[tor-bugs] #19647 [Core Tor/Tor]: Descriptors should only contain printable ASCII

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#19647: Descriptors should only contain printable ASCII
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     Reporter:  teor          |      Owner:
         Type:  enhancement   |     Status:  new
     Priority:  Medium        |  Milestone:  Tor: 0.2.???
    Component:  Core Tor/Tor  |    Version:
     Severity:  Normal        |   Keywords:  tor-hs, 030-proposed, prop224
Actual Points:                |  Parent ID:  #17238
       Points:                |   Reviewer:
      Sponsor:                |
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 In #18938, we discovered some relays publishing platform lines or
 extrainfo documents with non-ASCII characters.

 This seems to occur due to memory corruption.

 So let's make sure that a non-ASCII check is done on:
 * hidden services: unencrypted or encrypted descriptor
 * HSDirs: encrypted descriptor
 * clients: unencrypted or encrypted descriptor

 This might require a spec change - it's likely implicit in the spec
 already.

 For completeness, the set of printable ASCII characters is defined in dir-
 spec.txt as:
 {{{
     NL = The ascii LF character (hex value 0x0a).
     KeywordChar ::= 'A' ... 'Z' | 'a' ... 'z' | '0' ... '9' | '-'
     ArgumentChar ::= any printing ASCII character except NL.
     WS = (SP | TAB)+
 }}}

 Where I assume "printing ASCII" means "space to tilde", but we should also
 clarify that in the torspec.

--
Ticket URL: <https://trac.torproject.org/projects/tor/ticket/19647>
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