WTF eG (Hacker eG)

Werkkooperative der Technikfreundinnen e. G. i. G.

Samba backups provide a way to recover your Samba AD domain, in the unlikely event that it suffers a catastrophic failure. It does not backup individual DCs.

Scrapy is a fast high-level web crawling and web scraping framework, used to crawl websites and extract structured data from their pages. It can be used for a wide range of purposes, from data mining to monitoring and automated testing.

Add authentication to applications and secure services with minimum fuss. No need to deal with storing users or authenticating users. It's all available out of the box.

You'll even get advanced features such as User Federation, Identity Brokering and Social Login.

For more details go to about and documentation, and don't forget to try Keycloak. It's easy by design!

Hydra is an OAuth 2.0 and OpenID Connect Provider. In other words, an implementation of the OAuth 2.0 Authorization Framework as well as the OpenID Connect Core 1.0 framework. As such, it issues OAuth 2.0 Access, Refresh, and ID Tokens that enable third-parties to access your APIs in the name of your users.

Wir zeigen Euch, worauf es beim Hang-Off und der richtigen Sitzposition für die Rennstrecke ankommt!
Ein spannendes Thema, hier darf auch der oft diskutierte Lenkimpuls nicht fehlen!

Wenn Ihr Fragen habt zur Sitzposition, der Körperhaltung oder Anregungen für ein neues Video habt, schreibt sie gerne in die Kommentare.

Info page: 10.1.5 Formatting file timestamps

alias ls='ls --time-style="long-iso"' # Shows no seconds
alias ls='ls --time-style="%F %T"' # Shows seconds

... und/oder im shell profile script:

export TIME_STYLE='+%F %T'

!/bin/bash

#
# (c) Frank Matthieß 2020
#
#

NAME=$(basename $0)
info() { echo "$*">&2; }
error() { info "ERROR: $*"; }

APIURL=https://api.opensensemap.org/boxes
TMPFILE=$(mktemp)
STIDFILE=$(mktemp)
trap 'rm -f ${TMPFILE} ${STIDFILE} ' INT EXIT

# At the map, click on an station icon and you get, for example, this url:
#  https://opensensemap.org/explore/5b4d11485dc1ec001b5452c7
#
# Add the id tring at the end of the url with a proper name to the sensor id list

# Sensor id list
cat<<EOSTIDS>$STIDFILE
5c22ef44919bf8001a10acc7    Berlin Charlottenburg
5a9c2087bc2d4100191d6ff9    Stuttgart Unteraichen (A8)
5b4d11485dc1ec001b5452c7    München Fakultät Informatik
EOSTIDS

#
#
# Adjust the field length of the output
llen=0
while read stid location; do
    l=$(wc -c <<< "$location")
    if [ $llen -lt $l ]; then
        llen=$l
    fi
done < $STIDFILE

#
# .. and get the need values via opensensemap api
#
while read stid location; do
    curl -sL ${APIURL}/${stid} > ${TMPFILE}
    reallocation=$(jq .name < ${TMPFILE})
    temperature=$(jq '.sensors[]  | select(.title|test("Temperatur")) | .title, .lastMeasurement.value, .unit' < ${TMPFILE} | xargs )
    humidity=$(jq '.sensors[]  | select(.title|test("rel. Luftfeuchte")) | .title, .lastMeasurement.value, .unit' < ${TMPFILE} | xargs )
    rawcoordinates=$(jq '.currentLocation.coordinates[]' < ${TMPFILE} | xargs )
    coordinates=$(while read lon lat heigh; do echo "https://www.openstreetmap.org/?mlat=${lat}&mlon=${lon}#map=12/${lat}/$lon"; done <<< "${rawcoordinates}")

