1=pod 2 3=head1 NAME 4 5SSL_CTX_set0_chain, SSL_CTX_set1_chain, SSL_CTX_add0_chain_cert, 6SSL_CTX_add1_chain_cert, SSL_CTX_get0_chain_certs, SSL_CTX_clear_chain_certs, 7SSL_set0_chain, SSL_set1_chain, SSL_add0_chain_cert, SSL_add1_chain_cert, 8SSL_get0_chain_certs, SSL_clear_chain_certs, SSL_CTX_build_cert_chain, 9SSL_build_cert_chain, SSL_CTX_select_current_cert, 10SSL_select_current_cert, SSL_CTX_set_current_cert, SSL_set_current_cert - extra 11chain certificate processing 12 13=head1 SYNOPSIS 14 15 #include <openssl/ssl.h> 16 17 int SSL_CTX_set0_chain(SSL_CTX *ctx, STACK_OF(X509) *sk); 18 int SSL_CTX_set1_chain(SSL_CTX *ctx, STACK_OF(X509) *sk); 19 int SSL_CTX_add0_chain_cert(SSL_CTX *ctx, X509 *x509); 20 int SSL_CTX_add1_chain_cert(SSL_CTX *ctx, X509 *x509); 21 int SSL_CTX_get0_chain_certs(SSL_CTX *ctx, STACK_OF(X509) **sk); 22 int SSL_CTX_clear_chain_certs(SSL_CTX *ctx); 23 24 int SSL_set0_chain(SSL *ssl, STACK_OF(X509) *sk); 25 int SSL_set1_chain(SSL *ssl, STACK_OF(X509) *sk); 26 int SSL_add0_chain_cert(SSL *ssl, X509 *x509); 27 int SSL_add1_chain_cert(SSL *ssl, X509 *x509); 28 int SSL_get0_chain_certs(SSL *ssl, STACK_OF(X509) **sk); 29 int SSL_clear_chain_certs(SSL *ssl); 30 31 int SSL_CTX_build_cert_chain(SSL_CTX *ctx, flags); 32 int SSL_build_cert_chain(SSL *ssl, flags); 33 34 int SSL_CTX_select_current_cert(SSL_CTX *ctx, X509 *x509); 35 int SSL_select_current_cert(SSL *ssl, X509 *x509); 36 int SSL_CTX_set_current_cert(SSL_CTX *ctx, long op); 37 int SSL_set_current_cert(SSL *ssl, long op); 38 39=head1 DESCRIPTION 40 41SSL_CTX_set0_chain() and SSL_CTX_set1_chain() set the certificate chain 42associated with the current certificate of B<ctx> to B<sk>. 43 44SSL_CTX_add0_chain_cert() and SSL_CTX_add1_chain_cert() append the single 45certificate B<x509> to the chain associated with the current certificate of 46B<ctx>. 47 48SSL_CTX_get0_chain_certs() retrieves the chain associated with the current 49certificate of B<ctx>. 50 51SSL_CTX_clear_chain_certs() clears any existing chain associated with the 52current certificate of B<ctx>. (This is implemented by calling 53SSL_CTX_set0_chain() with B<sk> set to B<NULL>). 54 55SSL_CTX_build_cert_chain() builds the certificate chain for B<ctx>. 56Normally this uses the chain store 57or the verify store if the chain store is not set. 58If the function is successful the built chain will replace any existing chain. 59The B<flags> parameter can be set to B<SSL_BUILD_CHAIN_FLAG_UNTRUSTED> to use 60existing chain certificates as untrusted CAs, B<SSL_BUILD_CHAIN_FLAG_NO_ROOT> 61to omit the root CA from the built chain, B<SSL_BUILD_CHAIN_FLAG_CHECK> to 62use all existing chain certificates only to build the chain (effectively 63sanity checking and rearranging them if necessary), the flag 64B<SSL_BUILD_CHAIN_FLAG_IGNORE_ERROR> ignores any errors during verification: 65if flag B<SSL_BUILD_CHAIN_FLAG_CLEAR_ERROR> is also set verification errors 66are cleared from the error queue. 67Details of the chain building process are described in 68L<openssl-verification-options(1)/Certification Path Building>. 69 70Each of these functions operates on the I<current> end entity 71(i.e. server or client) certificate. This is the last certificate loaded or 72selected on the corresponding B<ctx> structure. 73 74SSL_CTX_select_current_cert() selects B<x509> as the current end entity 75certificate, but only if B<x509> has already been loaded into B<ctx> using a 76function such as SSL_CTX_use_certificate(). 77 78SSL_set0_chain(), SSL_set1_chain(), SSL_add0_chain_cert(), 79SSL_add1_chain_cert(), SSL_get0_chain_certs(), SSL_clear_chain_certs(), 80SSL_build_cert_chain(), SSL_select_current_cert() and SSL_set_current_cert() 81are similar except they apply to SSL structure B<ssl>. 