Fix nondeterministic test failure for X509CertificateLoader#124617
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vcsjones merged 3 commits intodotnet:mainfrom Feb 19, 2026
Merged
Fix nondeterministic test failure for X509CertificateLoader#124617vcsjones merged 3 commits intodotnet:mainfrom
vcsjones merged 3 commits intodotnet:mainfrom
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test-bug
OpenSSL does not "block" trailing data after an X.509 certificate that the test thought it did. OpenSSL permits trailing data... as long as it is valid ASN.1. Certain PIDs resemble ASN.1 enough that it allows the parsing to succeed and not throw an exception like the test expected. For example, if the PID was 32816, this would be 30 80 00 00 - an indefinite length ASN.1 BER SEQUENCE. The trailing data is ignored when the parsing succeeds, its just a matter of if the trailing data causes an error (invalid ASN.1) or is ignored (valid ASN.1, but remains unconsumed).
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Pull request overview
This PR fixes a nondeterministic test failure in X509CertificateLoader tests. The test LoadWrappingCertificate_PEM_WithTrailingData was failing intermittently because it used the process ID as trailing data after a certificate. OpenSSL permits trailing data as long as it is valid ASN.1, and certain PIDs could accidentally resemble valid ASN.1 structures (e.g., PID 32816 = 30 80 00 00 = indefinite length ASN.1 BER SEQUENCE), causing the test to behave differently on each run depending on the PID value.
Changes:
- Replaced nondeterministic PID-based trailing data with deterministic byte sequence
[1, 2, 3, 4] - Removed trailing whitespace on line 157
...ies/Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderTests.cs
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...ies/Common/tests/System/Security/Cryptography/X509Certificates/X509CertificateLoaderTests.cs
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Feb 19, 2026
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OpenSSL does not block trailing data after an X.509 certificate like the test thought it did. OpenSSL permits trailing data as long as it is valid ASN.1. The unit test in question used the process ID as the trailing data. Certain PIDs resemble ASN.1 enough that it allows the parsing to succeed and not throw an exception like the test expected. For example, if the PID was 32816, this would be 30 80 00 00 - an indefinite length ASN.1 BER SEQUENCE.
The trailing data is ignored when the parsing succeeds, it's just a matter of if the trailing data causes an error (invalid ASN.1) or is ignored (valid ASN.1, but remains unconsumed).
Fixes #123630