I am trying to send an email with Chinese characters in the subject line from my program to a gmail account, but the subject line appears as ????. This is how the subject line is encoded:
=?utf-8?B?Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos=?=
Is there anything wrong in the encoding? Is there anything that I have to bear in mind? The mail also contains Chinese characters in the body, but those get displayed just fine. I am using base64 to encode the body.
=?utf-8?B?Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos=?= is encoded by base64, and the string-buffer(after decoded by base64) is encoded by utf-8.
You can decode it in python:
>>> from base64 import b64decode
>>> b64decode(b'Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos=').decode('utf-8')
'FW: 請幫我給 與你起來的同事'
Also in python:
>>> from email.header import decode_header
>>> decode_header('=?utf-8?B?Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos=?=')
[(b'FW: \xe8\xab\x8b\xe5\xb9\xab\xe6\x88\x91\xe7\xb5\xa6 \xe8\x88\x87\xe4\xbd\xa0\xe8\xb5\xb7\xe4\xbe\x86\xe7\x9a\x84\xe5\x90\x8c\xe4\xba\x8b', 'utf-8')]
>>> _[0][0].decode(_[0][1])
'FW: 請幫我給 與你起來的同事'
Or in bash(maybe you should pipe to iconv):
~ $ echo Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos= | base64 -d
FW: 請幫我給 與你起來的同事
For those interested in the answer to this question, this string is a MIME header encoded as per RFC2047.
=?utf-8?B?Rlc6IOiri+W5q+aIkee1piDoiIfkvaDotbfkvobnmoTlkIzkuos=?= means it uses the UTF-8 charset, B means Base 64 encoding.
In PHP, use iconv_mime_decode.
Related
Using requests to query the DarkSky API says it returns UTF-8 encoded document, but string is defaulting to ASCII with error. If I explicitly encode as UTF-8, there are no errors, but string contains extra characters and raw unicode. What's going on? I've set my py file to use UTF-8 encoding in Sublime.
# Fetch weather data from DarkSky, parse resulting JSON
try:
url = "https://api.darksky.net/forecast/" + API_KEY + "/" + LAT + "," + LONG + "?exclude=[minutely,hourly,alerts,flags]&units=us"
response = requests.get(url)
data = response.json()
print(response.headers['content-type'])
print(response.encoding)
which returns:
application/json; charset=utf-8
d_summary = data['daily']['summary']
print("Daily Summary: ", d_summary.encode('utf-8'))
which returns: Daily Summary: b'No precipitation throughout the week, with temperatures rising to 82\xc2\xb0F on Tuesday.'
What's going on with the extra characters in front and quoted substring with unicode text?
I don't see any problem here. Decoding the JSON doesn't cause an error, and encoding to UTF-8 produces a byte string literal repr b'...' as expected. Top-bit-set bytes are expected to look like \xXX in byte string literals.
string is defaulting to ASCII with error
What do you mean by that? Please show us the actual problem.
My guess is you are trying to print non-ASCII characters to the terminal on Windows and getting UnicodeEncodeError. If so that's because the Windows Console is broken and can't print Unicode properly. PEP 528 works around the problem in Python 3.6.
I have a normal string in Powershell that is from a text file containing Base64 text; it is stored in $x. I am trying to decode it as such:
$z = [System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String($x));
This works if $x was a Base64 string created in Powershell (but it's not). And this does not work on the $x Base64 string that came from a file, $z simply ends up as something like 䐲券.
What am I missing? For example, $x could be YmxhaGJsYWg= which is Base64 for blahblah.
In a nutshell, YmxhaGJsYWg= is in a text file then put into a string in this Powershell code and I try to decode it but end up with 䐲券 etc.
Isn't encoding taking the text TO base64 and decoding taking base64 BACK to text? You seem be mixing them up here. When I decode using this online decoder I get:
BASE64: blahblah
UTF8: nVnV
not the other way around. I can't reproduce it completely in PS though. See sample below:
PS > [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String("blahblah"))
nV�nV�
PS > [System.Convert]::ToBase64String([System.Text.Encoding]::UTF8.GetBytes("nVnV"))
blZuVg==
EDIT I believe you're using the wrong encoder for your text. The encoded base64 string is encoded from UTF8(or ASCII) string.
