Sir,
I have send sms in PDU formate through AT commands.
AT+CMGS=18
0011000C912933634241140000AA04D370DA0C
Message send successfuly.But when i am trying to send message with UDH & UDHL i am using the Following At Command but show me Error .....
AT+CMGS=24
0011000C912933634241140000AA05000303020104D370DA0C
What is the wrong in my code please help me.
Is it 7 bit encoded? I'm trying to solve this problem myself, and the problem itself is that your UDH requires the message part (04D370DA0C) to be padded (at least in my case).
The text below is from https://en.wikipedia.org/wiki/Concatenated_SMS#PDU_Mode_SMS
the UDH is a total of (number of octets x bit size of octets) 6 x 8 = 48 bits long. Therefore, a single bit of padding has to be prepended to the message. The UDH is therefore (bits for UDH / bits per septet) = (48 + 1)/7 = 7 septets in length.
With a message of "Hello world", the [message] is encoded as
90 65 36 FB 0D BA BF E5 6C 32
as you need to prepend the least significant bits of the next 7bit
character whereas without padding, the [message] would be
C8 32 9B FD 06 DD DF 72 36 19
and the UDL is 7 (header septets) + 11 (message septets) = 18 septets.
Related
I'm using Socket-Communication between my PC and a SPS Unit. They are charing bytes to communicate, by using the python bytestring().
On PC side, I have to switch numeric commands (integer), but them into the bytestring and send it via socket.
Values from 8, 9, 12 and much more, produces an error on SPS side, because the are changed by UTF-8: 8 --> \t , 9 --> \n.
How can I keep this data in real hex and without coding UTF?
my_b = bytearray()
my_b.append(8) #fill with Bytevalues
my_b.append(9)
my_b.append(10)
my_b.append(11)
my_b.append(12)
my_b.append(13)
print (my_b)
>> bytearray(b'\x08\t\n\x0b\x0c\r')
They are not being changed. \t, \n and \r are simply built-in short-hand for expressing the byte values of 9, 10, and 13. Those values are ASCII control characters (tab, line-feed and carriage-return, specifically).
To prove this, add these lines to the end of your code snippet:
with open("/tmp/foo", "wb") as f:
f.write(my_b)
Then dump /tmp/foo as hex bytes:
od -tx1 /tmp/foo
0000000 08 09 0a 0b 0c 0d
0000006
I would appreciate if someone could please explain this to me.
I came across this post (not important just reference) and saw a token encoded with base64 where the guy decoded it.
EYl0htUzhivYzcIo+zrIyEFQUE1PQkk= -> t3+(:APPMOBI
I then tried to encode t3+(:APPMOBI again using base64 to see if I would get the same result, but was very surprised to get:
t3+(:APPMOBI - > dDMrKDpBUFBNT0JJ
Completly different token.
I then tried to decode the original token EYl0htUzhivYzcIo+zrIyEFQUE1PQkk= and got t3+(:APPMOBI with random characters between it. (I got ◄ëtå╒3å+╪═┬(√:╚╚APPMOBI could be wrong, I quickly did it off the top off my head)
What is the reason for the difference in tokens were they not supposed to be the same?
The whole purpose of base64 encoding is to encode binary data into text representation so that they can be transmitted over the network or displayed without corruption. But it ironically happened with the original post you were referring to,
EYl0htUzhivYzcIo+zrIyEFQUE1PQkk= does NOT decode to t3+(:APPMOBI
instead, it contains some binary bytes(not random btw) that you correctly showed. So the problem was due to the original post where either the author or the tool/browser that she/he used "cleaned up", or rather corrupted the decoded binary data.
There is always one-to-one relationship between encoded and decoded data (provided the same "base" is used, i.e. the same set of characters are used for encoded text.)
t3+(:APPMOBI indeed will be encoded into dDMrKDpBUFBNT0JJ
The problem is in the encoding that displayed the output to you, or in the encoding that you used to input the data to base64. This is actually the problem that base64 encoding was invented to help solve.
