x/net/publicsuffix: Error is returned when getting eTLD+1 for s3.amazonaws.com

[Nadavrbn]

Go version

go version go1.24.2 darwin/arm64

Output of go env in your module/workspace:

AR='ar'
CC='cc'
CGO_CFLAGS='-O2 -g'
CGO_CPPFLAGS=''
CGO_CXXFLAGS='-O2 -g'
CGO_ENABLED='1'
CGO_FFLAGS='-O2 -g'
CGO_LDFLAGS='-O2 -g'
CXX='c++'
GCCGO='gccgo'
GO111MODULE='on'
GOARCH='arm64'
GOARM64='v8.0'
GOAUTH='netrc'
GOBIN=''
GOCACHE='/Users/nadavrabinovich/Library/Caches/go-build'
GOCACHEPROG=''
GODEBUG=''
GOENV='/Users/nadavrabinovich/Library/Application Support/go/env'
GOEXE=''
GOEXPERIMENT=''
GOFIPS140='off'
GOFLAGS=''
GOGCCFLAGS='-fPIC -arch arm64 -pthread -fno-caret-diagnostics -Qunused-arguments -fmessage-length=0 -ffile-prefix-map=/var/folders/4y/k3g5jjxx05n9kh5pt_3pkf600000gn/T/go-build1151659047=/tmp/go-build -gno-record-gcc-switches -fno-common'
GOHOSTARCH='arm64'
GOHOSTOS='darwin'
GOINSECURE=''
GOMOD='/Users/nadavrabinovich/git/steps/steps/utils/infrastructure/pkg/go.mod'
GOMODCACHE='/Users/nadavrabinovich/.go/pkg/mod'
GONOPROXY='github.com/torqio,stackpulse.dev,torqio.dev'
GONOSUMDB='github.com/torqio,stackpulse.dev,torqio.dev'
GOOS='darwin'
GOPATH='/Users/nadavrabinovich/.go'
GOPRIVATE='github.com/torqio,stackpulse.dev,torqio.dev'
GOPROXY='https://proxy.golang.org,direct'
GOROOT='/opt/homebrew/opt/go/libexec'
GOSUMDB='sum.golang.org'
GOTELEMETRY='local'
GOTELEMETRYDIR='/Users/nadavrabinovich/Library/Application Support/go/telemetry'
GOTMPDIR=''
GOTOOLCHAIN='auto'
GOTOOLDIR='/opt/homebrew/opt/go/libexec/pkg/tool/darwin_arm64'
GOVCS=''
GOVERSION='go1.24.2'
GOWORK=''
PKG_CONFIG='pkg-config'

What did you do?

I tried using publicsuffic.EffectiveTLDPlusOne method to get the base domain with the input "s3.amazonaws.com" and received an error:

publicsuffix: cannot derive eTLD+1 for domain "s3.amazonaws.com"

What did you see happen?

list.go line 173 extracts the suffix, but it returns the full domain, which causes the method to fail in the next line.

What did you expect to see?

I would expect the output to be "amazonaws.com"

[prattmic]

cc @neild

[gabyhelp]

Related Issues

• x/net/publicsuffix: EffectiveTLDPlusOne fails on *.s3.amazonaws.com #20059 (closed)
• publicsuffix: cannot derive eTLD+1 for domain "s3.cn-north-1.amazonaws.com.cn" #14734 (closed)
• x/net/publicsuffix: publicsuffix.EffectiveTLDPlusOne fails on "*.amazonaws.com" #23671 (closed)
• x/net: public suffix package returns incorrect eTLD+1 values for domains with path suffixes #69026 (closed)
• x/net/publicsuffix: effectiveTDLPlusOne for subdomain of amazonaws.com yields wrong value #51510 (closed)
• x/net/publicsuffix: Not possible to check for suffix existence on list #31027 (closed)
• x/net/publicsuffix: EffectiveTLDPlusOne accepts IP Addresses #32979
• x/net/publicsuffix: issue in publicsuffix.EffectiveTLDPlusOne #69256 (closed)
• x/net/publicsuffix: entire host interpreted as TLD #24672 (closed)
• x/net/publicsuffix: EffectiveTLDPlusOne() parses domains incorrectly if there is a trailing dot #11686 (closed)

_{(Emoji vote if this was helpful or unhelpful; more detailed feedback welcome in this discussion.)}

[seankhliao]

I believe this is working as intended.
s3.amazonaws.com is an eTLD due to their legacy <bucket>.s3.amazonaws.com virtual hosted bucket urls.

This is the same as asking for the eTLD+1 of com, there's no plus one.