




 
A foreign pointer of type 
ssl-pointer
 or 
ssl-ctx-pointer
.
:server
 or 
:client
.
An integer, one of the symbols 
:never
, 
:always
, 
:once
, or a list of keywords.
A foreign function.
The function 
set-verification-mode
 sets the verification mode for CTX according to arguments 
ssl-side
 and 
mode
.
When 
ssl-side
 is 
:server
, 
mode
 can be:
mode
 is passed directly to 
SSL_set_verify
 or 
SSL_CTX_set_verify
.
The server will not send a client certificate request to the client, so the client will not send a certificate.
The server sends a client certificate request to the client. The certificate returned (if any) is checked. If the verification process fails, the TLS/SSL handshake is immediately terminated with an alert message containing the reason for the verification failure.
Same as 
:always
 except that the client certificate is checked only on the initial TLS/SSL handshake, and not again in case of renegotiation.
The list contains (some of) the keywords 
:verify-client-once
, 
:verify-peer
 and :
fail-if-no-peer-cert
. These keywords map to the corresponding C constants 
VERIFY_CLIENT_ONCE
, 
VERIFY_PEER
 and 
FAIL_IF_NO_PEER_CERT
 respectively. See the manual entry for 
SSL_CTX_set_verify
 for the meaning of the constants.
When 
ssl-side
 is 
:client
, 
mode
 can be:
mode
 is passed directly as for 
ssl-side
 
:server
.
If not using an anonymous cipher, the server will send a certificate which will be checked by the client. The handshake will be continued regardless of the verification result.
The server certificate is verified. If the verification process fails, the TLS/SSL handshake is immediately terminated with an alert message containing the reason for the verification failure. If no server certificate is sent because an anonymous cipher is used, verification is ignored.
The list contains keywords as described above for 
ssl-side
 
:server
.
If non-nil 
callback
 should be a symbol, function, string or foreign pointer designating a foreign function that is called to perform verification. The default value of 
callback
 is 
nil
.
LispWorks User Guide and Reference Manual - 21 Dec 2011