Instead of trying to copy and paste the non-ASCII characters, save the output as a binary file, then examine it. Then, encode the binary file. You'll see the same base64 string.
c:\TEMP>type b.txt
EYl0htUzhivYzcIo+zrIyEFQUE1PQkk=
c:\TEMP>base64 -d b.txt > b.bin
c:\TEMP>od -t x1 b.bin
0000000 11 89 74 86 d5 33 86 2b d8 cd c2 28 fb 3a c8 c8
0000020 41 50 50 4d 4f 42 49
c:\TEMP>base64 -e b.bin
EYl0htUzhivYzcIo+zrIyEFQUE1PQkk=
od is a tool (octal dump) that outputs binary data using hexadecimal notation, and shows each of the bytes.
EDIT:
You asked about a different string in your comments, dDMrKDpBUFBNT0JJ, and why does that decode to the same thing? Well, it doesn't decode to the same thing. It decodes to this string of bytes: 74 33 2b 28 3a 41 50 50 4d 4f 42 49. Your original string decoded to this string of bytes: 11 89 74 86 d5 33 86 2b d8 cd c2 28 fb 3a c8 c8 41 50 50 4d 4f 42 49.
Notice the differences: your original string decoded to 23 bytes, your second string decoded to only 12 bytes. The original string included non-ASCII bytes like 11, d5, d8, cd, c2, fb, c8, c8. These bytes don't print the same way on every system. You referred to them as "random bytes", but they're not. They're part of the data, and base64 is designed to make sure they can be transmitted.
I think to understand why these strings are different, you need to first understand the nature of character data, what base64 is, and why it exists. Remember that computers work only on numbers, but people need to work with familiar concepts like letters and digits. So ASCII was created as an "encoding" standard that represents a little number (we call this little number a "byte") as a letter or a digit, so that we humans can read it. If we line up a group of bytes, we can spell out a message. 41 50 50 4d 4f 42 49 are the bytes that represent the word APPMOBI. We call a group of bytes like this a "string".
Every letter from A-Z and every digit from 0-9 has a number specified in ASCII that represents it. But there are many extra numbers that are not in the standard, and not all of those represent visible or sensible letters or digits. We say they're non-printable. Your longer message includes many bytes that aren't printable (you called them random.)
When a computer program like email is dealing with a string, if the bytes are printable ASCII characters, it's easy. The email program knows what to do with them. But if your bytes instead represent a picture, the bytes could have values that aren't ASCII, and various email programs won't know what to do with them. Base64 was created to take all kinds of bytes, both printable and non-printable bytes, and translate them into a string of bytes representing only printable letters. Because they're all printable, a program like email or a web server can easily handle them, even if it doesn't know that they actually contain a picture.
Here's the decode of your new string:
c:\TEMP>type c.txt
dDMrKDpBUFBNT0JJ
c:\TEMP>base64 -d c.txt
t3+(:APPMOBI
c:\TEMP>base64 -d c.txt > c.bin
c:\TEMP>od -t x1 c.bin
0000000 74 33 2b 28 3a 41 50 50 4d 4f 42 49
0000014
c:\TEMP>type c.bin
t3+(:APPMOBI
c:\TEMP>
What "stack" of bad encoding would produce the following bytes of weirdness for the string "cinéma télédiffusion"? (I left out the space character, hex: 20)
cinÃ%ma
in HEX: 63 69 6E C3 83 25 6D 61
mapped: c i n ---�---- m a
tÃclÃcdiffusion
in HEX: 74 C3 83 63 6C C3 83 63 64 69 66 66 75 73 69 6F 6E
mapped: t ---�---- l ---�---- d i f f u s i o n
The ---�---- parts represent the bytes that aren't right.
I considered the idea "What if it was a messed up transcoding? How about a double encoding?", but, looking at http://www.fileformat.info/info/unicode/char/00e9/charset_support.htm (and the code page edition, too), I noted that there no encodings that could possibly end é with the hex bytes %25 or %63. It doesn't even look like double-UTF8 encoding at this point, because, http://en.wikipedia.org/wiki/UTF-8 clarified that bytes following a %C3 would need to be have the first bits set to 10xxxxxx.
