Replace SHA-1/RSA-1024 test data with SHA-256/RSA-2048 equivalents by joshuajyue · Pull Request #131783 · dotnet/runtime

joshuajyue · 2026-08-04T02:03:51Z

Summary

Platforms that enforce a strict crypto policy (CentOS Stream 10, Fedora 44, and similar RHEL-family distros) reject both SHA-1 signatures and RSA keys smaller than 2048 bits. This caused 29 tests in System.Security.Cryptography.Pkcs to be skipped behind [ConditionalFact(SupportsRsaSha1Signatures)].

This PR replaces the pre-built test documents and the certificates used to produce them with SHA-256 / RSA-2048 equivalents, reducing the number of conditionally-skipped tests from 29 → 3.

What changed

New test documents (`SignedDocuments.cs`)

Seven new pre-built CMS binary blobs were added (stored as hex byte arrays), all signed with RSA2048Sha256KeyTransfer1 (RSA-2048, SHA-256):

Document	Shape
`RsaPkcs1Sha256OneSignerIssuerAndSerialNumber`	One signer, IssuerAndSerialNumber, no counter-signers
`CounterSignedRsaPkcs1Sha256OneSigner`	One signer + one counter-signer (SKID)
`OneRsaSignerTwoRsaCounterSigners_Sha256`	One signer + two counter-signers (SKID + IssuerSerial)
`RsaPkcs1Sha256CounterSignedWithNoSignature`	One signer + one NoSignature counter-signer
`RsaSha256Transfer1_NoEmbeddedCert`	One signer, SKID, no embedded certificate
`SignedCmsOverEnvelopedCms_IssuerSerial_Sha256_NetFx`	SignedCms wrapping EnvelopedCms, IssuerSerial
`SignedCmsOverEnvelopedCms_SKID_Sha256_NetFx`	SignedCms wrapping EnvelopedCms, SubjectKeyIdentifier

All documents were generated using .NET Framework (net481), which is a thin wrapper over crypt32.dll. This preserves the Windows-native CMS encoding — in particular, counter-signers produced by crypt32 include a ContentType signed attribute that managed .NET does not emit, providing better interop coverage.

Tests re-enabled (removed `[ConditionalFact]`)

SignerInfoTests.cs

AddCounterSigner_DuplicateCert_RSA
AddCounterSigner_RSA
AddCounterSigner_ECDSA (SHA-256/384/512 variants — these never required a SHA-1 guard)
RemoveCounterSignature_MatchesIssuerAndSerialNumber
RemoveCounterSignature_MatchesSubjectKeyIdentifier
RemoveCounterSignature_MatchesNoSignature
RemoveCounterSignature_UsesLiveState

SignedCmsWholeDocumentTests.cs

ReadRsaPkcs1SimpleDocument
ReadRsaPkcs1CounterSigned
ReadRsaPkcs1DoubleCounterSigned
NonEmbeddedCertificate

SignedCmsTests.netcoreapp.cs

AddCertificate
AddCertificateWithPrivateKey
RemoveAllCertsAddBackSignerCert

SignedCmsTests.cs

CheckSignedEncrypted_IssuerSerial_FromNetFx
CheckSignedEncrypted_SKID_FromNetFx

Other changes

AddCounterSigner_ECDSA_Sha1 was split out from AddCounterSigner_ECDSA and re-guarded with the new SupportsEcdsaSha1Signatures property (previously it was incorrectly gated on SupportsRsaSha1Signatures). The SHA-256/384/512 ECDSA cases are now unconditional.
SignatureSupport.cs: added SupportsEcdsaSha1Signatures — probes ECDSA SHA-1 support independently from RSA.
CheckSignedEncrypted helper: made the decryptionCert parameter optional so the two new NetFx documents (which use RSA2048Sha256KeyTransfer1 for encryption) and the existing CoreFx documents (which use RSAKeyTransferCapi1) can share the same helper.

Remaining conditional tests (intentional)

Test	Reason
`AddCounterSigner_ECDSA_Sha1`	Deliberately tests SHA-1 ECDSA behavior; must skip where SHA-1 is banned
`CheckNoSignatureDocument`	Uses a `NoSignature` primary signer; `.NET Framework` throws `NullReferenceException` when creating this shape, so no crypt32-produced SHA-2 twin can be generated
`AddCounterSigner_DSA`	DSA platform availability, unrelated to this change

Testing

Verified locally on Windows:

net11.0-windows: 959 passed, 0 failed
net481: 386 passed, 0 failed

Note

This PR description was generated by GitHub Copilot.

azure-pipelines · 2026-08-04T02:04:34Z

Azure Pipelines: Successfully started running 3 pipeline(s). 13 pipeline(s) were filtered out due to trigger conditions. There may be pipelines that require an authorized user to comment /azp run to run.

