[SM2 encrypt/decrypt] The newest SM2 encrypt output buffer is (C1 || C3 || C2).

[wmfhust]

optee_os/core/lib/libtomcrypt/sm2-pke.c

Line 465 in b9436f3

* Output C = C1 || C2 || C3

Referrence url: https://openstd.samr.gov.cn/bzgk/std/newGbInfo?hcno=370AF152CB5CA4A377EB4D1B21DECAE0&refer=outter.
The newest SM2 public encrypt standard is: GB/T32918.4—2016, and the sm2 encrypt output buffer is (C1 || C3 || C2). I think the code and xtest golden data need to be updated according to the new standard.

[jenswikl]

That sounds like an incompatible change. Does the standard mention how to handle that?

[wmfhust]

I try to find the old sm2 standard, but I can't find the "C1 || C2 || C3" description in any standard. Please check it.
Both in "GMT 0003.4-2012" and "GB/T32918.4—2016", the description are all "C1 || C3 || C2".
GMT 0003.4-2012: http://www.gmbz.org.cn/main/viewfile/20180108023602687857.html
GB/T32918.4—2016: https://openstd.samr.gov.cn/bzgk/std/newGbInfo?hcno=370AF152CB5CA4A377EB4D1B21DECAE0&refer=outter