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Updated Security protection of various files in Win32 OpenSSH (markdown)

Manoj Ampalam 2017-05-25 11:42:12 -07:00
parent faef847664
commit ed1460d073
1 changed files with 8 additions and 3 deletions
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Security-protection-of-various-files-in-Win32-OpenSSH.md

@ -33,13 +33,16 @@ PS C:\>icacls .\ssh_host_dsa_key /setowner system
PS C:\>icacls .\ssh_host_dsa_key /remove otheruser
```
### authorized_keys
authorized_keys is an user associated file that represents a list of authorized public keys that could be used for (key-based) user authentication. Unauthorized access to this file compromises the associated user's account. This file should not be owned by not provide access to any other user. Note that sshd service needs access to authorized_keys for public key validation.
Following is a misconfigured authorized key because 'otheruser1' has access to the file (through inheritance) and 'otheruser2' has access to this file (explicit permission).
authorized_keys is an user associated file that represents a list of authorized public keys that could be used for (key-based) user authentication. Unauthorized access to this file compromises the associated user's account. This file should not be owned by, nor provide access to any other user. Note that sshd service needs **read** access to authorized_keys for public key validation.
Following is a misconfigured authorized key because
- 'otheruser1' has access to the file (through inheritance)
- 'otheruser2' has access to this file (explicit permission).
- sshd service has full access (it only needs read access)
```
PS C:\>(get-acl .\users\thisuser\.ssh\authorized_keys).owner
thisuser
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys
ssh_host_dsa_key NT SERVICE\sshd:(R)
ssh_host_dsa_key NT SERVICE\sshd:(F)
BUILTIN\Administrators:(F)
thisuser:(F)
otheruser1:(IR)
@ -50,5 +53,7 @@ Steps to fix these permissions - disable inheritance and remove access to otheru
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys /inheritance:d
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys /remove otheruser1
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys /remove otheruser2
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys /remove `"NT SERVICE\sshd`"
PS C:\>icacls .\users\thisuser\.ssh\authorized_keys /grant `"NT SERVICE\sshd`":`(R`)
```