ocf · emmatyping · Sep 23, 2021 · Aug 24, 2021 · Aug 24, 2021 · Sep 18, 2021
diff --git a/ocfweb/account/print.py b/ocfweb/account/print.py
@@ -0,0 +1,211 @@
+import base64
+import os.path
+import subprocess
+import uuid
+from email.message import EmailMessage
+from email.utils import make_msgid
+from io import BytesIO
+
+import qrcode
+from django import forms
+from django.forms import widgets
+from django.http import HttpRequest
+from django.http import HttpResponse
+from django.shortcuts import render
+from ocflib.misc.mail import MAIL_FROM
+from ocflib.misc.mail import SENDMAIL_PATH
+from paramiko import AuthenticationException
+from paramiko import SSHClient
+from paramiko.hostkeys import HostKeyEntry
+
+from ocfweb.component.forms import Form
+
+
+PRINT_FOLDER = '.user_print'
+
+EMAIL_BODY = '''
+<html>
+    <body>
+        <p>
+            Hi {username},
+        </p>
+
+        <p>
+            Below you can find the QR code to start your print in the OCF computer lab.
+            Show the QR code in front of the camera at the remote printing computer,
+            and it will start printing your document.
+        </p>
+        <img src="cid:{image_cid}">
+        <p>
+            Thanks for flying OCF! <br>
+            ~ OCF volunteer staff
+        </p>
+    </body>
+</html>
+'''
+
+
+def send_qr_mail(username: str, qr_code: bytes) -> None:
+    """Send the QR code needed to start the print in the lab to the user.
+
+    Based on https://stackoverflow.com/a/49098251/9688107
+    """
+
+    msg = EmailMessage()
+    msg['Subject'] = 'OCF Remote Printing QR Code'
+    msg['From'] = MAIL_FROM
+    msg['To'] = f'{username}@ocf.berkeley.edu'
+
+    msg.set_content(
+        'Sorry, we were unable to display your QR, please use the QR code on the website!.',
+    )
+
+    image_cid = make_msgid(domain='ocf.berkeley.edu')
+    msg.add_alternative(EMAIL_BODY.format(username=username, image_cid=image_cid), subtype='html')
+    msg.get_payload()[1].add_related(
+        qr_code,
+        maintype='image',
+        subtype='png',
+        cid=image_cid,
+    )
+    # we send the message via sendmail because direct traffic to port 25
+    # is firewalled off
+    p = subprocess.Popen(
+        (SENDMAIL_PATH, '-t', '-oi'),
+        stdin=subprocess.PIPE,
+    )
+    p.communicate(msg.as_string().encode('utf8'))
+
+
+def print(request: HttpRequest) -> HttpResponse:
+    if request.method == 'POST':
+        form = PrintForm(
+            request.POST,
+            request.FILES,
+            initial={
+                'double_or_single': 'single',
+            },
+        )
+        qr_b64 = b''
+        double_or_single = 'single'
+        error = ''
+        if form.is_valid():
+            username = form.cleaned_data['username']
+            password = form.cleaned_data['password']
+
+            file = request.FILES['file']
+
+            double_or_single = form.cleaned_data['double_or_single']
+
+            ssh = SSHClient()
+
+            host_keys = ssh.get_host_keys()
+            entry = HostKeyEntry.from_line(
+                'ssh.ocf.berkeley.edu ssh-rsa AAAAB3NzaC1yc2EAAAABIwAAAQEAqMkHVVoMl8md25iky7e2Xe3ARaC4H1PbIpv5Y+xT4KOT17gGvFSmfjGyW9P8ZTyqxq560iWdyELIn7efaGPbkUo9retcnT6WLmuh9nRIYwb6w7BGEEvlblBmH27Fkgt7JQ6+1sr5teuABfIMg22WTQAeDQe1jg0XsPu36OjbC7HjA3BXsiNBpxKDolYIXWzOD+r9FxZLP0lawh8dl//O5FW4ha1IbHklq2i9Mgl79wAH3jxf66kQJTvLmalKnQ0Dbp2+vYGGhIjVFXlGSzKsHAVhuVD6TBXZbxWOYoXanS7CC43MrEtBYYnc6zMn/k/rH0V+WeRhuzTnr/OZGJbBBw==',  # noqa
+            )
+            assert entry is not None  # should never be none as we are passing a static string above
+            host_keys.add(
+                'ssh.ocf.berkeley.edu',
+                'ssh-rsa',
+                entry.key,
+            )
+
+            try:
+                ssh.connect(
+                    'ssh.ocf.berkeley.edu',
+                    username=username,
+                    password=password,
+                )
+            except AuthenticationException:
+                error = 'Authentication failed. Did you type the wrong username or password?'
+
+            if not error:
+                sftp = ssh.open_sftp()
+                try:
+                    folder = sftp.stat(PRINT_FOLDER)
+                    if folder.FLAG_PERMISSIONS != 0o700:
+                        sftp.chmod(PRINT_FOLDER, 0o700)
