Security hardening: Expose Build flags for Position Independed Execution (PIE)

[openssl.git] / doc / man3 / X509_check_host.pod

diff --git a/doc/man3/X509_check_host.pod b/doc/man3/X509_check_host.pod
index 93848152b5ec1a6b27d599ab54e4949460371f05..0156194c9915e18c117e057f73e6e01fa05053dd 100644 (file)
--- a/doc/man3/X509_check_host.pod
+++ b/doc/man3/X509_check_host.pod
@@ -6,7 +6,7 @@ X509_check_host, X509_check_email, X509_check_ip, X509_check_ip_asc - X.509 cert
 
 =head1 SYNOPSIS
 
- #include <openssl/x509.h>
+ #include <openssl/x509v3.h>
 
  int X509_check_host(X509 *, const char *name, size_t namelen,
                      unsigned int flags, char **peername);
@@ -19,13 +19,13 @@ X509_check_host, X509_check_email, X509_check_ip, X509_check_ip_asc - X.509 cert
 =head1 DESCRIPTION
 
 The certificate matching functions are used to check whether a
-certificate matches a given host name, email address, or IP address.
+certificate matches a given hostname, email address, or IP address.
 The validity of the certificate and its trust level has to be checked by
 other means.
 
 X509_check_host() checks if the certificate Subject Alternative
-Name (SAN) or Subject CommonName (CN) matches the specified host
-name, which must be encoded in the preferred name syntax described
+Name (SAN) or Subject CommonName (CN) matches the specified hostname,
+which must be encoded in the preferred name syntax described
 in section 3.5 of RFC 1034.  By default, wildcards are supported
 and they match  only in the left-most label; but they may match
 part of that label with an explicit prefix or suffix.  For example,
@@ -37,7 +37,7 @@ Per section 6.4.2 of RFC 6125, B<name> values representing international
 domain names must be given in A-label form.  The B<namelen> argument
 must be the number of characters in the name string or zero in which
 case the length is calculated with strlen(B<name>).  When B<name> starts
-with a dot (e.g ".example.com"), it will be matched by a certificate
+with a dot (e.g. ".example.com"), it will be matched by a certificate
 valid for any sub-domain of B<name>, (see also
 B<X509_CHECK_FLAG_SINGLE_LABEL_SUBDOMAINS> below).
 
@@ -48,9 +48,13 @@ is responsible for freeing the peername via OPENSSL_free() when it
 is no longer needed.
 
 X509_check_email() checks if the certificate matches the specified
-email B<address>.  Only the mailbox syntax of RFC 822 is supported,
+email B<address>. The mailbox syntax of RFC 822 is supported,
 comments are not allowed, and no attempt is made to normalize quoted
-characters.  The B<addresslen> argument must be the number of
+characters. The mailbox syntax of RFC 6531 is supported for
+SmtpUTF8Mailbox address in subjectAltName according to RFC 8398,
+with similar limitations as for RFC 822 syntax, and no attempt
+is made to convert from A-label to U-label before comparison.
+The B<addresslen> argument must be the number of
 characters in the address string or zero in which case the length
 is calculated with strlen(B<address>).
 
@@ -58,7 +62,8 @@ X509_check_ip() checks if the certificate matches a specified IPv4 or
 IPv6 address.  The B<address> array is in binary format, in network
 byte order.  The length is either 4 (IPv4) or 16 (IPv6).  Only
 explicitly marked addresses in the certificates are considered; IP
-addresses stored in DNS names and Common Names are ignored.
+addresses stored in DNS names and Common Names are ignored. There are
+currently no B<flags> that would affect the behavior of this call.
 
 X509_check_ip_asc() is similar, except that the NUL-terminated
 string B<address> is first converted to the internal representation.
@@ -93,6 +98,9 @@ consider the subject DN even if the certificate contains no subject alternative
 names of the right type (DNS name or email address as appropriate); the default
 is to use the subject DN when no corresponding subject alternative names are
 present.
+If both B<X509_CHECK_FLAG_ALWAYS_CHECK_SUBJECT> and
+B<X509_CHECK_FLAG_NEVER_CHECK_SUBJECT> are specified, the latter takes
+precedence and the subject DN is not checked for matching names.
 
 If set, B<X509_CHECK_FLAG_NO_WILDCARDS> disables wildcard
 expansion; this only applies to B<X509_check_host>.
@@ -127,10 +135,10 @@ NULs.
 =head1 NOTES
 
 Applications are encouraged to use X509_VERIFY_PARAM_set1_host()
-rather than explicitly calling L<X509_check_host(3)>. Host name
-checks are out of scope with the DANE-EE(3) certificate usage,
+rather than explicitly calling L<X509_check_host(3)>. Hostname
+checks may be out of scope with the DANE-EE(3) certificate usage,
 and the internal checks will be suppressed as appropriate when
-DANE support is added to OpenSSL.
+DANE support is enabled.
 
 =head1 SEE ALSO
 
@@ -138,8 +146,7 @@ L<SSL_get_verify_result(3)>,
 L<X509_VERIFY_PARAM_set1_host(3)>,
 L<X509_VERIFY_PARAM_add1_host(3)>,
 L<X509_VERIFY_PARAM_set1_email(3)>,
-L<X509_VERIFY_PARAM_set1_ip(3)>,
-L<X509_VERIFY_PARAM_set1_ipasc(3)>
+L<X509_VERIFY_PARAM_set1_ip(3)>
 
 =head1 HISTORY
 
@@ -147,9 +154,9 @@ These functions were added in OpenSSL 1.0.2.
 
 =head1 COPYRIGHT
 
-Copyright 2012-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2012-2022 The OpenSSL Project Authors. All Rights Reserved.
 
-Licensed under the OpenSSL license (the "License").  You may not use
+Licensed under the Apache License 2.0 (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>.