IV generation for dm-crypt

external.Sharmila.D-Mykyq1cwIDpWk0Htik3J/[email protected] (EXTERNAL D Sharmila (Iwave, RBEI/PAC-PF)) Wed, 29 Jan 2020 08:18:09 +0000

Newsgroups	gmane.linux.kernel.device-mapper.dm-crypt
Message-ID	<[email protected]>

Hi team,
        I am able to successfully encrypt custom device physical
partition using dmsetup utility. I have used dm-crypt and dm-integrity
for the same. I have one query related to IV generation of dm-crypt.

Query:
        Whether Random number generator used to generate IV, generates
same IV repeatedly or unique IV will be generated ? How the IV
generation handled in dm-crypt ?

The commands I used to create dm-integrity and dm-crypt is as below

dmsetup create test-integrity --table '0 14240 integrity /dev/mmcblk0p5
0 32 J 1
internal_hash:hmac(sha256):30313233343536373839414243444546303132333435
36373839414243444546' 

dmsetup create test-integrity-crypt --table '0 14240 crypt aes-cbc-
essiv:sha256 :32:user:test-key 0 /dev/mapper/test-integrity 0'


Please give your valuable response for the above query. 

Regards,
Sharmila