    # 
    printf "%-${llen}s:\n\tStationsname : %s\n\t%s\n\t%s\n\tOpenstreetmap: %s\n"    \
        "${location}"               \
            "${reallocation//\"/}"      \
            "${temperature}"        \
            "${humidity}"           \
            "${coordinates}"

done < $STIDFILE

# vim:set ts=8 sts=8 sw=8 ft=sh ai tw=80:

${parameter:-word}
Use Default Values. If parameter is unset or null, the expansion of word is substituted. Otherwise,
the value of parameter is substituted.
${parameter:=word}
Assign Default Values. If parameter is unset or null, the expansion of word is assigned to parameter.
The value of parameter is then substituted. Positional parameters and special parameters may not be
assigned to in this way.
${parameter:?word}
Display Error if Null or Unset. If parameter is null or unset, the expansion of word (or a message to
that effect if word is not present) is written to the standard error and the shell, if it is not inter‐
active, exits. Otherwise, the value of parameter is substituted.
${parameter:+word}
Use Alternate Value. If parameter is null or unset, nothing is substituted, otherwise the expansion of
word is substituted.
${parameter:offset}
${parameter:offset:length}
Substring Expansion. Expands to up to length characters of the value of parameter starting at the
character specified by offset. If parameter is @, an indexed array subscripted by @ or *, or an asso‐
ciative array name, the results differ as described below. If length is omitted, expands to the sub‐
string of the value of parameter starting at the character specified by offset and extending to the end
of the value. length and offset are arithmetic expressions (see ARITHMETIC EVALUATION below).

          If offset evaluates to a number less than zero, the value is used as an offset in characters  from  the
          end of the value of parameter.  If length evaluates to a number less than zero, it is interpreted as an
          offset in characters from the end of the value of parameter rather than a number of characters, and the
          expansion  is the characters between offset and that result.  Note that a negative offset must be sepa‐
          rated from the colon by at least one space to avoid being confused with the :- expansion.

          If parameter is @, the result is length positional parameters beginning at offset.  A  negative  offset
          is  taken  relative to one greater than the greatest positional parameter, so an offset of -1 evaluates
          to the last positional parameter.  It is an expansion error if length evaluates to a number  less  than
          zero.

          If  parameter  is  an indexed array name subscripted by @ or *, the result is the length members of the
          array beginning with ${parameter[offset]}.  A negative offset is taken relative to one greater than the
          maximum  index  of  the specified array.  It is an expansion error if length evaluates to a number less
          than zero.

          Substring expansion applied to an associative array produces undefined results.

          Substring indexing is zero-based unless the positional parameters are used, in which case the  indexing
          starts  at 1 by default.  If offset is 0, and the positional parameters are used, $0 is prefixed to the
          list.

   ${!prefix*}
   ${!prefix@}
          Names matching prefix.  Expands to the names of variables whose names begin with prefix,  separated  by
          the  first character of the IFS special variable.  When @ is used and the expansion appears within dou‐
          ble quotes, each variable name expands to a separate word.

   ${!name[@]}
   ${!name[*]}
          List of array keys.  If name is an array variable, expands to the list of array indices (keys) assigned
          in  name.  If name is not an array, expands to 0 if name is set and null otherwise.  When @ is used and
          the expansion appears within double quotes, each key expands to a separate word.

  ${#parameter}
          Parameter length.  The length in characters of the value of parameter is substituted.  If parameter  is
          *  or  @,  the value substituted is the number of positional parameters.  If parameter is an array name
          subscripted by * or @, the value substituted is the number of elements in the array.  If  parameter  is
          an  indexed  array name subscripted by a negative number, that number is interpreted as relative to one
          greater than the maximum index of parameter, so negative indices count back from the end of the  array,
          and an index of -1 references the last element.

   ${parameter#word}
   ${parameter##word}
          Remove  matching  prefix pattern.  The word is expanded to produce a pattern just as in pathname expan‐
          sion, and matched against the expanded value of parameter  using  the  rules  described  under  Pattern
          Matching below.  If the pattern matches the beginning of the value of parameter, then the result of the
          expansion is the expanded value of parameter with the shortest matching pattern (the ``#'' case) or the
          longest matching pattern (the ``##'' case) deleted.  If parameter is @ or *, the pattern removal opera‐
          tion is applied to each positional parameter in turn, and the expansion is the resultant list.  If  pa‐
          rameter  is an array variable subscripted with @ or *, the pattern removal operation is applied to each
          member of the array in turn, and the expansion is the resultant list.

