Add user agent to online Rekor requests and TUF requests. (#216)

For #143

---------

Signed-off-by: Zach Steindler <[email protected]>

Makefile

@@ -12,21 +12,18 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-VERSION := `git describe --tags`
-LDFLAGS = -ldflags "-X main.Version=$(VERSION)"
-
 .PHONY: all
 all: build build-examples
 
 .PHONY: build
 build:
-	go build $(LDFLAGS) ./cmd/sigstore-go
-	go build $(LDFLAGS) -o conformance ./cmd/conformance
+	go build ./cmd/sigstore-go
+	go build -o conformance ./cmd/conformance
 
 .PHONY: build-examples
 build-examples:
-	go build -C ./examples/oci-image-verification $(LDFLAGS) -o oci-image-verification .
-	go build -C ./examples/sigstore-go-signing $(LDFLAGS) -o sigstore-go-signing .
+	go build -C ./examples/oci-image-verification -o oci-image-verification .
+	go build -C ./examples/sigstore-go-signing -o sigstore-go-signing .
 
 .PHONY: test
 test:

cmd/conformance/main.go

@@ -25,16 +25,17 @@ import (
 
 	protobundle "github.com/sigstore/protobuf-specs/gen/pb-go/bundle/v1"
 	protocommon "github.com/sigstore/protobuf-specs/gen/pb-go/common/v1"
+	"github.com/theupdateframework/go-tuf/v2/metadata/fetcher"
 	"google.golang.org/protobuf/encoding/protojson"
 
 	"github.com/sigstore/sigstore-go/pkg/bundle"
 	"github.com/sigstore/sigstore-go/pkg/root"
 	"github.com/sigstore/sigstore-go/pkg/sign"
 	"github.com/sigstore/sigstore-go/pkg/tuf"
+	"github.com/sigstore/sigstore-go/pkg/util"
 	"github.com/sigstore/sigstore-go/pkg/verify"
 )
 
-var Version string
 var bundlePath *string
 var certPath *string
 var certOIDC *string
@@ -60,6 +61,9 @@ func getTrustedRoot(staging bool) root.TrustedMaterial {
 		trustedRootJSON, err = os.ReadFile(*trustedRootPath)
 	} else {
 		opts := tuf.DefaultOptions()
+		fetcher := fetcher.DefaultFetcher{}
+		fetcher.SetHTTPUserAgent(util.ConstructUserAgent())
+		opts.Fetcher = &fetcher
 
 		if staging {
 			opts.Root = tuf.StagingRoot()
@@ -132,9 +136,8 @@ func signBundle(withRekor bool) (*protobundle.Bundle, error) {
 	}
 
 	fulcioOpts := &sign.FulcioOptions{
-		BaseURL:        fmt.Sprintf("https://fulcio.%s.dev", instance),
-		Timeout:        timeout,
-		LibraryVersion: Version,
+		BaseURL: fmt.Sprintf("https://fulcio.%s.dev", instance),
+		Timeout: timeout,
 	}
 	signingOptions.CertificateProvider = sign.NewFulcio(fulcioOpts)
 	signingOptions.CertificateProviderOptions = &sign.CertificateProviderOptions{
@@ -143,9 +146,8 @@ func signBundle(withRekor bool) (*protobundle.Bundle, error) {
 
 	if withRekor {
 		rekorOpts := &sign.RekorOptions{
-			BaseURL:        fmt.Sprintf("https://rekor.%s.dev", instance),
-			Timeout:        timeout,
-			LibraryVersion: Version,
+			BaseURL: fmt.Sprintf("https://rekor.%s.dev", instance),
+			Timeout: timeout,
 		}
 		signingOptions.TransparencyLogs = append(signingOptions.TransparencyLogs, sign.NewRekor(rekorOpts))
 	}

cmd/sigstore-go/main.go

@@ -27,11 +27,14 @@ import (
 	"os"
 	"time"
 
