Remove dependency on cosign/cli/fulcio.

This reimplements much of the behavior in
https://github.com/sigstore/cosign/blob/v1.9.0/cmd/cosign/cli/fulcio/fulcio.go
to remove the dependency on cosign for fulcio operations.

We may want to upstream this library to sigstore/sigstore, but starting
off here to get a feel for other changes we might want to make first.

Signed-off-by: Billy Lynch <[email protected]>

go.mod

@@ -3,16 +3,20 @@ module github.com/sigstore/gitsign
 go 1.17
 
 require (
+	github.com/coreos/go-oidc/v3 v3.2.0
 	github.com/github/smimesign v0.2.0
 	github.com/go-git/go-git/v5 v5.4.2
 	github.com/go-openapi/runtime v0.24.1
 	github.com/go-openapi/strfmt v0.21.2
 	github.com/go-openapi/swag v0.21.1
+	github.com/google/go-cmp v0.5.8
 	github.com/pborman/getopt v0.0.0-20180811024354-2b5b3bfb099b
 	github.com/sigstore/cosign v1.8.1-0.20220601172726-ae90c7495df6
+	github.com/sigstore/fulcio v0.1.2-0.20220114150912-86a2036f9bc7
 	github.com/sigstore/rekor v0.7.0
 	github.com/sigstore/sigstore v1.2.1-0.20220512194100-3ed986cc9758
 	golang.org/x/crypto v0.0.0-20220411220226-7b82a4e95df4
+	golang.org/x/oauth2 v0.0.0-20220411215720-9780585627b5
 )
 