   ${parameter%word}
   ${parameter%%word}
          Remove matching suffix pattern.  The word is expanded to produce a pattern just as in  pathname  expan‐
          sion,  and  matched  against  the  expanded  value of parameter using the rules described under Pattern
          Matching below.  If the pattern matches a trailing portion of the expanded value of parameter, then the
          result  of  the  expansion  is  the expanded value of parameter with the shortest matching pattern (the
          ``%'' case) or the longest matching pattern (the ``%%'' case) deleted.  If parameter is  @  or  *,  the
          pattern removal operation is applied to each positional parameter in turn, and the expansion is the re‐
          sultant list.  If parameter is an array variable subscripted with @ or *, the pattern removal operation
          is applied to each member of the array in turn, and the expansion is the resultant list.

   ${parameter/pattern/string}
          Pattern  substitution.  The pattern is expanded to produce a pattern just as in pathname expansion, Pa‐
          rameter is expanded and the longest match of pattern against its value is replaced  with  string.   The
          match  is  performed using the rules described under Pattern Matching below.  If pattern begins with /,
          all matches of pattern are replaced with string.  Normally only the first match is replaced.   If  pat‐
          tern  begins with #, it must match at the beginning of the expanded value of parameter.  If pattern be‐
          gins with %, it must match at the end of the expanded value of parameter.  If string is  null,  matches
          of  pattern are deleted and the / following pattern may be omitted.  If the nocasematch shell option is
          enabled, the match is performed without regard to the case of alphabetic characters.  If parameter is @
          or  *, the substitution operation is applied to each positional parameter in turn, and the expansion is
          the resultant list.  If parameter is an array variable subscripted with @ or *, the substitution opera‐
          tion is applied to each member of the array in turn, and the expansion is the resultant list.

   ${parameter^pattern}
   ${parameter^^pattern}
   ${parameter,pattern}
   ${parameter,,pattern}
          Case  modification.   This expansion modifies the case of alphabetic characters in parameter.  The pat‐
          tern is expanded to produce a pattern just as in pathname expansion.  Each character  in  the  expanded
          value  of  parameter  is tested against pattern, and, if it matches the pattern, its case is converted.
          The pattern should not attempt to match more than one character.  The  ^  operator  converts  lowercase
          letters matching pattern to uppercase; the , operator converts matching uppercase letters to lowercase.
          The ^^ and ,, expansions convert each matched character in the expanded value; the ^ and  ,  expansions
          match and convert only the first character in the expanded value.  If pattern is omitted, it is treated
          like a ?, which matches every character.  If parameter is @ or *, the case  modification  operation  is
          applied to each positional parameter in turn, and the expansion is the resultant list.  If parameter is
          an array variable subscripted with @ or *, the case modification operation is applied to each member of
          the array in turn, and the expansion is the resultant list.

   ${parameter@operator}
          Parameter transformation.  The expansion is either a transformation of the value of parameter or infor‐
          mation about parameter itself, depending on the value of operator.  Each operator is a single letter:

          Q      The expansion is a string that is the value of parameter quoted in a format that can  be  reused
                 as input.
          E      The  expansion  is  a  string that is the value of parameter with backslash escape sequences ex‐
                 panded as with the $'...' quoting mechanism.
          P      The expansion is a string that is the result of expanding the value of parameter as if it were a
                 prompt string (see PROMPTING below).
          A      The  expansion  is  a  string in the form of an assignment statement or declare command that, if
                 evaluated, will recreate parameter with its attributes and value.
          a      The expansion is a string consisting of flag values representing parameter's attributes.

          If parameter is @ or *, the operation is applied to each positional parameter in turn, and  the  expan‐
          sion  is  the resultant list.  If parameter is an array variable subscripted with @ or *, the operation
          is applied to each member of the array in turn, and the expansion is the resultant list.

          The result of the expansion is subject to word splitting and pathname expansion as described below.

