[openssl/openssl] a6ed37: rsa: Accept NULL OAEP label for backward compatibi...

[Daiki Ueno]

  Branch: refs/heads/openssl-3.1
  Home:   https://github.com/openssl/openssl
  Commit: a6ed37c2e2c50e93937e4ea3271a8af96e0303de
      https://github.com/openssl/openssl/commit/a6ed37c2e2c50e93937e4ea3271a8af96e0303de
  Author: Daiki Ueno <dueno at redhat.com>
  Date:   2023-10-18 (Wed, 18 Oct 2023)

  Changed paths:
    M crypto/rsa/rsa_lib.c
    M test/evp_extra_test.c

  Log Message:
  -----------
  rsa: Accept NULL OAEP label for backward compatibility

According to the manual page, EVP_PKEY_CTX_set0_rsa_oaep_label()
should accept NULL as the label argument, though the function
currently rejects it while setting the corresponding octet string
parameter with OSSL_PARAM_construct_octet_string, which expects
non-NULL input.  This adds a workaround to the caller for backward
compatibility.

Signed-off-by: Daiki Ueno <dueno at redhat.com>

Reviewed-by: Dmitry Belyavskiy <beldmit at gmail.com>
Reviewed-by: Tomas Mraz <tomas at openssl.org>
(Merged from https://github.com/openssl/openssl/pull/22397)

(cherry picked from commit 21b98da9d80c561b6273b0c51c259196d6740e70)