Go: crypto/tls: Client Side TLS Authentication fails for certs with long fields

[antevens]

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

go version go1.13.4 linux/amd64

Does this issue reproduce with the latest release?

Yes

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

go env Output

GO111MODULE=""

GOARCH="amd64"

GOBIN=""

GOCACHE="/home/user/.cache/go-build"

GOENV="/home/user/.config/go/env"

GOEXE=""

GOFLAGS=""

GOHOSTARCH="amd64"

GOHOSTOS="linux"

GONOPROXY=""

GONOSUMDB=""

GOOS="linux"

GOPATH="/home/user/Revisions/go"

GOPRIVATE=""

GOPROXY="https://proxy.golang.org,direct"

GOROOT="/usr/lib/go-1.13"

GOSUMDB="sum.golang.org"

GOTMPDIR=""

GOTOOLDIR="/usr/lib/go-1.13/pkg/tool/linux_amd64"

GCCGO="gccgo"

AR="ar"

CC="gcc"

CXX="g++"

CGO_ENABLED="1"

GOMOD="/home/user/go/src/helm.sh/helm/go.mod"

CGO_CFLAGS="-g -O2"

CGO_CPPFLAGS=""

CGO_CXXFLAGS="-g -O2"

CGO_FFLAGS="-g -O2"

CGO_LDFLAGS="-g -O2"

PKG_CONFIG="pkg-config"

GOGCCFLAGS="-fPIC -m64 -pthread -fmessage-length=0 -fdebug-prefix-map=/tmp/go-build386574731=/tmp/go-build -gno-record-gcc-switches"

What did you do?

package main

import (
"crypto/tls"
"fmt"
)

func main() {
cert, err := tls.LoadX509KeyPair("./helm-test-crt", "./helm-test.key")
fmt.Println(cert, err)
}

Test certs:
https://gist.github.com/antevens/a05409165d33bd771e39bc219fe2c6bb/archive/e56cf114dee64a6b367abf08ab1c34a405a62f88.zip

https://github.com/helm/helm/issues/7343

What did you expect to see?

Client side TLS authentication succeed.

What did you see instead?

asn1: structure error: base 128 integer too large

[mikedanese]

See also https://github.com/golang/go/issues/19933

Where did the OIDs in this cert come from? FWIW, derdump fails on it too:

$ derdump -i helm-test-crt 
C-0x0D  (45)
   C-0x0D  (45)
derdump: error -8183: SEC_ERROR_BAD_DER: security library: improperly formatted DER-encoded message.
derdump: errno=2: No such file or directory

[antevens]

Hi Mike, thanks for responding.

The certs and by extension the OIDs are created by a Foreman (RedHat Satellite) server, these are used to distribute things like RPMs/Debs/Containers and are at the core of things like rhn.redhat.com.

As far as I understand the reason the OIDs are so long is because they include authorization information in addition to the authentication info (gives the ability to grant access to specific repositories/life-cycles).

Perhaps someone more knowledgeable like @ohadlevy or @tbrisker from the @theforeman project could elaborate if needed.

https://github.com/theforeman/foreman

[awood]

The files provided in the bug report are not DER encoded. They are PEM encoded.

If you run openssl asn1parse -inform PEM -in helm-test-cert, you get normal output. If you run openssl asn1parse -inform DER -in helm-test-cert you get a message about an encoding error.

To convert them to DER, you'll need to strip the -----BEGIN... and -----END... markers and then base64 decode the rest. Hope that helps!

[toothrot]

/cc @agl @FiloSottile

[gopherbot]

Change https://golang.org/cl/248259 mentions this issue: encoding/asn1: add dynamic length integer support for base 128 integer parsing