 require (
@@ -21,54 +25,25 @@ require (
 	cloud.google.com/go/compute v1.6.1 // indirect
 	cloud.google.com/go/iam v0.3.0 // indirect
 	cloud.google.com/go/storage v1.22.1 // indirect
-	github.com/Azure/azure-sdk-for-go v64.0.0+incompatible // indirect
-	github.com/Azure/go-autorest v14.2.0+incompatible // indirect
-	github.com/Azure/go-autorest/autorest v0.11.27 // indirect
-	github.com/Azure/go-autorest/autorest/adal v0.9.18 // indirect
-	github.com/Azure/go-autorest/autorest/azure/auth v0.5.11 // indirect
-	github.com/Azure/go-autorest/autorest/azure/cli v0.4.5 // indirect
-	github.com/Azure/go-autorest/autorest/date v0.3.0 // indirect
-	github.com/Azure/go-autorest/logger v0.2.1 // indirect
-	github.com/Azure/go-autorest/tracing v0.6.0 // indirect
 	github.com/Microsoft/go-winio v0.5.2 // indirect
 	github.com/PaesslerAG/gval v1.0.0 // indirect
 	github.com/PaesslerAG/jsonpath v0.1.1 // indirect
 	github.com/ProtonMail/go-crypto v0.0.0-20210428141323-04723f9f07d7 // indirect
-	github.com/ThalesIgnite/crypto11 v1.2.5 // indirect
 	github.com/acomagu/bufpipe v1.0.3 // indirect
 	github.com/asaskevich/govalidator v0.0.0-20210307081110-f21760c49a8d // indirect
-	github.com/aws/aws-sdk-go-v2 v1.14.0 // indirect
-	github.com/aws/aws-sdk-go-v2/config v1.14.0 // indirect
-	github.com/aws/aws-sdk-go-v2/credentials v1.9.0 // indirect
-	github.com/aws/aws-sdk-go-v2/feature/ec2/imds v1.11.0 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/configsources v1.1.5 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/endpoints/v2 v2.3.0 // indirect
-	github.com/aws/aws-sdk-go-v2/internal/ini v1.3.6 // indirect
-	github.com/aws/aws-sdk-go-v2/service/ecr v1.15.0 // indirect
-	github.com/aws/aws-sdk-go-v2/service/ecrpublic v1.12.0 // indirect
-	github.com/aws/aws-sdk-go-v2/service/internal/presigned-url v1.8.0 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sso v1.10.0 // indirect
-	github.com/aws/aws-sdk-go-v2/service/sts v1.15.0 // indirect
-	github.com/aws/smithy-go v1.11.0 // indirect
-	github.com/awslabs/amazon-ecr-credential-helper/ecr-login v0.0.0-20220228164355-396b2034c795 // indirect
 	github.com/benbjohnson/clock v1.1.0 // indirect
 	github.com/beorn7/perks v1.0.1 // indirect
 	github.com/bgentry/speakeasy v0.1.0 // indirect
 	github.com/blang/semver v3.5.1+incompatible // indirect
 	github.com/census-instrumentation/opencensus-proto v0.3.0 // indirect
 	github.com/cespare/xxhash/v2 v2.1.2 // indirect
-	github.com/chrismellard/docker-credential-acr-env v0.0.0-20220119192733-fe33c00cee21 // indirect
 	github.com/cncf/udpa/go v0.0.0-20210930031921-04548b0d99d4 // indirect
 	github.com/cncf/xds/go v0.0.0-20211130200136-a8f946100490 // indirect
-	github.com/common-nighthawk/go-figure v0.0.0-20210622060536-734e95fb86be // indirect
 	github.com/containerd/stargz-snapshotter/estargz v0.10.1 // indirect
-	github.com/coreos/go-oidc/v3 v3.2.0 // indirect
 	github.com/coreos/go-semver v0.3.0 // indirect
 	github.com/coreos/go-systemd/v22 v22.3.2 // indirect
 	github.com/cpuguy83/go-md2man/v2 v2.0.1 // indirect
 	github.com/cyberphone/json-canonicalization v0.0.0-20210823021906-dc406ceaf94b // indirect
-	github.com/davecgh/go-spew v1.1.1 // indirect
-	github.com/dimchansky/utfbom v1.1.1 // indirect
 	github.com/docker/cli v20.10.12+incompatible // indirect
 	github.com/docker/distribution v2.8.0+incompatible // indirect
 	github.com/docker/docker v20.10.12+incompatible // indirect
@@ -84,53 +59,41 @@ require (
 	github.com/go-chi/chi v4.1.2+incompatible // indirect
 	github.com/go-git/gcfg v1.5.0 // indirect
 	github.com/go-git/go-billy/v5 v5.3.1 // indirect
-	github.com/go-logr/logr v1.2.2 // indirect
 	github.com/go-openapi/analysis v0.21.2 // indirect
 	github.com/go-openapi/errors v0.20.2 // indirect
 	github.com/go-openapi/jsonpointer v0.19.5 // indirect
 	github.com/go-openapi/jsonreference v0.20.0 // indirect
 	github.com/go-openapi/loads v0.21.1 // indirect
 	github.com/go-openapi/spec v0.20.6 // indirect
 	github.com/go-openapi/validate v0.21.0 // indirect
-	github.com/go-piv/piv-go v1.9.0 // indirect
 	github.com/go-playground/locales v0.14.0 // indirect
 	github.com/go-playground/universal-translator v0.18.0 // indirect
 	github.com/go-playground/validator/v10 v10.11.0 // indirect
 	github.com/go-stack/stack v1.8.1 // indirect
 	github.com/gogo/protobuf v1.3.2 // indirect
-	github.com/golang-jwt/jwt/v4 v4.3.0 // indirect
 	github.com/golang/glog v1.0.0 // indirect
 	github.com/golang/groupcache v0.0.0-20210331224755-41bb18bfe9da // indirect
 	github.com/golang/mock v1.6.0 // indirect
 	github.com/golang/protobuf v1.5.2 // indirect
 	github.com/golang/snappy v0.0.4 // indirect
 	github.com/google/btree v1.0.1 // indirect
 	github.com/google/certificate-transparency-go v1.1.2 // indirect
-	github.com/google/go-cmp v0.5.8 // indirect
