engine_pkcs11 and softhsm with ECC keys

Question

I have softhsm-v2.5.0-rc1 which has ec keys imported in it. Now, when I try to use these keys from openssl CLI using the pkcs11 engine, it fails.

1. SoftHSM version

   []:~$ softhsm2-util --version
   2.5.0rc1
   

2. SoftHSM token init

   []:~$ softhsm2-util --init-token --slot 0 --label "token 2.5.0-rc1"
   === SO PIN (4-255 characters) ===
   Please enter SO PIN: ****
   Please reenter SO PIN: ****
   === User PIN (4-255 characters) ===
   Please enter user PIN: ****
   Please reenter user PIN: ****
   The token has been initialized and is reassigned to slot 928024111
   

3. ECC key in pkcs8 format

   []:~$ openssl pkey -in ~/tmp/secp256k1-key.pem.pkcs8 -text
   -----BEGIN PRIVATE KEY-----
   MIGEAgEAMBAGByqGSM49AgEGBSuBBAAKBG0wawIBAQQgYCXpIJyEAexhkvrCMGlF
   A4sQItcIp6wm83WVoeOFzEyhRANCAATMfAkLtsynHRmRyYLn+uRpJUm6bOZJBQhK
   N81nJv06fN6MY0nEzWG9jJsvSNlf5jW7yecbje2wWQL/JYqviFwr
   -----END PRIVATE KEY-----
   Private-Key: (256 bit)
   priv:
       60:25:e9:20:9c:84:01:ec:61:92:fa:c2:30:69:45:
       03:8b:10:22:d7:08:a7:ac:26:f3:75:95:a1:e3:85:
       cc:4c
   pub:
       04:cc:7c:09:0b:b6:cc:a7:1d:19:91:c9:82:e7:fa:
       e4:69:25:49:ba:6c:e6:49:05:08:4a:37:cd:67:26:
       fd:3a:7c:de:8c:63:49:c4:cd:61:bd:8c:9b:2f:48:
       d9:5f:e6:35:bb:c9:e7:1b:8d:ed:b0:59:02:ff:25:
       8a:af:88:5c:2b
   ASN1 OID: secp256k1
   

4. Import the key into softhsm

   []:~$ softhsm2-util --import ~/tmp/secp256k1-key.pem.pkcs8 --label "ec key" --id 1111 --token "token 2.5.0-rc1"
   Found slot 928024111 with matching token label.
   === User PIN (4-255 characters) ===
   Please enter user PIN: ****
   Please reenter user PIN: ****
   The key pair has been imported.
   

5. Get the pkcs11 url for the private key

   []:~$ p11tool --login --provider=/usr/local/lib/softhsm/libsofthsm2.so --set-pin=1111 --list-all
   Object 0:
                   URL: pkcs11:model=SoftHSM%20v2;manufacturer=SoftHSM%20project;serial=6a160d52b750862f;token=token%202.5.0-rc1;id=%11%11;object=ec%20key;type=private
                   Type: Private key
                   Label: ec key
                   Flags: CKA_PRIVATE; CKA_SENSITIVE;
                   ID: 11:11
   
   Object 1:
                   URL: pkcs11:model=SoftHSM%20v2;manufacturer=SoftHSM%20project;serial=6a160d52b750862f;token=token%202.5.0-rc1;id=%11%11;object=ec%20key;type=public
                   Type: Public key
                   Label: ec key
                   ID: 11:11
   

6. Try to access key with openssl engine.

   []:~$ openssl version
   OpenSSL 1.1.1  11 Sep 2018
   
   []:~$ more ~/tmp/openssl.cnf
   openssl_conf = openssl_init
   
   [openssl_init]
   engines=engine_section
   
   [engine_section]
   pkcs11 = pkcs11_section
   
   [pkcs11_section]
   engine_id = pkcs11
   dynamic_path = /Users/parashah/Downloads/libp11-0.4.9/src/.libs/pkcs11.dylib
   MODULE_PATH = /usr/local/lib/softhsm/libsofthsm2.so
   init = 0
   
   []:~$ openssl pkey -in "pkcs11:model=SoftHSM%20v2;manufacturer=SoftHSM%20project;serial=6a160d52b750862f;token=token%202.5.0-rc1;id=%11%11;object=ec%20key;type=private" -inform ENGINE -engine pkcs11 -text
   engine "pkcs11" set.
   Enter PKCS#11 token PIN for token 2.5.0-rc1:
   140736065815424:error:100C0010:elliptic curve routines:i2d_ECPrivateKey:EC lib:crypto/ec/ec_asn1.c:995:
   140736065815424:error:100D6010:elliptic curve routines:eckey_priv_encode:EC lib:crypto/ec/ec_ameth.c:242:
   140736065815424:error:06071092:digital envelope routines:EVP_PKEY2PKCS8:private key encode error:crypto/evp/evp_pkey.c:72:
   140736065815424:error:0907E073:PEM routines:do_pk8pkey:error converting private key:crypto/pem/pem_pk8.c:73:
   

====

Just for completeness, doing the exact same steps but for a RSA key works fine