Ensure permissions on SSH public host key files are configured

СреднийУровень 1Автоматическаяlinux

Описание

An SSH public key is one of two files used in SSH public key authentication. In this authentication method, a public key is a key that can be used for verifying digital signatures generated using a corresponding private key. Only a public key that corresponds to a private key will be able to authenticate successfully.

Как проверяется

Метод проверки: Команда оболочки

shell

alt0() { o=$(bash -c 'find /etc/ssh -xdev -type f -name '"'"'ssh_host_*_key.pub'"'"' -exec stat {} \;' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_rsa_key.pub’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_rsa_key.pub’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 382 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 382 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631758 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631758 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)' || { echo step1: missing 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.861750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.861750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.861750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.861750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.881750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.881750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ecdsa_key.pub’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ecdsa_key.pub’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 162 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 162 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631761 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631761 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)' || { echo step1: missing 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.897750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.897750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.897750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.897750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.917750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.917750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ed25519_key.pub’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ed25519_key.pub’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 82 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 82 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631763 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631763 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)' || { echo step1: missing 'Access: (0644/-rw-r--r--) Uid: ( 0/ root) Gid: ( 0/ root)'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: 2018-10-22 18:24:56.945750616 +0000' || { echo step1: missing 'Access: 2018-10-22 18:24:56.945750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.945750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.945750616 +0000'; return 1; }; }; if alt0; then echo compliant; fi

Ожидаемый вывод: compliant

Как исправляется

Метод исправления: Рекомендация или патч инфраструктуры

Run the following commands to set permissions and ownership on the SSH host public key files # find /etc/ssh -xdev -type f -name 'ssh_host_*_key.pub' -exec chmod 0644 {} \; #find /etc/ssh -xdev -type f -name 'ssh_host_*_key.pub' -exec chown root:root {} \;

Свойства

Операционные системы: alinux-2
Теги: cis-convertedlinux
Источник: CIS Aliyun Linux 2 Benchmark v1.0.0 ARCHIVE - 5.2.4

Проверить этот хост

Выполните команду на компьютере, аудит которого вам разрешён. Сканирование работает только на чтение.

shell

tmaegis scan --target linux