Re: [Cbor] List of not-well-formed CBOR and test vectors

Carsten Bormann <cabo@tzi.org> Tue, 30 July 2019 09:23 UTC

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From: Carsten Bormann <cabo@tzi.org>
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Subject: Re: [Cbor] List of not-well-formed CBOR and test vectors
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> I think I’ve made a comprehensive list of all things that are not well formed by going through the latest draft and my decoder. There are about a dozen of them. I’ve also created 110 test vectors that cover them pretty thoroughly. 

Nice!
I actually find 111 vectors there.  
If I run these through the (slightly instrumented) pseudocode of the appendix, I get:

   2 SHORT
  10 FINITE
  14 SHORT
   1 BREAK
  14 SHORT
   7 BREAK
   2 RESIDUAL
  25 SIMPLE
   4 INDEF
   4 SHORT
  24 AI
   2 SHORT
   2 BREAK

Where:

- SHORT = premature EOF
- RESIDUAL = data remaining after decoding
1 AI = reserved AI
2 SIMPLE = impermissible coding of simple value
3 FINITE = indefinite inside indefinite length string
4 BREAK = break stop code outside indefinite length item or as map value
5 INDEF = wrong major type for indefinite length

(The numbers in this list enumerate the calls to “fail()” in the pseudocode in the appendix.)

Why are you testing only 25 of the 32 impermissible SIMPLE cases?

Grüße, Carsten

PS: These test vectors base64url-encoded in JSON:

[
  "X0EA",
  "f2EA",
  "X2EA_w",
  "f0EA_w",
  "XwD_",
  "XyH_",
  "X4D_",
  "X6D_",
  "X8AA_w",
  "X-D_",
  "X19BAP__",
  "f39hAP__",
  "gQ",
  "ggA",
  "mgH_AA",
  "oQ",
  "ogEC",
  "nw",
  "nwEC",
  "vw",
  "vwECAQI",
  "n4AA",
  "gZ8",
  "gYGBgYGBgYGB",
  "n5-fn5______",
  "n4GfgZ-f____",
  "n4KfgZ-f_____w",
  "GA",
  "GQ",
  "Gg",
  "Gw",
  "GQE",
  "GgEC",
  "GwECAwQFBgc",
  "OA",
  "WA",
  "eA",
  "mA",
  "uA",
  "2A",
  "-A",
  "gf8",
  "ggD_",
  "of8",
  "of8A",
  "oQD_",
  "ogAA_w",
  "_w",
  "gP8",
  "n___",
  "-AA",
  "-AE",
  "-AI",
  "-AM",
  "-AQ",
  "-AU",
  "-AY",
  "-Ac",
  "-Ag",
  "-Ak",
  "-Ao",
  "-As",
  "-Aw",
  "-A0",
  "-A4",
  "-A8",
  "-BA",
  "-BE",
  "-BI",
  "-BM",
  "-BQ",
  "-BU",
  "-BY",
  "-Bc",
  "-Bg",
  "Hw",
  "Pw",
  "3wA",
  "3w",
  "QQ",
  "YQ",
  "Wv____8A",
  "ev____8A",
  "HA",
  "HQ",
  "Hg",
  "PA",
  "PQ",
  "Pg",
  "XA",
  "XQ",
  "Xg",
  "fA",
  "fQ",
  "fg",
  "nA",
  "nQ",
  "ng",
  "vA",
  "vQ",
  "vg",
  "3A",
  "3Q",
  "3g",
  "_A",
  "_Q",
  "_g",
  "oQA",
  "ogAAAA",
  "vwD_",
  "vwAAAP8"
]