Ensure permissions on SSH public host key files are configured

보통레벨 1자동linux

설명

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.

점검 방법

감사 방식: 셸 명령

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

예상 출력: compliant

조치 방법

조치 방식: 가이드 또는 인프라 패치

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 {} \;

속성

운영 체제: alinux-2
태그: cis-convertedlinux
참고 자료: CIS Aliyun Linux 2 Benchmark v1.0.0 ARCHIVE - 5.2.4

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