mirror of
https://github.com/openssl/openssl.git
synced 2024-11-27 05:21:51 +08:00
116 lines
4.2 KiB
Plaintext
116 lines
4.2 KiB
Plaintext
=pod
|
|
|
|
=head1 NAME
|
|
|
|
SSL_set1_host, SSL_add1_host, SSL_set_hostflags, SSL_get0_peername -
|
|
SSL server verification parameters
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
#include <openssl/ssl.h>
|
|
#include <openssl/x509_vfy.h>
|
|
|
|
int SSL_set1_host(SSL *s, const char *hostname);
|
|
int SSL_add1_host(SSL *s, const char *hostname);
|
|
void SSL_set_hostflags(SSL *s, unsigned int flags);
|
|
const char *SSL_get0_peername(SSL *s);
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
These functions configure server hostname checks in the SSL client.
|
|
|
|
SSL_set1_host() sets the expected DNS hostname to B<name> clearing
|
|
any previously specified host name or names. If B<name> is NULL,
|
|
or the empty string the list of hostnames is cleared, and name
|
|
checks are not performed on the peer certificate. When a non-empty
|
|
B<name> is specified, certificate verification automatically checks
|
|
the peer hostname via L<X509_check_host(3)> with B<flags> as specified
|
|
via SSL_set_hostflags(). Clients that enable DANE TLSA authentication
|
|
via L<SSL_dane_enable(3)> should leave it to that function to set
|
|
the primary reference identifier of the peer, and should not call
|
|
SSL_set1_host().
|
|
|
|
SSL_add1_host() adds B<name> as an additional reference identifier
|
|
that can match the peer's certificate. Any previous names set via
|
|
SSL_set1_host() or SSL_add1_host() are retained, no change is made
|
|
if B<name> is NULL or empty. When multiple names are configured,
|
|
the peer is considered verified when any name matches. This function
|
|
is required for DANE TLSA in the presence of service name indirection
|
|
via CNAME, MX or SRV records as specified in RFC7671, RFC7672 or
|
|
RFC7673.
|
|
|
|
SSL_set_hostflags() sets the B<flags> that will be passed to
|
|
L<X509_check_host(3)> when name checks are applicable, by default
|
|
the B<flags> value is 0. See L<X509_check_host(3)> for the list
|
|
of available flags and their meaning.
|
|
|
|
SSL_get0_peername() returns the DNS hostname or subject CommonName
|
|
from the peer certificate that matched one of the reference
|
|
identifiers. When wildcard matching is not disabled, the name
|
|
matched in the peer certificate may be a wildcard name. When one
|
|
of the reference identifiers configured via SSL_set1_host() or
|
|
SSL_add1_host() starts with ".", which indicates a parent domain prefix
|
|
rather than a fixed name, the matched peer name may be a sub-domain
|
|
of the reference identifier. The returned string is allocated by
|
|
the library and is no longer valid once the associated B<ssl> handle
|
|
is cleared or freed, or a renegotiation takes place. Applications
|
|
must not free the return value.
|
|
|
|
SSL clients are advised to use these functions in preference to
|
|
explicitly calling L<X509_check_host(3)>. Hostname checks are out
|
|
of scope with the RFC7671 DANE-EE(3) certificate usage, and the
|
|
internal check will be suppressed as appropriate when DANE is
|
|
enabled.
|
|
|
|
=head1 RETURN VALUES
|
|
|
|
SSL_set1_host() and SSL_add1_host() return 1 for success and 0 for
|
|
failure.
|
|
|
|
SSL_get0_peername() returns NULL if peername verification is not
|
|
applicable (as with RFC7671 DANE-EE(3)), or no trusted peername was
|
|
matched. Otherwise, it returns the matched peername. To determine
|
|
whether verification succeeded call L<SSL_get_verify_result(3)>.
|
|
|
|
=head1 NOTES
|
|
|
|
=head1 EXAMPLE
|
|
|
|
Suppose "smtp.example.com" is the MX host of the domain "example.com".
|
|
The calls below will arrange to match either the MX hostname or the
|
|
destination domain name in the SMTP server certificate. Wildcards
|
|
are supported, but must match the entire label. The actual name
|
|
matched in the certificate (which might be a wildcard) is retrieved,
|
|
and must be copied by the application if it is to be retained beyond
|
|
the lifetime of the SSL connection.
|
|
|
|
SSL_set_hostflags(ssl, X509_CHECK_FLAG_NO_PARTIAL_WILDCARDS);
|
|
if (!SSL_set1_host(ssl, "smtp.example.com")) {
|
|
/* handle error */
|
|
}
|
|
if (!SSL_add1_host(ssl, "example.com")) {
|
|
/* handle error */
|
|
}
|
|
|
|
/* XXX: Perform SSL_connect() handshake and handle errors here */
|
|
|
|
if (SSL_get_verify_result(ssl) == X509_V_OK) {
|
|
const char *peername = SSL_get0_peername(ssl);
|
|
|
|
if (peername != NULL) {
|
|
/* Name checks were in scope and matched the peername */
|
|
}
|
|
}
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<X509_check_host(3)>,
|
|
L<SSL_get_verify_result(3)>.
|
|
L<SSL_dane_enable(3)>.
|
|
|
|
=head1 HISTORY
|
|
|
|
These functions were first added to OpenSSL 1.1.0.
|
|
|
|
=cut
|