SSL: updated comment about session sizes.

Previous numbers are somewhat outdated, typical ASN1 representations of
sessions are slightly bigger now.
This commit is contained in:
Maxim Dounin 2022-10-12 20:14:37 +03:00
parent 569325fc41
commit b1366da936
1 changed files with 6 additions and 6 deletions

View File

@ -3790,16 +3790,16 @@ ngx_ssl_session_cache_init(ngx_shm_zone_t *shm_zone, void *data)
/*
* The length of the session id is 16 bytes for SSLv2 sessions and
* between 1 and 32 bytes for SSLv3/TLSv1, typically 32 bytes.
* It seems that the typical length of the external ASN1 representation
* of a session is 118 or 119 bytes for SSLv3/TSLv1.
* between 1 and 32 bytes for SSLv3 and TLS, typically 32 bytes.
* Typical length of the external ASN1 representation of a session
* is about 150 bytes plus SNI server name.
*
* Thus on 32-bit platforms we allocate separately an rbtree node,
* On 32-bit platforms we allocate separately an rbtree node,
* a session id, and an ASN1 representation, they take accordingly
* 64, 32, and 128 bytes.
* 64, 32, and 256 bytes.
*
* On 64-bit platforms we allocate separately an rbtree node + session_id,
* and an ASN1 representation, they take accordingly 128 and 128 bytes.
* and an ASN1 representation, they take accordingly 128 and 256 bytes.
*
* OpenSSL's i2d_SSL_SESSION() and d2i_SSL_SESSION are slow,
* so they are outside the code locked by shared pool mutex