Ensure permissions on SSH private host key files are configured

中等級 1自動化cos

說明

An SSH private key is one of two files used in SSH public key authentication. In this authentication method, the possession of the private key is proof of identity. Only a private key that corresponds to a public key will be able to authenticate successfully. The private keys need to be stored and handled carefully, and no copies of the private key should be distributed. If an unauthorized user obtains the private SSH host key file, the host could be impersonated

檢查方式

稽核方法: Shell 指令

shell

alt0() { o=$(bash -c 'find /etc/ssh -xdev -type f -name '"'"'ssh_host_*_key'"'"' -exec stat {} \;' 2>&1); printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_rsa_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_rsa_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 1679 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 1679 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8628138 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8628138 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$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/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.873750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.873750616 +0000'; return 1; }; printf '%s\n' "$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/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ecdsa_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ecdsa_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 227 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 227 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631760 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631760 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$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/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.905750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.905750616 +0000'; return 1; }; printf '%s\n' "$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/ $//' | grep -Fxq -- 'File: ‘/etc/ssh/ssh_host_ed25519_key’' || { echo step1: missing 'File: ‘/etc/ssh/ssh_host_ed25519_key’'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Size: 387 Blocks: 8 IO Block: 4096 regular file' || { echo step1: missing 'Size: 387 Blocks: 8 IO Block: 4096 regular file'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Device: ca01h/51713d Inode: 8631762 Links: 1' || { echo step1: missing 'Device: ca01h/51713d Inode: 8631762 Links: 1'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)' || { echo step1: missing 'Access: (0600/-rw-------) Uid: ( 0/ root) Gid: ( 0/root)'; return 1; }; printf '%s\n' "$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/ $//' | grep -Fxq -- 'Modify: 2018-10-22 18:24:56.945750616 +0000' || { echo step1: missing 'Modify: 2018-10-22 18:24:56.945750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Change: 2018-10-22 18:24:56.957750616 +0000' || { echo step1: missing 'Change: 2018-10-22 18:24:56.957750616 +0000'; return 1; }; printf '%s\n' "$o" | tr -s ' \t' '  ' | sed 's/^ //;s/ $//' | grep -Fxq -- 'Birth: -' || { echo step1: missing 'Birth: -'; return 1; }; }; if alt0; then echo compliant; fi

預期輸出: compliant

修補方式

修補方法: 操作指南或基礎設施修補檔

Run the following commands to set ownership and permissions on the private SSH host key files # find /etc/ssh -xdev -type f -name 'ssh_host_*_key' -exec chown root:root {} \; # find /etc/ssh -xdev -type f -name 'ssh_host_*_key' -exec chmod 0600 {} \;

屬性

作業系統: 不限
標籤: access-controlcontainer-optimized-oscoscryptossh
參考資料: CIS Google Container-Optimized OS Benchmark v1.2.0 - 5.1.2 Ensure permissions on SSH private host key files are configured

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請在您有權稽核的機器上執行此指令。掃描為唯讀操作。

shell

tmaegis scan --target cos