summaryrefslogtreecommitdiff
path: root/doc/html/openssl-ssl.html
blob: 5aee0007b96bdbdb536124887adf7a6e8ceb9760 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
<html>
<head>
<title>3.3 SSL -- An interface to the SSL-specific parts of OpenSSL </title>
<META NAME="description" CONTENT="3.3 SSL -- An interface to the SSL-specific parts of OpenSSL ">
<META NAME="keywords" CONTENT="pyOpenSSL">
<META NAME="resource-type" CONTENT="document">
<META NAME="distribution" CONTENT="global">
<link rel="STYLESHEET" href="pyOpenSSL.css">
<LINK REL="previous" href="openssl-rand.html">
<LINK REL="up" href="openssl.html">
<LINK REL="next" href="openssl-context.html">
</head>
<body>
<DIV CLASS="navigation">
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td><A href="openssl-rand.html"><img src="previous.gif"
border="0" height="32"
  alt="Previous Page" width="32"></A></td>
<td><A href="openssl.html"><img src="up.gif"
border="0" height="32"
  alt="Up One Level" width="32"></A></td>
<td><A href="openssl-context.html"><img src="next.gif"
border="0" height="32"
  alt="Next Page" width="32"></A></td>
<td align="center" width="100%">Python OpenSSL Manual</td>
<td><A href="contents.html"><img src="contents.gif"
border="0" height="32"
  alt="Contents" width="32"></A></td>
<td><img src="blank.gif"
  border="0" height="32"
  alt="" width="32"></td>
<td><img src="blank.gif"
  border="0" height="32"
  alt="" width="32"></td>
</tr></table>
<b class="navlabel">Previous:</b> <a class="sectref" href="openssl-rand.html">3.2 rand  </A>
<b class="navlabel">Up:</b> <a class="sectref" href="openssl.html">3 OpenSSL  </A>
<b class="navlabel">Next:</b> <a class="sectref" href="openssl-context.html">3.3.1 Context objects</A>
<br><hr>
</DIV>
<!--End of Navigation Panel-->
<H2><A NAME="SECTION000430000000000000000">&nbsp;</A>
<BR>
3.3 <tt class="module">SSL</tt> -- An interface to the SSL-specific parts of OpenSSL 
</H2>
<P>
<EM><EM><EM>
</EM></EM></EM>
<P>
<EM><EM><EM>This module handles things specific to SSL. There are two objects defined:
Context, Connection.
</EM></EM></EM>
<P>
<dl><dt><b><a name='l2h-90'><tt>SSLv2_METHOD</tt></a></b>
<dd>
<dt><b><a name='l2h-104'><tt>SSLv3_METHOD</tt></a></b><dd>
<dt><b><a name='l2h-105'><tt>SSLv23_METHOD</tt></a></b><dd>
<dt><b><a name='l2h-106'><tt>TLSv1_METHOD</tt></a></b><dd>
These constants represent the different SSL methods to use when creating a
context object.
</dl>
<P>
<dl><dt><b><a name='l2h-91'><tt>VERIFY_NONE</tt></a></b>
<dd>
<dt><b><a name='l2h-107'><tt>VERIFY_PEER</tt></a></b><dd>
<dt><b><a name='l2h-108'><tt>VERIFY_FAIL_IF_NO_PEER_CERT</tt></a></b><dd>
These constants represent the verification mode used by the Context
object's <tt class="method">set_verify</tt> method.
</dl>
<P>
<dl><dt><b><a name='l2h-92'><tt>FILETYPE_PEM</tt></a></b>
<dd>
<dt><b><a name='l2h-109'><tt>FILETYPE_ASN1</tt></a></b><dd>
File type constants used with the <tt class="method">use_certificate_file</tt> and
<tt class="method">use_privatekey_file</tt> methods of Context objects.
</dl>
<P>
<dl><dt><b><a name='l2h-93'><tt>OP_SINGLE_DH_USE</tt></a></b>
<dd>
<dt><b><a name='l2h-110'><tt>OP_EPHEMERAL_RSA</tt></a></b><dd>
<dt><b><a name='l2h-111'><tt>OP_NO_SSLv2</tt></a></b><dd>
<dt><b><a name='l2h-112'><tt>OP_NO_SSLv3</tt></a></b><dd>
<dt><b><a name='l2h-113'><tt>OP_NO_TLSv1</tt></a></b><dd>
Constants used with <tt class="method">set_options</tt> of Context objects.
<tt class="constant">OP_SINGLE_DH_USE</tt> means to always create a new key when using ephemeral
Diffie-Hellman. <tt class="constant">OP_EPHEMERAL_RSA</tt> means to always use ephemeral RSA keys
when doing RSA operations. <tt class="constant">OP_NO_SSLv2</tt>, <tt class="constant">OP_NO_SSLv3</tt> and
<tt class="constant">OP_NO_TLSv1</tt> means to disable those specific protocols. This is
interesting if you're using e.g. <tt class="constant">SSLv23_METHOD</tt> to get an SSLv2-compatible
handshake, but don't want to use SSLv2.
</dl>
<P>
<dl><dt><b><a name='l2h-94'><tt>ContextType</tt></a></b>
<dd>
A Python type object representing the Context object type.
</dl>
<P>
<dl><dt><b><a name='l2h-95'><tt class='function'>Context</tt></a></b>(<var>method</var>)
<dd>
Factory function that creates a new Context object given an SSL method. The
method should be <tt class="constant">SSLv2_METHOD</tt>, <tt class="constant">SSLv3_METHOD</tt>,
<tt class="constant">SSLv23_METHOD</tt> or <tt class="constant">TLSv1_METHOD</tt>.
</dl>
<P>
<dl><dt><b><a name='l2h-96'><tt>ConnectionType</tt></a></b>
<dd>
A Python type object representing the Connection object type.
</dl>
<P>
<dl><dt><b><a name='l2h-97'><tt class='function'>Connection</tt></a></b>(<var>context, socket</var>)
<dd>
Factory fucnction that creates a new Connection object given an SSL context and
a socket <A NAME="tex2html5"
  HREF="#foot901"><SUP>4</SUP></A> object.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-98'><tt class='exception'>Error</tt></a></b>
<dd>
This exception is used as a base class for the other SSL-related
exceptions, but may also be raised directly.
</EM></EM></EM>
<P>
<EM><EM><EM>Whenever this exception is raised directly, it has a list of error messages
from the OpenSSL error queue, where each item is a tuple <code>(<var>lib</var>,
<var>function</var>, <var>reason</var>)</code>. Here <var>lib</var>, <var>function</var> and <var>reason</var>
are all strings, describing where and what the problem is. See <span class='manpage'><i>err</i>(3)</span>
for more information.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-99'><tt class='exception'>ZeroReturnError</tt></a></b>
<dd>
This exception matches the error return code <code>SSL_ERROR_ZERO_RETURN</code>, and
is raised when the SSL Connection has been closed. In SSL 3.0 and TLS 1.0, this
only occurs if a closure alert has occurred in the protocol, i.e. the
connection has been closed cleanly. Note that this does not necessarily
mean that the transport layer (e.g. a socket) has been closed.
</EM></EM></EM>
<P>
<EM><EM><EM>It may seem a little strange that this is an exception, but it does match an
<code>SSL_ERROR</code> code, and is very convenient.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-100'><tt class='exception'>WantReadError</tt></a></b>
<dd>
The operation did not complete; the same I/O method should be called again
later, with the same arguments. Any I/O method can lead to this since new
handshakes can occur at any time.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-101'><tt class='exception'>WantWriteError</tt></a></b>
<dd>
See <tt class="exception">WantReadError</tt>.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-102'><tt class='exception'>WantX509LookupError</tt></a></b>
<dd>
The operation did not complete because an application callback has asked to be
called again. The I/O method should be called again later, with the same
arguments. Note: This won't occur in this version, as there are no such
callbacks in this version.
</dl>
<P>
<dl><dt><b>exception <a name='l2h-103'><tt class='exception'>SysCallError</tt></a></b>
<dd>
The <tt class="exception">SysCallError</tt> occurs when there's an I/O error and OpenSSL's
error queue does not contain any information. This can mean two things: An
error in the transport protocol, or an end of file that violates the protocol.
The parameter to the exception is always a pair <code>(<var>errnum</var>,
<var>errstr</var>)</code>.
</dl>
<P>
<BR><HR><H4>Footnotes</H4>
<DL>
<DT><A NAME="foot901">... socket</A><A
 href="openssl-ssl.html#tex2html5"><SUP>4</SUP></A></DT>
<DD>Actually, all that is required is an object that
<i>behaves</i> like a socket, you could even use files, even though it'd be
tricky to get the handshakes right!

