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Add 'security' hint group (enabled by default): weak hashes, read on untrusted input
data/hlint.yaml: new group 'security', enabled: true. Rules: read x -> Text.Read.readMaybe x side: not (isLitString x) CWE-502 reads x -> Text.Read.readMaybe x side: not (isLitString x) CWE-502 Crypto.Hash.MD5.hash -> Crypto.Hash.SHA256.hash CWE-327 Crypto.Hash.MD5.hashlazy -> Crypto.Hash.SHA256.hashlazy CWE-327 Crypto.Hash.SHA1.hash -> Crypto.Hash.SHA256.hash CWE-327 Crypto.Hash.SHA1.hashlazy -> Crypto.Hash.SHA256.hashlazy CWE-327 Data.Digest.Pure.MD5.md5 -> Crypto.Hash.SHA256.hashlazy CWE-327 Data.Digest.Pure.SHA.sha1 -> Data.Digest.Pure.SHA.sha256 CWE-327 Disable per-rule via `-i "<name>"` or suppress the whole group with `- group: {name: security, enabled: false}` in .hlint.yaml. tests/security.test: four cases. 1. security-hash.hs : all six hash rules fire. 2. security-read-nonliteral.hs: `read x` fires for variable `x`. 3. security-read-literal.hs : `read "42"` and `read "3.14"` do not fire. 4. security-ignored.hs : per-rule -i suppression yields no hints. Self-test: 974 tests, 3 failures (all pre-existing on master: issue #1674 intercalate/OverloadedStrings and two record-pattern type-application cases from PR #1680). Running hlint with the new group on hlint's own source produces one finding: src/Test/InputOutput.hs:57 `read code` (parsing an EXIT line from a .test file). No HSEC advisory on github.com/haskell/security-advisories maps to CWE-327 or CWE-502 for these function classes.
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‎data/hlint.yaml‎

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- warn: {lhs: foldr' f c (reverse x), rhs: foldl' (flip f) c x, name: Use left fold instead of right fold}
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- warn: {lhs: foldl' f c (reverse x), rhs: foldr (flip f) c x, note: IncreasesLaziness, name: Use right fold instead of left fold}
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- group:
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# Security hints, enabled by default. Disable per-rule with
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# `- ignore: {name: "..."}` in .hlint.yaml, or suppress the whole
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# group with `- group: {name: security, enabled: false}`.
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#
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# Rule categories:
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# * `read` -> `readMaybe` on non-literal arguments (CWE-502)
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# * broken / weak hash primitives: MD5, SHA-1 (CWE-327)
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name: security
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enabled: true
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rules:
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# `read` throws a runtime exception on malformed input; it is the
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# Haskell analogue of Python's `pickle.load` / `ast.literal_eval` on
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# untrusted data. Replace with `readMaybe` from `Text.Read` and
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# handle `Nothing` explicitly. Literal arguments (e.g. `read "42"`)
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# are not flagged because the failure is a programmer bug caught on
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# first run, not a runtime attack surface.
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- warn: {lhs: read x, rhs: Text.Read.readMaybe x, side: not (isLitString x), name: "Use readMaybe on untrusted input (CWE-502)"}
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- warn: {lhs: reads x, rhs: Text.Read.readMaybe x, side: not (isLitString x), name: "Use readMaybe on untrusted input (CWE-502)"}
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# Broken or weak cryptographic hashes. MD5 and SHA-1 are
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# cryptographically broken (MD5: chosen-prefix collisions since 2008;
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# SHA-1: SHAttered, 2017) and must not be used for any security
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# purpose (authentication, integrity, digital signatures). Use
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# SHA-256 or stronger from `Crypto.Hash` (cryptonite/crypton); for
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# password hashing use `Crypto.KDF.BCrypt` or `Crypto.KDF.Argon2`.
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- warn: {lhs: Crypto.Hash.MD5.hash x, rhs: Crypto.Hash.SHA256.hash x, name: "Avoid broken hash MD5 (CWE-327)"}
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- warn: {lhs: Crypto.Hash.MD5.hashlazy x, rhs: Crypto.Hash.SHA256.hashlazy x, name: "Avoid broken hash MD5 (CWE-327)"}
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- warn: {lhs: Crypto.Hash.SHA1.hash x, rhs: Crypto.Hash.SHA256.hash x, name: "Avoid broken hash SHA-1 (CWE-327)"}
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- warn: {lhs: Crypto.Hash.SHA1.hashlazy x, rhs: Crypto.Hash.SHA256.hashlazy x, name: "Avoid broken hash SHA-1 (CWE-327)"}
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- warn: {lhs: Data.Digest.Pure.MD5.md5 x, rhs: Crypto.Hash.SHA256.hashlazy x, name: "Avoid broken hash MD5 (CWE-327)"}
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- warn: {lhs: Data.Digest.Pure.SHA.sha1 x, rhs: Data.Digest.Pure.SHA.sha256 x, name: "Avoid broken hash SHA-1 (CWE-327)"}
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- group:
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# used for tests, enabled when testing this file
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name: testing

