From 9ada868f43050020e2bcc20a2e978bdeddf9e2f4 Mon Sep 17 00:00:00 2001
From: Charles Herlin <charles.herlin@corp.ovh.com>
Date: Fri, 1 Mar 2019 12:12:42 +0100
Subject: [PATCH] IMP(8.2.4): add exceptions in check and apply

Apply shellcheck recommendations
---
 bin/hardening/8.2.4_set_logfile_perm.sh   | 101 ++++++++++++++++------
 tests/hardening/8.2.4_set_logfile_perm.sh |  19 +++-
 2 files changed, 92 insertions(+), 28 deletions(-)

diff --git a/bin/hardening/8.2.4_set_logfile_perm.sh b/bin/hardening/8.2.4_set_logfile_perm.sh
index 7d0ed25..72257e5 100755
--- a/bin/hardening/8.2.4_set_logfile_perm.sh
+++ b/bin/hardening/8.2.4_set_logfile_perm.sh
@@ -1,5 +1,6 @@
 #!/bin/bash
 
+# run-shellcheck
 #
 # CIS Debian Hardening
 #
@@ -11,33 +12,54 @@
 set -e # One error, it's over
 set -u # One variable unset, it's over
 
+# shellcheck disable=2034
 HARDENING_LEVEL=3
+# shellcheck disable=2034
 DESCRIPTION="Create and set permissions on syslog-ng logfiles."
 
-PERMISSIONS='640'
-USER='root'
-GROUP='adm'
+PERMISSIONS=''
+USER=''
+GROUP=''
+EXCEPTIONS=''
 
 # This function will be called if the script status is on enabled / audit mode
 audit () {
-    FILES=$(grep "file(" $SYSLOG_BASEDIR/syslog-ng.conf | grep '"' | cut -d'"' -f 2)
+    FILES=$(grep "file(" "$SYSLOG_BASEDIR"/syslog-ng.conf | grep '"' | cut -d'"' -f 2)
     for FILE in $FILES; do
-        does_file_exist $FILE
-        if [ $FNRET != 0 ]; then
+        does_file_exist "$FILE"
+        if [ "$FNRET" != 0 ]; then
             warn "$FILE does not exist"
         else
-            has_file_correct_ownership $FILE $USER $GROUP
-            if [ $FNRET = 0 ]; then
-                ok "$FILE has correct ownership"
+            FOUND_EXC=0
+            if grep "$FILE" <(tr ' ' '\n' <<< "$EXCEPTIONS" | cut -d ":" -f 1); then
+                debug "$FILE is found in exceptions"
+                debug "Setting special user:group:perm"
+                FOUND_EXC=1
+                local user_bak="$USER"
+                local group_bak="$GROUP"
+                local perm_bak="$PERMISSIONS"
+                USER="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 2)"
+                GROUP="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 3)"
+                PERMISSIONS="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 4)"
+            fi
+            has_file_correct_ownership "$FILE" "$USER" "$GROUP"
+            if [ "$FNRET" = 0 ]; then
+                ok "$FILE has correct ownership ($USER:$GROUP)"
             else
                 crit "$FILE ownership was not set to $USER:$GROUP"
             fi
-            has_file_correct_permissions $FILE $PERMISSIONS
-            if [ $FNRET = 0 ]; then
-                ok "$FILE has correct permissions"
+            has_file_correct_permissions "$FILE" "$PERMISSIONS"
+            if [ "$FNRET" = 0 ]; then
+                ok "$FILE has correct permissions ($PERMISSIONS)"
             else
                 crit "$FILE permissions were not set to $PERMISSIONS"
-            fi 
+            fi
+            if [ "$FOUND_EXC" = 1 ]; then
+                debug "Resetting user:group:perm"
+                USER="$user_bak"
+                GROUP="$group_bak"
+                PERMISSIONS="$perm_bak"
+            fi
         fi
     done
 }
@@ -45,24 +67,42 @@ audit () {
 # This function will be called if the script status is on enabled mode
 apply () {
     for FILE in $FILES; do
-        does_file_exist $FILE
-        if [ $FNRET != 0 ]; then
+        does_file_exist "$FILE"
+        if [ "$FNRET" != 0 ]; then
             info "$FILE does not exist"
-            touch $FILE
+            touch "$FILE"
         fi
-        has_file_correct_ownership $FILE $USER $GROUP
-        if [ $FNRET = 0 ]; then
+        FOUND_EXC=0
+        if grep "$FILE" <(tr ' ' '\n' <<< "$EXCEPTIONS" | cut -d ":" -f 1); then
+            debug "$FILE is found in exceptions"
+            debug "Setting special user:group:perm"
+            FOUND_EXC=1
+            local user_bak="$USER"
+            local group_bak="$GROUP"
+            local perm_bak="$PERMISSIONS"
+            USER="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 2)"
+            GROUP="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 3)"
+            PERMISSIONS="$(tr ' ' '\n' <<< "$EXCEPTIONS" | grep "$FILE" | cut -d':' -f 4)"
+        fi
+        has_file_correct_ownership "$FILE" "$USER" "$GROUP"
+        if [ "$FNRET" = 0 ]; then
             ok "$FILE has correct ownership"
         else
             warn "fixing $FILE ownership to $USER:$GROUP"
-            chown $USER:$GROUP $FILE
+            chown "$USER":"$GROUP" "$FILE"
         fi
-        has_file_correct_permissions $FILE $PERMISSIONS
-        if [ $FNRET = 0 ]; then
+        has_file_correct_permissions "$FILE" "$PERMISSIONS"
+        if [ "$FNRET" = 0 ]; then
             ok "$FILE has correct permissions"
         else
             info "fixing $FILE permissions to $PERMISSIONS"
-            chmod 0$PERMISSIONS $FILE
+            chmod 0"$PERMISSIONS" "$FILE"
+        fi
+        if [ "$FOUND_EXC" = 1 ]; then
+            debug "Resetting user:group:perm"
+            USER="$user_bak"
+            GROUP="$group_bak"
+            PERMISSIONS="$perm_bak"
         fi
     done
 }
@@ -72,18 +112,24 @@ create_config() {
     cat <<EOF
 status=audit
 SYSLOG_BASEDIR='/etc/syslog-ng'
+PERMISSIONS='640'
+USER='root'
+GROUP='adm'
+# Put exceptions here with file:user:group:permissions
+# example: /dev/null:root:root:666
+EXCEPTIONS=''
 EOF
 }
 
