CMS sign digest

CLI changes: New parameter -digest to CLI command openssl cms, to
provide pre-computed digest for use with -sign.

API changes: New function CMS_final_digest(), like CMS_final() but
uses a pre-computed digest instead of computing it from the data.

Reviewed-by: Tomas Mraz <tomas@openssl.org>
Reviewed-by: David von Oheimb <david.von.oheimb@siemens.com>
Reviewed-by: Todd Short <todd.short@me.com>
(Merged from https://github.com/openssl/openssl/pull/15348)

1 files changed, 13 insertions, 0 deletions

diff --git a/doc/man1/openssl-cms.pod.in b/doc/man1/openssl-cms.pod.in
index c63a7f330b..632d7fe857 100644
--- a/doc/man1/openssl-cms.pod.in
+++ b/doc/man1/openssl-cms.pod.in
@@ -25,6 +25,7 @@ Operation options:
 [B<-resign>]
 [B<-sign_receipt>]
 [B<-verify_receipt> I<receipt>]
+[B<-digest> I<digest>]
 [B<-digest_create>]
 [B<-digest_verify>]
 [B<-compress>]
@@ -207,6 +208,16 @@ Verify a signed receipt in filename B<receipt>. The input message B<must>
 contain the original receipt request. Functionality is otherwise similar
 to the B<-verify> operation.
 
+=item B<-digest> I<digest>
+
+When used with B<-sign>, provides the digest in hexadecimal form instead of
+computing it from the original message content. Cannot be combined with B<-in>
+or B<-nodetach>.
+
+This operation is the CMS equivalent of L<openssl-pkeyutl(1)> signing.
+When signing a pre-computed digest, the security relies on the digest and its
+computation from the original message being trusted.
+
 =item B<-digest_create>
 
 Create a CMS B<DigestedData> type.
@@ -900,6 +911,8 @@ The B<-nameopt> option was added in OpenSSL 3.0.0.
 
 The B<-engine> option was deprecated in OpenSSL 3.0.
 
+The B<-digest> option was added in OpenSSL 3.1.
+
 =head1 COPYRIGHT
 
 Copyright 2008-2021 The OpenSSL Project Authors. All Rights Reserved.