Merge branch 'design' of github.com:system-transparency/stfe into design

15 files changed, 834 insertions, 1549 deletions

diff --git a/doc/claimant.md b/doc/claimant.md
new file mode 100644
index 0000000..6728fef
--- /dev/null
+++ b/doc/claimant.md
@@ -0,0 +1,71 @@
+# Claimant model
+## **System<sup>CHECKSUM</sup>**
+System<sup>CHECKSUM</sup> is about the claims made by a data publisher.
+* **Claim<sup>CHECKSUM</sup>**:
+	_I, data publisher, claim that the data_:
+	1. has cryptographic hash X
+	2. is produced by no-one but myself
+* **Statement<sup>CHECKSUM</sup>**: signed checksum<br>
+* **Claimant<sup>CHECKSUM</sup>**: data publisher<br>
+	The data publisher is a party that wants to publish some data.
+* **Believer<sup>CHECKSUM</sup>**: end-user<br>
+	The end-user is a party that wants to use some published data.
+* **Verifier<sup>CHECKSUM</sup>**: data publisher<br>
+	Only the data publisher can verify the above claims.
+* **Arbiter<sup>CHECKSUM</sup>**:<br>
+    There's no official body.  Invalidated claims would affect reputation.
+
+System<sup>CHECKSUM\*</sup> can be defined to make more specific claims.  Below
+is a reproducible builds example.
+
+### **System<sup>CHECKSUM-RB</sup>**:
+System<sup>CHECKSUM-RB</sup> is about the claims made by a _software publisher_
+that makes reproducible builds available.
+* **Claim<sup>CHECKSUM-RB</sup>**:
+	_I, software publisher, claim that the data_:
+	1. has cryptographic hash X
+	2. is the output of a reproducible build for which the source can be located
+	using X as an identifier
+* **Statement<sup>CHECKSUM-RB</sup>**: Statement<sup>CHECKSUM</sup>
+* **Claimant<sup>CHECKSUM-RB</sup>**: software publisher<br>
+	The software publisher is a party that wants to publish the output of a
+	reproducible build.
+* **Believer<sup>CHECKSUM-RB</sup>**: end-user<br>
+	The end-user is a party that wants to run an executable binary that built
+	reproducibly.
+* **Verifier<sup>CHECKSUM-RB</sup>**: any interested party<br>
+	These parties try to verify the above claims.  For example:
+	* the software publisher itself (_"has my identity been compromised?"_)
+	* rebuilders that check for locatability and reproducibility
+* **Arbiter<sup>CHECKSUM-RB</sup>**:<br>
+    There's no official body.  Invalidated claims would affect reputation.
+
+## **System<sup>CHECKSUM-LOG</sup>**:
+System<sup>CHECKSUM-LOG</sup> is about the claims made by a _log operator_.
+It adds _discoverability_ into System<sup>CHECKSUM\*</sup>.  Discoverability
+means that Verifier<sup>CHECKSUM\*</sup> can see all
+Statement<sup>CHECKSUM</sup> that Believer<sup>CHECKSUM\*</sup> accept.
+
+* **Claim<sup>CHECKSUM-LOG</sup>**:
+	_I, log operator, make available:_
+	1. a globally consistent append-only log of Statement<sup>CHECKSUM</sup>
+* **Statement<sup>CHECKSUM-LOG</sup>**: signed tree head
+* **Claimant<sup>CHECKSUM-LOG</sup>**: log operator<br>
+   Possible operators might be:
+	* a small subset of data publishers
+	* members of relevant consortia
+* **Believer<sup>CHECKSUM-LOG</sup>**:
+	* Believer<sup>CHECKSUM\*</sup>
+	* Verifier<sup>CHECKSUM\*</sup><br>
+* **Verifier<sup>CHECKSUM-LOG</sup>**: third parties<br>
+	These parties verify the above claims.  Examples include:
+	* members of relevant consortia
+	* non-profits and other reputable organizations
+	* security enthusiasts and researchers
+	* log operators (cross-ecosystem)
+	* monitors (cross-ecosystem)
+	* a small subset of data publishers (cross-ecosystem)
+* **Arbiter<sup>CHECKSUM-LOG</sup>**:<br>
+	There is no official body.  The ecosystem at large should stop using an
+	instance of System<sup>CHECKSUM-LOG</sup> if cryptographic proofs of log
+	misbehavior are preseneted by some Verifier<sup>CHECKSUM-LOG</sup>.