Copilot

Pull request overview

This PR updates System.Security.Cryptography.Pkcs test data and tests to avoid SHA-1 / RSA-1024 artifacts by introducing SHA-256 / RSA-2048 CMS blobs and switching multiple tests from SHA-1-guarded [ConditionalFact] to unconditional [Fact]/[Theory], plus adding a dedicated ECDSA-SHA1 capability probe.

Changes:

Added SHA-256 / RSA-2048 “structural twin” CMS test documents and updated tests to decode/validate these new blobs.
Removed RSA-SHA1 conditional gating from many tests now backed by SHA-2 documents; split out an ECDSA-SHA1-only test and gated it with a new SupportsEcdsaSha1Signatures probe.
Updated helper logic to support decrypting both legacy and new encrypted-content shapes via an optional certificate loader.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignerInfoTests.cs	Switches multiple RSA-SHA1-gated tests to SHA-256 docs; adds ECDSA-SHA1-specific conditional test.
src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedDocuments.cs	Adds new SHA-256 / RSA-2048 CMS byte-array fixtures (including crypt32-produced variants).
src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsWholeDocumentTests.cs	Updates whole-document assertions (digest OIDs, signatures, SKI values, message-digest hashing) to match SHA-256 fixtures.
src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.netcoreapp.cs	Re-enables certificate mutation tests by switching to SHA-256 countersigned fixture.
src/libraries/System.Security.Cryptography.Pkcs/tests/SignedCms/SignedCmsTests.cs	Switches encrypted-content fixtures to SHA-256 NetFx variants and adds optional decrypt cert parameter.
src/libraries/System.Security.Cryptography.Pkcs/tests/SignatureSupport.cs	Adds `SupportsEcdsaSha1Signatures` capability probe.

        }

-        [ConditionalFact(typeof(SignatureSupport), nameof(SignatureSupport.SupportsRsaSha1Signatures))]
+        [Fact]


Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Platforms that enforce a strict crypto policy (e.g. CentOS Stream 10, Fedora 44) reject SHA-1 signatures and RSA keys smaller than 2048 bits, causing 29 tests in System.Security.Cryptography.Pkcs to be skipped behind [ConditionalFact(SupportsRsaSha1Signatures)]. This change replaces the pre-built test documents and the certificates used to produce them with SHA-256 / RSA-2048 equivalents, reducing the number of conditionally-skipped tests from 29 to 3. The three remaining skips are intentional: - AddCounterSigner_ECDSA_Sha1: deliberately tests SHA-1 ECDSA behavior - CheckNoSignatureDocument: uses a NoSignature primary signer that .NET Framework cannot reproduce (NullReferenceException in crypt32), so no SHA-2 twin can be generated New test documents were generated using .NET Framework (net481), which is a thin wrapper over crypt32, so the output carries the Windows-native encoding (counter-signers include a ContentType signed attribute, as crypt32 emits). Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com> Copilot-Session: 53916e59-38f7-4bcf-beba-f9662df3975b

Copilot

Pull request overview

Copilot reviewed 6 out of 6 changed files in this pull request and generated no new comments.

vcsjones · 2026-08-04T22:21:05Z

Something to call out for this change, by default I don't think any of our CI pipelines actually run with the RSA+SHA1 restriction. This is a Red Hat / Fedora thing.

In theory Azure Linux 4 also has the RSA+SHA1 restriction but that only runs with the runtime-extra-platforms pipeline, which doesn't run by default. We should make sure we run the pipeline once the PR is ready.

vcsjones · 2026-08-04T22:37:44Z

(I did run this on Fedora and its green)

joshuajyue self-assigned this Aug 4, 2026

Copilot AI review requested due to automatic review settings August 4, 2026 02:03

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build-analysis Bot mentioned this pull request Aug 4, 2026

[wasm] OpenQA.Selenium.WebDriverTimeoutException: timeout: Timed out receiving message from renderer #117486

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joshuajyue force-pushed the pkcs-sha2-test-data branch from 144f006 to 640e5dd Compare August 4, 2026 16:42

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Microsoft.Extensions.Configuration.Test.ConfigurationTests.ReloadOnChangeWorksAfterError failing in CI #131805

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joshuajyue force-pushed the pkcs-sha2-test-data branch from 640e5dd to 3dbc3f8 Compare August 4, 2026 21:54

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Replace SHA-1/RSA-1024 test data with SHA-256/RSA-2048 equivalents - #131783

Replace SHA-1/RSA-1024 test data with SHA-256/RSA-2048 equivalents#131783
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joshuajyue commented Aug 4, 2026

Summary

What changed

New test documents (SignedDocuments.cs)

Tests re-enabled (removed [ConditionalFact])

Other changes

Remaining conditional tests (intentional)

Testing

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New test documents (`SignedDocuments.cs`)

Tests re-enabled (removed `[ConditionalFact]`)