Yealink Teams Series Administrator's Manual page 84

Permitted Values
0-Disabled, the phone will decrypt the encrypted configuration files using
plaintext AES keys configured on the phone.
1-Enabled, the phone will download <xx_Security>.enc files (for example,
<sip_Security>.enc, <account_Security>.enc) during auto provisioning, and
then decrypts these files into the plaintext keys (for example, key2, key3)
respectively using the phone built-in key (for example, key1). The phone
then decrypts the encrypted configuration files using corresponding key (for
example, key2, key3).
Default 0
Parameter static.auto_provision.aes_key_16.com
Description
It configures the plaintext AES key for encrypting/decrypting the Common
CFG/Custom CFG file.
The valid characters contain: 0 ~ 9, A ~ Z, a ~ z and the following special
characters are also supported: # $ % * + , - . : = ? @ [ ] ^ _ { } ~.
Example:
static.auto_provision.aes_key_16.com = 0123456789abcdef
Note: For decrypting, it works only if "static.auto_provision.aes_key_in_file"
is set to 0 (Disabled). If the downloaded MAC-Oriented file is encrypted
and the parameter "static.auto_provision.aes_key_16.mac" is left blank, the
phone will try to encrypt/decrypt the MAC-Oriented file using the AES key
configured by the parameter "static.auto_provision.aes_key_16.com".
Permitted Values 16 characters
Default Blank
Web UI Settings > Auto Provision > Common AES Key
Parameter static.auto_provision.aes_key_16.mac
Description
It configures the plaintext AES key for encrypting/decrypting the MAC-
Oriented files (<MAC>.cfg, <MAC>-local.cfg and <MAC>-contact.xml).
The valid characters contain: 0 ~ 9, A ~ Z, a ~ z and the following special
characters are also supported: # $ % * + , - . : = ? @ [ ] ^ _ { } ~.
Example:
static.auto_provision.aes_key_16.mac = 0123456789abmins
Note: For decrypting, it works only if "static.auto_provision.aes_key_in_file"
is set to 0 (Disabled). If the downloaded MAC-Oriented file is encrypted
and the parameter "static.auto_provision.aes_key_16.mac" is left blank, the
phone will try to encrypt/decrypt the MAC-Oriented file using the AES key
configured by the parameter "static.auto_provision.aes_key_16.com".
Permitted Values 16 characters
Default Blank
Web UI Settings > Auto Provision > MAC-Oriented AES Key
| Security Features | 84
<y0000000000xx>.cfg
<y0000000000xx>.cfg