diff --git a/types/cmd/new-namespace/main.go b/types/cmd/new-namespace/main.go
deleted file mode 100644
index e338d7c..0000000
--- a/types/cmd/new-namespace/main.go
+++ /dev/null
@@ -1,56 +0,0 @@
-// Package main outputs the private and public parts of a new namespace
-package main
-
-import (
-	"flag"
-	"fmt"
-
-	"crypto/ed25519"
-	"crypto/rand"
-	"encoding/base64"
-
-	"github.com/golang/glog"
-	"github.com/system-transparency/stfe/types"
-)
-
-var (
-	format = flag.String("format", string(types.NamespaceFormatEd25519V1), "namespace format")
-)
-
-func main() {
-	flag.Parse()
-	defer glog.Flush()
-
-	switch *format {
-	case string(types.NamespaceFormatEd25519V1):
-		glog.Infof("generating new ed25519_v1 namespace")
-		sk, vk, namespace, err := genEd25519V1Namespace()
-		if err != nil {
-			glog.Errorf("genEd25519V1Namespace: %v", err)
-			break
-		}
-		fmt.Printf("sk: %s\n", base64.StdEncoding.EncodeToString(sk))
-		fmt.Printf("vk: %s\n", base64.StdEncoding.EncodeToString(vk))
-		fmt.Printf("ed25519_v1: %s\n", base64.StdEncoding.EncodeToString(namespace))
-	default:
-		glog.Errorf("unsupported namespace format: %s", format)
-	}
-}
-
-// genEd25519V1Namespace generates an Ed25519 secret key, verification key, and
-// serialized ed25519_v1 namespace.
-func genEd25519V1Namespace() ([]byte, []byte, []byte, error) {
-	vk, sk, err := ed25519.GenerateKey(rand.Reader)
-	if err != nil {
-		return nil, nil, nil, fmt.Errorf("ed25519.GenerateKey: %v", err)
-	}
-	namespace, err := types.NewNamespaceEd25519V1(vk[:])
-	if err != nil {
-		return nil, nil, nil, fmt.Errorf("types.NewNamespaceEd25519V1: %v", err)
-	}
-	serialized, err := types.Marshal(*namespace)
-	if err != nil {
-		fmt.Errorf("types.Marshal: %v", err)
-	}
-	return sk, vk, serialized, nil
-}
diff --git a/types/http.go b/types/http.go
new file mode 100644
index 0000000..8bbe26d
--- /dev/null
+++ b/types/http.go
@@ -0,0 +1,188 @@
+package types
+
+import (
+	"bytes"
+	"encoding/hex"
+	"fmt"
+	"net/http"
+	"strconv"
+	"strings"
+)
+
+const (
+	// HeaderPrefix is the start of every ST log HTTP header key
+	HeaderPrefix = "stlog-"
+
+	// New leaf
+	HeaderShardHint            = HeaderPrefix + "shard_hint"
+	HeaderChecksum             = HeaderPrefix + "checksum"
+	HeaderSignatureOverMessage = HeaderPrefix + "signature_over_message"
+	HeaderVerificationKey      = HeaderPrefix + "verification_key"
+	HeaderDomainHint           = HeaderPrefix + "domain_hint"
+
+	// Inclusion proof
+	HeaderLeafHash      = HeaderPrefix + "leaf_hash"
+	HeaderLeafIndex     = HeaderPrefix + "leaf_index"
+	HeaderInclusionPath = HeaderPrefix + "inclusion_path"
+
+	// Consistency proof
+	HeaderNewSize         = HeaderPrefix + "new_size"
+	HeaderOldSize         = HeaderPrefix + "old_size"
+	HeaderConsistencyPath = HeaderPrefix + "consistency_path"
+
+	// Range of leaves
+	HeaderStartSize = HeaderPrefix + "start_size"
+	HeaderEndSize   = HeaderPrefix + "end_size"
+
+	// Tree head
+	HeaderTimestamp = HeaderPrefix + "timestamp"
+	HeaderTreeSize  = HeaderPrefix + "tree_size"
+	HeaderRootHash  = HeaderPrefix + "root_hash"
+
+	// Signature and signer identity
+	HeaderSignature = HeaderPrefix + "signature"
+	HeaderKeyHash   = HeaderPrefix + "key_hash"
+)
+
+// ToHTTP returns a signed tree-head as HTTP key-value pairs
+func (sth *SignedTreeHead) ToHTTP() ([]byte, error) {
+	hdr := http.Header{}
+	hdr.Add(HeaderTimestamp, strconv.FormatUint(sth.Timestamp, 10))
+	hdr.Add(HeaderTreeSize, strconv.FormatUint(sth.TreeSize, 10))
+	hdr.Add(HeaderRootHash, hex.EncodeToString(sth.RootHash[:]))