+                except FileNotFoundError:
+                    sftp.mkdir(PRINT_FOLDER, 0o700)
+                try:
+                    rid = uuid.uuid4().hex
+                    filename = f'{rid}-{file.name}'
+                    with sftp.open(os.path.join(PRINT_FOLDER, filename), 'wb+') as dest:
+                        for chunk in file.chunks():
+                            dest.write(chunk)
+                except OSError as e:
+                    error = 'Failed to open file in user home directory, ' + \
+                        f'please report this to [email protected] with the traceback\n{e}'
+                else:
+                    qr = qrcode.QRCode(
+                        version=1,
+                        box_size=10,
+                        border=5,
+                    )
+                    qr.add_data(f'{username}:{filename}:{double_or_single}')
+                    qr.make(fit=True)
+                    img = qr.make_image(fill='black', back_color='white')
+                    buff = BytesIO()
+                    img.save(buff, format='PNG')
+                    qr_data = buff.getvalue()
+                    qr_b64 = b'data:image/png;base64,%b' % base64.b64encode(qr_data)
+        send_qr_mail(
+            username=username,
+            qr_code=qr_data,
+        )
+        return render(
+            request,
+            'account/print/qr.html',
+            {
+                'title': 'QR Code',
+                'qr_b64': qr_b64.decode('utf-8'),
+                'error': error,
+            },
+        )
+    else:
+        form = PrintForm(
+            initial={
+                'double_or_single': 'single',
+            },
+        )
+
+        return render(
+            request,
+            'account/print/index.html', {
+                'title': 'Print remotely',
+                'form': form,
+            },
+        )
+
+
+class PrintForm(Form):
+    username = forms.CharField(
+        label='OCF username',
+        min_length=3,
+        max_length=16,
+    )
+    password = forms.CharField(
+        widget=forms.PasswordInput,
+        label='Password',
+        min_length=8,
+        max_length=256,
+    )
+
+    file = forms.FileField()
+
+    PRINT_CHOICES = (
+        (
+            'single',
+            'single sided -- one page per piece of paper',
+        ),
+        (
+            'double',
+            'double sided -- two pages per piece of paper',
+        ),
+    )
+
+    double_or_single = forms.ChoiceField(
+        choices=PRINT_CHOICES,
+        label='Print double or single sided',
+        widget=widgets.RadioSelect,
+    )
diff --git a/ocfweb/account/templates/account/print/index.html b/ocfweb/account/templates/account/print/index.html
@@ -0,0 +1,21 @@
+{% extends "base.html" %}
+{% load bootstrap %}
+
+{% block content %}
+    <div class="row">
+        <div class="col-md-8 ocf-content-block">
+            <h3>Print remotely</h3>
+            <p>
+                Please select a PDF file you would like to print and whether you would like to print single or double sided.
+
+                Once you press submit, a QR code will displayed that you should bring to the OCF computer lab.
+            </p>
+
+            <form action="{% url 'print' %}" method="post" enctype="multipart/form-data">
+                {% csrf_token %}
+                {{form | bootstrap}}
+                <input class="btn btn-primary" type="submit" value="Submit print to queue" />
+            </form>
+        </div>
+    </div>
+{% endblock %}
diff --git a/ocfweb/account/templates/account/print/qr.html b/ocfweb/account/templates/account/print/qr.html
@@ -0,0 +1,21 @@
+{% extends "base.html" %}
+{% load bootstrap %}
+
+{% block content %}
+    <div class="row">
+        <div class="col-md-8 ocf-content-block">
+            <p>
+                Please bring this QR code to the lab to start your print job. A copy was emailed to you.
+            </p>
+            {% if qr_b64 %}
+                <div class="well">
+                    <img alt="QR code to print" src="{{ qr_b64 }}" />
+                </div>
+            {% endif %}
+
+            {% if error %}
+                <p><strong>{{ error|linebreaks }}</strong></p>
+            {% endif %}
+        </div>
+    </div>
+{% endblock %}
diff --git a/ocfweb/account/urls.py b/ocfweb/account/urls.py
@@ -2,6 +2,7 @@
 
