crypto API: make sure TEE_Attribute parameters are readable

[jforissier]

Fixes #161.

Services that take a TEE_Attribute array for input must check that the
memory is readable before using it. This is accomplished by
check_attr_read_access(), which is either called directly by the system
service or by tee_svc_cryp_check_attr(). Buffers pointed to by 'reference'
attributes are also validated.
Then, it is no longer necessary to check accessibility in other
functions such as tee_svc_cryp_obj_store_attr_raw().

Signed-off-by: Jerome Forissier jerome.forissier@linaro.org

[pascal-brand38]

xtest 7537 is wrong :(

This test does

ADBG_EXPECT(c, TEE_ERROR_BAD_PARAMETERS, Invoke_InitObjectAndAttributes(c, SESSION01, CMD_InitObjectAndAttributes, CASE_POPULATE_BAD_PARAM, TEE_TYPE_DES3, SIZE_DES3_192, TEE_ATTR_SECRET_VALUE, TEE_ATTR_DES3_192_VALUE01, sizeof(TEE_ATTR_DES3_192_VALUE01), TEE_ATTR_NONE, TEE_ATTR_VALUE_NONE, sizeof(TEE_ATTR_VALUE_NONE), TEE_ATTR_NONE, TEE_ATTR_VALUE_NONE, sizeof(TEE_ATTR_VALUE_NONE), TEE_ATTR_NONE, TEE_ATTR_VALUE_NONE, sizeof(TEE_ATTR_VALUE_NONE), TEE_ATTR_NONE, TEE_ATTR_VALUE_NONE, sizeof(TEE_ATTR_VALUE_NONE)));

This command panics the TA because of the change in tee_svc_cryp_check_attr(). check_attr_read_access() is called too earlier. Indeed, this test wait for a BAD_PARAMETER which is returned by tee_svc_cryp_obj_store_attr_raw(). In such a case, it does not panic.

[jforissier]

So if I understand correctly, the test injects two errors: bad parameter value and invalid memory reference. And my patch checks memory access fist, when it should check the values first. Is it correct? I don't have test 7537 in my test suite and the GP spec doesn't have much details about parameter checking.

[pascal-brand38]

A bug has been entered in GP. In the meantime, I propose to accept this patch if the XML test file is fixed with respect to this.

@jforissier Could you send me and Cedric the patch of the XML file to that the tests run ok?

Reviewed-by: Pascal Brand <pascal.brand@linaro.org>

[jforissier]

I have updated optee_test to take into account the new behavior introduced
by this PR. Please check branch optee-pr-167.

• XTEST_TEE_7537 9d-5c-6a
  ERR [629] TEEC:TEEC_InvokeCommand:402: Function returns with [-53212]
  XTEST_TEE_7537 OK

[jforissier]

Rebased with tags applied.

[pascal-brand38]

@jforissier can you rebase?