tree e8be11090da644e5fbbd1275b99d106648ac8abc
parent 72fe34746cc9d882cfaf7162e14fd075a0381edd
author Juan Castillo <juan.castillo@arm.com> 1425565800 +0000
committer Juan Castillo <juan.castillo@arm.com> 1435218806 +0100

TBB: use ASN.1 type DigestInfo to represent hashes

The cert_create tool calculates the hash of each BL image and includes
it as an ASN.1 OCTET STRING in the corresponding certificate extension.
Without additional information, the firmware running on the platform
has to know in advance the algorithm used to generate the hash.

This patch modifies the cert_create tool so the certificate extensions
that include an image hash are generated according to the following
ASN.1 structure:

    DigestInfo ::= SEQUENCE {
        digestAlgorithm  AlgorithmIdentifier,
        digest           OCTET STRING
    }

    AlgorithmIdentifier ::=  SEQUENCE  {
        algorithm        OBJECT IDENTIFIER,
        parameters       ANY DEFINED BY algorithm OPTIONAL
    }

The PolarSSL module has been updated to extract the image hash
from the certificate extension according to this structure.

Change-Id: I6d83430f12a8a0eea8447bec7c936e903f644c85