‎tests/security.test‎

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---------------------------------------------------------------------
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RUN tests/security-hash.hs --hint=data/hlint.yaml
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FILE tests/security-hash.hs
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module Sample where
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import qualified Crypto.Hash.MD5 as MD5
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import qualified Crypto.Hash.SHA1 as SHA1
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import qualified Data.Digest.Pure.MD5 as PMD5
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import qualified Data.Digest.Pure.SHA as PSHA
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import qualified Data.ByteString as BS
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input :: BS.ByteString
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input = BS.empty
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viaMD5, viaMD5Lazy, viaSHA1, viaSHA1Lazy :: BS.ByteString
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viaMD5 = MD5.hash input
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viaMD5Lazy = MD5.hashlazy undefined
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viaSHA1 = SHA1.hash input
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viaSHA1Lazy = SHA1.hashlazy undefined
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viaPureMD5 = PMD5.md5 undefined
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viaPureSHA1 = PSHA.sha1 undefined
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OUTPUT
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tests/security-hash.hs:13:10-23: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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MD5.hash input
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Perhaps:
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Crypto.Hash.SHA256.hash input
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tests/security-hash.hs:13:10-23: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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MD5.hash input
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Perhaps:
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Crypto.Hash.SHA256.hash input
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tests/security-hash.hs:14:14-35: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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MD5.hashlazy undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:14:14-35: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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MD5.hashlazy undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:15:11-25: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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SHA1.hash input
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Perhaps:
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Crypto.Hash.SHA256.hash input
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tests/security-hash.hs:15:11-25: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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SHA1.hash input
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Perhaps:
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Crypto.Hash.SHA256.hash input
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tests/security-hash.hs:16:15-37: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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SHA1.hashlazy undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:16:15-37: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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SHA1.hashlazy undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:18:14-31: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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PMD5.md5 undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:18:14-31: Warning: Avoid broken hash MD5 (CWE-327)
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Found:
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PMD5.md5 undefined
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Perhaps:
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Crypto.Hash.SHA256.hashlazy undefined
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tests/security-hash.hs:19:15-33: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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PSHA.sha1 undefined
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Perhaps:
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PSHA.sha256 undefined
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tests/security-hash.hs:19:15-33: Warning: Avoid broken hash SHA-1 (CWE-327)
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Found:
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PSHA.sha1 undefined
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Perhaps:
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PSHA.sha256 undefined
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12 hints
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---------------------------------------------------------------------
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RUN tests/security-read-nonliteral.hs --hint=data/hlint.yaml
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FILE tests/security-read-nonliteral.hs
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module Sample where
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parseStr :: String -> Int
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parseStr s = 1 + read s
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parseOther :: String -> Double
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parseOther raw = 0.5 * read raw
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OUTPUT
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tests/security-read-nonliteral.hs:4:18-23: Warning: Use readMaybe on untrusted input (CWE-502)
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Found:
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read s
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Perhaps:
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Text.Read.readMaybe s
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tests/security-read-nonliteral.hs:4:18-23: Warning: Use readMaybe on untrusted input (CWE-502)
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Found:
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read s
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Perhaps:
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Text.Read.readMaybe s
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tests/security-read-nonliteral.hs:7:24-31: Warning: Use readMaybe on untrusted input (CWE-502)
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Found:
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read raw
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Perhaps:
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Text.Read.readMaybe raw
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tests/security-read-nonliteral.hs:7:24-31: Warning: Use readMaybe on untrusted input (CWE-502)
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Found:
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read raw
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Perhaps:
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Text.Read.readMaybe raw
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4 hints
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---------------------------------------------------------------------
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RUN tests/security-read-literal.hs --hint=data/hlint.yaml
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FILE tests/security-read-literal.hs
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module Sample where
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answer :: Int
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answer = read "42"
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piApprox :: Double
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piApprox = read "3.14"
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OUTPUT
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No hints
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---------------------------------------------------------------------
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RUN tests/security-ignored.hs --hint=data/hlint.yaml -i "Avoid broken hash MD5 (CWE-327)" -i "Use readMaybe on untrusted input (CWE-502)"
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FILE tests/security-ignored.hs
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module Sample where
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import qualified Crypto.Hash.MD5 as MD5
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import qualified Data.ByteString as BS
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digest :: BS.ByteString
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digest = MD5.hash BS.empty
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parseStr :: String -> Int
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parseStr s = 1 + read s
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OUTPUT
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No hints

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