What is the default mode of operation supported by the SM4 encryption algorithm?

[wsg314]

The transparent data encryption feature in the cloudberry system supports the SM4 algorithm. What is the default mode of operation supported by the SM4 encryption algorithm?

[kongfanshen-0801]

SM4 encryption algorithm use OFB mode: Output FeedBack mode.
The code path is :
database/src/backend/crypto/sm4_ofb.c

[wsg314]

thanks