Latest update

doc/man3/SRP_VBASE_new.pod

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+=pod
+
+=head1 NAME
+
+SRP_VBASE_new,
+SRP_VBASE_free,
+SRP_VBASE_init,
+SRP_VBASE_add0_user,
+SRP_VBASE_get1_by_user,
+SRP_VBASE_get_by_user
+- Functions to create and manage a stack of SRP user verifier information
+
+=head1 SYNOPSIS
+
+ #include <openssl/srp.h>
+
+ SRP_VBASE *SRP_VBASE_new(char *seed_key);
+ void SRP_VBASE_free(SRP_VBASE *vb);
+
+ int SRP_VBASE_init(SRP_VBASE *vb, char *verifier_file);
+
+ int SRP_VBASE_add0_user(SRP_VBASE *vb, SRP_user_pwd *user_pwd);
+ SRP_user_pwd *SRP_VBASE_get1_by_user(SRP_VBASE *vb, char *username);
+ SRP_user_pwd *SRP_VBASE_get_by_user(SRP_VBASE *vb, char *username);
+
+=head1 DESCRIPTION
+
+The SRP_VBASE_new() function allocates a structure to store server side SRP
+verifier information.
+If B<seed_key> is not NULL a copy is stored and used to generate dummy parameters
+for users that are not found by SRP_VBASE_get1_by_user(). This allows the server
+to hide the fact that it doesn't have a verifier for a particular username,
+as described in section 2.5.1.3 'Unknown SRP' of RFC 5054.
+The seed string should contain random NUL terminated binary data (therefore
+the random data should not contain NUL bytes!).
+
+The SRP_VBASE_free() function frees up the B<vb> structure.
+If B<vb> is NULL, nothing is done.
+
+The SRP_VBASE_init() function parses the information in a verifier file and
+populates the B<vb> structure.
+The verifier file is a text file containing multiple entries, whose format is:
+flag base64(verifier) base64(salt) username gNid userinfo(optional)
+where the flag can be 'V' (valid) or 'R' (revoked).
+Note that the base64 encoding used here is non-standard so it is recommended
+to use L<srp(1)> to generate this file.
+
+The SRP_VBASE_add0_user() function adds the B<user_pwd> verifier information
+to the B<vb> structure. See L<SRP_user_pwd_new(3)> to create and populate this
+record.
+The library takes ownership of B<user_pwd>, it should not be freed by the caller.
+
+The SRP_VBASE_get1_by_user() function returns the password info for the user
+whose username matches B<username>. It replaces the deprecated
+SRP_VBASE_get_by_user().
+If no matching user is found but a seed_key and default gN parameters have been
+set, dummy authentication information is generated from the seed_key, allowing
+the server to hide the fact that it doesn't have a verifier for a particular
+username. When using SRP as a TLS authentication mechanism, this will cause
+the handshake to proceed normally but the first client will be rejected with
+a "bad_record_mac" alert, as if the password was incorrect.
+If no matching user is found and the seed_key is not set, NULL is returned.
+Ownership of the returned pointer is released to the caller, it must be freed
+with SRP_user_pwd_free().
+
+=head1 RETURN VALUES
+
+SRP_VBASE_init() returns B<SRP_NO_ERROR> (0) on success and a positive value
+on failure.
+The error codes are B<SRP_ERR_OPEN_FILE> if the file could not be opened,
+B<SRP_ERR_VBASE_INCOMPLETE_FILE> if the file could not be parsed,
+B<SRP_ERR_MEMORY> on memory allocation failure and B<SRP_ERR_VBASE_BN_LIB>
+for invalid decoded parameter values.
+
+SRP_VBASE_add0_user() returns 1 on success and 0 on failure.
+
+=head1 SEE ALSO
+
+L<srp(1)>,
+L<SRP_create_verifier(3)>,
+L<SRP_user_pwd_new(3)>,
+L<SSL_CTX_set_srp_password(3)>
+
+=head1 HISTORY
+
+SRP_VBASE_add0_user() was first added to OpenSSL 1.2.0.
+
+All other functions were first added to OpenSSL 1.0.1.
+
+=head1 COPYRIGHT
+
+Copyright 2018 The OpenSSL Project Authors. All Rights Reserved.
+
+Licensed under the OpenSSL license (the "License").  You may not use
+this file except in compliance with the License.  You can obtain a copy
+in the file LICENSE in the source distribution or at
+L<https://www.openssl.org/source/license.html>.
+
+=cut