Adapt all scripts to yescrypt (#216)

* Revert "fix: clean obsolete check 99.5.4.5.1, now handled by 5.3.4 (#215)"

This reverts commit 670c8c62f5.

We still want to verify the preexisting hashes in /etc/shadow,
even if the PAM configuration is correct for new passwords (5.3.4).

* Adapt 5.3.4, 99.5.4.5.1 and 99.5.4.5.2 to yescrypt

bin/hardening/5.3.4_acc_pam_sha512.sh

@@ -15,20 +15,18 @@ set -u # One variable unset, it's over
 # shellcheck disable=2034
 HARDENING_LEVEL=2
 # shellcheck disable=2034
-DESCRIPTION="Check that any password that may exist in /etc/shadow is yescrypt (or SHA512 for debian 10) hashed and salted"
+DESCRIPTION="Check that the algorithm declared in PAM for password changes is sha512 (or yescrypt for Debian 11+)"
 
 CONF_FILE="/etc/pam.d/common-password"
-CONF_LINE="^\s*password\s.+\s+pam_unix\.so\s+.*sha512"
+# CONF_LINE is defined in _set_vars_jit below
 
 # This function will be called if the script status is on enabled / audit mode
 audit() {
+    _set_vars_jit
     # Check conf file for default SHA512 hash
     if $SUDO_CMD [ ! -r "$CONF_FILE" ]; then
         crit "$CONF_FILE is not readable"
     else
-        if [ "$DEB_MAJ_VER" -ge "11" ]; then
-            CONF_LINE="^\s*password\s.+\s+pam_unix\.so\s+.*yescrypt" # https://github.com/ovh/debian-cis/issues/158
-        fi
         # shellcheck disable=SC2001
         does_pattern_exist_in_file "$CONF_FILE" "$(sed 's/ /[[:space:]]+/g' <<<"$CONF_LINE")"
         if [ "$FNRET" = 0 ]; then
@@ -41,6 +39,7 @@ audit() {
 
 # This function will be called if the script status is on enabled mode
 apply() {
+    _set_vars_jit
     if $SUDO_CMD [ ! -r "$CONF_FILE" ]; then
         crit "$CONF_FILE is not readable"
     else
@@ -64,6 +63,18 @@ check_config() {
     :
 }
 
+# As we use DEB_MAJ_VER, which is set by constants.sh, itself sourced by main.sh below,
+# We need to call this in the subs called by main.sh when it is sourced, otherwise it would
+# either be too soon (DEB_MAJ_VER not defined) or too late (test has already been run)
+_set_vars_jit() {
+    if [ "$DEB_MAJ_VER" -ge "11" ]; then
+        CONF_LINE="^\s*password\s.+\s+pam_unix\.so\s+.*(sha512|yescrypt)" # https://github.com/ovh/debian-cis/issues/158
+    else
+        CONF_LINE="^\s*password\s.+\s+pam_unix\.so\s+.*sha512"
+    fi
+    unset -f _set_vars_jit
+}
+
 # Source Root Dir Parameter
 if [ -r /etc/default/cis-hardening ]; then
     # shellcheck source=../../debian/default

bin/hardening/99.5.4.5.1_acc_logindefs_sha512.sh

@@ -6,7 +6,7 @@
 #
 
 #
-# 99.5.4.5.1 Check that any password that will be created will be SHA512 hashed and salted
+# 99.5.4.5.1 Check that any password that will be created will use sha512crypt (or yescrypt for Debian 11+)
 #
 
 set -e # One error, it's over
@@ -15,31 +15,33 @@ set -u # One variable unset, it's over
 # shellcheck disable=2034
 HARDENING_LEVEL=2
 # shellcheck disable=2034
-DESCRIPTION="Check that any password that will be created will be SHA512 hashed and salted"
+DESCRIPTION="Check that any password that will be created will use sha512crypt (or yescrypt for Debian 11+)"
 
 CONF_FILE="/etc/login.defs"
-CONF_LINE="ENCRYPT_METHOD SHA512"
+# CONF_LINE and CONF_LINE_REGEX are defined in _set_vars_jit below
 
 # This function will be called if the script status is on enabled / audit mode
 audit() {
+    _set_vars_jit
     # Check conf file for default SHA512 hash
     if $SUDO_CMD [ ! -r "$CONF_FILE" ]; then
         crit "$CONF_FILE is not readable"
     else
-        does_pattern_exist_in_file "$CONF_FILE" "^ *${CONF_LINE/ /[[:space:]]+}"
+        does_pattern_exist_in_file "$CONF_FILE" "^ *${CONF_LINE_REGEX/ /[[:space:]]+}"
         if [ "$FNRET" = 0 ]; then
-            ok "$CONF_LINE is present in $CONF_FILE"
+            ok "$CONF_LINE_REGEX is present in $CONF_FILE"
         else
-            crit "$CONF_LINE is not present in $CONF_FILE"
+            crit "$CONF_LINE_REGEX is not present in $CONF_FILE"
         fi
     fi
 }
 
