xref: /freebsd-src/contrib/libevent/sample/openssl_hostname_validation.h (revision c6879c6c14eedbd060ba588a3129a6c60ebbe783)
1*c43e99fdSEd Maste /* Obtained from: https://github.com/iSECPartners/ssl-conservatory */
2*c43e99fdSEd Maste 
3*c43e99fdSEd Maste /*
4*c43e99fdSEd Maste Copyright (C) 2012, iSEC Partners.
5*c43e99fdSEd Maste 
6*c43e99fdSEd Maste Permission is hereby granted, free of charge, to any person obtaining a copy of
7*c43e99fdSEd Maste this software and associated documentation files (the "Software"), to deal in
8*c43e99fdSEd Maste the Software without restriction, including without limitation the rights to
9*c43e99fdSEd Maste use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies
10*c43e99fdSEd Maste of the Software, and to permit persons to whom the Software is furnished to do
11*c43e99fdSEd Maste so, subject to the following conditions:
12*c43e99fdSEd Maste 
13*c43e99fdSEd Maste The above copyright notice and this permission notice shall be included in all
14*c43e99fdSEd Maste copies or substantial portions of the Software.
15*c43e99fdSEd Maste 
16*c43e99fdSEd Maste THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
17*c43e99fdSEd Maste IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
18*c43e99fdSEd Maste FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
19*c43e99fdSEd Maste AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
20*c43e99fdSEd Maste LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
21*c43e99fdSEd Maste OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*c43e99fdSEd Maste SOFTWARE.
23*c43e99fdSEd Maste  */
24*c43e99fdSEd Maste 
25*c43e99fdSEd Maste /*
26*c43e99fdSEd Maste  * Helper functions to perform basic hostname validation using OpenSSL.
27*c43e99fdSEd Maste  *
28*c43e99fdSEd Maste  * Please read "everything-you-wanted-to-know-about-openssl.pdf" before
29*c43e99fdSEd Maste  * attempting to use this code. This whitepaper describes how the code works,
30*c43e99fdSEd Maste  * how it should be used, and what its limitations are.
31*c43e99fdSEd Maste  *
32*c43e99fdSEd Maste  * Author:  Alban Diquet
33*c43e99fdSEd Maste  * License: See LICENSE
34*c43e99fdSEd Maste  *
35*c43e99fdSEd Maste  */
36*c43e99fdSEd Maste 
37*c43e99fdSEd Maste typedef enum {
38*c43e99fdSEd Maste         MatchFound,
39*c43e99fdSEd Maste         MatchNotFound,
40*c43e99fdSEd Maste         NoSANPresent,
41*c43e99fdSEd Maste         MalformedCertificate,
42*c43e99fdSEd Maste         Error
43*c43e99fdSEd Maste } HostnameValidationResult;
44*c43e99fdSEd Maste 
45*c43e99fdSEd Maste /**
46*c43e99fdSEd Maste * Validates the server's identity by looking for the expected hostname in the
47*c43e99fdSEd Maste * server's certificate. As described in RFC 6125, it first tries to find a match
48*c43e99fdSEd Maste * in the Subject Alternative Name extension. If the extension is not present in
49*c43e99fdSEd Maste * the certificate, it checks the Common Name instead.
50*c43e99fdSEd Maste *
51*c43e99fdSEd Maste * Returns MatchFound if a match was found.
52*c43e99fdSEd Maste * Returns MatchNotFound if no matches were found.
53*c43e99fdSEd Maste * Returns MalformedCertificate if any of the hostnames had a NUL character embedded in it.
54*c43e99fdSEd Maste * Returns Error if there was an error.
55*c43e99fdSEd Maste */
56*c43e99fdSEd Maste HostnameValidationResult validate_hostname(const char *hostname, const X509 *server_cert);
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