tree 403bac7eab399feab8af86028ca3b8f1e02505bb
parent c0691130969b2629f6a772dd9543244e6c92a57b
author Jerome Forissier <jerome@forissier.org> 1576570796 +0100
committer Jérôme Forissier <jerome@forissier.org> 1578402876 +0100

core: ltc: add support for SM2 PKE

SM2 is a set of public key cryptographic algorithms based on elliptic
curves published by the Chinese Commercial Cryptography Administration
Office [1]. The standard has three main parts which define:

 - A Digital Signature Algorithm (part 2)
 - A Key Exchange Protocol (part 3)
 - A Public Key Encryption method (part 4)

This commit implements the PKE LibTomcrypt for use by the OP-TEE core.
It uses the LibTomCrypt ECC and arithmetic helper functions as well as
the OP-TEE hash interface for the SM3 algorithm.

As far as the ECC point encoding goes, only the uncompressed form is
supported, as permitted by the standard. In practice, it means that the
cipher text always starts with the byte value 0x04. Other forms cannot
be decrypted by this implementation.

Signed-off-by: Jerome Forissier <jerome@forissier.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>