PS > [System.Text.Encoding]::UTF8.GetString([System.Convert]::FromBase64String("YmxhaGJsYWg="))
blahblah
PS > [System.Text.Encoding]::Unicode.GetString([System.Convert]::FromBase64String("YmxhaGJsYWg="))
汢桡汢桡
PS > [System.Text.Encoding]::ASCII.GetString([System.Convert]::FromBase64String("YmxhaGJsYWg="))
blahblah
There are no PowerShell-native commands for Base64 conversion - yet (as of PowerShell [Core] 7.1), but adding dedicated cmdlets has been suggested in GitHub issue #8620.
For now, direct use of .NET is needed.
Important:
Base64 encoding is an encoding of binary data using bytes whose values are constrained to a well-defined 64-character subrange of the ASCII character set representing printable characters, devised at a time when sending arbitrary bytes was problematic, especially with the high bit set (byte values > 0x7f).
Therefore, you must always specify explicitly what character encoding the Base64 bytes do / should represent.
Ergo:
on converting TO Base64, you must first obtain a byte representation of the string you're trying to encode using the character encoding the consumer of the Base64 string expects.
on converting FROM Base64, you must interpret the resultant array of bytes as a string using the same encoding that was used to create the Base64 representation.
Examples:
Note:
The following examples convert to and from UTF-8 encoded strings:
To convert to and from UTF-16LE ("Unicode") instead, substitute [Text.Encoding]::Unicode for [Text.Encoding]::UTF8
Convert TO Base64:
PS> [Convert]::ToBase64String([Text.Encoding]::UTF8.GetBytes('Motörhead'))
TW90w7ZyaGVhZA==
Convert FROM Base64:
PS> [Text.Encoding]::Utf8.GetString([Convert]::FromBase64String('TW90w7ZyaGVhZA=='))
Motörhead
This page shows up when you google how to convert to base64, so for completeness:
$b = [System.Text.Encoding]::UTF8.GetBytes("blahblah")
[System.Convert]::ToBase64String($b)
Base64 encoding converts three 8-bit bytes (0-255) into four 6-bit bytes (0-63 aka base64). Each of the four bytes indexes an ASCII string which represents the final output as four 8-bit ASCII characters. The indexed string is typically 'A-Za-z0-9+/' with '=' used as padding. This is why encoded data is 4/3 longer.
Base64 decoding is the inverse process. And as one would expect, the decoded data is 3/4 as long.
While base64 encoding can encode plain text, its real benefit is encoding non-printable characters which may be interpreted by transmitting systems as control characters.
I suggest the original poster render $z as bytes with each bit having meaning to the application. Rendering non-printable characters as text typically invokes Unicode which produces glyphs based on your system's localization.
Base64decode("the answer to life the universe and everything") = 00101010
If anyone would like to do it with a pipe in Powershell (like a filter) (e.g. read file contents and decode it), it can be achieved with a one-liner like that:
Get-Content base64.txt | %{[Text.Encoding]::UTF8.GetString([Convert]::FromBase64String($_))}
I had issues with spaces showing in between my output and there was no answer online at all to fix this issue. I literally spend many hours trying to find a solution and found one from playing around with the code to the point that I almost did not even know what I typed in at the time that I got it to work. Here is my fix for the issue: [System.Text.Encoding]::UTF8.GetString(([System.Convert]::FromBase64String($base64string)|?{$_}))
Still not a "built-in", but published to gallery, authored by MS:
https://github.com/powershell/textutility
TextUtility
ConvertFrom-Base64
Return a string decoded from base64.
ConvertTo-Base64
Return a base64 encoded representation of a string.
Set out to write a simple procmail recipie that would forward the mail to me if it found the text "Unprovisioned" in the subject.
