xF4\xBF\xBF\xBF
,̆ was particularly evil. I see it as combined on ubuntu.
comma-breve
This might not be exactly what OP asked but it's somewhat related :
if you happen to already have byte ordinance values (0 - 255) and wanna know whether a byte# is a valid UTF-8 starting point byte or not, I came up with this strange unified formula that returns a 1 (true) or 0 (false) :
function newUTF8start(__) {
return 118^(+__< 194) < (246-__) }
Fuzz Testing - generate a random sequence of octets. Most likely you'll get some illegal sequences sooner than later.
This question already has answers here:
Using Regex to generate Strings rather than match them
(12 answers)
Closed 3 years ago.
I would like to know if there is software that, given a regex and of course some other constraints like length, produces random text that always matches the given regex.
Thanks
Yes, software that can generate a random match to a regex:
Exrex, Python
Pxeger, Javascript
regex-genex, Haskell
Xeger, Java
Xeger, Python
Generex, Java
rxrdg, C#
String::Random, Perl
regldg, C
paggern, PHP
ReverseRegex, PHP
randexp.js, Javascript
EGRET, Python/C++
MutRex, Java
Fare, C#
rstr, Python
randexp, Ruby
goregen, Go
bfgex, Java
regexgen, Javascript
strgen, Python
random-string, Java
regexp-unfolder, Clojure
string-random, Haskell
rxrdg, C#
Regexp::Genex, Perl
StringGenerator, Python
strrand, Go
regen, Go
Rex, C#
regexp-examples, Ruby
genex.js, JavaScript
genex, Go
Xeger is capable of doing it:
String regex = "[ab]{4,6}c";
Xeger generator = new Xeger(regex);
String result = generator.generate();
assert result.matches(regex);
All regular expressions can be expressed as context free grammars. And there is a nice algorithm already worked out for producing random sentences, from any CFG, of a given length. So upconvert the regex to a cfg, apply the algorithm, and wham, you're done.
If you want a Javascript solution, try randexp.js.
Check out the RandExp Ruby gem. It does what you want, though only in a limited fashion. (It won't work with every possible regexp, only regexps which meet some restrictions.)
Too late but it could help newcomer , here is a useful java library that provide many features for using regex to generate String (random generation ,generate String based on it's index, generate all String..) check it out here .
Example :
Generex generex = new Generex("[0-3]([a-c]|[e-g]{1,2})");
// generate the second String in lexicographical order that match the given Regex.
String secondString = generex.getMatchedString(2);
System.out.println(secondString);// it print '0b'
// Generate all String that matches the given Regex.
List<String> matchedStrs = generex.getAllMatchedStrings();
// Using Generex iterator
Iterator iterator = generex.iterator();
while (iterator.hasNext()) {
System.out.print(iterator.next() + " ");
}
// it print 0a 0b 0c 0e 0ee 0e 0e 0f 0fe 0f 0f 0g 0ge 0g 0g 1a 1b 1c 1e
// 1ee 1e 1e 1f 1fe 1f 1f 1g 1ge 1g 1g 2a 2b 2c 2e 2ee 2e 2e 2f 2fe 2f 2f 2g
// 2ge 2g 2g 3a 3b 3c 3e 3ee 3e 3e 3f 3fe 3f 3f 3g 3ge 3g 3g 1ee
// Generate random String
String randomStr = generex.random();
System.out.println(randomStr);// a random value from the previous String list
We did something similar in Python not too long ago for a RegEx game that we wrote. We had the constraint that the regex had to be randomly generated, and the selected words had to be real words. You can download the completed game EXE here, and the Python source code here.
Here is a snippet:
def generate_problem(level):
keep_trying = True
while(keep_trying):
regex = gen_regex(level)
# print 'regex = ' + regex
counter = 0
match = 0
notmatch = 0
goodwords = []
badwords = []
num_words = 2 + level * 3
if num_words > 18:
num_words = 18
max_word_length = level + 4
while (counter < 10000) and ((match < num_words) or (notmatch < num_words)):
counter += 1
rand_word = words[random.randint(0,max_word)]
if len(rand_word) > max_word_length:
continue
mo = re.search(regex, rand_word)
if mo:
match += 1
if len(goodwords) < num_words:
goodwords.append(rand_word)
else:
notmatch += 1
if len(badwords) < num_words:
badwords.append(rand_word)
if counter < 10000:
new_prob = problem.problem()
new_prob.title = 'Level ' + str(level)
new_prob.explanation = 'This is a level %d puzzle. ' % level
new_prob.goodwords = goodwords
new_prob.badwords = badwords
new_prob.regex = regex
keep_trying = False
return new_prob
Instead of starting from a regexp, you should be looking into writing a small context free grammer, this will allow you to easily generate such random text. Unfortunately, I know of no tool which will do it directly for you, so you would need to do a bit of code yourself to actually generate the text. If you have not worked with grammers before, I suggest you read a bit about bnf format and "compiler compilers" before proceeding...
I'm not aware of any, although it should be possible. The usual approach is to write a grammar instead of a regular expression, and then create functions for each non-terminal that randomly decide which production to expand. If you could post a description of the kinds of strings that you want to generate, and what language you are using, we may be able to get you started.