51369b610e
When an include is not surrounded by empty lines, its content is inlined on the same line as the adjacent content. That can lead to broken tags and other display issues. This PR fixes all such includes and introduces a validation step that forbids introducing the same problem again.
63 lines
1.7 KiB
Plaintext
63 lines
1.7 KiB
Plaintext
== How to fix it in Node.js
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=== Code examples
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include::../../common/fix/code-rationale.adoc[]
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==== Noncompliant code example
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[source,javascript,diff-id=1,diff-type=noncompliant]
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----
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const { execSync } = require('child_process')
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cmd = req.query.cmd
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execSync(cmd) // Noncompliant
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----
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==== Compliant solution
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[source,javascript,diff-id=1,diff-type=compliant]
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----
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const { spawnSync } = require('child_process')
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const cmdId = parseInt(req.query.cmdId)
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let host = req.query.host
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host = typeof host === "string"? host : "example.org"
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const allowedCommands = [
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{exe:"/bin/ping", args:["-c","1","--"]},
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{exe:"/bin/host", args:["--"]}
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]
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const cmd = allowedCommands[cmdId]
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spawnSync(cmd.exe, cmd.args.concat(host))
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----
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=== How does this work?
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include::../../common/fix/introduction.adoc[]
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include::../../common/fix/pre-approved-list.adoc[]
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In the example compliant code, a static list of trusted commands is used. Users are only allowed to
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submit an index in this array in place of a full command name.
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:sanitizationLib: child_process.spawn
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include::../../common/fix/sanitize-meta-characters.adoc[]
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In the example compliant code, the `spawn` function from `child_process` is used in place of its less
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secure `exec` counterpart. It accepts command arguments as an array and
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performs a proper escaping of its element before building the command line to
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run.
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include::../../common/fix/shell_integration.adoc[]
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The `spawn` function that is used in the example compliant code disables shell integration by default.
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=== Pitfalls
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include::../common/pitfalls/loose-typing.adoc[]
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In the above compliant code example, the ambiguous `concat` function is used.
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However, a type check has been introduced to prevent any unexpected issue.
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