Revision and client identifier regex formats accept newlines

[crodriguezvega]

This issue was found by Trail of Bits during the audit of ICS27 Interchain Accounts

Problem Definition

The IsRevisionFormat and IsClientIDFormat regular expressions (regexes) implemented in the 02-client module use the [^-] regex element to ensure that two components are delimited by only a single dash in the respective {chainID}-{revision} and {client-type}-{N} formats. However, this regex element also accepts newline characters, which could cause unwanted “revision” and “client identifier” formats to be accepted.

Proposal

• Fix the IsRevisionFormat and IsClientIDFormat regexes by changing the [^-] element to [^\n-] so that newline characters are not accepted before the - delimiter.
• Extend the TestParseClientIdentifier and TestParseChainID test cases to check for client and chain IDs that contain newline characters before the - delimiter.

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For Admin Use

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• Appropriate labels applied
• Appropriate contributors tagged/assigned

[colin-axner]

I think newlines should be allowed in IsRevisionFormat. We shouldn't impose chainID naming restrictions more than appending the revision number

[crodriguezvega]

We will fix only the client ID regex.

[colin-axner]

On second thought the IsRevisionFormat should be updated. I didn't realize we already enforce chainIDs not to have newlines. The proposed change is just ensuring newlines aren't used before the -<revision number>. Since we are already imposing the naming restriction in of no newlines in the chainID to be a valid revision number, we can leave this as so until we receive requests otherwise