I have implemented the SCP03t and would like to install my DER encoded network profile package on my ISD-P on my eUICC. Upon sending the 1st segment of my command with tag ´86´ I get 8600response from eUICC which means successful. On sending the 2nd segment eUICC responds with a non-sense random (at least to me) string, then responds with error tag of 9F460102on the 3rd command and aborts the installation.
This is an example of what I get on my 2nd command response:
6B23AC8C1666439B66C126ECAA9B069B00800000000000000000000000000000
Can anyone please tell me what am I missing?
So it turns out my eUICC OS doesn't accept SMS PP data Download Envelope at 140 bytes (characters); it should be 130 bytes per SMS. Also, the binary counter string used for generating the ICV should be hex in my case whereas the standard explicitly states that the counter shall be binary.