Comment 1 for bug 2003701

setting PKCS7_NOATTR is not enough, as that only removes the smime capabilities signed attribute, whilst signature timestamp remains.

--- ./regular.text 2023-01-23 11:42:49.992929526 +0000
+++ noattr.text 2023-01-23 11:42:59.288981639 +0000
@@ -128,7 +128,7 @@

             object: signingTime (1.2.840.113549.1.9.5)
             set:
- UTCTIME:Jan 23 11:41:20 2023 GMT
+ UTCTIME:Jan 23 11:41:53 2023 GMT

             object: messageDigest (1.2.840.113549.1.9.4)
             set:
@@ -136,56 +136,32 @@
                 0000 - f8 cf 89 70 c1 6c 14 26-6d 56 c1 25 96 ...p.l.&mV.%.
                 000d - ce 74 11 77 a0 36 47 4d-3b 28 bf 7f 5b .t.w.6GM;(..[
                 001a - 1e b6 04 ed 21 f8 ....!.
-
- object: S/MIME Capabilities (1.2.840.113549.1.9.15)
- set:
- SEQUENCE:
- 0:d=0 hl=2 l= 106 cons: SEQUENCE
- 2:d=1 hl=2 l= 11 cons: SEQUENCE
- 4:d=2 hl=2 l= 9 prim: OBJECT :aes-256-cbc
- 15:d=1 hl=2 l= 11 cons: SEQUENCE
- 17:d=2 hl=2 l= 9 prim: OBJECT :aes-192-cbc
- 28:d=1 hl=2 l= 11 cons: SEQUENCE
- 30:d=2 hl=2 l= 9 prim: OBJECT :aes-128-cbc
- 41:d=1 hl=2 l= 10 cons: SEQUENCE
- 43:d=2 hl=2 l= 8 prim: OBJECT :des-ede3-cbc
- 53:d=1 hl=2 l= 14 cons: SEQUENCE
- 55:d=2 hl=2 l= 8 prim: OBJECT :rc2-cbc
- 65:d=2 hl=2 l= 2 prim: INTEGER :80
- 69:d=1 hl=2 l= 13 cons: SEQUENCE
- 71:d=2 hl=2 l= 8 prim: OBJECT :rc2-cbc
- 81:d=2 hl=2 l= 1 prim: INTEGER :40
- 84:d=1 hl=2 l= 7 cons: SEQUENCE
- 86:d=2 hl=2 l= 5 prim: OBJECT :des-cbc
- 93:d=1 hl=2 l= 13 cons: SEQUENCE
- 95:d=2 hl=2 l= 8 prim: OBJECT :rc2-cbc
- 105:d=2 hl=2 l= 1 prim: INTEGER :28
         digest_enc_alg: