various improvements in bash comments

This commit is contained in:
Joshua Tauberer 2014-10-13 10:00:26 -04:00
parent 06e074bd32
commit 0b5bf602aa
6 changed files with 84 additions and 46 deletions

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@ -1,5 +1,5 @@
# OpenDKIM
# ========
# --------
#
# OpenDKIM provides a service that puts a DKIM signature on outbound mail.
#

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@ -39,7 +39,9 @@ mkdir -p /var/run/nsd
mkdir -p "$STORAGE_ROOT/dns/dnssec";
# TLDs don't all support the same algorithms, so we'll generate keys using a few
# different algorithms.
# different algorithms. RSASHA1-NSEC3-SHA1 was possibly the first widely used
# algorithm that supported NSEC3, which is a security best practice. However TLDs
# will probably be moving away from it to a a SHA256-based algorithm.
#
# Supports `RSASHA1-NSEC3-SHA1` (didn't test with `RSASHA256`):
#
@ -58,11 +60,9 @@ if [ ! -f "$STORAGE_ROOT/dns/dnssec/$algo.conf" ]; then
FIRST=0 #NODOC
fi
# Create the Key-Signing Key (KSK) (-k) which is the so-called
# Secure Entry Point. Use a NSEC3-compatible algorithm (best
# practice), and a nice and long keylength. The domain name we
# provide ("_domain_") doesn't matter -- we'll use the same
# keys for all our domains.
# Create the Key-Signing Key (KSK) (with `-k`) which is the so-called
# Secure Entry Point. The domain name we provide ("_domain_") doesn't
# matter -- we'll use the same keys for all our domains.
#
# `ldns-keygen` outputs the new key's filename to stdout, which
# we're capturing into the `KSK` variable.
@ -71,13 +71,13 @@ if [ ! -f "$STORAGE_ROOT/dns/dnssec/$algo.conf" ]; then
# Now create a Zone-Signing Key (ZSK) which is expected to be
# rotated more often than a KSK, although we have no plans to
# rotate it (and doing so would be difficult to do without
# disturbing DNS availability.) Omit '-k' and use a shorter key.
# disturbing DNS availability.) Omit `-k` and use a shorter key length.
ZSK=$(umask 077; cd $STORAGE_ROOT/dns/dnssec; ldns-keygen -a $algo -b 1024 _domain_);
# These generate two sets of files like:
#
# * `K_domain_.+007+08882.ds`: DS record normally provided to domain name registrar (but it's actually invalid with "_domain_")
# * `K_domain_.+007+08882.key`: public key (goes into DS record & upstream DNS provider like your registrar)
# * `K_domain_.+007+08882.ds`: DS record normally provided to domain name registrar (but it's actually invalid with `_domain_`)
# * `K_domain_.+007+08882.key`: public key
# * `K_domain_.+007+08882.private`: private key (secret!)
# The filenames are unpredictable and encode the key generation

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@ -52,8 +52,9 @@ tools/editconf.py /etc/dovecot/conf.d/10-ssl.conf \
"ssl_protocols=!SSLv3 !SSLv2" \
"ssl_cipher_list=TLSv1+HIGH !SSLv2 !RC4 !aNULL !eNULL !3DES @STRENGTH"
# Disable in-the-clear IMAP and POP because we're paranoid (we haven't even
# enabled POP).
# Disable in-the-clear IMAP because there is no reason for a user to transmit
# login credentials outside of an encrypted connection. Although we haven't
# even installed the POP server, ensure it is disabled too.
sed -i "s/#port = 143/port = 0/" /etc/dovecot/conf.d/10-master.conf
sed -i "s/#port = 110/port = 0/" /etc/dovecot/conf.d/10-master.conf