 from ocfweb.account.chpass import change_password
 from ocfweb.account.commands import commands
+from ocfweb.account.print import print
 from ocfweb.account.register import account_created
 from ocfweb.account.register import account_pending
 from ocfweb.account.register import recommend
@@ -19,6 +20,7 @@
 urlpatterns = [
     url(r'^password/$', change_password, name='change_password'),
     url(r'^commands/$', commands, name='commands'),
+    url(r'^print/$', print, name='print'),
 
     # account creation
     url(r'^register/$', request_account, name='register'),

diff --git a/ocfweb/main/templates/main/home.html b/ocfweb/main/templates/main/home.html
@@ -102,6 +102,7 @@ <h3>OCF Computer Lab</h3>
         <ul>
             <li><a href="{% url 'commands' %}">Check Account</a></li>
             <li><a href="{% url 'change_password' %}">Reset Password</a></li>
+            <li><a href="{% url 'print' %}">Print Remotely</a></li>
 
             {% if is_ocf_ip %}
                 <li><a href="https://printhost.ocf.berkeley.edu/jobs/">View Print Queue</a></li>

diff --git a/ocfweb/templates/base.html b/ocfweb/templates/base.html
@@ -81,6 +81,7 @@
 
                                     <li><a href="{% url 'commands' %}">Commands</a></li>
                                     <li><a href="{% url 'change_password' %}">Change Password</a></li>
+                                    <li><a href="{% url 'print' %}">Print Remotely</a></li>
                                     <li><a href="{% url 'logout' %}?next={{request_full_path}}">Log Out</a></li>
                                 </ul>
                             </li>

diff --git a/requirements-dev-minimal.txt b/requirements-dev-minimal.txt
@@ -7,6 +7,13 @@ pytest-django
 pytest-env
 pytest-xdist
 requirements-tools
+types-cryptography
+types-enum34
+types-ipaddress
 types-paramiko
 types-python-dateutil
+types-pytz
+types-PyYAML
 types-requests
+types-setuptools
+types-toml
diff --git a/requirements-dev.txt b/requirements-dev.txt
@@ -34,4 +34,6 @@ types-python-dateutil==2.8.0
 types-pytz==2021.1.2
 types-PyYAML==5.4.10
 types-requests==2.25.6
+types-setuptools==57.0.2
+types-toml==0.1.5
 virtualenv==20.7.2
diff --git a/requirements-minimal.txt b/requirements-minimal.txt
@@ -14,8 +14,10 @@ mistune
 numpy
 ocflib
 paramiko
+pillow
 pyasn1
 pycryptodome
 pygments
 pymysql
 python-dateutil
+qrcode
diff --git a/requirements.txt b/requirements.txt
@@ -59,6 +59,7 @@ pysnmp==4.4.12
 python-dateutil==2.8.2
 pytz==2021.1
 PyYAML==5.4.1
+qrcode==7.3
 redis==3.5.3
 requests==2.24.0
 setuptools==58.0.4