summaryrefslogtreecommitdiff
path: root/manual/html_node/Overriding-algorithms.html
blob: 9b6b9b13a18a6d156841ffdf2a8666b2e4cea791 (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
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
<!DOCTYPE html PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN" "http://www.w3.org/TR/html4/loose.dtd">
<html>
<!-- This manual is last updated 4 March 2015 for version
3.5.4 of GnuTLS.

Copyright (C) 2001-2015 Free Software Foundation, Inc.\\
Copyright (C) 2001-2015 Nikos Mavrogiannopoulos

Permission is granted to copy, distribute and/or modify this document
under the terms of the GNU Free Documentation License, Version 1.3 or
any later version published by the Free Software Foundation; with no
Invariant Sections, no Front-Cover Texts, and no Back-Cover Texts.  A
copy of the license is included in the section entitled "GNU Free
Documentation License". -->
<!-- Created by GNU Texinfo 6.1, http://www.gnu.org/software/texinfo/ -->
<head>
<title>GnuTLS 3.5.4: Overriding algorithms</title>

<meta name="description" content="GnuTLS 3.5.4: Overriding algorithms">
<meta name="keywords" content="GnuTLS 3.5.4: Overriding algorithms">
<meta name="resource-type" content="document">
<meta name="distribution" content="global">
<meta name="Generator" content="makeinfo">
<meta http-equiv="Content-Type" content="text/html; charset=utf-8">
<link href="index.html#Top" rel="start" title="Top">
<link href="Function-and-Data-Index.html#Function-and-Data-Index" rel="index" title="Function and Data Index">
<link href="index.html#SEC_Contents" rel="contents" title="Table of Contents">
<link href="Using-GnuTLS-as-a-cryptographic-library.html#Using-GnuTLS-as-a-cryptographic-library" rel="up" title="Using GnuTLS as a cryptographic library">
<link href="Other-included-programs.html#Other-included-programs" rel="next" title="Other included programs">
<link href="Random-number-generation.html#Random-number-generation" rel="prev" title="Random number generation">
<style type="text/css">
<!--
a.summary-letter {text-decoration: none}
blockquote.indentedblock {margin-right: 0em}
blockquote.smallindentedblock {margin-right: 0em; font-size: smaller}
blockquote.smallquotation {font-size: smaller}
div.display {margin-left: 3.2em}
div.example {margin-left: 3.2em}
div.lisp {margin-left: 3.2em}
div.smalldisplay {margin-left: 3.2em}
div.smallexample {margin-left: 3.2em}
div.smalllisp {margin-left: 3.2em}
kbd {font-style: oblique}
pre.display {font-family: inherit}
pre.format {font-family: inherit}
pre.menu-comment {font-family: serif}
pre.menu-preformatted {font-family: serif}
pre.smalldisplay {font-family: inherit; font-size: smaller}
pre.smallexample {font-size: smaller}
pre.smallformat {font-family: inherit; font-size: smaller}
pre.smalllisp {font-size: smaller}
span.nolinebreak {white-space: nowrap}
span.roman {font-family: initial; font-weight: normal}
span.sansserif {font-family: sans-serif; font-weight: normal}
ul.no-bullet {list-style: none}
body { 
	margin: 2%;
	padding: 0 5%;
	background: #ffffff;
}
h1,h2,h3,h4,h5 {
    font-weight: bold;
    padding: 5px 5px 5px 5px;
    background-color: #c2e0ff;
    color: #336699;
}
h1 {
    padding: 2em 2em 2em 5%;
    color: white;
    background: #336699;
    text-align: center;
    letter-spacing: 3px;
}
h2 { text-decoration: underline; }
pre {
  margin: 0 5%;
  padding: 0.5em;
}
pre.example,pre.verbatim {
  padding-bottom: 1em;

  border: solid #c2e0ff;
  background: #f0faff;
  border-width: 1px 1px 1px 5px;
  margin: 1em auto;
  width: 90%;
}

div.node {
  margin: 0 -5% 0 -2%;
  padding: 0.5em 0.5em;
  margin-top: 0.5em;
  margin-bottom: 0.5em;
  font-weight: bold;
}
dd, li {
  padding-top: 0.1em;
  padding-bottom: 0.1em;
}
div.float {

  margin-bottom: 0.5em;
  text-align: center;
}

table {
  text-align: left;
  margin-left:auto;
  margin-right:auto;
  border-spacing: 7px;
  width: 50%;
}

th {
  padding: 0;
  color: #336699;
  background-color: #c2e0ff;
  border: solid #000000;
  border-width: 0px;
  margin: 1em auto;
  text-align: center;
  margin-left:auto;
  margin-right:auto;
}

td {
  padding: 0;
  border: solid #000000;
  background-color: #f0faff;
  border-width: 0px;
  margin: 1em auto;
  text-align: left;
  margin-left:auto;
  margin-right:auto;
  padding-left: 1em;
}

dl {
  text-align: left;
  margin-left:auto;
  margin-right:auto;
  width: 50%;

  padding-left: 1em;
  border: solid #c2e0ff;
  background: #f0faff;
  border-width: 5px 1px 1px 1px;
  margin: 1em auto;
}