</DD>
</DL>
<p><hr>

<!--Table of Child-Links-->
<A NAME="CHILD_LINKS"><STRONG>Subsections</STRONG></A>

<UL CLASS="ChildLinks">
<LI><A NAME="tex2html263"
  href="openssl-context.html">3.3.1 Context objects </A>
<LI><A NAME="tex2html264"
  href="openssl-connection.html">3.3.2 Connection objects </A>
</UL>
<!--End of Table of Child-Links-->

<DIV CLASS="navigation">
<p><hr>
<table align="center" width="100%" cellpadding="0" cellspacing="2">
<tr>
<td><A href="openssl-rand.html"><img src="previous.gif"
border="0" height="32"
  alt="Previous Page" width="32"></A></td>
<td><A href="openssl.html"><img src="up.gif"
border="0" height="32"
  alt="Up One Level" width="32"></A></td>
<td><A href="openssl-context.html"><img src="next.gif"
border="0" height="32"
  alt="Next Page" width="32"></A></td>
<td align="center" width="100%">Python OpenSSL Manual</td>
<td><A href="contents.html"><img src="contents.gif"
border="0" height="32"
  alt="Contents" width="32"></A></td>
<td><img src="blank.gif"
  border="0" height="32"
  alt="" width="32"></td>
<td><img src="blank.gif"
  border="0" height="32"
  alt="" width="32"></td>
</tr></table>
<b class="navlabel">Previous:</b> <a class="sectref" href="openssl-rand.html">3.2 rand  </A>
<b class="navlabel">Up:</b> <a class="sectref" href="openssl.html">3 OpenSSL  </A>
<b class="navlabel">Next:</b> <a class="sectref" href="openssl-context.html">3.3.1 Context objects</A>
<hr>
<span class="release-info">Release 0.6.</span>
</DIV>
<!--End of Navigation Panel-->

</BODY>
</HTML>