REF: https://bugzilla.tianocore.org/show_bug.cgi?id=4177
Because the current Mbedlts pkcs7 library doesn't support
authenticatedAttributes
and only support 0 or 1 certificates in Signed data,
the patch implement Pkcs7 by low Mbedtls Api.
And the implementation has pass unit_tes and integration test.
Cc: Jiewen Yao <jiewen.yao@intel.com>
Cc: Yi Li <yi1.li@intel.com>
Signed-off-by: Wenxing Hou <wenxing.hou@intel.com>
Reviewed-by: Yi Li <yi1.li@intel.com>
Acked-by: Jiewen Yao <Jiewen.yao@intel.com>