From c70013e4bc92fb449f6b04416fdfc7fdcad676aa Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Manuel=20P=C3=A9gouri=C3=A9-Gonnard?= Date: Thu, 10 Feb 2022 13:07:22 +0100 Subject: [PATCH] Clarify the trailer field situation MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Signed-off-by: Manuel Pégourié-Gonnard --- docs/architecture/psa-migration/psa-limitations.md | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/docs/architecture/psa-migration/psa-limitations.md b/docs/architecture/psa-migration/psa-limitations.md index 45c78063fd..a7c4afb9f3 100644 --- a/docs/architecture/psa-migration/psa-limitations.md +++ b/docs/architecture/psa-migration/psa-limitations.md @@ -83,7 +83,8 @@ the hash algorithm potentially used to hash the message being signed: - a mask generation function - most commonly MGF1, which in turn is parametrized by a hash algorithm - a salt length -- a trailer field - this is universally 0xBC as far as I've seen +- a trailer field - the value is fixed to 0xBC by PKCS#1 v2.1, but was left + configurable in the original scheme; 0xBC is used everywhere in pratice. Both the existing `mbedtls_` API and the PSA API support only MGF1 as the generation function (and only 0xBC as the trailer field), but there are