Hello and thank you!

Yes, I did tried that, but unfortunately it doesn't change the way how 3rd 
party openssl decrypted string looks, the only difference is that in case of 
fixed IV first 16 symbols of string are the same for any password.

For example:
Password: kamailio
Encoded: QVFMbEZ4MzZpQ1dPNEp3SsEUkYkN9MYynvOmKYddD6A=
Decoded: çò<õ"×ÅÇR*u¢þn½Ýkamailio

Password: kamailio_qwerty123
Encoded: QVFMbEZ4MzZpQ1dPNEp3Sju/bdBKyeVCEgiRrvpBdGs36brwNM+VqNmAzbeQTiy7
Decoded: çò<õ"×ÅÇR*u¢þn½Ýkamailio_qwerty123

Best regards,
Arsenijs

________________________________
From: Henning Westerholt <[email protected]>
Sent: Monday, January 9, 2023 16:00
To: Kamailio (SER) - Users Mailing List <[email protected]>
Cc: Arsenijs Kabihno <[email protected]>
Subject: RE: Kamailio Crypto module and 3rd party openssl


Hello,



did you tried to actually set a fixed IV in the cfg? Otherwise it will generate 
a random IV.



https://www.kamailio.org/docs/modules/devel/modules/crypto.html#crypto.p.init_vector



This was added to provider interoperability to other implementations.



Cheers,



Henning



--

Henning Westerholt – https://skalatan.de/blog/

Kamailio services – https://gilawa.com<https://gilawa.com/>



From: Arsenijs Kabihno <[email protected]>
Sent: Monday, January 9, 2023 1:54 PM
To: [email protected]
Subject: [SR-Users] Kamailio Crypto module and 3rd party openssl



Hello,



I am trying to make use of crypto module. The scenario is the following:

1.      Encrypt plaintext passwords on kamailio side using crypto_aes_encrypt 
function of crypto module

2.      Decrypt them outside of kamailio using 3rd party tools, such as PHP 
openssl_decrypt



Crypto module parametrs are the following:



modparam("crypto", "salt", "")
modparam("crypto", "key_derivation", 0)



If encryption and decription are handled by kamailio, the initial password 
matches the decrypted string (initial password -> encrypted string -> decrypted 
string)

For example:



sql_query("ds_dburl", "select secret from kamailio_sip_buddies where 
username='$au'", "secret");

$avp(secret_plain) = $dbr(secret=>[0,0]); //value: 'kamailio'



crypto_aes_encrypt("$avp(secret_plain)", 
"YUZySHVtdlVTYjI0TGJNd3JTeVV0MlRaRWFraFNBRlM=", "$var(encrypted)"); //value: 
'qfOqTMoJMgGAherGCqLRRQc4zTlqsEj3MEtcORurFf0='



crypto_aes_decrypt("$avp(secret_plain)", 
"YUZySHVtdlVTYjI0TGJNd3JTeVV0MlRaRWFraFNBRlM=", "$var(decrypted)"); //value: 
'kamailio'



But in case I try to decrypt the value of $var(encrypted) using PHP 
openssl_decrypt or online tool like 
https://www.devglan.com/online-tools/aes-encryption-decryption, I am getting 
the result 'kamailio' prepended by 16 random bytes, like:

6“¤›¿Ð+IÊ\ñžïZkamailio

or

6�����+I\��Zkamailio



I believe this 16 bytes are actually random initialization vector in some 
encoding.

Possibly kamailio is trimming them from result here:

https://github.com/kamailio/kamailio/blob/master/src/modules/crypto/crypto_mod.c#L511



Moreover, if secret was encrypted using crypto_aes_encrypt and random IV, you 
can use any IV while decrypting and get 16 different bytes+result



Please advice if someone have used crypto module in similar way and what are 
the possible ways to acheive results consistency
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