+	"github.com/sigstore/sigstore/pkg/signature"
+	"github.com/theupdateframework/go-tuf/v2/metadata/fetcher"
+
 	"github.com/sigstore/sigstore-go/pkg/bundle"
 	"github.com/sigstore/sigstore-go/pkg/root"
 	"github.com/sigstore/sigstore-go/pkg/tuf"
+	"github.com/sigstore/sigstore-go/pkg/util"
 	"github.com/sigstore/sigstore-go/pkg/verify"
-	"github.com/sigstore/sigstore/pkg/signature"
 )
 
 var artifact *string
@@ -129,6 +132,9 @@ func run() error {
 	if *tufRootURL != "" {
 		opts := tuf.DefaultOptions()
 		opts.RepositoryBaseURL = *tufRootURL
+		fetcher := fetcher.DefaultFetcher{}
+		fetcher.SetHTTPUserAgent(util.ConstructUserAgent())
+		opts.Fetcher = &fetcher
 
 		// Load the tuf root.json if provided, if not use public good
 		if *tufTrustedRoot != "" {

examples/oci-image-verification/go.mod

@@ -68,12 +68,12 @@ require (
 	github.com/sourcegraph/conc v0.3.0 // indirect
 	github.com/spf13/afero v1.11.0 // indirect
 	github.com/spf13/cast v1.6.0 // indirect
-	github.com/spf13/cobra v1.8.0 // indirect
+	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/spf13/viper v1.18.2 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect
 	github.com/theupdateframework/go-tuf v0.7.0 // indirect
-	github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63 // indirect
+	github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9 // indirect
 	github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 // indirect
 	github.com/transparency-dev/merkle v0.0.2 // indirect
 	github.com/vbatts/tar-split v0.11.3 // indirect

examples/oci-image-verification/go.sum

@@ -71,7 +71,7 @@ github.com/codahale/rfc6979 v0.0.0-20141003034818-6a90f24967eb/go.mod h1:ZjrT6AX
 github.com/containerd/stargz-snapshotter/estargz v0.14.3 h1:OqlDCK3ZVUO6C3B/5FSkDwbkEETK84kQgEeFwDC+62k=
 github.com/containerd/stargz-snapshotter/estargz v0.14.3/go.mod h1:KY//uOCIkSuNAHhJogcZtrNHdKrA99/FCCRjE3HD36o=
 github.com/cpuguy83/go-md2man/v2 v2.0.2/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
-github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/cyberphone/json-canonicalization v0.0.0-20220623050100-57a0ce2678a7 h1:vU+EP9ZuFUCYE0NYLwTSob+3LNEJATzNfP/DC7SWGWI=
 github.com/cyberphone/json-canonicalization v0.0.0-20220623050100-57a0ce2678a7/go.mod h1:uzvlm1mxhHkdfqitSA92i7Se+S9ksOn3a3qmv/kyOCw=
 github.com/danieljoos/wincred v1.2.0 h1:ozqKHaLK0W/ii4KVbbvluM91W2H3Sh0BncbUNPS7jLE=
@@ -295,8 +295,8 @@ github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=
 github.com/spf13/afero v1.11.0/go.mod h1:GH9Y3pIexgf1MTIWtNGyogA5MwRIDXGUr+hbWNoBjkY=
 github.com/spf13/cast v1.6.0 h1:GEiTHELF+vaR5dhz3VqZfFSzZjYbgeKDpBxQVS4GYJ0=
 github.com/spf13/cast v1.6.0/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
-github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
-github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
+github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
+github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/spf13/viper v1.18.2 h1:LUXCnvUvSM6FXAsj6nnfc8Q2tp1dIgUfY9Kc8GsSOiQ=
@@ -317,8 +317,8 @@ github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/theupdateframework/go-tuf v0.7.0 h1:CqbQFrWo1ae3/I0UCblSbczevCCbS31Qvs5LdxRWqRI=
 github.com/theupdateframework/go-tuf v0.7.0/go.mod h1:uEB7WSY+7ZIugK6R1hiBMBjQftaFzn7ZCDJcp1tCUug=
-github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63 h1:27XWhDZHPD+cufF6qSdYx6PgGQvD2jJ6pq9sDvR6VBk=
-github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63/go.mod h1:+gWwqe1pk4nvGeOKosGJqPgD+N/kbD9M0QVLL9TGIYU=
+github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9 h1:AH/4455EGJqYHx6KcrWJ9Bv/h9xae+SP5EGgmmbQBSA=
+github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9/go.mod h1:baB22nBHeHBCeuGZcIlctNq4P61PcOdyARlplg5xmLA=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 h1:e/5i7d4oYZ+C1wj2THlRK+oAhjeS/TRQwMfkIuet3w0=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399/go.mod h1:LdwHTNJT99C5fTAzDz0ud328OgXz+gierycbcIx2fRs=
 github.com/transparency-dev/merkle v0.0.2 h1:Q9nBoQcZcgPamMkGn7ghV8XiTZ/kRxn1yCG81+twTK4=