 # This function will be called if the script status is on enabled mode
 apply() {
-    does_pattern_exist_in_file "$CONF_FILE" "^ *${CONF_LINE/ /[[:space:]]+}"
+    _set_vars_jit
+    does_pattern_exist_in_file "$CONF_FILE" "^ *${CONF_LINE_REGEX/ /[[:space:]]+}"
     if [ "$FNRET" = 0 ]; then
-        ok "$CONF_LINE is present in $CONF_FILE"
+        ok "$CONF_LINE_REGEX is present in $CONF_FILE"
     else
         warn "$CONF_LINE is not present in $CONF_FILE, adding it"
         does_pattern_exist_in_file "$CONF_FILE" "^$(echo "$CONF_LINE" | cut -d ' ' -f1)"
@@ -57,6 +59,20 @@ check_config() {
     :
 }
 
+# As we use DEB_MAJ_VER, which is set by constants.sh, itself sourced by main.sh below,
+# We need to call this in the subs called by main.sh when it is sourced, otherwise it would
+# either be too soon (DEB_MAJ_VER not defined) or too late (test has already been run)
+_set_vars_jit() {
+    if [ "$DEB_MAJ_VER" -ge "11" ]; then
+        CONF_LINE_REGEX="ENCRYPT_METHOD (SHA512|yescrypt|YESCRYPT)"
+        CONF_LINE="ENCRYPT_METHOD YESCRYPT"
+    else
+        CONF_LINE_REGEX="ENCRYPT_METHOD SHA512"
+        CONF_LINE="ENCRYPT_METHOD SHA512"
+    fi
+    unset -f _set_vars_jit
+}
+
 # Source Root Dir Parameter
 if [ -r /etc/default/cis-hardening ]; then
     # shellcheck source=../../debian/default

bin/hardening/99.5.4.5.2_acc_shadow_sha512.sh

@@ -0,0 +1,93 @@
+#!/bin/bash
+
+# run-shellcheck
+#
+# OVH Security audit
+#
+
+#
+# 99.5.4.5.2 Check that passwords in /etc/shadow are sha512crypt (or yescrypt for Debian 11+) hashed and salted
+#
+
+set -e # One error, it's over
+set -u # One variable unset, it's over
+
+# shellcheck disable=2034
+HARDENING_LEVEL=2
+# shellcheck disable=2034
+DESCRIPTION="Check that passwords in /etc/shadow are sha512crypt (or yescrypt for Debian 11+) hashed and salted"
+FILE="/etc/shadow"
+
+# This function will be called if the script status is on enabled / audit mode
+audit() {
+    # Review shadow file for existing passwords
+    pw_found=""
+    users_reviewed=""
+    if $SUDO_CMD [ ! -r "$FILE" ]; then
+        crit "$FILE is not readable"
+        return
+    fi
+    for line in $($SUDO_CMD cut -d ":" -f 1,2 /etc/shadow); do
+        users_reviewed+="$line "
+        user=$(echo "$line" | cut -d ":" -f 1)
+        passwd=$(echo "$line" | cut -d ":" -f 2)
+        if [[ $passwd = '!' || $passwd = '*' ]]; then
+            continue
+        elif [[ $passwd =~ ^!.*$ ]]; then
+            pw_found+="$user "
+            ok "User $user has a disabled password."
+        # yescrypt: Check password against $y$<salt>$<base64>
+        elif [ "$DEB_MAJ_VER" -ge "11" ] && [[ $passwd =~ ^\$y\$[./A-Za-z0-9]+\$[./A-Za-z0-9]{,86}\$[./A-Za-z0-9]{43} ]]; then
+            pw_found+="$user "
+            ok "User $user has suitable yescrypt hashed password."
+        # sha512: Check password against $6$<salt>$<base64>, see `man 3 crypt`
+        elif [[ $passwd =~ ^\$6(\$rounds=[0-9]+)?\$[a-zA-Z0-9./]{2,16}\$[a-zA-Z0-9./]{86}$ ]]; then
+            pw_found+="$user "
+            ok "User $user has suitable sha512crypt hashed password."
+        else
+            pw_found+="$user "
+            if [ "$DEB_MAJ_VER" -ge "11" ]; then
+                crit "User $user has a password that is not sha512crypt nor yescrypt hashed."
+            else
+                crit "User $user has a password that is not sha512crypt hashed."
+            fi
+        fi
+    done
+    if [[ -z "$users_reviewed" ]]; then
+        crit "No users were reviewed in $FILE !"
+        return
+    fi
+    if [[ -z "$pw_found" ]]; then
+        ok "There is no password in $FILE"
+    fi
+}
+
+# This function will be called if the script status is on enabled mode
+apply() {
+    :
+}
+
+# This function will check config parameters required
+check_config() {
+    :
+}
+
+# Source Root Dir Parameter
+if [ -r /etc/default/cis-hardening ]; then
+    # shellcheck source=../../debian/default
+    . /etc/default/cis-hardening
+fi
+if [ -z "$CIS_LIB_DIR" ]; then
+    echo "There is no /etc/default/cis-hardening file nor cis-hardening directory in current environment."
+    echo "Cannot source CIS_LIB_DIR variable, aborting."
+    exit 128
+fi
+
+# Main function, will call the proper functions given the configuration (audit, enabled, disabled)
+if [ -r "${CIS_LIB_DIR}"/main.sh ]; then
+    # shellcheck source=../../lib/main.sh
+    . "${CIS_LIB_DIR}"/main.sh
+else
+    echo "Cannot find main.sh, have you correctly defined your root directory? Current value is $CIS_LIB_DIR in /etc/default/cis-hardening"
+    exit 128
+fi

