Unable to identify string encoding from barcode - ios

Question

I am tasked with decoding data stored on a Aztec barcode using an iOS device. I have access to the code that assembles the string sent to the barcode printer, but the printing itself is a black box.
As I step through the process, I can see that the string sent to the printer looks like this (note that other than the first 8 characters this is a encrypted string):
_36_30_30_30_30_34_7c_5d_49_0b_ea_f7_93_ba_89_d2_c6_c2_41_2a_d7_1c_49_8c_6d_4b_5c_07_5a_ca_7a_6a_c6_d5_d0_6c_f7_20_76_5b_e0_18_46_93_7e_2a_30_0d_14_3a_1a_e5_66_7c_05_f9_df_96_8a_f1_45_a5_4a_6e_2f_89_3f_f0_93_1f_bc_3e_77_5b_27_0c_58_df_55_37_4c_ae_8a_e7_c3_c6_16_5b_57_db_7c_2d_2c_8b_1c_e3_a4_44_1b_c4_ba_6a_c6_98_93_ae_2d_20_6e_9f_e8_0f_eb_bc_9f_2e_8a_e7_cf_da_22_96_e1_74_de_b2_f0_29_ec_b1_c1_75_43_1f_b2_e5_1f_a5_f6_06_3e_97_a1_a1_93_f4_51_4a_c4_14_9f_1a_c2_5b_ba_02_45_44_2b_b3_c2_5b_ba_02_45_44_2b_b3_c2_5b_ba_02_45_44_2b_b3_c2_5b_ba_02_45_44_2b_b3_c2_5b_ba_02_45_44_2b_b3_c2_5b_ba_02_45_44_2b_b3_06_0b_12_75_85_8b_07_fb
And the printed barcode looks like this:
However, when I use a generic iOS barcode reader to read it back (I've tried a few), I get the following:
600004|]I�ê÷ºÒÆÂA*×�ImK\�ZÊzjÆÕÐl÷ v[à�F~*0
�:�åf|�ùßñE¥Jn/?ð�¼>w['�XßU7L®çÃÆ�[WÛ|-,�ã¤D�ĺjÆ®- nè�PÐk^¡±xOS5·Óþ�ßá×D¢\���¥ö�>¡¡ôQJÄ��Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³���u�û
This bares a resemblance the original string (for example the first few characters). But I have no idea what type of encoding this is, or how to translate it to the hex codes I was expecting to see.
I would love to know:
1) What am I looking at here?
2) How can I convert this string back into the original format?