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@ -63,7 +63,7 @@ tools/editconf.py /etc/postfix/main.cf \
# Enable the 'submission' port 587 smtpd server and tweak its settings.
#
# * Require the best ciphers for incoming connections per http://baldric.net/2013/12/07/tls-ciphers-in-postfix-and-dovecot/.
# but without affecting opportunistic TLS on incoming mail, which will allow any cipher (it's better than none).
# By putting this setting here we leave opportunistic TLS on incoming mail at default cipher settings (any cipher is better than none).
# * Give it a different name in syslog to distinguish it from the port 25 smtpd server.
# * Add a new cleanup service specific to the submission service ('authclean')
# that filters out privacy-sensitive headers on mail being sent out by
@ -96,9 +96,9 @@ tools/editconf.py /etc/postfix/main.cf \
# relayed elsewhere. We don't want to be an "open relay". On outbound
# mail, require one of:
#
# * permit_sasl_authenticated: Authenticated users (i.e. on port 587).
# * permit_mynetworks: Mail that originates locally.
# * reject_unauth_destination: No one else. (Permits mail whose destination is local and rejects other mail.)
# * `permit_sasl_authenticated`: Authenticated users (i.e. on port 587).
# * `permit_mynetworks`: Mail that originates locally.
# * `reject_unauth_destination`: No one else. (Permits mail whose destination is local and rejects other mail.)
tools/editconf.py /etc/postfix/main.cf \
smtpd_relay_restrictions=permit_sasl_authenticated,permit_mynetworks,reject_unauth_destination
@ -142,20 +142,20 @@ tools/editconf.py /etc/postfix/main.cf virtual_transport=lmtp:[127.0.0.1]:10025
# Who can send mail to us? Some basic filters.
#
# * reject_non_fqdn_sender: Reject not-nice-looking return paths.
# * reject_unknown_sender_domain: Reject return paths with invalid domains.
# * reject_rhsbl_sender: Reject return paths that use blacklisted domains.
# * permit_sasl_authenticated: Authenticated users (i.e. on port 587) can skip further checks.
# * permit_mynetworks: Mail that originates locally can skip further checks.
# * reject_rbl_client: Reject connections from IP addresses blacklisted in zen.spamhaus.org
# * reject_unlisted_recipient: Although Postfix will reject mail to unknown recipients, it's nicer to reject such mail ahead of greylisting rather than after.
# * check_policy_service: Apply greylisting using postgrey.
# * `reject_non_fqdn_sender`: Reject not-nice-looking return paths.
# * `reject_unknown_sender_domain`: Reject return paths with invalid domains.
# * `reject_rhsbl_sender`: Reject return paths that use blacklisted domains.
# * `permit_sasl_authenticated`: Authenticated users (i.e. on port 587) can skip further checks.
# * `permit_mynetworks`: Mail that originates locally can skip further checks.
# * `reject_rbl_client`: Reject connections from IP addresses blacklisted in zen.spamhaus.org
# * `reject_unlisted_recipient`: Although Postfix will reject mail to unknown recipients, it's nicer to reject such mail ahead of greylisting rather than after.
# * `check_policy_service`: Apply greylisting using postgrey.
#
# Notes:
# permit_dnswl_client can pass through mail from whitelisted IP addresses, which would be good to put before greylisting
# so these IPs get mail delivered quickly. But when an IP is not listed in the permit_dnswl_client list (i.e. it is not
# whitelisted) then postfix does a DEFER_IF_REJECT, which results in all "unknown user" sorts of messages turning into
# "450 4.7.1 Client host rejected: Service unavailable". This is a retry code, so the mail doesn't properly bounce.
# Notes: #NODOC
# permit_dnswl_client can pass through mail from whitelisted IP addresses, which would be good to put before greylisting #NODOC
# so these IPs get mail delivered quickly. But when an IP is not listed in the permit_dnswl_client list (i.e. it is not #NODOC
# whitelisted) then postfix does a DEFER_IF_REJECT, which results in all "unknown user" sorts of messages turning into #NODOC
# "450 4.7.1 Client host rejected: Service unavailable". This is a retry code, so the mail doesn't properly bounce. #NODOC
tools/editconf.py /etc/postfix/main.cf \
smtpd_sender_restrictions="reject_non_fqdn_sender,reject_unknown_sender_domain,reject_rhsbl_sender dbl.spamhaus.org" \
smtpd_recipient_restrictions=permit_sasl_authenticated,permit_mynetworks,"reject_rbl_client zen.spamhaus.org",reject_unlisted_recipient,"check_policy_service inet:127.0.0.1:10023"

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@ -1,6 +1,6 @@
#!/bin/bash
# Spam filtering with spamassassin via spampd
# ===========================================
# -------------------------------------------
#
# spampd sits between postfix and dovecot. It takes mail from postfix
# over the LMTP protocol, runs spamassassin on it, and then passes the