tests/hardening/5.3.4_acc_pam_sha512.sh

@@ -3,7 +3,7 @@
 test_audit() {
     describe Running on blank host
     register_test retvalshouldbe 0
-    register_test contain REGEX "[ OK ] .*(sha512|yescrypt) is present in /etc/pam.d/common-password"
+    register_test contain "is present in /etc/pam.d/common-password"
     # shellcheck disable=2154
     run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
 }

tests/hardening/99.5.4.5.1_acc_logindefs_sha512.sh

@@ -3,7 +3,7 @@
 test_audit() {
     describe Running on blank host
     register_test retvalshouldbe 0
-    register_test contain "ENCRYPT_METHOD SHA512 is present in /etc/login.defs"
+    register_test contain "is present in /etc/login.defs"
     # shellcheck disable=2154
     run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
 
@@ -11,7 +11,7 @@ test_audit() {
     describe Line as comment
     sed -i 's/\(ENCRYPT_METHOD SHA512\)/# \1/' /etc/login.defs
     register_test retvalshouldbe 1
-    register_test contain "SHA512 is not present"
+    register_test contain "is not present in /etc/login.defs"
     run commented "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
 
     rm /etc/login.defs
@@ -24,7 +24,7 @@ test_audit() {
     sed -ir 's/ENCRYPT_METHOD[[:space:]]\+SHA512/ENCRYPT_METHOD MD5/' /etc/login.defs
     describe Fail: wrong hash function configuration
     register_test retvalshouldbe 1
-    register_test contain "SHA512 is not present"
+    register_test contain "is not present in /etc/login.defs"
     run wrongconf "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
 
     describe Correcting situation

tests/hardening/99.5.4.5.2_acc_shadow_sha512.sh

@@ -0,0 +1,40 @@
+# shellcheck shell=bash
+# run-shellcheck
+test_audit() {
+    describe Running on blank host
+    register_test retvalshouldbe 0
+    register_test contain "There is no password in /etc/shadow"
+    dismiss_count_for_test
+    # shellcheck disable=2154
+    run blank "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    cp -a /etc/shadow /tmp/shadow.bak
+    sed -i 's/secaudit:!/secaudit:mypassword/' /etc/shadow
+    describe Fail: Found unsecure password
+    register_test retvalshouldbe 1
+    register_test contain "User secaudit has a password that is not"
+    run unsecpasswd "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    sed -i 's/secaudit:mypassword/secaudit:!!/' /etc/shadow
+    describe Fail: Found disabled password
+    register_test retvalshouldbe 0
+    register_test contain "User secaudit has a disabled password"
+    run lockedpasswd "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    mv /tmp/shadow.bak /etc/shadow
+    chpasswd -c SHA512 <<EOF
+secaudit:mypassword
+EOF
+    describe Pass: Found properly hashed password
+    register_test retvalshouldbe 0
+    register_test contain "User secaudit has suitable"
+    run sha512pass "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+
+    chpasswd -c SHA512 -s 1000 <<EOF
+secaudit:mypassword
+EOF
+    describe Pass: Found properly hashed password with custom round number
+    register_test retvalshouldbe 0
+    register_test contain "User secaudit has suitable"
+    run sha512pass "${CIS_CHECKS_DIR}/${script}.sh" --audit-all
+}

tests/launch_tests.sh

@@ -140,6 +140,11 @@ _run() {
     echo $? >"$outdir/$usecase_name.retval"
     ret=$(<"$outdir"/"$usecase_name".retval)
     get_stdout
+    if [ -s "$outdir/${usecase_name}_err.log" ]; then
+        echo ">>> stderr follows"
+        cat "$outdir/${usecase_name}_err.log"
+        echo "<<< end of stderr"
+    fi
 }
 
 # Load assertion functions for functionnal tests