1=pod
2
3=head1 NAME
4
5SRP_VBASE_new,
6SRP_VBASE_free,
7SRP_VBASE_init,
8SRP_VBASE_add0_user,
9SRP_VBASE_get1_by_user,
10SRP_VBASE_get_by_user
11- Functions to create and manage a stack of SRP user verifier information
12
13=head1 SYNOPSIS
14
15 #include <openssl/srp.h>
16
17Deprecated since OpenSSL 3.0, can be hidden entirely by defining
18B<OPENSSL_API_COMPAT> with a suitable version value, see
19L<openssl_user_macros(7)>:
20
21 SRP_VBASE *SRP_VBASE_new(char *seed_key);
22 void SRP_VBASE_free(SRP_VBASE *vb);
23
24 int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file);
25
26 int SRP_VBASE_add0_user(SRP_VBASE *vb, SRP_user_pwd *user_pwd);
27 SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username);
28 SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username);
29
30=head1 DESCRIPTION
31
32All of the functions described on this page are deprecated. There are no
33available replacement functions at this time.
34
35The SRP_VBASE_new() function allocates a structure to store server side SRP
36verifier information.
37If B<seed_key> is not NULL a copy is stored and used to generate dummy parameters
38for users that are not found by SRP_VBASE_get1_by_user(). This allows the server
39to hide the fact that it doesn't have a verifier for a particular username,
40as described in section 2.5.1.3 'Unknown SRP' of RFC 5054.
41The seed string should contain random NUL terminated binary data (therefore
42the random data should not contain NUL bytes!).
43
44The SRP_VBASE_free() function frees up the B<vb> structure.
45If B<vb> is NULL, nothing is done.
46
47The SRP_VBASE_init() function parses the information in a verifier file and
48populates the B<vb> structure.
49The verifier file is a text file containing multiple entries, whose format is:
50flag base64(verifier) base64(salt) username gNid userinfo(optional)
51where the flag can be 'V' (valid) or 'R' (revoked).
52Note that the base64 encoding used here is non-standard so it is recommended
53to use L<openssl-srp(1)> to generate this file.
54
55The SRP_VBASE_add0_user() function adds the B<user_pwd> verifier information
56to the B<vb> structure. See L<SRP_user_pwd_new(3)> to create and populate this
57record.
58The library takes ownership of B<user_pwd>, it should not be freed by the caller.
59
60The SRP_VBASE_get1_by_user() function returns the password info for the user
61whose username matches B<username>. It replaces the deprecated
62SRP_VBASE_get_by_user().
63If no matching user is found but a seed_key and default gN parameters have been
64set, dummy authentication information is generated from the seed_key, allowing
65the server to hide the fact that it doesn't have a verifier for a particular
66username. When using SRP as a TLS authentication mechanism, this will cause
67the handshake to proceed normally but the first client will be rejected with
68a "bad_record_mac" alert, as if the password was incorrect.
69If no matching user is found and the seed_key is not set, NULL is returned.
70Ownership of the returned pointer is released to the caller, it must be freed
71with SRP_user_pwd_free().
72
73=head1 RETURN VALUES
74
75SRP_VBASE_init() returns B<SRP_NO_ERROR> (0) on success and a positive value
76on failure.
77The error codes are B<SRP_ERR_OPEN_FILE> if the file could not be opened,
78B<SRP_ERR_VBASE_INCOMPLETE_FILE> if the file could not be parsed,
79B<SRP_ERR_MEMORY> on memory allocation failure and B<SRP_ERR_VBASE_BN_LIB>
80for invalid decoded parameter values.
81
82SRP_VBASE_add0_user() returns 1 on success and 0 on failure.
83
84=head1 SEE ALSO
85
86L<openssl-srp(1)>,
87L<SRP_create_verifier(3)>,
88L<SRP_user_pwd_new(3)>,
89L<SSL_CTX_set_srp_password(3)>
90
91=head1 HISTORY
92
93The SRP_VBASE_add0_user() function was added in OpenSSL 3.0.
94
95All other functions were added in OpenSSL 1.0.1.
96
97All of these functions were deprecated in OpenSSL 3.0.
98
99=head1 COPYRIGHT
100
101Copyright 2018-2021 The OpenSSL Project Authors. All Rights Reserved.
102
103Licensed under the Apache License 2.0 (the "License").  You may not use
104this file except in compliance with the License.  You can obtain a copy
105in the file LICENSE in the source distribution or at
106L<https://www.openssl.org/source/license.html>.
107
108=cut
109