Using ecc keys with sscep throws error about sscep

[gkauraneja]

i am trying to use ecc keys for scep call to my server. Each time i am facing below error:

[root@localhost sscep]# ./sscep_static enroll -u http://10.97.57.229:8030/csrscep/CSRESEPA -k /root/ecc_certificates/key.pem -c ca.crt-0 ca.crt-1 ca.crt-2 -r /root/ecc_certificates/csr.csr -l local.crt -S sha1 -v
./sscep_static: starting sscep, version 0.6.1
./sscep_static: new transaction
./sscep_static: transaction id: D41D8CD98F00B204E9800998ECF8427E
./sscep_static: hostname: 10.97.57.229
./sscep_static: directory: csrscep/CSRESEPA
./sscep_static: port: 8030
./sscep_static: Read request with transaction id: A6358A3B391CC53F8C2E91CA8CF45F5C
./sscep_static: generating selfsigned certificate
./sscep_static: SCEP_OPERATION_ENROLL
./sscep_static: sending certificate request
./sscep_static: creating inner PKCS#7
./sscep_static: inner PKCS#7 in mem BIO
./sscep_static: request data dump
-----BEGIN CERTIFICATE REQUEST-----
MIIBSTCB8AIBADCBjTELMAkGA1UEBhMCQ0ExEDAOBgNVBAgMB09udGFyaW8xETAP
BgNVBAcMCEJheXNob3JlMRAwDgYDVQQKDAdFbnRydXN0MRAwDgYDVQQLDAdJT1RS
VVNUMQswCQYDVQQDDAJDTjEoMCYGCSqGSIb3DQEJARYZZ3VycHJlZXQua2F1ckBl
bnRydXN0LmNvbTBZMBMGByqGSM49AgEGCCqGSM49AwEHA0IABB6geve4NJUGxoPb
rO6t3C6BQVuH3GATrFjkd5qsm9nw0dGdvUSMvuZ6u43s1HCJ52kZfRZCcBfaFqB+
ZnrdzNKgADAKBggqhkjOPQQDAgNIADBFAiBcZP41hfNsxcagSPcQYh2T0B/Co2Vn
lX0pvbQAiE/7vgIhAItV8S22hUKjzr6ocWG055RRBgyxYLI71kweUHK5ZlC3
-----END CERTIFICATE REQUEST-----
./sscep_static: data payload size: 333 bytes
./sscep_static: request payload encrypt failed
140148955121328:error:21082096:PKCS7 routines:PKCS7_RECIP_INFO_set:encryption not supported for this key type:pk7_lib.c:541:
140148955121328:error:21073078:PKCS7 routines:PKCS7_encrypt:error adding recipient:pk7_smime.c:503:
[root@localhost sscep]#

Could you elaborate what could be done to make ecc keys work with it?

[mbartosch]

40148955121328:error:21082096:PKCS7 routines:PKCS7_RECIP_INFO_set:encryption not supported for this key type:pk7_lib.c:541:

gives you the reason.

EC keys can be used for Digital Signatures but they are not (directly) usable for encryption. (This requires a workaround involving static ECDH parameters)
I suspect that the SCEP RA Server certificate ca.crt-0 is also an EC certificate. Try an RSA certificate for the SCEP server certificate instead. (I would be surprised if this actually works with an EC SCEP RA server certificate with the static ECDH parameters, though).

I also have never tried to use sscep with EC end entity keys. From your test and from a quick glance at the code it looks like it could work, but I would not bet on it.