>>Or atleast add documentation in <curl.h> for the following properties, that
>>DER is not yet supported.
>>
>>CURLOPT_SSLCERTTYPE
>>CURLOPT_SSLKEYTYPE
>
> That documentation is better put in the curl_easy_setopt.3 man pages where
> these options are documented, IMHO.
>
> Care to make a patch for that?

Here you go. "DER" works for SSLCERTTYPE option, but not for SSLKEYTYPE.
I tested it. I added a one line comment to the SSLKEYTYPE "NOTE:"
section. While I was at it, I also fixed some formatting issues. Patch
attached.

Regards
-Seshubabu Pasam
-S

Index: curl_easy_setopt.3
===================================================================
RCS file: /repository/curl/docs/libcurl/curl_easy_setopt.3,v
retrieving revision 1.84
diff -r1.84 curl_easy_setopt.3
525c525
< \fBNOTE:\fPThe most commonly replaced headers have "shortcuts" in the options

---
> \fBNOTE:\fP The most commonly replaced headers have "shortcuts" in the options
538c538
< \fBNOTE:\fPThe alias itself is not parsed for any version strings.  So if your
---
> \fBNOTE:\fP The alias itself is not parsed for any version strings.  So if your
709,713c709,713
< NOTE: many people have wrongly used this option to replace the entire request
< with their own, including multiple headers and POST contents. While that might
< work in many cases, it will cause libcurl to send invalid requests and it
< could possibly confuse the remote server badly. Use \fICURLOPT_POST\fP and
< \fICURLOPT_POSTFIELDS\fP to set POST data. Use \fICURLOPT_HTTPHEADER\fP to
---
> \fBNOTE:\fP Many people have wrongly used this option to replace the entire
> request with their own, including multiple headers and POST contents. While
> that might work in many cases, it will cause libcurl to send invalid requests
> and it could possibly confuse the remote server badly. Use \fICURLOPT_POST\fP
> and \fICURLOPT_POSTFIELDS\fP to set POST data. Use \fICURLOPT_HTTPHEADER\fP to
743,745c743,745
< NOTE: The file size is not always known prior to download, and for such files
< this option has no effect even if the file transfer ends up being larger than
< this given limit. This concerns both FTP and HTTP transfers.
---
> \fBNOTE:\fP The file size is not always known prior to download, and for such
> files this option has no effect even if the file transfer ends up being larger
> than this given limit. This concerns both FTP and HTTP transfers.
752,754c752,754
< NOTE: The file size is not always known prior to download, and for such files
< this option has no effect even if the file transfer ends up being larger than
< this given limit. This concerns both FTP and HTTP transfers.
---
> \fBNOTE:\fP The file size is not always known prior to download, and for such
> files this option has no effect even if the file transfer ends up being larger
> than this given limit. This concerns both FTP and HTTP transfers.
760c760
< NOTE: The last modification time of a file is not always known and in such
---
> \fBNOTE:\fP The last modification time of a file is not always known and in such
869,870c869,870
< \fBNOTE:\fPThe format "ENG" enables you to load the private key from a crypto
< engine. in this case \fICURLOPT_SSLKEY\fP is used as an identifier passed to
---
> \fBNOTE:\fP The format "ENG" enables you to load the private key from a crypto
> engine. In this case \fICURLOPT_SSLKEY\fP is used as an identifier passed to
871a872
> "DER" format key file currently does not work because of a bug in OpenSSL.
880c881
< \fBNOTE:\fPIf the crypto device cannot be loaded,
---
> \fBNOTE:\fP If the crypto device cannot be loaded,
886c887
< \fBNOTE:\fPIf the crypto device cannot be set,
---
> \fBNOTE:\fP If the crypto device cannot be set,