+	for _, sigident := range sth.SigIdent {
+		hdr.Add(HeaderSignature, hex.EncodeToString(sigident.Signature[:]))
+		hdr.Add(HeaderKeyHash, hex.EncodeToString(sigident.KeyHash[:]))
+	}
+	return headerToBytes(hdr)
+}
+
+// ToHTTP returns a consistency proof as HTTP key-value pairs
+func (p *ConsistencyProof) ToHTTP() ([]byte, error) {
+	hdr := http.Header{}
+	hdr.Add(HeaderNewSize, strconv.FormatUint(p.NewSize, 10))
+	hdr.Add(HeaderOldSize, strconv.FormatUint(p.OldSize, 10))
+	for _, hash := range p.Path {
+		hdr.Add(HeaderConsistencyPath, hex.EncodeToString(hash[:]))
+	}
+	return headerToBytes(hdr)
+}
+
+// ToHTTP returns an inclusion proof as HTTP key-value pairs
+func (p *InclusionProof) ToHTTP() ([]byte, error) {
+	hdr := http.Header{}
+	hdr.Add(HeaderTreeSize, strconv.FormatUint(p.TreeSize, 10))
+	hdr.Add(HeaderLeafIndex, strconv.FormatUint(p.LeafIndex, 10))
+	for _, hash := range p.Path {
+		hdr.Add(HeaderInclusionPath, hex.EncodeToString(hash[:]))
+	}
+	return headerToBytes(hdr)
+}
+
+// ToHTTP returns a leaf as HTTP key-value pairs
+func (l *Leaf) ToHTTP() ([]byte, error) {
+	hdr := http.Header{}
+	hdr.Add(HeaderShardHint, strconv.FormatUint(l.ShardHint, 10))
+	hdr.Add(HeaderChecksum, hex.EncodeToString(l.Checksum[:]))
+	hdr.Add(HeaderSignature, hex.EncodeToString(l.Signature[:]))
+	hdr.Add(HeaderKeyHash, hex.EncodeToString(l.KeyHash[:]))
+	return headerToBytes(hdr)
+}
+
+// SignedTreeHeadFromHTTP parses a signed tree head from HTTP key-value pairs
+func SignedTreeHeadFromHTTP(buf []byte) (*SignedTreeHead, error) {
+	hdr, err := headerFromBuf(buf)
+	if err != nil {
+		return nil, fmt.Errorf("headerFromBuf(): %v", err)
+	}
+
+	// TreeHead
+	var sth SignedTreeHead
+	sth.Timestamp, err = strconv.ParseUint(hdr.Get(HeaderTimestamp), 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("invalid timestamp: %v", err)
+	}
+	sth.TreeSize, err = strconv.ParseUint(hdr.Get(HeaderTreeSize), 10, 64)
+	if err != nil {
+		return nil, fmt.Errorf("invalid tree size: %v", err)
+	}
+	if err := decodeHex(hdr.Get(HeaderRootHash), sth.RootHash[:]); err != nil {
+		return nil, fmt.Errorf("decodeHex(): %v", err)
+	}
+
+	// SigIdent
+	signatures := hdr.Values(HeaderSignature)
+	keyHashes := hdr.Values(HeaderKeyHash)
+	if len(signatures) == 0 {
+		return nil, fmt.Errorf("no signer")
+	}
+	if len(signatures) != len(keyHashes) {
+		return nil, fmt.Errorf("mismatched signature-signer count")
+	}
+	for i := 0; i < len(signatures); i++ {
+		var sigident SigIdent
+		if err := decodeHex(signatures[i], sigident.Signature[:]); err != nil {
+			return nil, fmt.Errorf("decodeHex(): %v", err)
+		}
+		if err := decodeHex(keyHashes[i], sigident.KeyHash[:]); err != nil {
+			return nil, fmt.Errorf("decodeHex(): %v", err)
+		}
+		sth.SigIdent = append(sth.SigIdent, sigident)
+	}
+	return &sth, nil
+}
+
+// ConsistencyProofFromHTTP parses a consistency proof from HTTP key-value pairs
+func ConsistencyProofFromHTTP(buf []byte) (*ConsistencyProof, error) {
+	return nil, nil // TODO
+}
+
+// InclusionProofFromHTTP parses an inclusion proof from HTTP key-value pairs
+func InclusionProofFromHTTP(buf []byte) (*InclusionProof, error) {
+	return nil, nil // TODO
+}
+
+// LeavesFromHTTP parses a list of leaves from HTTP key-value pairs
+func LeavesFromHTTP(buf []byte) ([]*Leaf, error) {
+	return nil, nil // TODO
+}
+
+// headerFromBuf parses ST log HTTP header key-value pairs from a response body
+func headerFromBuf(buf []byte) (http.Header, error) {
+	hdr := http.Header{}
+	lines := strings.Split(string(buf), "\r\n")