examples/sigstore-go-signing/main.go

@@ -21,14 +21,15 @@ import (
 	"os"
 	"time"
 
+	"github.com/theupdateframework/go-tuf/v2/metadata/fetcher"
 	"google.golang.org/protobuf/encoding/protojson"
 
 	"github.com/sigstore/sigstore-go/pkg/root"
 	"github.com/sigstore/sigstore-go/pkg/sign"
 	"github.com/sigstore/sigstore-go/pkg/tuf"
+	"github.com/sigstore/sigstore-go/pkg/util"
 )
 
-var Version string
 var idToken *string
 var intoto *bool
 var tsa *bool
@@ -83,9 +84,13 @@ func main() {
 	opts := sign.BundleOptions{}
 
 	// Get trusted_root.json
+	fetcher := fetcher.DefaultFetcher{}
+	fetcher.SetHTTPUserAgent(util.ConstructUserAgent())
+
 	tufOptions := &tuf.Options{
 		Root:              tuf.StagingRoot(),
 		RepositoryBaseURL: tuf.StagingMirror,
+		Fetcher:           &fetcher,
 	}
 	tufClient, err := tuf.New(tufOptions)
 	if err != nil {
@@ -109,7 +114,6 @@ func main() {
 			BaseURL:        "https://fulcio.sigstage.dev",
 			Timeout:        time.Duration(30 * time.Second),
 			Retries:        1,
-			LibraryVersion: Version,
 		}
 		opts.CertificateProvider = sign.NewFulcio(fulcioOpts)
 		opts.CertificateProviderOptions = &sign.CertificateProviderOptions{
@@ -122,7 +126,6 @@ func main() {
 			URL:            "https://timestamp.githubapp.com/api/v1/timestamp",
 			Timeout:        time.Duration(30 * time.Second),
 			Retries:        1,
-			LibraryVersion: Version,
 		}
 		opts.TimestampAuthorities = append(opts.TimestampAuthorities, sign.NewTimestampAuthority(tsaOpts))
 
@@ -135,7 +138,6 @@ func main() {
 			BaseURL:        "https://rekor.sigstage.dev",
 			Timeout:        time.Duration(90 * time.Second),
 			Retries:        1,
-			LibraryVersion: Version,
 		}
 		opts.TransparencyLogs = append(opts.TransparencyLogs, sign.NewRekor(rekorOpts))
 	}

go.mod

@@ -16,7 +16,7 @@ require (
 	github.com/sigstore/sigstore v1.8.4
 	github.com/sigstore/timestamp-authority v1.2.2
 	github.com/stretchr/testify v1.9.0
-	github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63
+	github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9
 	golang.org/x/crypto v0.24.0
 	golang.org/x/mod v0.18.0
 	google.golang.org/protobuf v1.34.2
@@ -67,7 +67,7 @@ require (
 	github.com/sourcegraph/conc v0.3.0 // indirect
 	github.com/spf13/afero v1.11.0 // indirect
 	github.com/spf13/cast v1.6.0 // indirect
-	github.com/spf13/cobra v1.8.0 // indirect
+	github.com/spf13/cobra v1.8.1 // indirect
 	github.com/spf13/pflag v1.0.5 // indirect
 	github.com/spf13/viper v1.18.2 // indirect
 	github.com/subosito/gotenv v1.6.0 // indirect