82 83SSL_CTX_set_current_cert() changes the current certificate to a value based 84on the B<op> argument. Currently B<op> can be B<SSL_CERT_SET_FIRST> to use 85the first valid certificate or B<SSL_CERT_SET_NEXT> to set the next valid 86certificate after the current certificate. These two operations can be 87used to iterate over all certificates in an B<SSL_CTX> structure. 88 89SSL_set_current_cert() also supports the option B<SSL_CERT_SET_SERVER>. 90If B<ssl> is a server and has sent a certificate to a connected client 91this option sets that certificate to the current certificate and returns 1. 92If the negotiated cipher suite is anonymous (and thus no certificate will 93be sent) 2 is returned and the current certificate is unchanged. If B<ssl> 94is not a server or a certificate has not been sent 0 is returned and 95the current certificate is unchanged. 96 97All these functions are implemented as macros. Those containing a B<1> 98increment the reference count of the supplied certificate or chain so it must 99be freed at some point after the operation. Those containing a B<0> do 100not increment reference counts and the supplied certificate or chain 101B<MUST NOT> be freed after the operation. 102 103=head1 NOTES 104 105The chains associate with an SSL_CTX structure are copied to any SSL 106structures when SSL_new() is called. SSL structures will not be affected 107by any chains subsequently changed in the parent SSL_CTX. 108 109One chain can be set for each key type supported by a server. So, for example, 110an RSA and a DSA certificate can (and often will) have different chains. 111 112The functions SSL_CTX_build_cert_chain() and SSL_build_cert_chain() can 113be used to check application configuration and to ensure any necessary 114subordinate CAs are sent in the correct order. Misconfigured applications 115sending incorrect certificate chains often cause problems with peers. 116 117For example an application can add any set of certificates using 118SSL_CTX_use_certificate_chain_file() then call SSL_CTX_build_cert_chain() 119with the option B<SSL_BUILD_CHAIN_FLAG_CHECK> to check and reorder them. 120 121Applications can issue non fatal warnings when checking chains by setting 122the flag B<SSL_BUILD_CHAIN_FLAG_IGNORE_ERRORS> and checking the return 123value. 124 125Calling SSL_CTX_build_cert_chain() or SSL_build_cert_chain() is more 126efficient than the automatic chain building as it is only performed once. 127Automatic chain building is performed on each new session. 128 129If any certificates are added using these functions no certificates added 130using SSL_CTX_add_extra_chain_cert() will be used. 131 132=head1 RETURN VALUES 133 134SSL_set_current_cert() with B<SSL_CERT_SET_SERVER> return 1 for success, 2 if 135no server certificate is used because the cipher suites is anonymous and 0 136for failure. 137 138SSL_CTX_build_cert_chain() and SSL_build_cert_chain() return 1 for success 139and 0 for failure. If the flag B<SSL_BUILD_CHAIN_FLAG_IGNORE_ERROR> and 140a verification error occurs then 2 is returned. 141 142All other functions return 1 for success and 0 for failure. 143 144=head1 SEE ALSO 145 146L<ssl(7)>, 147L<SSL_CTX_add_extra_chain_cert(3)> 148 149=head1 HISTORY 150 151These functions were added in OpenSSL 1.0.2. 152 153=head1 COPYRIGHT 154 155Copyright 2013-2021 The OpenSSL Project Authors. All Rights Reserved. 156 157Licensed under the Apache License 2.0 (the "License"). You may not use 158this file except in compliance with the License. You can obtain a copy 159in the file LICENSE in the source distribution or at 160L<https://www.openssl.org/source/license.html>. 161 162=cut 163