+	lines = lines[:len(lines)-1] // skip the final empty line
+	for _, line := range lines {
+		split := strings.Split(line, ":")
+		if len(split) != 2 {
+			return nil, fmt.Errorf("invalid ST log HTTP header: %s", line)
+		}
+		if !strings.HasPrefix(strings.ToLower(split[0]), HeaderPrefix) {
+			return nil, fmt.Errorf("invalid ST log HTTP header prefix: %s", line)
+		}
+		hdr.Add(split[0], strings.TrimSpace(split[1]))
+	}
+	return hdr, nil
+}
+
+// decodeHex decodes a hex-encoded string into a fixed-size output slice
+func decodeHex(str string, out []byte) error {
+	buf, err := hex.DecodeString(str)
+	if err != nil {
+		return fmt.Errorf("hex.DecodeString(): %v", err)
+	}
+	if len(buf) != len(out) {
+		return fmt.Errorf("invalid length: %v", len(buf))
+	}
+	copy(out, buf)
+	return nil
+}
+
+// headerToBytes encodes a header as HTTP key-value pairs
+func headerToBytes(hdr http.Header) ([]byte, error) {
+	buf := bytes.NewBuffer(nil)
+	if err := hdr.Write(buf); err != nil {
+		return nil, fmt.Errorf("hdr.Write(): %v", err) // should not happen
+	}
+	return buf.Bytes(), nil
+}
diff --git a/types/http_test.go b/types/http_test.go
new file mode 100644
index 0000000..527bcdf
--- /dev/null
+++ b/types/http_test.go
@@ -0,0 +1,331 @@
+package types
+
+import (
+	"bytes"
+	"encoding/hex"
+	"net/http"
+	"reflect"
+	"strings"
+	"testing"
+)
+
+var (
+	testZeroBuffer32 = [32]byte{}
+	testZeroBuffer64 = [64]byte{}
+)
+
+func TestSignedTreeHeadToHTTP(t *testing.T) {
+	description := "valid: cosigned tree head with two signatures"
+	sth := &SignedTreeHead{
+		TreeHead: TreeHead{
+			Timestamp: 0,
+			TreeSize:  0,
+			RootHash:  testBuffer32,
+		},
+		SigIdent: []SigIdent{
+			SigIdent{
+				Signature: testZeroBuffer64,
+				KeyHash:   testZeroBuffer32,
+			},
+			SigIdent{
+				Signature: testBuffer64,
+				KeyHash:   testBuffer32,
+			},
+		},
+	}
+	want := map[string][]string{
+		HeaderTimestamp: []string{"0"},
+		HeaderTreeSize:  []string{"0"},
+		HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+		HeaderSignature: []string{
+			hex.EncodeToString(testZeroBuffer64[:]),
+			hex.EncodeToString(testBuffer64[:]),
+		},
+		HeaderKeyHash: []string{
+			hex.EncodeToString(testZeroBuffer32[:]),
+			hex.EncodeToString(testBuffer32[:]),
+		},
+	}
+	buf, err := sth.ToHTTP()
+	if err != nil {
+		t.Fatalf("sth.ToHTTP: %v", err)
+	}
+	hdr, err := headerFromBuf(buf)
+	if err != nil {
+		t.Fatalf("headerFromBuf: %v", err)
+	}
+	compareHeaderWithMap(t, description, hdr, want)
+}
+
+func TestConsistencyProofToHTTP(t *testing.T) { // TODO
+}
+
+func TestInclusionProofToHTTP(t *testing.T) { // TODO
+}
+
+func TestLeafToHTTP(t *testing.T) { // TODO
+}
+
+func TestSignedTreeHeadFromHTTP(t *testing.T) {
+	for _, table := range []struct {
+		description string
+		buf         []byte
+		wantErr     bool
+		wantSth     *SignedTreeHead
+	}{
+		{
+			description: "invalid: not ST log HTTP header",
+			buf: newHeaderBuf(t, map[string][]string{
+				"user-agent": []string{"secret"},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: timestamp",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer64[:])},
+				HeaderKeyHash:   []string{hex.EncodeToString(testBuffer32[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: tree size",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer64[:])},
+				HeaderKeyHash:   []string{hex.EncodeToString(testBuffer32[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: root hash",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer64[:])},
