x/crypto: TestDsa failure on Linux ARM

[toothrot]

What version of Go are you using (go version)?

Tip

Does this issue reproduce with the latest release?

Also failing on release-branch.go1.13 and 1.12

What operating system and processor architecture are you using (go env)?

(ARM buildlet)

What did you do?

https://build.golang.org/log/610cd72794e4757d8207300f9740caed3cb65ee4

What did you expect to see?

OK

What did you see instead?

--- FAIL: TestDsa (0.11s)
panic: runtime error: slice bounds out of range [:-2147483643] [recovered]
	panic: runtime error: slice bounds out of range [:-2147483643]

goroutine 34 [running]:
testing.tRunner.func1(0x5a40a0)
	/workdir/go/src/testing/testing.go:916 +0x534
panic(0x19d9a0, 0x66d7c0)
	/workdir/go/src/runtime/panic.go:967 +0x118
golang.org/x/crypto/cryptobyte.(*String).read(...)
	/workdir/gopath/src/golang.org/x/crypto/cryptobyte/string.go:30
golang.org/x/crypto/cryptobyte.(*String).ReadBytes(...)
	/workdir/gopath/src/golang.org/x/crypto/cryptobyte/string.go:144
golang.org/x/crypto/cryptobyte.(*String).readASN1(0x5c1e88, 0x5c1e94, 0x5c1e5c, 0x191d01, 0x59c101)
	/workdir/gopath/src/golang.org/x/crypto/cryptobyte/asn1.go:743 +0x32c
golang.org/x/crypto/cryptobyte.(*String).ReadAnyASN1(...)
	/workdir/gopath/src/golang.org/x/crypto/cryptobyte/asn1.go:546
golang.org/x/crypto/cryptobyte.(*String).ReadASN1(0x5c1e88, 0x5c1e94, 0x59de30, 0x166ce4)
	/workdir/gopath/src/golang.org/x/crypto/cryptobyte/asn1.go:521 +0x3c
golang.org/x/crypto/internal/wycheproof/internal/dsa.VerifyASN1(0x5f7ee0, 0x664c60, 0x14, 0x20, 0x59de30, 0x33, 0x70, 0x0)
	/workdir/gopath/src/golang.org/x/crypto/internal/wycheproof/internal/dsa/dsa.go:25 +0x80
golang.org/x/crypto/internal/wycheproof.TestDsa(0x5a40a0)
	/workdir/gopath/src/golang.org/x/crypto/internal/wycheproof/dsa_test.go:117 +0x210
testing.tRunner(0x5a40a0, 0x1bac0c)
	/workdir/go/src/testing/testing.go:954 +0xbc
created by testing.(*T).Run
	/workdir/go/src/testing/testing.go:1005 +0x2b0
FAIL	golang.org/x/crypto/internal/wycheproof	20.094s

/cc @katiehockman @FiloSottile

[gopherbot]

Change https://golang.org/cl/212625 mentions this issue: internal/wycheproof: skip failing test on arm architectures