diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/lib/libssl/man/SSL_CTX_set_generate_session_id.3 | 93 |
1 files changed, 58 insertions, 35 deletions
diff --git a/src/lib/libssl/man/SSL_CTX_set_generate_session_id.3 b/src/lib/libssl/man/SSL_CTX_set_generate_session_id.3 index 29ff6a123e..5166b90605 100644 --- a/src/lib/libssl/man/SSL_CTX_set_generate_session_id.3 +++ b/src/lib/libssl/man/SSL_CTX_set_generate_session_id.3 | |||
| @@ -1,7 +1,54 @@ | |||
| 1 | .\" $OpenBSD: SSL_CTX_set_generate_session_id.3,v 1.2 2016/11/30 18:07:12 schwarze Exp $ | ||
| 2 | .\" OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100 | ||
| 1 | .\" | 3 | .\" |
| 2 | .\" $OpenBSD: SSL_CTX_set_generate_session_id.3,v 1.1 2016/11/05 15:32:19 schwarze Exp $ | 4 | .\" This file was written by Lutz Jaenicke <jaenicke@openssl.org>. |
| 5 | .\" Copyright (c) 2001, 2014 The OpenSSL Project. All rights reserved. | ||
| 3 | .\" | 6 | .\" |
| 4 | .Dd $Mdocdate: November 5 2016 $ | 7 | .\" Redistribution and use in source and binary forms, with or without |
| 8 | .\" modification, are permitted provided that the following conditions | ||
| 9 | .\" are met: | ||
| 10 | .\" | ||
| 11 | .\" 1. Redistributions of source code must retain the above copyright | ||
| 12 | .\" notice, this list of conditions and the following disclaimer. | ||
| 13 | .\" | ||
| 14 | .\" 2. Redistributions in binary form must reproduce the above copyright | ||
| 15 | .\" notice, this list of conditions and the following disclaimer in | ||
| 16 | .\" the documentation and/or other materials provided with the | ||
| 17 | .\" distribution. | ||
| 18 | .\" | ||
| 19 | .\" 3. All advertising materials mentioning features or use of this | ||
| 20 | .\" software must display the following acknowledgment: | ||
| 21 | .\" "This product includes software developed by the OpenSSL Project | ||
| 22 | .\" for use in the OpenSSL Toolkit. (http://www.openssl.org/)" | ||
| 23 | .\" | ||
| 24 | .\" 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to | ||
| 25 | .\" endorse or promote products derived from this software without | ||
| 26 | .\" prior written permission. For written permission, please contact | ||
| 27 | .\" openssl-core@openssl.org. | ||
| 28 | .\" | ||
| 29 | .\" 5. Products derived from this software may not be called "OpenSSL" | ||
| 30 | .\" nor may "OpenSSL" appear in their names without prior written | ||
| 31 | .\" permission of the OpenSSL Project. | ||
| 32 | .\" | ||
| 33 | .\" 6. Redistributions of any form whatsoever must retain the following | ||
| 34 | .\" acknowledgment: | ||
| 35 | .\" "This product includes software developed by the OpenSSL Project | ||
| 36 | .\" for use in the OpenSSL Toolkit (http://www.openssl.org/)" | ||
| 37 | .\" | ||
| 38 | .\" THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY | ||
| 39 | .\" EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE | ||
| 40 | .\" IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR | ||
| 41 | .\" PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR | ||
| 42 | .\" ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, | ||
| 43 | .\" SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT | ||
| 44 | .\" NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; | ||
| 45 | .\" LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) | ||
| 46 | .\" HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, | ||
| 47 | .\" STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) | ||
| 48 | .\" ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED | ||
| 49 | .\" OF THE POSSIBILITY OF SUCH DAMAGE. | ||
| 50 | .\" | ||
| 51 | .Dd $Mdocdate: November 30 2016 $ | ||
| 5 | .Dt SSL_CTX_SET_GENERATE_SESSION_ID 3 | 52 | .Dt SSL_CTX_SET_GENERATE_SESSION_ID 3 |
| 6 | .Os | 53 | .Os |
| 7 | .Sh NAME | 54 | .Sh NAME |
| @@ -11,10 +58,12 @@ | |||
| 11 | .Nd manipulate generation of SSL session IDs (server only) | 58 | .Nd manipulate generation of SSL session IDs (server only) |
| 12 | .Sh SYNOPSIS | 59 | .Sh SYNOPSIS |
| 13 | .In openssl/ssl.h | 60 | .In openssl/ssl.h |
| 14 | .Bd -literal | 61 | .Ft typedef int |
| 15 | typedef int (*GEN_SESSION_CB)(const SSL *ssl, unsigned char *id, | 62 | .Fo (*GEN_SESSION_CB) |
| 16 | unsigned int *id_len); | 63 | .Fa "const SSL *ssl" |
| 17 | .Ed | 64 | .Fa "unsigned char *id" |
| 65 | .Fa "unsigned int *id_len" | ||
| 66 | .Fc | ||
| 18 | .Ft int | 67 | .Ft int |
| 19 | .Fn SSL_CTX_set_generate_session_id "SSL_CTX *ctx" "GEN_SESSION_CB cb" | 68 | .Fn SSL_CTX_set_generate_session_id "SSL_CTX *ctx" "GEN_SESSION_CB cb" |
