Commit c0f5dd07 authored by Lutz Jänicke's avatar Lutz Jänicke
Browse files

Make maximum certifcate chain size accepted from the peer application 

settable (proposed by "Douglas E. Engert" <deengert@anl.gov>).
parent 9d7a8d35

CHANGES

+5 −0
Original line number Diff line number Diff line
@@ -12,6 +12,11 @@ 
         *) applies to 0.9.6a/0.9.6b/0.9.6c and 0.9.7

         +) applies to 0.9.7 only



  +) Make maximum certificate chain size accepted from the peer application

     settable (SSL*_get/set_max_cert_list()), as proposed by

     "Douglas E. Engert" <deengert@anl.gov>.

     [Lutz Jaenicke]



  +) Add support for shared libraries for Unixware-7 and support including

     shared libraries for OpenUNIX-8 (Boyd Lynn Gerber <gerberb@zenez.com>).

     [Lutz Jaenicke]

doc/ssl/SSL_CTX_set_max_cert_list.pod

0 → 100644
+77 −0
Original line number Diff line number Diff line 
=pod



=head1 NAME



SSL_CTX_set_max_cert_list, SSL_CTX_get_max_cert_list, SSL_set_max_cert_list, SSL_get_max_cert_list, - manipulate allowed for the peer's certificate chain



=head1 SYNOPSIS



 #include <openssl/ssl.h>



 long SSL_CTX_set_max_cert_list(SSL_CTX *ctx, long size);

 long SSL_CTX_get_max_cert_list(SSL_CTX *ctx);



 long SSL_set_max_cert_list(SSL *ssl, long size);

 long SSL_get_max_cert_list(SSL *ctx);



=head1 DESCRIPTION



SSL_CTX_set_max_cert_list() sets the maximum size allowed for the peer's

certificate chain for all SSL objects created from B<ctx> to be <size> bytes.

The SSL objects inherit the setting valid for B<ctx> at the time

L<SSL_new(3)|SSL_new(3)> is being called.



SSL_CTX_get_max_cert_list() returns the currently set maximum size for B<ctx>.



SSL_set_max_cert_list() sets the maximum size allowed for the peer's

certificate chain for B<ssl> to be <size> bytes. This setting stays valid

until a new value is set.



SSL_get_max_cert_list() returns the currently set maximum size for B<ssl>.



=head1 NOTES



During the handshake process, the peer may send a certificate chain.

The TLS/SSL standard does not give any maximum size of the certificate chain.

The OpenSSL library handles incoming data by a dynamically allocated buffer.

In order to prevent this buffer from growing without bounds due to data

received from a faulty or malicious peer, a maximum size for the certificate

chain is set.



The default value for the maximum certificate chain size is 100kB (30kB

on the 16bit DOS platform). This should be sufficient for usual certificate

chains (OpenSSL's default maximum chain length is 10, see

L<SSL_CTX_set_verify(3)|SSL_CTX_set_verify(3)>, and certificates

without special extensions have a typical size of 1-2kB).



For special applications it can be necessary to extend the maximum certificate

chain size allowed to be sent by the peer, see e.g. the work on

"Internet X.509 Public Key Infrastructure Proxy Certificate Profile"

and "TLS Delegation Protocol" at http://www.ietf.org/ and

http://www.globus.org/ .



Under normal conditions it should never be necessary to set a value smaller

than the default, as the buffer is handled dynamically and only uses the

memory actually required by the data sent by the peer.



If the maximum certificate chain size allowed is exceeded, the handshake will

fail with a SSL_R_EXCESSIVE_MESSAGE_SIZE error.



=head1 RETURN VALUES



SSL_CTX_set_max_cert_list() and SSL_set_max_cert_list() return the previously

set value.



SSL_CTX_get_max_cert_list() and SSL_get_max_cert_list() return the currently

set value.



=head1 SEE ALSO



L<ssl(3)|ssl(3)>, L<SSL_new(3)|SSL_new(3)>,

L<SSL_CTX_set_verify(3)|SSL_CTX_set_verify(3)>



=head1 HISTORY



SSL*_set/get_max_cert_list() have been introduced in OpenSSL 0.9.7.



=cut

doc/ssl/ssl.pod

+1 −0
Original line number Diff line number Diff line
@@ -669,6 +669,7 @@ L<SSL_CTX_set_client_CA_list(3)|SSL_CTX_set_client_CA_list(3)>, 
L<SSL_CTX_set_default_passwd_cb(3)|SSL_CTX_set_default_passwd_cb(3)>,

L<SSL_CTX_set_generate_session_id(3)|SSL_CTX_set_generate_session_id(3)>,

L<SSL_CTX_set_info_callback(3)|SSL_CTX_set_info_callback(3)>,

L<SSL_CTX_set_max_cert_list(3)|SSL_CTX_set_max_cert_list(3)>,

L<SSL_CTX_set_mode(3)|SSL_CTX_set_mode(3)>,

L<SSL_CTX_set_options(3)|SSL_CTX_set_options(3)>,

L<SSL_CTX_set_quiet_shutdown(3)|SSL_CTX_set_quiet_shutdown(3)>,

ssl/s3_clnt.c

+3 −15
Original line number Diff line number Diff line
@@ -695,11 +695,7 @@ static int ssl3_get_server_certificate(SSL *s) 
		SSL3_ST_CR_CERT_A,

		SSL3_ST_CR_CERT_B,

		-1,

#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)

		1024*30, /* 30k max cert list :-) */

#else

		1024*100, /* 100k max cert list :-) */

#endif

		s->max_cert_list,

		&ok);



	if (!ok) return((int)n);
@@ -890,11 +886,7 @@ static int ssl3_get_key_exchange(SSL *s) 
		SSL3_ST_CR_KEY_EXCH_A,

		SSL3_ST_CR_KEY_EXCH_B,

		-1,

#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)

		1024*30,  /* 30k max cert list :-) */

#else

		1024*100, /* 100k max cert list :-) */

#endif

		s->max_cert_list,

		&ok);



	if (!ok) return((int)n);
@@ -1196,11 +1188,7 @@ static int ssl3_get_certificate_request(SSL *s) 
		SSL3_ST_CR_CERT_REQ_A,

		SSL3_ST_CR_CERT_REQ_B,

		-1,

#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)

		1024*30,  /* 30k max cert list :-) */

#else

		1024*100, /* 100k max cert list :-) */

#endif

		s->max_cert_list,

		&ok);



	if (!ok) return((int)n);

ssl/s3_srvr.c

+2 −10
Original line number Diff line number Diff line
@@ -550,11 +550,7 @@ static int ssl3_check_client_hello(SSL *s) 
		SSL3_ST_SR_CERT_A,

		SSL3_ST_SR_CERT_B,

		-1,

#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)

		1024*30, /* 30k max cert list :-) */

#else

		1024*100, /* 100k max cert list :-) */

#endif

		s->max_cert_list,

		&ok);

	if (!ok) return((int)n);

	s->s3->tmp.reuse_message = 1;
@@ -1775,11 +1771,7 @@ static int ssl3_get_client_certificate(SSL *s) 
		SSL3_ST_SR_CERT_A,

		SSL3_ST_SR_CERT_B,

		-1,

#if defined(OPENSSL_SYS_MSDOS) && !defined(OPENSSL_SYS_WIN32)

		1024*30, /* 30k max cert list :-) */

#else

		1024*100, /* 100k max cert list :-) */

#endif

		s->max_cert_list,

		&ok);



	if (!ok) return((int)n);