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@ -67,6 +67,10 @@ def generate_documentation():
padding-bottom: 1em;
}
ul {
padding-left: 1.25em;
}
pre {
color: black;
border: 0;
@ -82,7 +86,7 @@ def generate_documentation():
margin: 0;
}
div.write-to .filename {
padding: .25em;
padding: .25em .5em;
background-color: #666;
color: white;
font-family: monospace;
@ -94,7 +98,7 @@ def generate_documentation():
}
div.write-to pre {
margin: 0;
padding: .25em;
padding: .5em;
border: 1px solid #999;
border-radius: 0;
font-size: 90%;
@ -197,11 +201,11 @@ class HideOutput(Grammar):
def value(self):
return self[1].value()
class SuppressedLine(Grammar):
class EchoLine(Grammar):
grammar = (OPTIONAL(SPACE), L("echo "), REST_OF_LINE, EOL)
def value(self):
if "|" in self.string or ">" in self.string:
return "<pre class='shell'><div>" + cgi.escape(self.string.strip()) + "</div></pre>\n"
return "<pre class='shell'><div>" + recode_bash(self.string.strip()) + "</div></pre>\n"
return ""
class EditConf(Grammar):
@ -244,10 +248,10 @@ class EchoPipe(Grammar):
grammar = OPTIONAL(SPACE), L("echo "), REST_OF_LINE, L(' | '), REST_OF_LINE, EOL
def value(self):
text = " ".join("\"%s\"" % s for s in self[2].string.split(" "))
return "<pre class='shell'><div>echo " + cgi.escape(text) + " \<br> | " + self[4].string + "</div></pre>\n"
return "<pre class='shell'><div>echo " + recode_bash(text) + " \<br> | " + recode_bash(self[4].string) + "</div></pre>\n"
def shell_line(bash):
return "<pre class='shell'><div>" + cgi.escape(bash.strip()) + "</div></pre>\n"
return "<pre class='shell'><div>" + recode_bash(bash.strip()) + "</div></pre>\n"
class AptGet(Grammar):
grammar = (ZERO_OR_MORE(SPACE), L("apt_install "), REST_OF_LINE, EOL)
@ -268,18 +272,25 @@ class OtherLine(Grammar):
if self.string.strip() == "": return ""
if "source setup/functions.sh" in self.string: return ""
if "source /etc/mailinabox.conf" in self.string: return ""
return "<pre class='shell'><div>" + cgi.escape(self.string.strip()) + "</div></pre>\n"
return "<pre class='shell'><div>" + recode_bash(self.string.strip()) + "</div></pre>\n"
class BashElement(Grammar):
grammar = Comment | CatEOF | EchoPipe | SuppressedLine | HideOutput | EditConf | SedReplace | AptGet | UfwAllow | RestartService | OtherLine
grammar = Comment | CatEOF | EchoPipe | EchoLine | HideOutput | EditConf | SedReplace | AptGet | UfwAllow | RestartService | OtherLine
def value(self):
return self[0].value()
# Make some special characters to private use Unicode code points.
bash_special_characters = {
bash_special_characters1 = {
"\n": "\uE000",
" ": "\uE001",
}
bash_special_characters2 = {
"$": "\uE010",
}
bash_escapes = {
"n": "\uE020",
"t": "\uE021",
}
def quasitokenize(bashscript):
# Make a parse of bash easier by making the tokenization easy.
@ -297,11 +308,13 @@ def quasitokenize(bashscript):
elif escape_next:
# Previous character was a \. Normally the next character
# comes through literally, but escaped newlines are line
# continuations.
# continuations and some escapes are for special characters
# which we'll recode and then turn back into escapes later.
if c == "\n":
c = " "
else:
newscript += c
elif c in bash_escapes:
c = bash_escapes[c]
newscript += c
escape_next = False
elif c == "\\":
# Escaping next character.
@ -312,10 +325,10 @@ def quasitokenize(bashscript):
elif c == quote_mode:
# Ending a quoted word.
quote_mode = None
elif quote_mode is not None and quote_mode != "EOF" and c in bash_special_characters:
elif quote_mode is not None and quote_mode != "EOF" and c in bash_special_characters1:
# Replace special tokens within quoted words so that they
# don't interfere with tokenization later.
newscript += bash_special_characters[c]
newscript += bash_special_characters1[c]
elif quote_mode is None and c == '#':
# Start of a line comment.
newscript += c
@ -335,6 +348,12 @@ def quasitokenize(bashscript):
# Make these just spaces.
if newscript[-1] != " ":
newscript += " "
elif quote_mode is None and c == ' ':
# Collapse consecutive spaces.
if newscript[-1] != " ":
newscript += " "
elif c in bash_special_characters2:
newscript += bash_special_characters2[c]
else:
# All other characters.
newscript += c
@ -347,9 +366,27 @@ def quasitokenize(bashscript):
return newscript
def recode_bash(s):
def requote(tok):
tok = tok.replace("\\", "\\\\")
for c in bash_special_characters2:
tok = tok.replace(c, "\\" + c)
tok = fixup_tokens(tok)
if " " in tok or '"' in tok:
tok = tok.replace("\"", "\\\"")
tok = '"' + tok +'"'
else:
tok = tok.replace("'", "\\'")
return tok
return cgi.escape(" ".join(requote(tok) for tok in s.split(" ")))
def fixup_tokens(s):
for c, enc in bash_special_characters.items():
for c, enc in bash_special_characters1.items():
s = s.replace(enc, c)
for c, enc in bash_special_characters2.items():
s = s.replace(enc, c)
for esc, c in bash_escapes.items():
s = s.replace(c, "\\" + esc)
return s
class BashScript(Grammar):
@ -364,7 +401,7 @@ class BashScript(Grammar):
# tokenize
string = re.sub(".* #NODOC\n", "", string)
string = re.sub("\n\s*if .*\n.*then.*|\n\s*fi|\n\s*else|\n\s*elif .*", "", string)
string = re.sub("\n\s*if .*then.*|\n\s*fi|\n\s*else|\n\s*elif .*", "", string)
string = quasitokenize(string)
string = re.sub("hide_output ", "", string)