which is returned if the setup of the SSL/TLS session has failed due to a
mismatch with the issuer of peer certificate (\fICURLOPT_SSL_VERIFYPEER(3)\fP
has to be set too for the check to fail). (Added in 7.19.0)
+
+The application does not have to keep the string around after setting this
+option.
.SH DEFAULT
NULL
.SH PROTOCOLS