-->
</style>


</head>

<body lang="en">
<a name="Overriding-algorithms"></a>
<div class="header">
<p>
Previous: <a href="Random-number-generation.html#Random-number-generation" accesskey="p" rel="prev">Random number generation</a>, Up: <a href="Using-GnuTLS-as-a-cryptographic-library.html#Using-GnuTLS-as-a-cryptographic-library" accesskey="u" rel="up">Using GnuTLS as a cryptographic library</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Function-and-Data-Index.html#Function-and-Data-Index" title="Index" rel="index">Index</a>]</p>
</div>
<hr>
<a name="Overriding-algorithms-1"></a>
<h3 class="section">8.5 Overriding algorithms</h3>
<a name="index-overriding-algorithms"></a>

<p>In systems which provide a hardware accelerated cipher implementation
that is not directly supported by GnuTLS, it is possible to utilize it.
There are functions which allow overriding the default cipher, digest and MAC
implementations. Those are described below.
</p>
<p>To override public key operations see <a href="Abstract-private-keys.html#Abstract-private-keys">Abstract private keys</a>.
</p>




<dl>
<dt><a name="index-gnutls_005fcrypto_005fregister_005fcipher"></a>Function: <em>int</em> <strong>gnutls_crypto_register_cipher</strong> <em>(gnutls_cipher_algorithm_t <var>algorithm</var>, int <var>priority</var>, gnutls_cipher_init_func <var>init</var>, gnutls_cipher_setkey_func <var>setkey</var>, gnutls_cipher_setiv_func <var>setiv</var>, gnutls_cipher_encrypt_func <var>encrypt</var>, gnutls_cipher_decrypt_func <var>decrypt</var>, gnutls_cipher_deinit_func <var>deinit</var>)</em></dt>
<dd><p><var>algorithm</var>: is the gnutls algorithm identifier
</p>
<p><var>priority</var>: is the priority of the algorithm
</p>
<p><var>init</var>: A function which initializes the cipher
</p>
<p><var>setkey</var>: A function which sets the key of the cipher
</p>
<p><var>setiv</var>: A function which sets the nonce/IV of the cipher (non-AEAD)
</p>
<p><var>encrypt</var>: A function which performs encryption (non-AEAD)
</p>
<p><var>decrypt</var>: A function which performs decryption (non-AEAD)
</p>
<p><var>deinit</var>: A function which deinitializes the cipher
</p>
<p>This function will register a cipher algorithm to be used by
gnutls.  Any algorithm registered will override the included
algorithms and by convention kernel implemented algorithms have
priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be
used by gnutls.
</p>
<p>In the case the registered init or setkey functions return <code>GNUTLS_E_NEED_FALLBACK</code> ,
GnuTLS will attempt to use the next in priority registered cipher.
</p>
<p>The functions which are marked as non-AEAD they are not required when
registering a cipher to be used with the new AEAD API introduced in
GnuTLS 3.4.0. Internally GnuTLS uses the new AEAD API.
</p>
<p><strong>Returns:</strong> <code>GNUTLS_E_SUCCESS</code>  on success, otherwise a negative error code.
</p>
<p><strong>Since:</strong> 3.4.0
</p></dd></dl>




<dl>
<dt><a name="index-gnutls_005fcrypto_005fregister_005faead_005fcipher"></a>Function: <em>int</em> <strong>gnutls_crypto_register_aead_cipher</strong> <em>(gnutls_cipher_algorithm_t <var>algorithm</var>, int <var>priority</var>, gnutls_cipher_init_func <var>init</var>, gnutls_cipher_setkey_func <var>setkey</var>, gnutls_cipher_aead_encrypt_func <var>aead_encrypt</var>, gnutls_cipher_aead_decrypt_func <var>aead_decrypt</var>, gnutls_cipher_deinit_func <var>deinit</var>)</em></dt>
<dd><p><var>algorithm</var>: is the gnutls AEAD cipher identifier
</p>
<p><var>priority</var>: is the priority of the algorithm
</p>
<p><var>init</var>: A function which initializes the cipher
</p>
<p><var>setkey</var>: A function which sets the key of the cipher
</p>
<p><var>aead_encrypt</var>: Perform the AEAD encryption
</p>
<p><var>aead_decrypt</var>: Perform the AEAD decryption
</p>
<p><var>deinit</var>: A function which deinitializes the cipher
</p>
<p>This function will register a cipher algorithm to be used by
gnutls.  Any algorithm registered will override the included
algorithms and by convention kernel implemented algorithms have
priority of 90 and CPU-assisted of 80.  The algorithm with the lowest priority will be
used by gnutls.
</p>
<p>In the case the registered init or setkey functions return <code>GNUTLS_E_NEED_FALLBACK</code> ,
GnuTLS will attempt to use the next in priority registered cipher.
</p>
<p>The functions registered will be used with the new AEAD API introduced in
GnuTLS 3.4.0. Internally GnuTLS uses the new AEAD API.
</p>
<p><strong>Returns:</strong> <code>GNUTLS_E_SUCCESS</code>  on success, otherwise a negative error code.
</p>
<p><strong>Since:</strong> 3.4.0
</p></dd></dl>




