[COMMON] Fix ${!name} bashisms

pointed out by checkbashisms.

Note this kind of indirections can only be replaced directly in POSIX
by commands using eval.
Security risks must be evaluated for each context where eval is called.
For a safe use, the context must ensure that only a limited number of
possible constrainted values are passed to eval.

https://mywiki.wooledge.org/Bashism#Parameter_Expansions
https://mywiki.wooledge.org/BashFAQ/006#Indirection

Issue-ID: OOM-264
Signed-off-by: Guillaume Lambert <guillaume.lambert@orange.com>
Change-Id: Id27f3ffd1ddb092a9c038d3a45d9e3278720eb62

3 files changed, 23 insertions, 6 deletions

diff --git a/kubernetes/common/cassandra/resources/config/docker-entrypoint.sh b/kubernetes/common/cassandra/resources/config/docker-entrypoint.sh
index 5b652228a6..ff1908c1bb 100644
--- a/kubernetes/common/cassandra/resources/config/docker-entrypoint.sh
+++ b/kubernetes/common/cassandra/resources/config/docker-entrypoint.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+
 set -e
 
 # first arg is `-f` or `--some-option`
@@ -71,7 +72,8 @@ if [ "$1" = 'cassandra' ]; then
                 authenticator \
         ; do
                 var="CASSANDRA_${yaml^^}"
-                val="${!var}"
+                # eval presents no security issue here because of limited possible values of var
+                eval val=\$$var
                 if [ "$val" ]; then
                         _sed-in-place "$CASSANDRA_CONFIG/cassandra.yaml" \
                                 -r 's/^(# )?('"$yaml"':).*/\2 '"$val"'/'
@@ -80,7 +82,8 @@ if [ "$1" = 'cassandra' ]; then
 
         for rackdc in dc rack; do
                 var="CASSANDRA_${rackdc^^}"
-                val="${!var}"
+                # eval presents no security issue here because of limited possible values of var
+                eval val=\$$var
                 if [ "$val" ]; then
                         _sed-in-place "$CASSANDRA_CONFIG/cassandra-rackdc.properties" \
                                 -r 's/^('"$rackdc"'=).*/\1 '"$val"'/'
diff --git a/kubernetes/common/mariadb-init/resources/config/db_init.sh b/kubernetes/common/mariadb-init/resources/config/db_init.sh
index fa4b007a5a..f130bb5118 100755
--- a/kubernetes/common/mariadb-init/resources/config/db_init.sh
+++ b/kubernetes/common/mariadb-init/resources/config/db_init.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+
 {{/*
 # Copyright © 2019 Orange
 # Copyright © 2020 Samsung Electronics
@@ -22,8 +23,15 @@ set -e
 while read DB ; do
     USER_VAR="MYSQL_USER_${DB^^}"
     PASS_VAR="MYSQL_PASSWORD_${DB^^}"
-    USER=${!USER_VAR}
-    PASS=`echo -n ${!PASS_VAR} | sed -e "s/'/''/g"`
+{{/*
+    # USER=${!USER_VAR}
+    # PASS=`echo -n ${!PASS_VAR} | sed -e "s/'/''/g"`
+    # eval replacement of the bashism equivalents above might present a security issue here
+    # since it reads content from DB values filled by helm at the end of the script.
+    # These possible values has to be constrainted and/or limited by helm for a safe use of eval.
+*/}}
+    eval USER=\$$USER_VAR
+    PASS=$(eval echo -n \$$PASS_VAR | sed -e "s/'/''/g")
     MYSQL_OPTS=( -h ${DB_HOST} -P ${DB_PORT} -uroot -p${MYSQL_ROOT_PASSWORD} )
 
     echo "Creating database ${DB} and user ${USER}..."
diff --git a/kubernetes/portal/components/portal-mariadb/resources/config/mariadb/docker-entrypoint.sh b/kubernetes/portal/components/portal-mariadb/resources/config/mariadb/docker-entrypoint.sh
index c4a21b927f..41069bd927 100644
--- a/kubernetes/portal/components/portal-mariadb/resources/config/mariadb/docker-entrypoint.sh
+++ b/kubernetes/portal/components/portal-mariadb/resources/config/mariadb/docker-entrypoint.sh
@@ -1,4 +1,5 @@
 #!/bin/bash
+
 set -eo pipefail
 shopt -s nullglob
 
@@ -30,10 +31,15 @@ file_env() {
 		mysql_error "Both $var and $fileVar are set (but are exclusive)"
 	fi
 	local val="$def"
+	# val="${!var}"
+	# val="$(< "${!fileVar}")"
+	# eval replacement of the bashism equivalents above presents no security issue here
+	# since var and fileVar variables contents are derived from the file_env() function arguments.
+	# This method is only called inside this script with a limited number of possible values.
 	if [ "${!var:-}" ]; then
-		val="${!var}"
+		eval val=\$$var
 	elif [ "${!fileVar:-}" ]; then
-		val="$(< "${!fileVar}")"
+		val="$(< "$(eval echo "\$$fileVar")")"
 	fi
 	export "$var"="$val"
 	unset "$fileVar"