Contract of d2i_SSL_SESSION ?

[Jesper Pedersen]

Hi,

I have a use-case where I need to reuse the SSL session in another 
process that created it. So, it looks like

Process 1:
  * Create SSL_CTX
  * Create SSL
  * Use SSL
  * i2d_SSL_SESSION into shared memory [1] -- this works
  * Free SSL (no SSL_shutdown as I need socket descriptor as well)
  * Transfer socket descriptor to parent process

Process 2:
  * Create SSL_CTX
  * Create SSL
  * Attach SSL_SESSION through d2i_SSL_SESSION [2]
  * Associate the socket descriptor (as its number may have changed)
  * Call SSL_connect (same result as SSL_set_connect_state + 
SSL_do_handshake)

After the SSL_connect call SSL_pending [3] will show 19 0-bytes in the 
buffer which leads to

AFTER CONNECT: 19
00000000000000000000000000000000000000
???????????????????
SSL_ERROR_SSL: FD 15
error:140940F4:SSL routines:ssl3_read_bytes:unexpected message
SSL routines
unexpected message

so I must be missing something in the contract of d2i_SSL_SESSION.

The SSL session cache is SSL_SESS_CACHE_CLIENT | 
SSL_SESS_CACHE_NO_INTERNAL_STORE.

Using OpenSSL 1.1.1l

[1] 
https://github.com/jesperpedersen/pgagroal/commit/05f6c65bf95b932faf3fb583d484100d83211634#diff-b0ad697326050bb80fb89068786852d7b974e1f648103fe382acea69097fd152R3446
[2] 
https://github.com/jesperpedersen/pgagroal/commit/05f6c65bf95b932faf3fb583d484100d83211634#diff-b0ad697326050bb80fb89068786852d7b974e1f648103fe382acea69097fd152R5857
[3] 
https://github.com/jesperpedersen/pgagroal/commit/05f6c65bf95b932faf3fb583d484100d83211634#diff-b0ad697326050bb80fb89068786852d7b974e1f648103fe382acea69097fd152R5899

Full patch: 
https://github.com/jesperpedersen/pgagroal/commit/05f6c65bf95b932faf3fb583d484100d83211634

Upstream project: https://github.com/agroal/pgagroal

Thanks in advance for questions, suggestions, hints or comments on the 
current code !

Best regards,
  Jesper