libwebsockets/scripts/mozilla-trust-gen.sh
Andy Green 2f9bb7a30a tls: JIT Trust
Add support for dynamically determining the CAs needed to validate server
certificates.  This allows you to avoid instantiating > 120 X.509 trusted
CA certs and have them take up heap the whole time.

Works for both openssl and mbedtls.

See READMEs/README.jit-trust.md for the documentation

You likely want the next patch for http redirect enhancements as well.
2021-06-22 15:55:29 +01:00

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#!/bin/bash
# This script fetches the current list of trusted CAs blessed by Mozilla
# for web tls validation, and processes it into two outputs
#
# - ./trust/webroot/* consisting of ./_trust/webroot/der a static, serveable set
# of trusted DER certs, with symlinks in ./_trust/webroot/by-skid and
# ./_trust/webroot/by-iss allowing serving the DER matching a given
# SubjectKeyIdentifier or Issuer + serial combination (suitably encoded)
#
# - ./_trust/blob-XXXX.bin a single blob containing indexes and DER CA certs
#
# - ./_trust/trust_blob.h a C uint8_t array formatted copy of blob-XXXX.bin
# The trust blob layout is currently
#
# 54 42 4c 42 Magic "TBLB"
# 00 01 MSB-first trust blob layout version
# XX XX MSB-first count of certificates
# XX XX XX XX MSB-first trust blob generation unix time
# XX XX XX XX MSB-first offset of cert length table (MSB-first 16-bit length-per-cert)
# XX XX XX XX MSB-first offset of SKID length table (8-bit length-per-cert)
# XX XX XX XX MSB-first offset of SKID table
# XX XX XX XX MSB-first total blob length
#
# XX .. XX DER certs (start at +0x1c)
# XX .. XX DER cert length table (MSB-first 16-bit per cert)
# XX .. XX SKID length table (8-bit per cert)
# XX .. XX SKID table (variable per cert)
#
echo "Mozilla trust bundle for TLS validation processing Andy Green <andy@warmcat.com>"
echo
rm -rf _trust
mkdir _trust
wget -O _trust/trusted.txt "https://ccadb-public.secure.force.com/mozilla/IncludedRootsPEMTxt?TrustBitsInclude=Websites"
#cp ~/Downloads/IncludedRootsPEM.txt _trust/trusted.txt
if [ $? -ne 0 ]; then
echo "Failed to get current website trust bundle"
exit 1
fi
mkdir -p _trust/webroot/by-skid _trust/webroot/by-iss _trust/webroot/der
echo 0 > _trust/ofs
echo 0 > _trust/count
echo 0 > _trust/skidtab
GT=`date +%s`
BN=_trust/blob-$GT.bin
cat _trust/trusted.txt | while read _line ; do
line=`echo -n $_line | sed 's/\r$//g'`
if [ "$line" == "-----BEGIN CERTIFICATE-----" ] ; then
echo $line > _trust/single
else
echo $line >> _trust/single
if [ "$line" == "-----END CERTIFICATE-----" ] ; then
openssl x509 -in _trust/single -text -noout > _trust/c1
if [ $? -ne 0 ] ; then
echo "FAILED"
exit 1
fi
ISS=`cat _trust/c1 | grep Issuer: | sed "s/.*://g" | sed "s/^\ *//g"`
SER=`cat _trust/c1 | grep "Serial Number:" | sed "s/.*://g" | sed "s/^\ *//g" | sed "s/\ .*//g"`
if [ -z "$SER" ] ; then
SER=`cat _trust/c1 | sed -e "1,/.*Serial Number:/ d" | head -n 1 | sed "s/^\ *//g" | sed "s/\ .*//g"`
fi
SKID=`cat _trust/c1 | sed -e '1,/.*X509v3 Subject Key Identifier:/ d' | sed -n '/Signature.*/q;p' | \
grep ':' | grep -v ': ' | grep -v ':$' | grep -v U | grep -v k | grep -v T | grep -v "i" | \
grep -v "S" | grep -v "V" | sed "s/^\ *//g"`
SKID_NO_COLONS=`echo -n $SKID | sed "s/://g"`
