### Question:
DefaultRiskAnalysis implements RiskAnalysis { public static RuleViolation isInputStandard(TransactionInput input) { for (ScriptChunk chunk : input.getScriptSig().getChunks()) { if (chunk.data != null && !chunk.isShortestPossiblePushData()) return RuleViolation.SHORTEST_POSSIBLE_PUSHDATA; if (chunk.isPushData()) { ECDSASignature signature; try { signature = ECKey.ECDSASignature.decodeFromDER(chunk.data); } catch (SignatureDecodeException x) { signature = null; } if (signature != null) { if (!TransactionSignature.isEncodingCanonical(chunk.data)) return RuleViolation.SIGNATURE_CANONICAL_ENCODING; if (!signature.isCanonical()) return RuleViolation.SIGNATURE_CANONICAL_ENCODING; } } } return RuleViolation.NONE; } private  DefaultRiskAnalysis(Wallet wallet, Transaction tx, List<Transaction> dependencies); @Override Result analyze(); static RuleViolation isStandard(Transaction tx); static RuleViolation isOutputStandard(TransactionOutput output); static RuleViolation isInputStandard(TransactionInput input); @Nullable Transaction getNonStandard(); @Nullable Transaction getNonFinal(); @Override String toString(); static final Coin MIN_ANALYSIS_NONDUST_OUTPUT; static Analyzer FACTORY; }### Answer:
@Test public void canonicalSignature() { TransactionSignature sig = TransactionSignature.dummy(); Script scriptOk = ScriptBuilder.createInputScript(sig); assertEquals(RuleViolation.NONE, DefaultRiskAnalysis.isInputStandard(new TransactionInput(MAINNET, null, scriptOk.getProgram()))); byte[] sigBytes = sig.encodeToBitcoin(); Script scriptUncanonicalEncoding = new ScriptBuilder().data(Arrays.copyOf(sigBytes, sigBytes.length + 1)) .build(); assertEquals(RuleViolation.SIGNATURE_CANONICAL_ENCODING, DefaultRiskAnalysis.isInputStandard(new TransactionInput(MAINNET, null, scriptUncanonicalEncoding .getProgram()))); }