[SSHD-294] Dubious SSH_FXP_REALPATH handling

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.10.0
• Fix Version/s: 0.11.0
• Assignee: Guillaume Nodet
• Reporter: Kohsuke Kawaguchi
• Created: 27/Feb/14 00:14
• Updated: 14/Apr/14 11:39
• Resolved: 17/Mar/14 14:09

Description

SSH_FXP_REALPATH is used to canonicalizing path on the server side, so clients often send path names that do not exist. The procol (http://tools.ietf.org/html/draft-ietf-secsh-filexfer-02) clearly states that it should respond with dummy attribute values.

SftpSubsystem class, OTOH, attempts to return actual file attributes, which could fail on non-existent paths (or if the path exists but is at the location the user doesn't have access to.)

Handler for SSH_FXP_REALPATH shouldn't attempt to get attributes, or if you do, it must recover from errors in SshFile and report dummy values instead.