mention what happens if OPENSSL_NO_RC2 is defined

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

diff --git a/doc/man3/SSL_CTX_set_tlsext_ticket_key_cb.pod b/doc/man3/SSL_CTX_set_tlsext_ticket_key_cb.pod
index 71f879227535a0701fdf31abecc452518dfe22b7..88e70c5fa23591f308edcc014970cae4b94e1dac 100644 (file)
--- a/doc/man3/SSL_CTX_set_tlsext_ticket_key_cb.pod
+++ b/doc/man3/SSL_CTX_set_tlsext_ticket_key_cb.pod
@@ -9,9 +9,9 @@ SSL_CTX_set_tlsext_ticket_key_cb - set a callback for session ticket processing
  #include <openssl/tls1.h>
 
  long SSL_CTX_set_tlsext_ticket_key_cb(SSL_CTX sslctx,
  #include <openssl/tls1.h>
 
  long SSL_CTX_set_tlsext_ticket_key_cb(SSL_CTX sslctx,

-        int (*cb)(SSL *s, unsigned char key_name[16],
-                  unsigned char iv[EVP_MAX_IV_LENGTH],
-                  EVP_CIPHER_CTX *ctx, HMAC_CTX *hctx, int enc));
+     int (*cb)(SSL *s, unsigned char key_name[16],
+               unsigned char iv[EVP_MAX_IV_LENGTH],
+               EVP_CIPHER_CTX *ctx, HMAC_CTX *hctx, int enc));

 
 =head1 DESCRIPTION
 
 
 =head1 DESCRIPTION
 


@@ -38,7 +38,7 @@ ticket information or it starts a full TLS handshake to create a new session
 ticket.
 
 Before the callback function is started I<ctx> and I<hctx> have been
 ticket.
 
 Before the callback function is started I<ctx> and I<hctx> have been

-initialised with EVP_CIPHER_CTX_init and HMAC_CTX_init respectively.
+initialised with L<EVP_CIPHER_CTX_reset(3)> and L<HMAC_CTX_reset(3)> respectively.

 
 For new sessions tickets, when the client doesn't present a session ticket, or
 an attempted retrieval of the ticket failed, or a renew option was indicated,
 
 For new sessions tickets, when the client doesn't present a session ticket, or
 an attempted retrieval of the ticket failed, or a renew option was indicated,


@@ -112,70 +112,72 @@ exactly as if a full negotiation had occurred.
 
 If an attacker can obtain the key used to encrypt a session ticket, they can
 obtain the master secret for any ticket using that key and decrypt any traffic
 
 If an attacker can obtain the key used to encrypt a session ticket, they can
 obtain the master secret for any ticket using that key and decrypt any traffic

-using that session: even if the ciphersuite supports forward secrecy. As
+using that session: even if the cipher suite supports forward secrecy. As

 a result applications may wish to use multiple keys and avoid using long term
 keys stored in files.
 
 Applications can use longer keys to maintain a consistent level of security.
 a result applications may wish to use multiple keys and avoid using long term
 keys stored in files.
 
 Applications can use longer keys to maintain a consistent level of security.

-For example if a ciphersuite uses 256 bit ciphers but only a 128 bit ticket key
+For example if a cipher suite uses 256 bit ciphers but only a 128 bit ticket key

 the overall security is only 128 bits because breaking the ticket key will
 enable an attacker to obtain the session keys.
 
 the overall security is only 128 bits because breaking the ticket key will
 enable an attacker to obtain the session keys.
 

-=head1 EXAMPLES
-
-Reference Implementation:
-  SSL_CTX_set_tlsext_ticket_key_cb(SSL, ssl_tlsext_ticket_key_cb);
-  ....
-
-  static int ssl_tlsext_ticket_key_cb(SSL *s, unsigned char key_name[16], unsigned char *iv, EVP_CIPHER_CTX *ctx, HMAC_CTX *hctx, int enc)
-  {
-      if (enc) { /* create new session */
-          if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) ) {
-              return -1; /* insufficient random */
-          }
-
-          key = currentkey(); /* something that you need to implement */
-          if ( !key ) {
-              /* current key doesn't exist or isn't valid */
-              key = createkey(); /* something that you need to implement.
-                                   * createkey needs to initialise, a name,
-                                   * an aes_key, a hmac_key and optionally
-                                   * an expire time. */
-              if ( !key ) { /* key couldn't be created */
-                  return 0;
-              }
-          }
-          memcpy(key_name, key->name, 16);
-
-          EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key->aes_key, iv);
-          HMAC_Init_ex(&hctx, key->hmac_key, 16, EVP_sha256(), NULL);
-
-          return 1;
-
-      } else { /* retrieve session */
-          key = findkey(name);
-
-          if (!key || key->expire < now() ) {
-              return 0;
-          }
-
-          HMAC_Init_ex(&hctx, key->hmac_key, 16, EVP_sha256(), NULL);
-          EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key->aes_key, iv );
-
-          if (key->expire < ( now() - RENEW_TIME ) )
-              /* return 2 - this session will get a new ticket even though the current is still valid */
-              return 2;
-
-          return 1;
-
-      }
-  }
+=head1 RETURN VALUES

 
 

+returns 0 to indicate the callback function was set.

 
 

+=head1 EXAMPLES

 
 

-=head1 RETURN VALUES
+Reference Implementation:

 
 

-returns 0 to indicate the callback function was set.
+ SSL_CTX_set_tlsext_ticket_key_cb(SSL, ssl_tlsext_ticket_key_cb);
+ ...
+
+ static int ssl_tlsext_ticket_key_cb(SSL *s, unsigned char key_name[16],
+                                     unsigned char *iv, EVP_CIPHER_CTX *ctx,
+                                     HMAC_CTX *hctx, int enc)
+ {
+     if (enc) { /* create new session */
+         if (RAND_bytes(iv, EVP_MAX_IV_LENGTH) <= 0)
+             return -1; /* insufficient random */
+
+         key = currentkey(); /* something that you need to implement */
+         if (key == NULL) {
+             /* current key doesn't exist or isn't valid */
+             key = createkey(); /*
+                                 * Something that you need to implement.
+                                 * createkey needs to initialise a name,
+                                 * an aes_key, a hmac_key and optionally
+                                 * an expire time.
+                                 */
+             if (key == NULL) /* key couldn't be created */
+                 return 0;
+         }
+         memcpy(key_name, key->name, 16);
+
+         EVP_EncryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key->aes_key, iv);
+         HMAC_Init_ex(&hctx, key->hmac_key, 16, EVP_sha256(), NULL);
+
+         return 1;
+
+     } else { /* retrieve session */
+         key = findkey(name);
+
+         if (key == NULL || key->expire < now())
+             return 0;
+
+         HMAC_Init_ex(&hctx, key->hmac_key, 16, EVP_sha256(), NULL);
+         EVP_DecryptInit_ex(&ctx, EVP_aes_128_cbc(), NULL, key->aes_key, iv);
+
+         if (key->expire < now() - RENEW_TIME) {
+             /*
+              * return 2 - This session will get a new ticket even though the
+              * current one is still valid.
+              */
+             return 2;
+         }
+         return 1;
+     }
+ }

 
 =head1 SEE ALSO
 
 
 =head1 SEE ALSO
 


@@ -188,9 +190,9 @@ L<SSL_CTX_set_session_id_context(3)>,
 
 =head1 COPYRIGHT
 
 
 =head1 COPYRIGHT
 

-Copyright 2014-2016 The OpenSSL Project Authors. All Rights Reserved.
+Copyright 2014-2018 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>.
 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>.