How could some program have turned the accented é into an "Ã followed by %" as well as "Ã followed by c"? I want to trace back the history of the misencoding so that I can try to come up with something that can take steps at repairing the mangled strings.
There also exists the possibility that the é weren't ever é to begin with, but I can't fathom what kind of typo someone could have made in the same phrase to get two different versions of é that eventually get misencoded into two completely different sets of bytes.
Extra context details: I find these mangled strings inside of an XML file. The file has no <?xml version="1.0"?> header, so it's presumed to be UTF-8. There exists nodes containing phrases that have perfectly good é characters in them at the same time that there exists nodes containing phrases with mangled é characters.
iconv-and-family don't do anything at all to help this situation, as far as I've attempted.
A couple of trailing considerations that I now hold are: Should I suspect MySQL and its infamously lazy character set transcodings? Could it be somebody's really badly written custom encoding function as they exported the XML?
The encoding looks a bit strange:
Taken the é from cinéma results in for utf-8 encoding:
é = C3 A9
where you got:
C3 83 25
So when it will be double encoded the following should happen:
c3: Ã -> c3 83
a9: © -> c2 a9
But this will not explain the 25 within your result.
25: %
So the question is if this is encode once, then unknown characters like © will be replaced by % and then it's encoded a second time?
I'm working with smartcard chips and using its PIV app, {00 A4 P1 P2 Le Data Lc} all the verficatives are fine {00 20 P1 P2 Le Data Lc} and {00 21 P1 P2 Le Data Lc}.
But as you know the piv apllication have a counter of failed tries; in this case 00 20 have a 3 and 00 21 have 15 as number of failed tries before it locks.
I want to know if there is any APDU command available that actually reads the number of tries, without increasing it.
You can send the exact command with no Command Data, i.e. the Lc is '00'.
The card shall return SW1-SW2='63 CX', where X denotes remaining tries.
The APDU shall look like the following:
Command APDU: 00 20 P1 P2 00
Response APDU: 63 C3
NOTE: I have been using this for INS '20', but never tried for INS '21'.
I'm working on a little Streamserve project (google it :P) where I get some Base64 encoded content. I've tried to decode the base64 string with multiple decoders and all return the correct result.. except the Base64DecodeString method in Streamserve.
The encoded string is: 'VABlAHMAdABpAG4AZwAgAGIAYQBzAGUANgA0AA==' The expected result is: 'Testing base64'
However within Streamserve the result is: 'Tsig ae4'
It simply skips every other letter. Now I know most people dont know Streamserve, but I have a hunch that this might be a character encoding problem.. problem and was hoping someone has a clue what might be happening here.
I can without any problem encode/decode strings within streamserve.. just not strings I get as input
The issue is that you're encoding in UTF-16 and decoding back to ASCII or UTF8. Change your string encoding to UTF8 before encoding the string to base64 and it should work fine.
Here's the hex dump of that base64 blob:
54 00 65 00 73 00 74 00 69 00 6e 00 67 00 20 00 62 00 61 00 73 00 65 00 36 00 34 00
If you remove the null bytes, you get this:
54 65 73 74 69 6e 67 20 62 61 73 65 36 34
Which translates to the following ASCII text:
Testing base64
The result of decoding base64 is binary data (and likewise the input when encoding it is binary data). To go from binary data to a string or vice versa, you need to apply an encoding such as UTF-8 or UTF-16. You need to find out which encoding Streamserve is using, and use the same encoding when you convert your text data to binary data to start with, before base64-encoding it.
It sounds like you might want to use UTF-16 to encode your text to start with, although in that case I'm surprised you're not just getting garbage out... it looks like it's actually ignoring every other byte in the decoded base64, rather than taking it as the high byte in a UTF-16 code unit.