go.sum

@@ -69,7 +69,7 @@ github.com/cespare/xxhash/v2 v2.2.0 h1:DC2CZ1Ep5Y4k3ZQ899DldepgrayRUGE6BBZ/cd9Cj
 github.com/cespare/xxhash/v2 v2.2.0/go.mod h1:VGX0DQ3Q6kWi7AoAeZDth3/j3BFtOZR5XLFGgcrjCOs=
 github.com/codahale/rfc6979 v0.0.0-20141003034818-6a90f24967eb h1:EDmT6Q9Zs+SbUoc7Ik9EfrFqcylYqgPZ9ANSbTAntnE=
 github.com/codahale/rfc6979 v0.0.0-20141003034818-6a90f24967eb/go.mod h1:ZjrT6AXHbDs86ZSdt/osfBi5qfexBrKUdONk989Wnk4=
-github.com/cpuguy83/go-md2man/v2 v2.0.3/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
+github.com/cpuguy83/go-md2man/v2 v2.0.4/go.mod h1:tgQtvFlXSQOSOSIRvRPT7W67SCa46tRHOmNcaadrF8o=
 github.com/cyberphone/json-canonicalization v0.0.0-20220623050100-57a0ce2678a7 h1:vU+EP9ZuFUCYE0NYLwTSob+3LNEJATzNfP/DC7SWGWI=
 github.com/cyberphone/json-canonicalization v0.0.0-20220623050100-57a0ce2678a7/go.mod h1:uzvlm1mxhHkdfqitSA92i7Se+S9ksOn3a3qmv/kyOCw=
 github.com/danieljoos/wincred v1.2.0 h1:ozqKHaLK0W/ii4KVbbvluM91W2H3Sh0BncbUNPS7jLE=
@@ -273,16 +273,14 @@ github.com/sigstore/sigstore/pkg/signature/kms/hashivault v1.8.3 h1:h9G8j+Ds21zq
 github.com/sigstore/sigstore/pkg/signature/kms/hashivault v1.8.3/go.mod h1:zgCeHOuqF6k7A7TTEvftcA9V3FRzB7mrPtHOhXAQBnc=
 github.com/sigstore/timestamp-authority v1.2.2 h1:X4qyutnCQqJ0apMewFyx+3t7Tws00JQ/JonBiu3QvLE=
 github.com/sigstore/timestamp-authority v1.2.2/go.mod h1:nEah4Eq4wpliDjlY342rXclGSO7Kb9hoRrl9tqLW13A=
-github.com/sirupsen/logrus v1.9.3 h1:dueUQJ1C2q9oE3F7wvmSGAaVtTmUizReu6fjN8uqzbQ=
-github.com/sirupsen/logrus v1.9.3/go.mod h1:naHLuLoDiP4jHNo9R0sCBMtWGeIprob74mVsIT4qYEQ=
 github.com/sourcegraph/conc v0.3.0 h1:OQTbbt6P72L20UqAkXXuLOj79LfEanQ+YQFNpLA9ySo=
 github.com/sourcegraph/conc v0.3.0/go.mod h1:Sdozi7LEKbFPqYX2/J+iBAM6HpqSLTASQIKqDmF7Mt0=
 github.com/spf13/afero v1.11.0 h1:WJQKhtpdm3v2IzqG8VMqrr6Rf3UYpEF239Jy9wNepM8=
 github.com/spf13/afero v1.11.0/go.mod h1:GH9Y3pIexgf1MTIWtNGyogA5MwRIDXGUr+hbWNoBjkY=