| 20 | .Ft int | 69 | .Ft int |
| @@ -46,12 +95,11 @@ checks, whether a session with id | |||
| 46 | is already contained in the internal session cache | 95 | is already contained in the internal session cache |
| 47 | of the parent context of | 96 | of the parent context of |
| 48 | .Fa ssl . | 97 | .Fa ssl . |
| 49 | .Sh NOTES | 98 | .Pp |
| 50 | When a new session is established between client and server, | 99 | When a new session is established between client and server, |
| 51 | the server generates a session id. | 100 | the server generates a session id. |
| 52 | The session id is an arbitrary sequence of bytes. | 101 | The session id is an arbitrary sequence of bytes. |
| 53 | The length of the session id is 16 bytes for SSLv2 sessions and between 1 and | 102 | The length of the session id is between 1 and 32 bytes. |
| 54 | 32 bytes for SSLv3/TLSv1. | ||
| 55 | The session id is not security critical but must be unique for the server. | 103 | The session id is not security critical but must be unique for the server. |
| 56 | Additionally, the session id is transmitted in the clear when reusing the | 104 | Additionally, the session id is transmitted in the clear when reusing the |
| 57 | session so it must not contain sensitive information. | 105 | session so it must not contain sensitive information. |
| @@ -80,17 +128,6 @@ or write to the location | |||
| 80 | .Fa id | 128 | .Fa id |
| 81 | exceeding the given limit. | 129 | exceeding the given limit. |
| 82 | .Pp | 130 | .Pp |
| 83 | If a SSLv2 session id is generated and | ||
| 84 | .Fa id_len | ||
| 85 | is reduced, it will be restored after the callback has finished and the session | ||
| 86 | id will be padded with 0x00. | ||
| 87 | It is not recommended to change the | ||
| 88 | .Fa id_len | ||
| 89 | for SSLv2 sessions. | ||
| 90 | The callback can use the | ||
| 91 | .Xr SSL_get_version 3 | ||
| 92 | function to check whether the session is of type SSLv2. | ||
| 93 | .Pp | ||
| 94 | The location | 131 | The location |
| 95 | .Fa id | 132 | .Fa id |
| 96 | is filled with 0x00 before the callback is called, | 133 | is filled with 0x00 before the callback is called, |
| @@ -101,7 +138,7 @@ untouched while maintaining reproducibility. | |||
| 101 | Since the sessions must be distinguished, session ids must be unique. | 138 | Since the sessions must be distinguished, session ids must be unique. |
| 102 | Without the callback a random number is used, | 139 | Without the callback a random number is used, |
| 103 | so that the probability of generating the same session id is extremely small | 140 | so that the probability of generating the same session id is extremely small |
| 104 | (2^128 possible ids for an SSLv2 session, 2^256 for SSLv3/TLSv1). | 141 | (2^256 for TLSv1). |
| 105 | In order to ensure the uniqueness of the generated session id, | 142 | In order to ensure the uniqueness of the generated session id, |
| 106 | the callback must call | 143 | the callback must call |
| 107 | .Fn SSL_has_matching_session_id | 144 | .Fn SSL_has_matching_session_id |
| @@ -128,13 +165,6 @@ since the external cache is not tested with | |||
| 128 | .Fn SSL_has_matching_session_id | 165 | .Fn SSL_has_matching_session_id |
| 129 | and the same race condition applies. | 166 | and the same race condition applies. |
| 130 | .Pp | 167 | .Pp |
| 131 | When calling | ||
| 132 | .Fn SSL_has_matching_session_id | ||
| 133 | for an SSLv2 session with reduced | ||
| 134 | .Fa id_len Ns , | ||
| 135 | the match operation will be performed using the fixed length required and with | ||
| 136 | a 0x00 padded id. | ||
| 137 | .Pp | ||
| 138 | The callback must return 0 if it cannot generate a session id for whatever | 168 | The callback must return 0 if it cannot generate a session id for whatever |
| 139 | reason and return 1 on success. | 169 | reason and return 1 on success. |
| 140 | .Sh RETURN VALUES | 170 | .Sh RETURN VALUES |
| @@ -157,13 +187,6 @@ generate_session_id(const SSL *ssl, unsigned char *id, | |||
| 157 | unsigned int *id_len) | 187 | unsigned int *id_len) |
| 158 | { | 188 | { |
| 159 | unsigned int count = 0; | 189 | unsigned int count = 0; |
| 160 | const char *version; | ||
| 161 | |||
| 162 | version = SSL_get_version(ssl); | ||
| 163 | if (!strcmp(version, "SSLv2")) { | ||
| 164 | /* we must not change id_len */ | ||
| 165 | ; | ||
| 166 | } | ||
| 167 | 190 | ||
| 168 | do { | 191 | do { |
| 169 | RAND_pseudo_bytes(id, *id_len); | 192 | RAND_pseudo_bytes(id, *id_len); |
