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How to support STAT LIST SFTP command on CA APIM gateway

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Article ID: 113408

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Updated On:

Products

STARTER PACK-7 CA Rapid App Security CA API Gateway

Issue/Introduction

Case description:
CA API Gateway is acting as an SFTP server, and translating SFTP request to an HTTP call to a backend service. PUT a file was implemented, and it successfully routes via HTTP to backend services. The problem is the LIST/STAT commands which the SFTP client issues to verify the PUT has been successful. How to get the gateway to respond to these commands properly? 

Environment

Release:
Component: APIGTW

Resolution

xml response for LIST/STAT are the same, here is a template, 
<?xml version="1.0" encoding="UTF-8"?> 
<files> 
<file file="<true/false>" lastModified="<timestamp>" 
name="<filename>" permissions="<file permission number>" size="<filesize>"/> 
</files> 

example: 
<?xml version="1.0" encoding="UTF-8"?> 
<files> 
<file file="true" lastModified="1535619386000" 
name="${request.ssh.file}" permissions="664" size="666"/> 
</files> 

NOTE: 
1. file="true" for a file, file="false" for a directory 
2. on sftp client, input ls (or ls -l), it will send LIST command, input ls <file> (or ls -l <file>, or change directory, etc.), it will send STAT command 
3. for LIST command response, we can have multiple <file> elements 
4. the backend needs to provide rest API to return the properties of the uploaded file as below, 
- file type (file or directory) 
- file name (could be optional, we can get it from ${request.ssh.file}) 
- last modify timestamp 
- file permission number 
- file size 

 

Additional Information

The attached sample policy returns fake sftp response (it's hard coded and it's not returned from a real backend, just to show what response is accepted by what command.)
And the listen port needs to be configured to accept sftp request, here is an example,

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Attachments

1558695904932000113408_sktwi1f5rjvs16ic1.png get_app
1558695902913000113408_sktwi1f5rjvs16ic0.png get_app
1558695901103000113408_sktwi1f5rjvs16ibz.png get_app
1558536790282sftpLISTSTATPUTexample.xml get_app