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https://github.com/SpotlightKid/micropython-ftplib

An FTP client library for MicroPython.
https://github.com/SpotlightKid/micropython-ftplib

ftp ftp-client ftplib micropython python

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An FTP client library for MicroPython.

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# micropython-ftplib



An FTP client library for MicroPython.



This is an adaption of the [ftplib] module from the CPython standard library to

MicroPython. Apart from making it compatible with the `socket` module

implementation of MicroPython and removing the use of the `re` library, some

parts of the original library have been removed and the code and docstrings

have been cleaned up somewhat.



The `FTP_TLS` class has been moved to a separate module file (`ftplibtls.py`)

and the `all_errors` module global variable has been removed. The test code has

been moved to a separate script and reworked too. The `ftpcp` function has been

moved to the `ftpcp.py` module file.



The code has been tested under the following MicroPython ports against the FTP

server from the [pyftpdlib] package.



* `unix`

* `stm32` (using W5500 ethernet module)

* `esp8266`

* `esp32`

* `rp2` (Raspberry Pi Pico W)



For the `esp8266` port the code needed to be slighty altered to make it work

with the `ssl` module there and to reduce the memory usage. This version can

be found in the [esp](./esp) directory (this version also works with the

`esp32` port, but there you should be able to use the normal version too).



## FTP over TLS



FTP-over-TLS support is available in a separate `ftplibtls` module:



```py

>>> from ftplibtls import FTP_TLS

>>> ftp = FTP_TLS('example.com')  # default port 21

>>> ftp.login('username', 'password')

>>> ftp.prot_p()

>>> ftp.retrlines('LIST')

```



Note that you must call the `prot_b` method after connecting and

authentication to actually establish secure communication for data transfers.



If you require server certificate validation (recommended):



```py

>>> from ftplib import FTP_TLS, ssl

>>> ctx = ssl.SSLContext(ssl.PROTOCOL_TLS_CLIENT)

>>> ctx.verify_mode = ssl.CERT_REQUIRED

>>> ctx.load_verify_locations(cafile="cert.der")  # Certificate file must be in DER format

>>> ftp = FTP_TLS(ssl_context=ctx, server_hostname="example.com")

>>> ftp.connect('example.com')

>>> ftp.prot_p()

>>> ftp.retrlines('LIST')

```



Use the `server_hostname` constructor argument if the common name in the

server's certificate differs from the host name used for connecting.



Note: the version of `ftplibtls` in the `esp` directory does not support the

`ssl_context` and `server_hostname` constructor arguments, since the `ssl`

module of the `esp2866` port unfortunately does not support server certificate

validation.



### Testing FTP over TLS



The `tests` directory contains the `pyftplib-server.py` script to start an FTP

server, which is based on the [pyftpdlib] library for CPython and which

supports FTP over TLS.



To run this script with TLS support enabled, you first need to create a server

certificate. For testing, a self-signed certificate can be used and created

with:



```con

openssl req -new -x509 -nodes -out cert.pem -keyout tests/key.pem

```



Specify the country, code, location, organization and common name, when

prompted. (Note: the test scripts in the `tests` directory assume that the

common name you choose is `example.com`. If you choose a different common name,

these scripts will fail with an error due to certificate verification failure.)



Combine the server certificate and the key into one file:



```con

cat tests/key.pem tests/cert.pem > tests/keycert.pem

```



The `ftplibtls` module needs the server certificate in DER format, so convert

it with:



```con

openssl x509 -in tests/cert.pem -out tests/cert.der -outform DER

```



Now you can start the test FTP server:



```con

mkdir -p tests/ftproot

python3 tests/pyftpdlib-server.py -w -s -p 2121 -c tests/keycert.pem tests/ftproot

```



The FTP server will listen on port 2121, support TLS using the certificate in the

file `tests/keycert.pem` and allow clients to read files from the directory

`tests/ftproot` and also upload files there.



To upload a file to the test FTP server using the `ftplibtls` module, run the

`tests/test_upload.py` script:



```con

MICROPYPATH=`pwd` micropython tests/test_upload.py ftps://localhost:2121 

```



This should upload the file `` to the FTP server using FTP over TLS

and the file should appear in the `tests/ftproot` directory.



[ftplib]: https://docs.python.org/3/library/ftplib.html

[pyftpdlib]: https://github.com/giampaolo/pyftpdlib/