<dl>
<dt><a name="index-gnutls_005fcrypto_005fregister_005fmac"></a>Function: <em>int</em> <strong>gnutls_crypto_register_mac</strong> <em>(gnutls_mac_algorithm_t <var>algorithm</var>, int <var>priority</var>, gnutls_mac_init_func <var>init</var>, gnutls_mac_setkey_func <var>setkey</var>, gnutls_mac_setnonce_func <var>setnonce</var>, gnutls_mac_hash_func <var>hash</var>, gnutls_mac_output_func <var>output</var>, gnutls_mac_deinit_func <var>deinit</var>, gnutls_mac_fast_func <var>hash_fast</var>)</em></dt>
<dd><p><var>algorithm</var>: is the gnutls MAC identifier
</p>
<p><var>priority</var>: is the priority of the algorithm
</p>
<p><var>init</var>: A function which initializes the MAC
</p>
<p><var>setkey</var>: A function which sets the key of the MAC
</p>
<p><var>setnonce</var>: A function which sets the nonce for the mac (may be <code>NULL</code>  for common MAC algorithms)
</p>
<p><var>hash</var>: Perform the hash operation
</p>
<p><var>output</var>: Provide the output of the MAC
</p>
<p><var>deinit</var>: A function which deinitializes the MAC
</p>
<p><var>hash_fast</var>: Perform the MAC operation in one go
</p>
<p>This function will register a MAC algorithm to be used by gnutls.
Any algorithm registered will override the included algorithms and
by convention kernel implemented algorithms have priority of 90
and CPU-assisted of 80.
The algorithm with the lowest priority will be used by gnutls.
</p>
<p><strong>Returns:</strong> <code>GNUTLS_E_SUCCESS</code>  on success, otherwise a negative error code.
</p>
<p><strong>Since:</strong> 3.4.0
</p></dd></dl>




<dl>
<dt><a name="index-gnutls_005fcrypto_005fregister_005fdigest"></a>Function: <em>int</em> <strong>gnutls_crypto_register_digest</strong> <em>(gnutls_digest_algorithm_t <var>algorithm</var>, int <var>priority</var>, gnutls_digest_init_func <var>init</var>, gnutls_digest_hash_func <var>hash</var>, gnutls_digest_output_func <var>output</var>, gnutls_digest_deinit_func <var>deinit</var>, gnutls_digest_fast_func <var>hash_fast</var>)</em></dt>
<dd><p><var>algorithm</var>: is the gnutls digest identifier
</p>
<p><var>priority</var>: is the priority of the algorithm
</p>
<p><var>init</var>: A function which initializes the digest
</p>
<p><var>hash</var>: Perform the hash operation
</p>
<p><var>output</var>: Provide the output of the digest
</p>
<p><var>deinit</var>: A function which deinitializes the digest
</p>
<p><var>hash_fast</var>: Perform the digest operation in one go
</p>
<p>This function will register a digest algorithm to be used by gnutls.
Any algorithm registered will override the included algorithms and
by convention kernel implemented algorithms have priority of 90
and CPU-assisted of 80.
The algorithm with the lowest priority will be used by gnutls.
</p>
<p><strong>Returns:</strong> <code>GNUTLS_E_SUCCESS</code>  on success, otherwise a negative error code.
</p>
<p><strong>Since:</strong> 3.4.0
</p></dd></dl>

<hr>
<div class="header">
<p>
Previous: <a href="Random-number-generation.html#Random-number-generation" accesskey="p" rel="prev">Random number generation</a>, Up: <a href="Using-GnuTLS-as-a-cryptographic-library.html#Using-GnuTLS-as-a-cryptographic-library" accesskey="u" rel="up">Using GnuTLS as a cryptographic library</a> &nbsp; [<a href="index.html#SEC_Contents" title="Table of contents" rel="contents">Contents</a>][<a href="Function-and-Data-Index.html#Function-and-Data-Index" title="Index" rel="index">Index</a>]</p>
</div>



</body>
</html>