crypto/x509: Verify on macOS does not return typed errors [1.18 backport]

[gopherbot]

@rolandshoemaker requested issue #56891 to be considered for backport to the next 1.18 minor release.

@gopherbot please open backport issues. This issue makes macOS behave differently from every other platform, which otherwise return consistent types for verification errors. This was an inadvertent breaking API change introduced in 1.18, and is likely causing silent issues in code that expects consistent behavior across platforms when verifying certificates. Currently working around this requires adding macOS specific code in order to catch specific verification failures.

[heschi]

Ping: this issue is at risk of missing the next minor release, which will be the last for 1.18.

[heschi]

cc @golang/security

[gopherbot]

Change https://go.dev/cl/460896 mentions this issue: [release-branch.go1.18] crypto/x509: return typed verification errors on macOS

[gopherbot]

Closed by merging 476384e to release-branch.go1.18.

[gopherbot]

Change https://go.dev/cl/461176 mentions this issue: misc/cgo/testcshared: handle unsuffixed dlltool path