Ausgabe des aktuellen timestamp mit bash printf ohne $(date +…):

printf "%(%FT%T%z)T\n"

… aber nicht ganz …

~$ printf "%(%FT%T%z)T msg: %s\n" "mjggjgjh"
bash: printf: mjggjgjh: invalid number
1970-01-01T01:00:00+0100 msg: 

~$ printf "%(%FT%T%z)T\n" "123456"
1970-01-02T11:17:36+0100

~$ printf "%(%FT%T%z)T msg: %s\n" "$(date +%s)" "wrether the rztj rtzhj"
2020-10-19T07:46:27+0200 msg: wrether the rztj rtzhj

man bash:
printf [-v var] format [arguments]
Write the formatted arguments to the standard output under the control of the format. The -v option
causes the output to be assigned to the variable var rather than being printed to the standard output.

          The  format  is  a  character string which contains three types of objects: plain characters, which are
          simply copied to standard output, character escape sequences, which are converted  and  copied  to  the
          standard  output, and format specifications, each of which causes printing of the next successive argu‐
          ment.  In addition to the standard printf(1) format specifications, printf interprets the following ex‐
          tensions:
          %b     causes printf to expand backslash escape sequences in the corresponding argument in the same way
                 as echo -e.
          %q     causes printf to output the corresponding argument in a format that can be reused as  shell  in‐
                 put.
          %(datefmt)T
                 causes printf to output the date-time string resulting from using datefmt as a format string for
                 strftime(3).  The corresponding argument is an integer representing the number of seconds  since
                 the epoch.  Two special argument values may be used: -1 represents the current time, and -2 rep‐
                 resents the time the shell was invoked.  If no argument is specified, conversion behaves  as  if
                 -1 had been given.  This is an exception to the usual printf behavior.

          Arguments to non-string format specifiers are treated as C constants, except that a leading plus or mi‐
          nus sign is allowed, and if the leading character is a single or double quote, the value is  the  ASCII
          value of the following character.

          The  format  is reused as necessary to consume all of the arguments.  If the format requires more argu‐
          ments than are supplied, the extra format specifications behave as if a zero value or null  string,  as
          appropriate, had been supplied.  The return value is zero on success, non-zero on failure.

To send messages to the Microsoft teams channel, we will use the requests module.

This post highlights a few powerful lines of CSS that do some serious heavy lifting and help you build robust modern layouts.

Computer networks use the Domain Name System (DNS) to determine the IP address associated with a domain name. This process is also known as forward DNS resolution. Reverse DNS (rDNS) is the inverse process of this: the resolution of an IP address to its designated domain name. This document explains how reverse DNS works and how to configure it for your zone.

IPv4
One or more /24 type zones need to be created if your address space has a prefix length between /17 and /24. If your prefix length is between /16 and /9 you will have to request one or more delegations for /16 type zones.

For example, if you have been allocated 10.155.16.0/22, you need to create four reverse zones:

16.155.10.in-addr.arpa.
17.155.10.in-addr.arpa.
18.155.10.in-addr.arpa.
19.155.10.in-addr.arpa.

IPv6
If you have been allocated an IPv6 block that is not on a nibble boundary, you will need to go down to the next nibble and create multiple zones to cover the entire block.

For example, an allocation such as 2001:db8::/29 will result in eight reverse zones of /32 each:

8.b.d.0.1.0.0.2.ip6.arpa.
9.b.d.0.1.0.0.2.ip6.arpa.
a.b.d.0.1.0.0.2.ip6.arpa.
b.b.d.0.1.0.0.2.ip6.arpa.
c.b.d.0.1.0.0.2.ip6.arpa.
d.b.d.0.1.0.0.2.ip6.arpa.
e.b.d.0.1.0.0.2.ip6.arpa.
f.b.d.0.1.0.0.2.ip6.arpa.

Auswertungen basierend auf den aus den Gesundheitsämtern gemäß IfSG übermittelten Meldedaten

I'm writing a third edition of Security Engineering, which will be published in November 2020.

With both the first edition in 2001 and the second edition in 2008, I put six chapters online for free at once, then added the others four years after publication. For the third edition, I negotiated an agreement with the publishers to put the chapters online for review as I wrote them. So the book came out by instalments, like Dickens' novels, from April 2019 to Septamber 2020. On the first of November 2020, all except seven sample chapters will disappear for a period of 42 months. I'm afraid the publishers insist on that. But therearefter the whole book will be free online forever.

You may pre-order the paper book here for delivery at the end of November in the USA and here for delivery in January 2021 in the UK.