+				HeaderKeyHash:   []string{hex.EncodeToString(testBuffer32[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: signature",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderKeyHash:   []string{hex.EncodeToString(testBuffer32[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: key hash",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer64[:])},
+				HeaderKeyHash:   []string{hex.EncodeToString(testBuffer64[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: sigident count",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{hex.EncodeToString(testBuffer64[:])},
+				HeaderKeyHash: []string{
+					hex.EncodeToString(testZeroBuffer32[:]),
+					hex.EncodeToString(testBuffer32[:]),
+				},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "invalid: no signer",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+			}),
+			wantErr: true,
+		},
+		{
+			description: "valid: cosigned tree head with two signatures",
+			buf: newHeaderBuf(t, map[string][]string{
+				HeaderTimestamp: []string{"0"},
+				HeaderTreeSize:  []string{"0"},
+				HeaderRootHash:  []string{hex.EncodeToString(testBuffer32[:])},
+				HeaderSignature: []string{
+					hex.EncodeToString(testZeroBuffer64[:]),
+					hex.EncodeToString(testBuffer64[:]),
+				},
+				HeaderKeyHash: []string{
+					hex.EncodeToString(testZeroBuffer32[:]),
+					hex.EncodeToString(testBuffer32[:]),
+				},
+			}),
+			wantSth: &SignedTreeHead{
+				TreeHead: TreeHead{
+					Timestamp: 0,
+					TreeSize:  0,
+					RootHash:  testBuffer32,
+				},
+				SigIdent: []SigIdent{
+					SigIdent{
+						Signature: testZeroBuffer64,
+						KeyHash:   testZeroBuffer32,
+					},
+					SigIdent{
+						Signature: testBuffer64,
+						KeyHash:   testBuffer32,
+					},
+				},
+			},
+		},
+	} {
+		sth, err := SignedTreeHeadFromHTTP(table.buf)
+		if got, want := err != nil, table.wantErr; got != want {
+			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+		}
+		if err != nil {
+			continue // nothing more to check on error
+		}
+		if got, want := sth, table.wantSth; !reflect.DeepEqual(got, want) {
+			t.Errorf("got signed tree head\n\t%v\nbut wanted\n\t%v\nin test %q", got, want, table.description)
+		}
+	}
+}
+
+func TestHeaderFromBuf(t *testing.T) {
+	for _, table := range []struct {
+		description string
+		buf         []byte
+		wantErr     bool
+		wantMap     map[string][]string
+	}{
+		{
+			description: "invalid: split",
+			buf:         []byte(HeaderPrefix + "k1: v1:v2\r\n"),
+			wantErr:     true,
+		},
+		{
+			description: "invalid: prefix",
+			buf:         []byte("user-agent: secret\r\n"),
+			wantErr:     true,
+		},
+		{
+			description: "valid: one key with funky case",
+			buf:         []byte(funkyCase(t, HeaderPrefix) + "k1: v1\r\n"),
+			wantMap: map[string][]string{
+				HeaderPrefix + "k1": []string{"v1"},
+			},
+		},
+		{
+			description: "valid: two keys where one has multiple values",
+			buf: []byte(
+				HeaderPrefix + "k1: v1 \r\n" +
+					HeaderPrefix + "k2: v2\r\n" +
+					HeaderPrefix + "k2: v3\r\n",
+			),
+			wantMap: map[string][]string{
+				HeaderPrefix + "k1": []string{"v1"},
+				HeaderPrefix + "k2": []string{"v2", "v3"},
+			},
+		},
+	} {
+		hdr, err := headerFromBuf(table.buf)
+		if got, want := err != nil, table.wantErr; got != want {
+			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+		}
+		if err != nil {
+			continue // nothing more to check on error
+		}
+		compareHeaderWithMap(t, table.description, hdr, table.wantMap)
+	}
+}
+
+func TestDecodeHex(t *testing.T) {
+	for _, table := range []struct {
+		description string
+		hex         string