na=`cat _trust/c1 | grep "Not\ After\ :" | sed "s/.*\ :\ //g"`
ct=`date +%s`
ts=`date --date="$na" +%s`
life_days=`echo -n "$(( ( $ts - $ct ) / 86400 ))"`
echo "$life_days $safe" >> _trust/life
if [ $life_days -lt 1095 ] ; then
echo "$life_days $safe" >> _trust/life_lt_3y
fi
echo "issuer=\"$ISS\", serial=\"${SER^^}\", skid=\"${SKID_NO_COLONS^^}\", life_days=\"${life_days}\""
issname=`echo -n "$ISS"_"$SER" | tr -cd '[a-zA-Z0-9]_'`
skidname=`echo -n "$SKID_NO_COLONS" | tr -cd '[a-zA-Z0-9]_'`
safe=$issname"_"$skidname
cat _trust/single | grep -v -- '---' | base64 -d > _trust/webroot/der/$safe
cd _trust/webroot/by-skid
ln -sf ../der/$safe $SKID_NO_COLONS
cd ../../..
cd _trust/webroot/by-iss
ln -sf ../der/$safe $issname
cd ../../..
DERSIZ=`cat _trust/single | grep -v -- '---' | base64 -d | wc -c | cut -d' ' -f1`
cat _trust/single | grep -v -- '---' | base64 -d | hexdump -C | tr -s ' ' | sed 's/\ $//g' | \
cut -d' ' -f 2-17 | cut -d'|' -f1 | grep -v 000 | sed "s/\ //g" | sed ':a;N;$!ba;s/\n//g' | xxd -r -p >> _trust/_ders
printf "%04x" $DERSIZ | xxd -r -p >> _trust/_derlens
echo $SKID
if [ ! -z "$SKID" ] ; then
echo -n "$SKID_NO_COLONS" | xxd -r -p >> _trust/_skid
fi
SKIDSIZ=`echo -n $SKID_NO_COLONS | xxd -r -p | wc -c | cut -d' ' -f1`
printf "%02x" $SKIDSIZ | xxd -r -p >> _trust/_skidlens
OFS=`cat _trust/ofs`
echo -n $(( $OFS + $DERSIZ )) > _trust/ofs
COUNT=`cat _trust/count`
echo -n $(( $COUNT +1 )) > _trust/count
ST=`cat _trust/skidtab`
echo -n $(( $ST + ( `echo -n $skidname | wc -c | cut -d' ' -f1` / 2 ) )) > _trust/skidtab
rm -f _trust/single
fi
fi
done
COUNT=`cat _trust/count`
OFS=`cat _trust/ofs`
ST=`cat _trust/skidtab`
# everything in the layout framing is MSB-first
# magic
echo -n "TBLB" > $BN
# blob layout version
echo -n 0001 | xxd -r -p >> $BN
# number of certs in the blob
printf "%04x" $COUNT | xxd -r -p >> $BN
# unix time blob was created
printf "%08x" $GT | xxd -r -p >> $BN
POS=28
POS=$(( $POS + `cat _trust/_ders | wc -c | cut -d' ' -f1` ))
# blob offset of start of cert length table
printf "%08x" $POS | xxd -r -p >> $BN
POS=$(( $POS + `cat _trust/_derlens | wc -c | cut -d' ' -f1` ))
# blob offset of start of SKID length table
printf "%08x" $POS | xxd -r -p >> $BN
POS=$(( $POS + `cat _trust/_skidlens | wc -c | cut -d' ' -f1` ))
# blob offset of start of SKID table
printf "%08x" $POS | xxd -r -p >> $BN
POS=$(( $POS + `cat _trust/_skid | wc -c | cut -d' ' -f1` ))
# blob total length
printf "%08x" $POS | xxd -r -p >> $BN
# the DER table, start at +0x1c
cat _trust/_ders >> $BN
# the DER length table
cat _trust/_derlens >> $BN
# the SKID length table
cat _trust/_skidlens >> $BN
# the SKID table
cat _trust/_skid >> $BN
# produce a C-friendly version of the blob
cat $BN | hexdump -v -C | tr -s ' ' | sed 's/\ $//g' | \
cut -d' ' -f 2-17 | cut -d'|' -f1 | grep -v 000 | sed "s/\ /,\ 0x/g" | sed "s/^/0x/g" | \
sed 's/\, 0x$//g' | sed 's/$/,/g' >> _trust/trust_blob.h
echo
echo "$COUNT CA certs, $POS byte blob"
echo
echo "CAs expiring in less than 3 years (days left):"
sort -h _trust/life_lt_3y
rm -f _trust/count _trust/_idx _trust/_idx_skid _trust/ofs _trust/_skid _trust/skidtab _trust/life _trust/life_lt_3y _trust/c1 _trust/single _trust/_derlens _trust/_ders _trust/_skid _trust/_skidlens
exit 0