Answer 1

Note: For clarity, what you refer to as the encrypted string, I will refer to as the hex code, to further differentiate from the random-looking string at the end of your post.
Summary
I believe the encoding you're seeing in the string is a bungled ASCII/ISO-8859-1 encoding. It is omitting some characters, making it impossible to recover your original hex code from that string. After finding a scanner that properly handles the barcode, it turns out the barcode does not match your hex code.
Encoding
Wikipedia says that by default1, byte codes in Aztec are interpreted as ASCII when between 0 and 127, and as ISO-8859-1 when between 128 and 255. So when you substitute the letters and symbols you're getting with the proper hex values from those two encodings, you get the following:
36 30 30 30 30 34 7C 5D 49 EA F7 BA D2 C6 C2 41 2A D7 49 6D 4B 5C 5A CA 7A 6A C6 D5 D0 6C F7 20 76 5B E0 46 7E 2A 30 0A 3A E5 66 7C F9 DF F1 45 A5 4A 6E 2F 3F F0 BC 3E 77 5B 27 58 DF 55 37 4C AE E7 C3 C6 5B 57 DB 7C 2D 2C E3 A4 44 C4 BA 6A C6 AE 2D 20 6E E8 50 D0 6B 5E A1 B1 78 4F 53 35 B7 D3 FE DF E1 D7 44 A2 5C
This is similar to your encrypted hex code, but with some bytes omitted, and the stuff after the bolded E8 byte is different. The omitted bytes are all from the 00 - 1F and 80 - 9F ranges. The 00 - 1F range in ASCII are control codes, most of which are rarely used and not well supported by many applications. The other range is undefined in ISO-8859-12. So any application trying to interpret these bytes as ASCII/ISO-8859-1 strings may result in unpredictable behaviour.
If you remove bytes from these ranges in your encrypted hex code, you get essentially3 the same thing I got, up to the E8 byte. The byte you have after E8 is 0F. I've never heard of this control code before, but apparently it's called "Shift In" and its function is to "Return to regular character set after Shift Out." Since we're already having trouble with character sets, I can only assume that this control code is responsible for the interpretation errors after the E8 byte.
Edit: One of your recent edits modified the string, and it now contains a few of these characters: �. This is Unicode's replacement character, a character that often replaces others when there is character encoding issues, or a process has trouble interpreting a particular character. In this case, it is replacing many bytes from the 00 - 1F range, which are the ASCII controls. It remains impossible to recover. The 80 - 9F range is still omitted.
A better barcode reader
In order to properly interpret the barcode, you'll need a reader that does not interpret the hex code as encoded strings, but as a byte stream. At the very least, you need a reader that will still preserve the 00 - 1F and 80 - 9F ranges.
One such reader that I've found is NeoReader. It is entirely possible you've already tried it, but copy-pasting can cause errors with these special code ranges.
I scanned the code with it on an iOS 7 device, then hit the "Copy to Clipboard" button that the app provides. Then, I pasted the string at the top of this converter and hit convert. I usually use this converter for Unicode stuff, but other dedicated text to hex converters I found were not able to handle the string and its special codes. If you scroll down to the "Hexadecimal code points," you should be able to see the needed hexadecimal codes, though they are prefixed with an extra 004.
The string it produces (though take it with a grain of salt, I had some copy paste-errors and it appears the special controls were removed upon posting it):
600004|]I ê÷ºÒÆÂA*×ImK\ZÊzjÆÕÐl÷ v[àF~*0
:åf|ùßñE¥Jn/?ð¼>w[' XßU7L®çÃÆ[WÛ|-,ã¤DĺjÆ®- nèPÐk^¡±xOS5·Óþßá×D¢\¥ö>¡¡ôQJÄÂ[ºED+³Â[ºED+³Â[ºED+³Â[ºED+³Â[ºED+³Â[ºED+³ uû
Hex code comparison (differences are marked by < >):
Your hex code: 36 30 30 30 30 34 7C 5D 49 0B EA F7 93 BA 89 D2 C6 C2 41 2A D7 1C 49 8C 6D 4B 5C 07 5A CA 7A 6A C6 D5 D0 6C F7 20 76 5B E0 18 46 93 7E 2A 30 <0D> 14 3A 1A E5 66 7C 05 F9 DF 96 8A F1 45 A5 4A 6E 2F 89 3F F0 93 1F BC 3E 77 5B 27 0C 58 DF 55 37 4C AE 8A E7 C3 C6 16 5B 57 DB 7C 2D 2C 8B 1C E3 A4 44 1B C4 BA 6A C6 98 93 AE 2D 20 6E 9F E8 0F <EB BC 9F 2E 8A E7 CF DA 22 96 E1 74 DE B2 F0 29 EC B1 C1 75 43 1F B2 E5> 1F A5 F6 06 3E 97 A1 A1 93 F4 51 4A C4 14 9F 1A C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 06 0B 12 75 85 8B 07 FB
NeoReader string: 36 30 30 30 30 34 7C 5D 49 0B EA F7 93 BA 89 D2 C6 C2 41 2A D7 1C 49 8C 6D 4B 5C 07 5A CA 7A 6A C6 D5 D0 6C F7 20 76 5B E0 18 46 93 7E 2A 30 <0A> 14 3A 1A E5 66 7C 05 F9 DF 96 8A F1 45 A5 4A 6E 2F 89 3F F0 93 1F BC 3E 77 5B 27 0C 58 DF 55 37 4C AE 8A E7 C3 C6 16 5B 57 DB 7C 2D 2C 8B 1C E3 A4 44 1B C4 BA 6A C6 98 93 AE 2D 20 6E 9F E8 0F <81 50 D0 6B 5E A1 B1 78 4F 53 35 B7 D3 FE 1F DF E1 90 D7 44 A2 5C 00 19> 1F A5 F6 06 3E 97 A1 A1 93 F4 51 4A C4 14 9F 1A C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 C2 5B BA 02 45 44 2B B3 06 0B 12 75 85 8B 07 FB
The difference explained
It turns out, that the barcode does not actually match your hex code. Where our two codes diverge, at that 0F byte, the barcode actually follows what NeoReader suggests. This is shown in the image below, which is zoomed in on the bottom-right quadrant of the barcode (the blue lines indicate parts that do not encode data, they are to help orient the scanner).
I managed to manually5 decode that section of barcode, with help from this video tutorial. Your barcode, however, does not use the string encoding method shown there, as it uses a binary shift escape to work with 8-bit values. From there I believe the one 0A <-> 0D difference is due to a copy paste error on my part.
Unfortunately, since the printer is a black box to you, it does not appear as though you can fix this problem yourself.
Footnotes
I could not find an Aztec Code specification, but the behaviour seems to be relatively consistent with the default.
ISO-8859-1 is essentially a superset of ASCII, but it technically leaves the ASCII control code range undefined. This is usually ignored in practice.
The only difference is the italicized 0A character I have, which is a new line character. Your string has 0D, another new line character. Different systems handle new lines differently, and its not uncommon for them to automatically change the new line characters. Unlike most other ASCII control codes, new line characters are usually well supported.
The reason for this is complicated. Glossing over a few details, I believe that upon hitting the convert button, it is first converted to UTF-16 (Javascript's native string encoding). The byte values for the ASCII/ISO-8859-1 characters are the same in UTF-16. However, UTF-16 is a 16-bit encoding rather than an 8-bit encoding, hence, the extra 00.
That was painful.