+		wantErr     bool
+		wantBuf     [4]byte
+	}{
+		{
+			description: "invalid: too short input",
+			hex:         "000102",
+			wantErr:     true,
+		},
+		{
+			description: "invalid: too large input",
+			hex:         "0001020304",
+			wantErr:     true,
+		},
+		{
+			description: "invalid: not hex (1/2)",
+			hex:         "000102030",
+			wantErr:     true,
+		},
+		{
+			description: "invalid: not hex (2/2)",
+			hex:         "0001020q",
+			wantErr:     true,
+		},
+		{
+			description: "valid",
+			hex:         "00010203",
+			wantBuf:     [4]byte{0, 1, 2, 3},
+		},
+	} {
+		var buf [4]byte
+		err := decodeHex(table.hex, buf[:])
+		if got, want := err != nil, table.wantErr; got != want {
+			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+		}
+		if err != nil {
+			continue // nothing more to check on error
+		}
+		if got, want := buf[:], table.wantBuf[:]; !bytes.Equal(got, want) {
+			t.Errorf("got buf %v but wanted %v in test %q", got, want, table.description)
+		}
+	}
+}
+
+func newHeaderBuf(t *testing.T, kv map[string][]string) []byte {
+	t.Helper()
+	hdr := http.Header{}
+	for key, values := range kv {
+		for _, value := range values {
+			hdr.Add(key, value)
+		}
+	}
+	buf := bytes.NewBuffer(nil)
+	if err := hdr.Write(buf); err != nil {
+		t.Fatalf("hdr.Write(): %v", err)
+	}
+	return buf.Bytes()
+}
+
+func compareHeaderWithMap(t *testing.T, description string, hdr http.Header, wantMap map[string][]string) {
+	t.Helper()
+	if got, want := len(hdr), len(wantMap); got != want {
+		t.Errorf("got %d keys but wanted %d in test %q", got, want, description)
+	}
+	for key, value := range wantMap {
+		if got, want := hdr.Values(key), value; !reflect.DeepEqual(got, want) {
+			t.Errorf("got value %v but wanted %v for key %v in test %q", got, want, key, description)
+		}
+	}
+}
+
+func funkyCase(t *testing.T, str string) string {
+	t.Helper()
+	splitIndex := len(str) / 2
+	return strings.ToLower(str[:splitIndex]) + strings.ToUpper(str[splitIndex:])
+}
diff --git a/types/namespace.go b/types/namespace.go
deleted file mode 100644
index 376ebcd..0000000
--- a/types/namespace.go
+++ /dev/null
@@ -1,91 +0,0 @@
-package types
-
-import (
-	"fmt"
-
-	"crypto/ed25519"
-
-	"github.com/google/certificate-transparency-go/tls"
-)
-
-// NamespaceFormat defines a particular namespace type that is versioend
-type NamespaceFormat tls.Enum
-
-const (
-	NamespaceFormatReserved  NamespaceFormat = 0
-	NamespaceFormatEd25519V1 NamespaceFormat = 1
-
-	NamespaceFingerprintSize = 32
-)
-
-// Namespace references a versioned namespace based on a given format specifier
-type Namespace struct {
-	Format    NamespaceFormat `tls:"maxval:65535"`
-	Ed25519V1 *Ed25519V1      `tls:"selector:Format,val:1"`
-}
-
-// Ed25519V1 uses an Ed25519 verification key as namespace.  Encoding,
-// signing, and verification operations are defined by RFC 8032.
-type Ed25519V1 struct {
-	Namespace [32]byte
-}
-
-func (f NamespaceFormat) String() string {
-	switch f {
-	case NamespaceFormatReserved:
-		return "reserved"
-	case NamespaceFormatEd25519V1:
-		return "ed25519_v1"
-	default:
-		return fmt.Sprintf("unknown NamespaceFormat: %d", f)
-	}
-}
-
-func (n Namespace) String() string {
-	switch n.Format {
-	case NamespaceFormatReserved:
-		return fmt.Sprintf("Format(%s)", n.Format)
-	case NamespaceFormatEd25519V1:
-		return fmt.Sprintf("Format(%s): %+v", n.Format, n.Ed25519V1)
-	default:
-		return fmt.Sprintf("unknown Namespace: %v", n.Format)
-	}
-}
-
-// Fingerprint returns a fixed-size namespace fingerprint that is unique.