 # This function will check config parameters required
 check_config() {
-    does_user_exist $USER
-    if [ $FNRET != 0 ]; then
+    does_user_exist "$USER"
+    if [ "$FNRET" != 0 ]; then
         crit "$USER does not exist"
         exit 128
     fi
     does_group_exist $GROUP
-    if [ $FNRET != 0 ]; then
+    if [ "$FNRET" != 0 ]; then
         crit "$GROUP does not exist"
         exit 128
     fi
@@ -100,8 +146,9 @@ if [ -z "$CIS_ROOT_DIR" ]; then
 fi
 
 # Main function, will call the proper functions given the configuration (audit, enabled, disabled)
-if [ -r $CIS_ROOT_DIR/lib/main.sh ]; then
-    . $CIS_ROOT_DIR/lib/main.sh
+if [ -r "$CIS_ROOT_DIR"/lib/main.sh ]; then
+    # shellcheck source=/opt/debian-cis/lib/main.sh
+    . "$CIS_ROOT_DIR"/lib/main.sh
 else
     echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_ROOT_DIR in /etc/default/cis-hardening"
     exit 128
diff --git a/tests/hardening/8.2.4_set_logfile_perm.sh b/tests/hardening/8.2.4_set_logfile_perm.sh
index b333419..c5fc1a6 100644
--- a/tests/hardening/8.2.4_set_logfile_perm.sh
+++ b/tests/hardening/8.2.4_set_logfile_perm.sh
@@ -6,5 +6,22 @@ test_audit() {
     # shellcheck disable=2154
     run blank /opt/debian-cis/bin/hardening/"${script}".sh --audit-all
 
-    # TODO fill comprehensive tests
+
+    describe Creating failed state
+    touch /var/log/auth.log
+    touch /var/log/kern.log
+    register_test retvalshouldbe 1
+    run failing /opt/debian-cis/bin/hardening/"${script}".sh --audit-all
+
+    describe Setting exceptions
+    echo 'EXCEPTIONS=/var/log/auth.log:root:root:600' >> /opt/debian-cis/etc/conf.d/"${script}".cfg
+    register_test retvalshouldbe 1
+    run excepandfail /opt/debian-cis/bin/hardening/"${script}".sh --audit-all
+
+    describe Correcting situation
+    sed -i 's/audit/enabled/' /opt/debian-cis/etc/conf.d/"${script}".cfg
+    /opt/debian-cis/bin/hardening/"${script}".sh || true
+
+    register_test retvalshouldbe 0
+    run resolved /opt/debian-cis/bin/hardening/"${script}".sh --audit-all
 }