:0:
* ^Subject:.*Unprovisioned.*
! me#test.com
Unfortunately the subject field in the mail message coming from the mail server was in MIME encoded-word syntax.
The form is: "=?charset?encoding?encoded text?=".
Subject: =?UTF-8?B?QURWSVNPUlk6IEJNRFMgMTg0NSwgTkVXIFlPUksgLSBVbnByb3Zpc2lvbmVkIENvbm4gQQ==?=
=?UTF-8?B?bGVydA==?=
The above subject is utf-8 charset, base64 encoding with text folded to two lines. So was wondering if there are any mechanisms/scripts/utilities to parse this and convert to string format so that I could apply my procmail filter. Ofcourse I can write a perl script to parse this an perform the required validations, but looking to avoid it if possible.
Encode::MIME::Header, which ships with Perl, accessed directly through Encode:
use Encode qw(encode decode);
my $header_text = decode('MIME-Header', $header);
I decided to use Python 3 for making my website, but I encountered a problem with Unicode output.
It seems like plain print(html) #html is astr should be working, but it's not. I get UnicodeEncodeError: 'ascii' codec can't encode characters[...]: ordinal not in range(128). This must be because the webserver doesn't support unicode output.
The next thing I tried was print(html.encode('utf-8')), but I got something like repr output of the byte string: it is placed inside b'...' and all the escape characters are in raw form (e.g. \n and \xd0\x9c)
Please show me the correct way to output a Unicode (str) string as a raw UTF-8 encoded bytes string in Python 3.1
The problem here is that you stdout isn't attached to an actual terminal and will use the ASCII encoding by default. Therefore you need to write to sys.stdout.buffer, which is the "raw" binary output of sys.stdout. This can be done in various ways, the most common one seems to be:
import codecs, sys
writer = codecs.getwriter('utf8')(sys.stdout.buffer)
And the use writer. In a CGI script you may be able to replace sys.stdout with the writer so:
sys.stdout = codecs.getwriter('utf8')(sys.stdout.buffer)
Might actually work so you can print normally. Try that!
I have an email subject of the form:
=?utf-8?B?T3.....?=
The body of the email is utf-8 base64 encoded - and has decoded fine.
I am current using Perl's Email::MIME module to decode the email.
What is the meaning of the =?utf-8 delimiter and how do I extract information from this string?
The encoded-word tokens (as per RFC 2047) can occur in values of some headers. They are parsed as follows:
=?<charset>?<encoding>?<data>?=
Charset is UTF-8 in this case, the encoding is B which means base64 (the other option is Q which means Quoted Printable).
To read it, first decode the base64, then treat it as UTF-8 characters.
Also read the various Internet Mail RFCs for more detail, mainly RFC 2047.
Since you are using Perl, Encode::MIME::Header could be of use:
SYNOPSIS
use Encode qw/encode decode/;
$utf8 = decode('MIME-Header', $header);
$header = encode('MIME-Header', $utf8);
ABSTRACT
This module implements RFC 2047 Mime
Header Encoding. There are 3 variant
encoding names; MIME-Header, MIME-B
and MIME-Q. The difference is
described below
decode() encode()
MIME-Header Both B and Q =?UTF-8?B?....?=
MIME-B B only; Q croaks =?UTF-8?B?....?=
MIME-Q Q only; B croaks =?UTF-8?Q?....?=
I think that the Encode module handles that with the MIME-Header encoding, so try this:
use Encode qw(decode);
my $decoded = decode("MIME-Header", $encoded);
Check out RFC2047. The 'B' means that the part between the last two '?'s is base64-encoded. The 'utf-8' naturally means that the decoded data should be interpreted as UTF-8.
MIME::Words from MIME-tools work well too for this. I ran into some issue with Encode and found MIME::Words succeeded on some strings where Encode did not.
use MIME::Words qw(:all);
$decoded = decode_mimewords(
'To: =?ISO-8859-1?Q?Keld_J=F8rn_Simonsen?= <keld#dkuug.dk>',
);
This is a standard extension for charset labeling of headers, specified in RFC2047.