-func (n *Namespace) Fingerprint() (*[NamespaceFingerprintSize]byte, error) {
-	switch n.Format {
-	case NamespaceFormatEd25519V1:
-		return &n.Ed25519V1.Namespace, nil
-	default:
-		return nil, fmt.Errorf("unsupported NamespaceFormat: %v", n.Format)
-	}
-}
-
-// Verify checks that signature is valid over message for this namespace
-func (ns *Namespace) Verify(message, signature []byte) error {
-	switch ns.Format {
-	case NamespaceFormatEd25519V1:
-		if !ed25519.Verify(ed25519.PublicKey(ns.Ed25519V1.Namespace[:]), message, signature) {
-			return fmt.Errorf("ed25519 signature verification failed")
-		}
-	default:
-		return fmt.Errorf("namespace not supported: %v", ns.Format)
-	}
-	return nil
-}
-
-// NewNamespaceEd25519V1 returns an new Ed25519V1 namespace based on a
-// verification key.
-func NewNamespaceEd25519V1(vk []byte) (*Namespace, error) {
-	if len(vk) != 32 {
-		return nil, fmt.Errorf("invalid verification key: must be 32 bytes")
-	}
-
-	var ed25519v1 Ed25519V1
-	copy(ed25519v1.Namespace[:], vk)
-	return &Namespace{
-		Format:    NamespaceFormatEd25519V1,
-		Ed25519V1: &ed25519v1,
-	}, nil
-}
diff --git a/types/namespace_pool.go b/types/namespace_pool.go
deleted file mode 100644
index 1e9e8f6..0000000
--- a/types/namespace_pool.go
+++ /dev/null
@@ -1,69 +0,0 @@
-package types
-
-import (
-	"fmt"
-)
-
-// NamespacePool is a pool of namespaces that contain complete verification keys
-type NamespacePool struct {
-	pool map[[NamespaceFingerprintSize]byte]*Namespace
-	list []*Namespace
-	// If we need to update this structure without a restart => add mutex.
-}
-
-// NewNameSpacePool creates a new namespace pool from a list of namespaces.  An
-// error is returned if there are duplicate namespaces or namespaces without a
-// complete verification key.  The latter is determined by namespaceWithKey().
-func NewNamespacePool(namespaces []*Namespace) (*NamespacePool, error) {
-	np := &NamespacePool{
-		pool: make(map[[NamespaceFingerprintSize]byte]*Namespace),
-		list: make([]*Namespace, 0),
-	}
-	for _, namespace := range namespaces {
-		if !namespaceWithKey(namespace.Format) {
-			return nil, fmt.Errorf("need verification key in namespace pool: %v", namespace.Format)
-		}
-		fpr, err := namespace.Fingerprint()
-		if err != nil {
-			return nil, fmt.Errorf("need fingerprint in namespace pool: %v", err)
-		}
-		if _, ok := np.pool[*fpr]; ok {
-			return nil, fmt.Errorf("duplicate namespace: %v", namespace.String())
-		}
-		np.pool[*fpr] = namespace
-		np.list = append(np.list, namespace)
-	}
-	return np, nil
-}
-
-// Find checks if namespace is a member of the namespace pool.
-func (np *NamespacePool) Find(namespace *Namespace) (*Namespace, bool) {
-	fpr, err := namespace.Fingerprint()
-	if err != nil {
-		return nil, false
-	}
-	if _, ok := np.pool[*fpr]; !ok {
-		return nil, false
-	}
-	// If the passed namespace is a key fingerprint the actual key needs to be
-	// attached before returning.  Not applicable for Ed25519.  Docdoc later.
-	return namespace, true
-}
-
-// List returns a copied list of namespaces that is used by this pool.
-func (np *NamespacePool) List() []*Namespace {
-	namespaces := make([]*Namespace, len(np.list))
-	copy(namespaces, np.list)
-	return namespaces
-}
-
-// namespaceWithKey returns true if a namespace format contains a complete
-// verification key.  I.e., some formats might have a key fingerprint instead.
