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Diffstat (limited to 'src/lib/libssl/doc/SSL_SESSION_free.3')
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diff --git a/src/lib/libssl/doc/SSL_SESSION_free.3 b/src/lib/libssl/doc/SSL_SESSION_free.3 new file mode 100644 index 0000000000..f7d2350b55 --- /dev/null +++ b/src/lib/libssl/doc/SSL_SESSION_free.3 | |||
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| 1 | .Dd $Mdocdate: October 12 2014 $ | ||
| 2 | .Dt SSL_SESSION_FREE 3 | ||
| 3 | .Os | ||
| 4 | .Sh NAME | ||
| 5 | .Nm SSL_SESSION_free | ||
| 6 | .Nd free an allocated SSL_SESSION structure | ||
| 7 | .Sh SYNOPSIS | ||
| 8 | .In openssl/ssl.h | ||
| 9 | .Ft void | ||
| 10 | .Fn SSL_SESSION_free "SSL_SESSION *session" | ||
| 11 | .Sh DESCRIPTION | ||
| 12 | .Fn SSL_SESSION_free | ||
| 13 | decrements the reference count of | ||
| 14 | .Fa session | ||
| 15 | and removes the | ||
| 16 | .Vt SSL_SESSION | ||
| 17 | structure pointed to by | ||
| 18 | .Fa session | ||
| 19 | and frees up the allocated memory, if the reference count has reached 0. | ||
| 20 | .Sh NOTES | ||
| 21 | .Vt SSL_SESSION | ||
| 22 | objects are allocated when a TLS/SSL handshake operation is successfully | ||
| 23 | completed. | ||
| 24 | Depending on the settings, see | ||
| 25 | .Xr SSL_CTX_set_session_cache_mode 3 , | ||
| 26 | the | ||
| 27 | .Vt SSL_SESSION | ||
| 28 | objects are internally referenced by the | ||
| 29 | .Vt SSL_CTX | ||
| 30 | and linked into its session cache. | ||
| 31 | .Vt SSL | ||
| 32 | objects may be using the | ||
| 33 | .Vt SSL_SESSION | ||
| 34 | object; as a session may be reused, several | ||
| 35 | .Vt SSL | ||
| 36 | objects may be using one | ||
| 37 | .Vt SSL_SESSION | ||
| 38 | object at the same time. | ||
| 39 | It is therefore crucial to keep the reference count (usage information) correct | ||
| 40 | and not delete a | ||
| 41 | .Vt SSL_SESSION | ||
| 42 | object that is still used, as this may lead to program failures due to dangling | ||
| 43 | pointers. | ||
| 44 | These failures may also appear delayed, e.g., when an | ||
| 45 | .Vt SSL_SESSION | ||
| 46 | object is completely freed as the reference count incorrectly becomes 0, but it | ||
| 47 | is still referenced in the internal session cache and the cache list is | ||
| 48 | processed during a | ||
| 49 | .Xr SSL_CTX_flush_sessions 3 | ||
| 50 | operation. | ||
| 51 | .Pp | ||
| 52 | .Fn SSL_SESSION_free | ||
| 53 | must only be called for | ||
| 54 | .Vt SSL_SESSION | ||
| 55 | objects, for which the reference count was explicitly incremented (e.g., by | ||
| 56 | calling | ||
| 57 | .Xr SSL_get1_session 3 ; | ||
| 58 | see | ||
| 59 | .Xr SSL_get_session 3 ) | ||
| 60 | or when the | ||
| 61 | .Vt SSL_SESSION | ||
| 62 | object was generated outside a TLS handshake operation, e.g., by using | ||
| 63 | .Xr d2i_SSL_SESSION 3 . | ||
| 64 | It must not be called on other | ||
| 65 | .Vt SSL_SESSION | ||
| 66 | objects, as this would cause incorrect reference counts and therefore program | ||
| 67 | failures. | ||
| 68 | .Sh RETURN VALUES | ||
| 69 | .Fn SSL_SESSION_free | ||
| 70 | does not provide diagnostic information. | ||
| 71 | .Sh SEE ALSO | ||
| 72 | .Xr d2i_SSL_SESSION 3 , | ||
| 73 | .Xr ssl 3 , | ||
| 74 | .Xr SSL_CTX_flush_sessions 3 , | ||
| 75 | .Xr SSL_CTX_set_session_cache_mode 3 , | ||
| 76 | .Xr SSL_get_session 3 | ||