 	github.com/google/go-containerregistry v0.8.1-0.20220209165246-a44adc326839 // indirect
-	github.com/google/go-github/v42 v42.0.0 // indirect
-	github.com/google/go-querystring v1.1.0 // indirect
-	github.com/google/gofuzz v1.2.0 // indirect
 	github.com/google/trillian v1.4.1 // indirect
 	github.com/google/uuid v1.3.0 // indirect
 	github.com/googleapis/gax-go/v2 v2.4.0 // indirect
-	github.com/googleapis/gnostic v0.5.5 // indirect
 	github.com/googleapis/go-type-adapters v1.0.0 // indirect
 	github.com/gorilla/websocket v1.4.2 // indirect
 	github.com/grpc-ecosystem/go-grpc-middleware v1.3.0 // indirect
 	github.com/grpc-ecosystem/go-grpc-prometheus v1.2.0 // indirect
 	github.com/grpc-ecosystem/grpc-gateway v1.16.0 // indirect
-	github.com/hashicorp/go-cleanhttp v0.5.2 // indirect
-	github.com/hashicorp/go-retryablehttp v0.7.1 // indirect
 	github.com/hashicorp/golang-lru v0.5.4 // indirect
 	github.com/hashicorp/hcl v1.0.0 // indirect
-	github.com/imdario/mergo v0.3.12 // indirect
 	github.com/in-toto/in-toto-golang v0.3.4-0.20211211042327-af1f9fb822bf // indirect
 	github.com/inconshreveable/mousetrap v1.0.0 // indirect
 	github.com/jbenet/go-context v0.0.0-20150711004518-d14ea06fba99 // indirect
 	github.com/jedisct1/go-minisign v0.0.0-20211028175153-1c139d1cc84b // indirect
 	github.com/jhump/protoreflect v1.10.3 // indirect
-	github.com/jmespath/go-jmespath v0.4.0 // indirect
 	github.com/jonboulle/clockwork v0.3.0 // indirect
 	github.com/josharian/intern v1.0.0 // indirect
 	github.com/json-iterator/go v1.1.12 // indirect
@@ -141,7 +104,6 @@ require (
 	github.com/mailru/easyjson v0.7.7 // indirect
 	github.com/mattn/go-runewidth v0.0.13 // indirect
 	github.com/matttproud/golang_protobuf_extensions v1.0.2-0.20181231171920-c182affec369 // indirect
-	github.com/miekg/pkcs11 v1.1.1 // indirect
 	github.com/mitchellh/go-homedir v1.1.0 // indirect
 	github.com/mitchellh/mapstructure v1.5.0 // indirect
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
@@ -166,7 +128,6 @@ require (
 	github.com/segmentio/ksuid v1.0.4 // indirect
 	github.com/sergi/go-diff v1.2.0 // indirect
 	github.com/shibumi/go-pathspec v1.3.0 // indirect
-	github.com/sigstore/fulcio v0.1.2-0.20220114150912-86a2036f9bc7 // indirect
 	github.com/sirupsen/logrus v1.8.1 // indirect
 	github.com/skratchdot/open-golang v0.0.0-20200116055534-eef842397966 // indirect
 	github.com/soheilhy/cmux v0.1.5 // indirect
@@ -180,14 +141,12 @@ require (
 	github.com/subosito/gotenv v1.3.0 // indirect
 	github.com/syndtr/goleveldb v1.0.1-0.20210819022825-2ae1ddf74ef7 // indirect
 	github.com/tent/canonical-json-go v0.0.0-20130607151641-96e4ba3a7613 // indirect
-	github.com/thales-e-security/pool v0.0.2 // indirect
 	github.com/theupdateframework/go-tuf v0.3.0 // indirect
 	github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 // indirect
 	github.com/tmc/grpc-websocket-proxy v0.0.0-20201229170055-e5319fda7802 // indirect
 	github.com/transparency-dev/merkle v0.0.1 // indirect
 	github.com/urfave/cli v1.22.7 // indirect
 	github.com/vbatts/tar-split v0.11.2 // indirect
-	github.com/xanzy/go-gitlab v0.68.0 // indirect
 	github.com/xiang90/probing v0.0.0-20190116061207-43a291ad63a2 // indirect
 	github.com/zeebo/errs v1.2.2 // indirect
 	go.etcd.io/bbolt v1.3.6 // indirect
@@ -219,7 +178,6 @@ require (
 	go.uber.org/zap v1.21.0 // indirect
 	golang.org/x/mod v0.6.0-dev.0.20220106191415-9b9b3d81d5e3 // indirect
 	golang.org/x/net v0.0.0-20220520000938-2e3eb7b945c2 // indirect
-	golang.org/x/oauth2 v0.0.0-20220411215720-9780585627b5 // indirect
 	golang.org/x/sync v0.0.0-20220513210516-0976fa681c29 // indirect
 	golang.org/x/sys v0.0.0-20220520151302-bc2c85ada10a // indirect
 	golang.org/x/term v0.0.0-20210927222741-03fcf44c2211 // indirect
@@ -233,23 +191,13 @@ require (
 	google.golang.org/grpc v1.46.2 // indirect
 	google.golang.org/protobuf v1.28.0 // indirect
 	gopkg.in/cheggaaa/pb.v1 v1.0.28 // indirect
-	gopkg.in/inf.v0 v0.9.1 // indirect
 	gopkg.in/ini.v1 v1.66.4 // indirect
 	gopkg.in/natefinch/lumberjack.v2 v2.0.0 // indirect
 	gopkg.in/square/go-jose.v2 v2.6.0 // indirect
 	gopkg.in/warnings.v0 v0.1.2 // indirect
 	gopkg.in/yaml.v2 v2.4.0 // indirect
 	gopkg.in/yaml.v3 v3.0.0 // indirect
 	gotest.tools/v3 v3.1.0 // indirect
-	k8s.io/api v0.23.5 // indirect
-	k8s.io/apimachinery v0.23.5 // indirect
-	k8s.io/client-go v0.23.5 // indirect
-	k8s.io/klog/v2 v2.60.1-0.20220317184644-43cc75f9ae89 // indirect
-	k8s.io/kube-openapi v0.0.0-20220124234850-424119656bbf // indirect
-	k8s.io/utils v0.0.0-20220210201930-3a6ce19ff2f9 // indirect
 	knative.dev/pkg v0.0.0-20220325200448-1f7514acd0c2 // indirect
-	sigs.k8s.io/json v0.0.0-20211208200746-9f7c6b3444d2 // indirect
-	sigs.k8s.io/release-utils v0.6.0 // indirect
-	sigs.k8s.io/structured-merge-diff/v4 v4.2.1 // indirect
 	sigs.k8s.io/yaml v1.3.0 // indirect
 )