How to set key spec or KEYEXCHANGE property when generating a self-signed certificate using openssl

I am using open ssl on 'windows 2012R2' to generate a self-signed certificate. Using the command below I have generated the certificate

openssl genrsa -des3 -out ab.key 
openssl req -new -x509 -key ab.key -out ab.crt
openssl pkcs12 -inkey ab.key -in ab.crt -export -out ab.pkcs12
openssl x509 -in ab.crt -out ab.pem

Getting the error while import the certificate - The selected certificate  does not have the KeySpec 
Exchange property. This property is required by SQL Server to import a certificat Import error: 0x2, Windows Native Error: 0x80092004

I have checked the opennssl config file but could not get like where to set this property.

One way of doing it is to convert your certificate to pfx (pkcs12) format and it will get the default value for KeySpec i.e KeySpec = 1 -- At_KEYEXCHANGE

Use the openssl command 'pkcs12' as following:

openssl pkcs12 -inkey mssql-key.pem -in mssql-cert.crt -export -out mssql-cert.pfx

You will get follwoing in the output of certutil:

certutil -dump -v .\mssql-cert.pfx

Output Extract:

.......

hCryptProv = 000001372C300D00

KeySpec = 1 -- AT_KEYEXCHANGE

......