From 05a16147fb39fb323ecdf2b53f175816196eb9d7 Mon Sep 17 00:00:00 2001
From: Kyle Evans <kevans@FreeBSD.org>
Date: Wed, 9 Sep 2020 09:08:09 +0000
Subject: [PATCH] certctl: fix hashed link generation with duplicate subjects

Currently, certctl rehash will just keep clobbering .0 rather than
incrementing the suffix upon encountering a duplicate. Do this, and do it
for blacklisted certs as well.

This also improves the situation with the blacklist to be a little less
flakey, comparing cert fingerprints for all certs with a matching subject
hash in the blacklist to determine if the cert we're looking at can be
installed.

Future work needs to completely revamp the blacklist to align more with how
it's described in PR 246614. In particular, /etc/ssl/blacklisted should go
away to avoid potential confusion -- OpenSSL will not read it, it's
basically certctl internal.

PR:		246614
Reviewed by:	Michael Osipov <michael.osipov siemens com>
Tested by:	Michael Osipov
With suggestions from:	Michael Osipov
MFC after:	1 week
Differential Revision:	https://reviews.freebsd.org/D26167
---
 usr.sbin/certctl/certctl.sh | 61 ++++++++++++++++++++++++++++---------
 1 file changed, 47 insertions(+), 14 deletions(-)

diff --git a/usr.sbin/certctl/certctl.sh b/usr.sbin/certctl/certctl.sh
index aaddfeb3115b..b687a7706041 100755
--- a/usr.sbin/certctl/certctl.sh
+++ b/usr.sbin/certctl/certctl.sh
@@ -30,7 +30,7 @@
 ############################################################ CONFIGURATION
 
 : ${DESTDIR:=}
-: ${FILEPAT:="\.pem$|\.crt$|\.cer$|\.crl$|\.0$"}
+: ${FILEPAT:="\.pem$|\.crt$|\.cer$|\.crl$"}
 : ${VERBOSE:=0}
 
 ############################################################ GLOBALS
@@ -56,31 +56,58 @@ do_hash()
 	fi
 }
 
+get_decimal()
+{
+	local checkdir hash decimal
+
+	checkdir=$1
+	hash=$2
+	decimal=0
+
+	while [ -e "$checkdir/$hash.$decimal" ]; do
+		decimal=$((decimal + 1))
+	done
+
+	echo ${decimal}
+	return 0
+}
+
 create_trusted_link()
 {
-	local hash
+	local blisthash certhash hash
+	local suffix
 
 	hash=$( do_hash "$1" ) || return
-	if [ -e "$BLACKLISTDESTDIR/$hash.0" ]; then
-		echo "Skipping blacklisted certificate $1 ($BLACKLISTDESTDIR/$hash.0)"
-		return 1
-	fi
-	[ $VERBOSE -gt 0 ] && echo "Adding $hash.0 to trust store"
-	[ $NOOP -eq 0 ] && install ${INSTALLFLAGS} -lrs $(realpath "$1") "$CERTDESTDIR/$hash.0"
+	certhash=$( openssl x509 -sha1 -in "$1" -noout -fingerprint )
+	for blistfile in $(find $BLACKLISTDESTDIR -name "$hash.*"); do
+		blisthash=$( openssl x509 -sha1 -in "$blistfile" -noout -fingerprint )
+		if [ "$certhash" = "$blisthash" ]; then
+			echo "Skipping blacklisted certificate $1 ($blistfile)"
+			return 1
+		fi
+	done
+	suffix=$(get_decimal "$CERTDESTDIR" "$hash")
+	[ $VERBOSE -gt 0 ] && echo "Adding $hash.$suffix to trust store"
+	[ $NOOP -eq 0 ] && \
+		install ${INSTALLFLAGS} -lrs $(realpath "$1") "$CERTDESTDIR/$hash.$suffix"
 }
 
 create_blacklisted()
 {
 	local hash srcfile filename
+	local suffix
 
 	# If it exists as a file, we'll try that; otherwise, we'll scan
 	if [ -e "$1" ]; then
 		hash=$( do_hash "$1" ) || return
 		srcfile=$(realpath "$1")
-		filename="$hash.0"
+		suffix=$(get_decimal "$BLACKLISTDESTDIR" "$hash")
+		filename="$hash.$suffix"
 	elif [ -e "${CERTDESTDIR}/$1" ];  then
 		srcfile=$(realpath "${CERTDESTDIR}/$1")
-		filename="$1"
+		hash=$(echo "$1" | sed -Ee 's/\.([0-9])+$//')
+		suffix=$(get_decimal "$BLACKLISTDESTDIR" "$hash")
+		filename="$hash.$suffix"
 	else
 		return
 	fi
@@ -115,7 +142,7 @@ do_list()
 
 	if [ -e "$1" ]; then
 		cd "$1"
-		for CFILE in *.0; do
+		for CFILE in *.[0-9]; do
 			if [ ! -s "$CFILE" ]; then
 				echo "Unable to read $CFILE" >&2
 				ERRORS=$(( $ERRORS + 1 ))
@@ -174,14 +201,20 @@ cmd_blacklist()
 
 cmd_unblacklist()
 {
-	local BFILE hash
+	local BFILE blisthash certhash hash
 
 	shift # verb
 	for BFILE in "$@"; do
 		if [ -s "$BFILE" ]; then
 			hash=$( do_hash "$BFILE" )
-			echo "Removing $hash.0 from blacklist"
-			[ $NOOP -eq 0 ] && rm -f "$BLACKLISTDESTDIR/$hash.0"
+			certhash=$( openssl x509 -sha1 -in "$BFILE" -noout -fingerprint )
+			for BLISTEDFILE in $(find $BLACKLISTDESTDIR -name "$hash.*"); do
+				blisthash=$( openssl x509 -sha1 -in "$BLISTEDFILE" -noout -fingerprint )
+				if [ "$certhash" = "$blisthash" ]; then
+					echo "Removing $(basename "$BLISTEDFILE") from blacklist"
+					[ $NOOP -eq 0 ] && rm -f $BLISTEDFILE
+				fi
+			done
 		elif [ -e "$BLACKLISTDESTDIR/$BFILE" ]; then
 			echo "Removing $BFILE from blacklist"
 			[ $NOOP -eq 0 ] && rm -f "$BLACKLISTDESTDIR/$BFILE"