 github.com/spf13/cast v1.6.0 h1:GEiTHELF+vaR5dhz3VqZfFSzZjYbgeKDpBxQVS4GYJ0=
 github.com/spf13/cast v1.6.0/go.mod h1:ancEpBxwJDODSW/UG4rDrAqiKolqNNh2DX3mk86cAdo=
-github.com/spf13/cobra v1.8.0 h1:7aJaZx1B85qltLMc546zn58BxxfZdR/W22ej9CFoEf0=
-github.com/spf13/cobra v1.8.0/go.mod h1:WXLWApfZ71AjXPya3WOlMsY9yMs7YeiHhFVlvLyhcho=
+github.com/spf13/cobra v1.8.1 h1:e5/vxKd/rZsfSJMUX1agtjeTDf+qv1/JdBF8gg5k9ZM=
+github.com/spf13/cobra v1.8.1/go.mod h1:wHxEcudfqmLYa8iTfL+OuZPbBZkmvliBWKIezN3kD9Y=
 github.com/spf13/pflag v1.0.5 h1:iy+VFUOCP1a+8yFto/drg2CJ5u0yRoB7fZw3DKv/JXA=
 github.com/spf13/pflag v1.0.5/go.mod h1:McXfInJRrz4CZXVZOBLb0bTZqETkiAhM9Iw0y3An2Bg=
 github.com/spf13/viper v1.18.2 h1:LUXCnvUvSM6FXAsj6nnfc8Q2tp1dIgUfY9Kc8GsSOiQ=
@@ -301,8 +299,8 @@ github.com/subosito/gotenv v1.6.0 h1:9NlTDc1FTs4qu0DDq7AEtTPNw6SVm7uBMsUCUjABIf8
 github.com/subosito/gotenv v1.6.0/go.mod h1:Dk4QP5c2W3ibzajGcXpNraDfq2IrhjMIvMSWPKKo0FU=
 github.com/theupdateframework/go-tuf v0.7.0 h1:CqbQFrWo1ae3/I0UCblSbczevCCbS31Qvs5LdxRWqRI=
 github.com/theupdateframework/go-tuf v0.7.0/go.mod h1:uEB7WSY+7ZIugK6R1hiBMBjQftaFzn7ZCDJcp1tCUug=
-github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63 h1:27XWhDZHPD+cufF6qSdYx6PgGQvD2jJ6pq9sDvR6VBk=
-github.com/theupdateframework/go-tuf/v2 v2.0.0-20240223092044-1e7978e83f63/go.mod h1:+gWwqe1pk4nvGeOKosGJqPgD+N/kbD9M0QVLL9TGIYU=
+github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9 h1:AH/4455EGJqYHx6KcrWJ9Bv/h9xae+SP5EGgmmbQBSA=
+github.com/theupdateframework/go-tuf/v2 v2.0.0-20240701122707-5abb6219c8d9/go.mod h1:baB22nBHeHBCeuGZcIlctNq4P61PcOdyARlplg5xmLA=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399 h1:e/5i7d4oYZ+C1wj2THlRK+oAhjeS/TRQwMfkIuet3w0=
 github.com/titanous/rocacheck v0.0.0-20171023193734-afe73141d399/go.mod h1:LdwHTNJT99C5fTAzDz0ud328OgXz+gierycbcIx2fRs=
 github.com/transparency-dev/merkle v0.0.2 h1:Q9nBoQcZcgPamMkGn7ghV8XiTZ/kRxn1yCG81+twTK4=