Answer 2

First of all, I've tried the following online barcode reader:
intbusoft : server error
onlinebarcodereader : no code found
datasymbol : code different from yours
pqscan : no code found
zxing : code longer than your.
This makes me think that your bar-code may be not so well construct...
Here's your output:
600004|]Iê÷ºÒÆÂA*×ImK\ZÊzjÆÕÐl÷ v[àF~*0
:åf|ùßñE¥Jn/?ð¼>w['XßU7L®çÃÆ[WÛ|-,ã¤DĺjÆ®- nèPÐk^¡±xOS5·Óþßá×D¢\
and here's the one from zxing:
600004|]I�ê÷ºÒÆÂA*×�ImK\�ZÊzjÆÕÐl÷ v[à�F~*0
�:�åf|�ùßñE¥Jn/?ð�¼>w['�XßU7L®çÃÆ�[WÛ|-,�ã¤D�ĺjÆ®- nè�PÐk^¡±xOS5·Óþ�ßá×D¢\���¥ö�>¡¡ôQJÄ��Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³Â[º�ED+³���u�û
(maybe this difference is due to a copy/paste manipulation on your side)
This is the matching that I was able to find:
6 0 0 0 0 4 | ] I � ê ÷ º Ò Æ Â
36 30 30 30 30 34 7c 5d 49 0b ea f7 93 ba 89 d2 c6 c2
A * × � I m K \ � Z Ê z j Æ Õ Ð l
41 2a d7 1c 49 8c 6d 4b 5c 07 5a ca 7a 6a c6 d5 d0 6c
÷ v [ à � F ~ * 0 � : � å f |
f7 20 76 5b e0 18 46 93 7e 2a 30 0d 14 3a 1a e5 66 7c
� ù ß ñ E ¥ J n / ? ð � ¼ >
05 f9 df 96 8a f1 45 a5 4a 6e 2f 89 3f f0 93 1f bc 3e
w [ ' � X ß U 7 L ® ç Ã Æ � [ W Û
77 5b 27 0c 58 df 55 37 4c ae 8a e7 c3 c6 16 5b 57 db
| - , � ã ¤ D � Ä º j Æ ® -
7c 2d 2c 8b 1c e3 a4 44 1b c4 ba 6a c6 98 93 ae 2d 20
n è � P
6e 9f e8 0f eb
And this seems to be some Unicode UCS-2 encoding.
After this, I can't explain the difference between output and expected hexadecimal values