So why not fix pwgen? Remember the unix philosophy »tools should *do one thing*, and *do* it well«. If you think you can do a better job, then you should fork it.
Since entropy is a combination of size and distribution, random number generators play a major role for generating a good password, but password generators in software are not perfect. So a user should consider this and choose a large password x > 40. The entropy of pwgen is way better than thinking of a password yourself. The distribution generated by people is catastrophic compared to pwgen. On 17.12.2016 23:02, Antoine Beaupré wrote: > pwgen has a long history of generating insecure passphrases. up until > 2014 (pwgen 2.07, shipped only in Debian jessie, and Ubuntu Vivid) it > had two serious security vulnerabilities (CVE-2013-4440 and > CVE-2013-4442) that specifically affect pass. it still defaults to an > insecure "phoneme" password generation, although pass uses the more > secure "-s" flag. more information about those issues and more can be > found in those discussions: > > http://www.openwall.com/lists/oss-security/2012/01/22/6 > http://www.openwall.com/lists/oss-security/2013/05/24/7 > > it is still unclear how actually secure the `--secure` flag is: the > manpage doesn't say how much entropy is actually used to generate > passwords. (according to a quick review of the source code: each > character is chosen randomly based on a byte taken from the > non-blocking /dev/urandom PRNG, and not all bytes are used in some > cases, wasting possible entropy.) > > since we use pwgen only to generate passphrases, it seems reasonable > we generate those ourselves. generating passphrases is simple: take a > source of entropy (UNIX has /dev/random) and turn bytes into > transportable strings (UNIX has base64): > > head -c 18 /dev/random | base64 > > a 18 bytes password contains (naturally) 144 bits of entropy and > base64 turns that in a 25 character password, the current default > length in pass. 20 bytes may be better because we like to think in > round numbers, which would give us 160 bits of entropy and 28 > character passwords. we could even cram an extra byte in there to get > 168 bytes of entropy and keep 28 character passwords, but I chose to > retain the same default to make this patch more acceptable. > > base64 passwords are more portable and incur only a ~13% size increase > compared to original byte stream. we also have a more direct control > over the entropy level than what pwgen provides: we don't actually > know how much entropy a given pwgen password has, as it's > implementation specific. > > we depend on GNU coreutils' base46 command because its CLI is > different from the traditionnal BSD one (BSD requires -e or -d, GNU > refuses -e) - I assume this can be fixed in the BSD ports. > > this removes a dependency and encourages stronger passwords. > > ideally, the password generation program would be made configurable > instead of being hardcoded. that way people could use diceware, pwqgen > or other software more easily. > --- > README | 4 ++-- > contrib/emacs/password-store.el | 1 - > man/pass.1 | 12 +++++------- > src/completion/pass.bash-completion | 2 +- > src/completion/pass.fish-completion | 1 - > src/completion/pass.zsh-completion | 4 +--- > src/password-store.sh | 21 ++++++++++++--------- > 7 files changed, 21 insertions(+), 24 deletions(-) > > diff --git a/README b/README > index 1cc01b9..394d078 100644 > --- a/README > +++ b/README > @@ -21,8 +21,8 @@ Depends on: > http://www.git-scm.com/ > - xclip > http://sourceforge.net/projects/xclip/ > -- pwgen > - http://sourceforge.net/projects/pwgen/ > +- base64 from GNU coreutils > + http://www.gnu.org/software/coreutils/coreutils.html > - tree >= 1.7.0 > http://mama.indstate.edu/users/ice/tree/ > - GNU getopt > diff --git a/contrib/emacs/password-store.el b/contrib/emacs/password-store.el > index a1be788..0d12595 100644 > --- a/contrib/emacs/password-store.el > +++ b/contrib/emacs/password-store.el > @@ -104,7 +104,6 @@ outputs error message on failure." > (defun password-store--run-generate (entry password-length &optional force > no-symbols) > (password-store--run "generate" > (if force "--force") > - (if no-symbols "--no-symbols") > entry > (number-to-string password-length))) > > diff --git a/man/pass.1 b/man/pass.1 > index 33b6036..a47afc8 100644 > --- a/man/pass.1 > +++ b/man/pass.1 > @@ -111,12 +111,10 @@ ensure that temporary files are created in > \fI/dev/shm\fP in order to avoid writ > difficult-to-erase disk sectors. If \fI/dev/shm\fP is not accessible, > fallback to > the ordinary \fITMPDIR\fP location, and print a warning. > .TP > -\fBgenerate\fP [ \fI--no-symbols\fP, \fI-n\fP ] [ \fI--clip\fP, \fI-c\fP ] [ > \fI--in-place\fP, \fI-i\fP | \fI--force\fP, \fI-f\fP ] \fIpass-name > [pass-length]\fP > -Generate a new password using > -.BR pwgen (1) > -of length \fIpass-length\fP (or \fIPASSWORD_STORE_GENERATED_LENGTH\fP if > unspecified) > -and insert into \fIpass-name\fP. If \fI--no-symbols\fP or \fI-n\fP > -is specified, do not use any non-alphanumeric characters in the generated > password. > +\fBgenerate\fP [ \fI--clip\fP, \fI-c\fP ] [ \fI--in-place\fP, \fI-i\fP | > \fI--force\fP, \fI-f\fP ] \fIpass-name [pass-entropy]\fP > +Generate a new password of given entropy \fIpass-entropy\fP (or > \fIPASSWORD_STORE_GENERATED_ENTROPY\fP if unspecified) > +and insert into \fIpass-name\fP. Password is generated by extracting > +\fIpass-entropy\P bytes from \fI/dev/random\fP en base64 encoding them. > If \fI--clip\fP or \fI-c\fP is specified, do not print the password but > instead copy > it to the clipboard using > .BR xclip (1) > @@ -424,7 +422,7 @@ is unspecified. > The location of the text editor used by \fBedit\fP. > .SH SEE ALSO > .BR gpg2 (1), > -.BR pwgen (1), > +.BR base64 (1), > .BR git (1), > .BR xclip (1). > > diff --git a/src/completion/pass.bash-completion > b/src/completion/pass.bash-completion > index 456485b..fdc3fe6 100644 > --- a/src/completion/pass.bash-completion > +++ b/src/completion/pass.bash-completion > @@ -106,7 +106,7 @@ _pass() > _pass_complete_entries > ;; > generate) > - COMPREPLY+=($(compgen -W "-n --no-symbols -c > --clip -f --force -i --in-place" -- ${cur})) > + COMPREPLY+=($(compgen -W "-c --clip -f --force > -i --in-place" -- ${cur})) > _pass_complete_entries > ;; > cp|copy|mv|rename) > diff --git a/src/completion/pass.fish-completion > b/src/completion/pass.fish-completion > index c32a42c..25fa835 100644 > --- a/src/completion/pass.fish-completion > +++ b/src/completion/pass.fish-completion > @@ -74,7 +74,6 @@ complete -c $PROG -f -A -n '__fish_pass_uses_command > insert' -s f -l force -d 'D > complete -c $PROG -f -A -n '__fish_pass_uses_command insert' -a > "(__fish_pass_print_entry_dirs)" > > complete -c $PROG -f -A -n '__fish_pass_needs_command' -a generate -d > 'Command: generate new password' > -complete -c $PROG -f -A -n '__fish_pass_uses_command generate' -s n -l > no-symbols -d 'Do not use special symbols' > complete -c $PROG -f -A -n '__fish_pass_uses_command generate' -s c -l clip > -d 'Put the password in clipboard' > complete -c $PROG -f -A -n '__fish_pass_uses_command generate' -s f -l force > -d 'Do not prompt before overwritting' > complete -c $PROG -f -A -n '__fish_pass_uses_command generate' -s i -l > in-place -d 'Replace only the first line with the generated password' > diff --git a/src/completion/pass.zsh-completion > b/src/completion/pass.zsh-completion > index 27ce15a..06659c5 100644 > --- a/src/completion/pass.zsh-completion > +++ b/src/completion/pass.zsh-completion > @@ -48,8 +48,6 @@ _pass () { > ;; > generate) > _arguments : \ > - "-n[don't include symbols in password]" > \ > - "--no-symbols[don't include symbols in > password]" \ > "-c[copy password to the clipboard]" \ > "--clip[copy password to the > clipboard]" \ > "-f[force overwrite]" \ > @@ -97,7 +95,7 @@ _pass () { > "grep:Search inside decrypted password files for > matching pattern" > "show:Decrypt and print a password" > "insert:Insert a new password" > - "generate:Generate a new password using pwgen" > + "generate:Generate a new password" > "edit:Edit a password with \$EDITOR" > "mv:Rename the password" > "cp:Copy the password" > diff --git a/src/password-store.sh b/src/password-store.sh > index 63be840..8de4eac 100755 > --- a/src/password-store.sh > +++ b/src/password-store.sh > @@ -15,7 +15,9 @@ which gpg2 &>/dev/null && GPG="gpg2" > PREFIX="${PASSWORD_STORE_DIR:-$HOME/.password-store}" > X_SELECTION="${PASSWORD_STORE_X_SELECTION:-clipboard}" > CLIP_TIME="${PASSWORD_STORE_CLIP_TIME:-45}" > -GENERATED_LENGTH="${PASSWORD_STORE_GENERATED_LENGTH:-25}" > +# backwards compatibility > +PASSWORD_STORE_GENERATED_ENTROPY="${PASSWORD_STORE_GENERATED_LENGTH:-$PASSWORD_STORE_GENERATED_ENTROPY}" > +GENERATED_ENTROPY="${PASSWORD_STORE_GENERATED_ENTROPY:-18}" > > export GIT_DIR="${PASSWORD_STORE_GIT:-$PREFIX}/.git" > export GIT_WORK_TREE="${PASSWORD_STORE_GIT:-$PREFIX}" > @@ -235,8 +237,8 @@ cmd_usage() { > overwriting existing password unless forced. > $PROGRAM edit pass-name > Insert a new password or edit an existing password using > ${EDITOR:-vi}. > - $PROGRAM generate [--no-symbols,-n] [--clip,-c] [--in-place,-i | > --force,-f] pass-name [pass-length] > - Generate a new password of pass-length (or $GENERATED_LENGTH if > unspecified) with optionally no symbols. > + $PROGRAM generate [--clip,-c] [--in-place,-i | --force,-f] > pass-name [entropy] > + Generate a new password of given entropy (or $GENERATED_ENTROPY > if unspecified). > Optionally put it on the clipboard and clear board after > $CLIP_TIME seconds. > Prompt before overwriting existing password unless forced. > Optionally replace only the first line of an existing file with > a new password. > @@ -431,30 +433,31 @@ cmd_edit() { > } > > cmd_generate() { > - local opts clip=0 force=0 symbols="-y" inplace=0 > + local opts clip=0 force=0 symbols="" inplace=0 > opts="$($GETOPT -o ncif -l no-symbols,clip,in-place,force -n "$PROGRAM" > -- "$@")" > local err=$? > eval set -- "$opts" > while true; do case $1 in > - -n|--no-symbols) symbols=""; shift ;; > + -n|--no-symbols) echo '--no-symbols deprecated'; shift ;; > -c|--clip) clip=1; shift ;; > -f|--force) force=1; shift ;; > -i|--in-place) inplace=1; shift ;; > --) shift; break ;; > esac done > > - [[ $err -ne 0 || ( $# -ne 2 && $# -ne 1 ) || ( $force -eq 1 && $inplace > -eq 1 ) ]] && die "Usage: $PROGRAM $COMMAND [--no-symbols,-n] [--clip,-c] > [--in-place,-i | --force,-f] pass-name [pass-length]" > + [[ $err -ne 0 || ( $# -ne 2 && $# -ne 1 ) || ( $force -eq 1 && $inplace > -eq 1 ) ]] && die "Usage: $PROGRAM $COMMAND [--clip,-c] [--in-place,-i | > --force,-f] pass-name [pass-length]" > local path="$1" > - local length="${2:-$GENERATED_LENGTH}" > + local entropy="${2:-$GENERATED_ENTROPY}" > check_sneaky_paths "$path" > - [[ ! $length =~ ^[0-9]+$ ]] && die "Error: pass-length \"$length\" must > be a number." > + [[ ! $entropy =~ ^[0-9]+$ ]] && die "Error: pass-entropy \"$entropy\" > must be a number." > mkdir -p -v "$PREFIX/$(dirname "$path")" > set_gpg_recipients "$(dirname "$path")" > local passfile="$PREFIX/$path.gpg" > > [[ $inplace -eq 0 && $force -eq 0 && -e $passfile ]] && yesno "An entry > already exists for $path. Overwrite it?" > > - local pass="$(pwgen -s $symbols $length 1)" > + # strip possible newlines if output is wrapped and trailing = signs > as they add nothing to the password's entropy > + local pass="$(head -c $entropy /dev/random | base64 | tr -d '\n=')" > [[ -n $pass ]] || exit 1 > if [[ $inplace -eq 0 ]]; then > $GPG -e "${GPG_RECIPIENT_ARGS[@]}" -o "$passfile" > "${GPG_OPTS[@]}" <<<"$pass" || die "Password encryption aborted." _______________________________________________ Password-Store mailing list [email protected] https://lists.zx2c4.com/mailman/listinfo/password-store