pkg/sign/certificate.go

@@ -27,6 +27,8 @@ import (
 	"net/http"
 	"strings"
 	"time"
+
+	"github.com/sigstore/sigstore-go/pkg/util"
 )
 
 type CertificateProviderOptions struct {
@@ -50,8 +52,6 @@ type FulcioOptions struct {
 	Timeout time.Duration
 	// Optional number of times to retry on HTTP 5XX
 	Retries uint
-	// Optional version string for user agent
-	LibraryVersion string
 	// Optional Transport (for dependency injection)
 	Transport http.RoundTripper
 }
@@ -169,7 +169,7 @@ func (f *Fulcio) GetCertificate(ctx context.Context, keypair Keypair, opts *Cert
 		}
 		request.Header.Add("Authorization", "Bearer "+opts.IDToken)
 		request.Header.Add("Content-Type", "application/json")
-		request.Header.Add("User-Agent", constructUserAgent(f.options.LibraryVersion))
+		request.Header.Add("User-Agent", util.ConstructUserAgent())
 
 		response, err = f.client.Do(request)
 		if err != nil {

pkg/sign/timestamping.go

@@ -26,6 +26,8 @@ import (
 	"time"
 
 	"github.com/digitorus/timestamp"
+
+	"github.com/sigstore/sigstore-go/pkg/util"
 )
 
 type TimestampAuthorityOptions struct {
@@ -35,8 +37,6 @@ type TimestampAuthorityOptions struct {
 	Timeout time.Duration
 	// Optional number of times to retry on HTTP 5XX
 	Retries uint
-	// Optional version string for user agent
-	LibraryVersion string
 	// Optional Transport (for dependency injection)
 	Transport http.RoundTripper
 }
@@ -83,7 +83,7 @@ func (ta *TimestampAuthority) GetTimestamp(ctx context.Context, signature []byte
 			return nil, err
 		}
 		request.Header.Add("Content-Type", "application/timestamp-query")
-		request.Header.Add("User-Agent", constructUserAgent(ta.options.LibraryVersion))
+		request.Header.Add("User-Agent", util.ConstructUserAgent())
 
 		response, err = ta.client.Do(request)
 		if err != nil {
@@ -122,13 +122,3 @@ func (ta *TimestampAuthority) GetTimestamp(ctx context.Context, signature []byte
 
 	return body, nil
 }
-
-func constructUserAgent(version string) string {
-	userAgent := "sigstore-go"
-	if version != "" {
-		userAgent += "/"
-		userAgent += version
-	}
-
-	return userAgent
-}

pkg/sign/transparency.go

@@ -31,11 +31,13 @@ import (
 	"github.com/sigstore/rekor/pkg/types"
 	"github.com/sigstore/rekor/pkg/types/dsse"
 	"github.com/sigstore/rekor/pkg/types/hashedrekord"
-	"github.com/sigstore/rekor/pkg/util"
+	rekorUtil "github.com/sigstore/rekor/pkg/util"
 
 	// To initialize rekor types
 	_ "github.com/sigstore/rekor/pkg/types/dsse/v0.0.1"
 	_ "github.com/sigstore/rekor/pkg/types/hashedrekord/v0.0.1"
+
+	"github.com/sigstore/sigstore-go/pkg/util"
 )
 
 type RekorClient interface {
@@ -57,8 +59,6 @@ type RekorOptions struct {
 	Timeout time.Duration
 	// Optional number of times to retry
 	Retries uint
-	// Optional version string for user agent
-	LibraryVersion string
 	// Optional client (for dependency injection)
 	Client RekorClient
 }
@@ -105,7 +105,7 @@ func (r *Rekor) GetTransparencyLogEntry(pubKeyPEM []byte, b *protobundle.Bundle)
 
 		artifactProperties.PKIFormat = string(pki.X509)
 		artifactProperties.SignatureBytes = messageSignature.Signature
-		artifactProperties.ArtifactHash = util.PrefixSHA(hexDigest)
+		artifactProperties.ArtifactHash = rekorUtil.PrefixSHA(hexDigest)
 
 		var err error
 		proposedEntry, err = hashedrekordType.CreateProposedEntry(context.TODO(), "", artifactProperties)
@@ -126,7 +126,7 @@ func (r *Rekor) GetTransparencyLogEntry(pubKeyPEM []byte, b *protobundle.Bundle)
 	params.SetProposedEntry(proposedEntry)
 
 	if r.options.Client == nil {
-		client, err := client.GetRekorClient(r.options.BaseURL, client.WithUserAgent(constructUserAgent(r.options.LibraryVersion)), client.WithRetryCount(r.options.Retries))
+		client, err := client.GetRekorClient(r.options.BaseURL, client.WithUserAgent(util.ConstructUserAgent()), client.WithRetryCount(r.options.Retries))
 		if err != nil {
 			return err
 		}

pkg/tuf/client.go

@@ -21,7 +21,10 @@ import (
 	"time"
 
 	"github.com/theupdateframework/go-tuf/v2/metadata/config"
+	"github.com/theupdateframework/go-tuf/v2/metadata/fetcher"
 	"github.com/theupdateframework/go-tuf/v2/metadata/updater"
+
+	"github.com/sigstore/sigstore-go/pkg/util"
 )
 
 // Client is a Sigstore TUF client
@@ -56,6 +59,10 @@ func New(opts *Options) (*Client, error) {
 
 	if opts.Fetcher != nil {
 		c.cfg.Fetcher = opts.Fetcher
+	} else {
+		fetcher := fetcher.DefaultFetcher{}
+		fetcher.SetHTTPUserAgent(util.ConstructUserAgent())
+		c.cfg.Fetcher = &fetcher
 	}
 
 	// Upon client creation, we may not perform a full TUF update,