-func namespaceWithKey(format NamespaceFormat) bool {
-	switch format {
-	case NamespaceFormatEd25519V1:
-		return true
-	default:
-		return false
-	}
-}
diff --git a/types/namespace_pool_test.go b/types/namespace_pool_test.go
deleted file mode 100644
index f5810a2..0000000
--- a/types/namespace_pool_test.go
+++ /dev/null
@@ -1,91 +0,0 @@
-package types
-
-import (
-	"bytes"
-	"reflect"
-	"testing"
-)
-
-func TestNewNamespacePool(t *testing.T) {
-	ns1 := mustInitNamespaceEd25519V1(t, 0x00)
-	ns2 := mustInitNamespaceEd25519V1(t, 0xff)
-	nsr := &Namespace{Format: NamespaceFormatReserved}
-	for _, table := range []struct {
-		description string
-		namespaces  []*Namespace
-		wantErr     bool
-	}{
-		{
-			description: "invalid: duplicate namespace",
-			namespaces:  []*Namespace{ns1, ns1, ns2},
-			wantErr:     true,
-		},
-		{
-			description: "invalid: namespace without key",
-			namespaces:  []*Namespace{ns1, nsr, ns2},
-			wantErr:     true,
-		},
-		{
-			description: "valid: empty",
-			namespaces:  []*Namespace{},
-		},
-		{
-			description: "valid: one namespace",
-			namespaces:  []*Namespace{ns1},
-		},
-		{
-			description: "valid: two namespaces",
-			namespaces:  []*Namespace{ns1, ns2},
-		},
-	} {
-		_, err := NewNamespacePool(table.namespaces)
-		if got, want := err != nil, table.wantErr; got != want {
-			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
-		}
-	}
-}
-
-func TestFind(t *testing.T) {
-	ns1 := mustInitNamespaceEd25519V1(t, 0x00)
-	ns2 := mustInitNamespaceEd25519V1(t, 0xff)
-
-	// Empty pool
-	pool, err := NewNamespacePool(nil)
-	if err != nil {
-		t.Fatalf("must create new namespace pool: %v", err)
-	}
-	if _, ok := pool.Find(ns1); ok {
-		t.Errorf("found namespace in empty pool")
-	}
-
-	// Pool with one namespace
-	pool, err = NewNamespacePool([]*Namespace{ns1})
-	if err != nil {
-		t.Fatalf("must create new namespace pool: %v", err)
-	}
-	if ns, ok := pool.Find(ns1); !ok {
-		t.Errorf("could not find namespace that is a member of the pool")
-	} else if !reflect.DeepEqual(ns, ns1) {
-		t.Errorf("found namespace but it is wrong")
-	}
-	if _, ok := pool.Find(ns2); ok {
-		t.Errorf("found namespace although it is not a member of the pool")
-	}
-}
-
-func TestList(t *testing.T) {
-	ns1 := mustInitNamespaceEd25519V1(t, 0x00)
-	ns2 := mustInitNamespaceEd25519V1(t, 0xff)
-	namespaces := []*Namespace{ns1, ns2}
-	pool, err := NewNamespacePool(namespaces)
-	if err != nil {
-		t.Fatalf("must create new namespace pool: %v", err)
-	}
-	if got, want := len(pool.List()), len(namespaces); got != want {
-		t.Errorf("got len %v but wanted %v", got, want)
-	}
-	pool.List()[0] = ns2
-	if got, want := pool.List()[0].Ed25519V1.Namespace[:], ns1.Ed25519V1.Namespace[:]; !bytes.Equal(got, want) {
-		t.Errorf("returned list is not a copy")
-	}
-}
diff --git a/types/namespace_test.go b/types/namespace_test.go
deleted file mode 100644
index a5847ef..0000000
--- a/types/namespace_test.go
+++ /dev/null
@@ -1,200 +0,0 @@
-package types
-
-import (
-	"bytes"
-	"strings"
-	"testing"
-
-	"crypto/ed25519"
-)
-
-// TestNamespaceString checks that the String() function prints the right
-// format, and that the body is printed without a nil-pointer panic.
-func TestNamespaceString(t *testing.T) {
-	wantPrefix := map[NamespaceFormat]string{
-		NamespaceFormatReserved:    "Format(reserved)",
-		NamespaceFormatEd25519V1:   "Format(ed25519_v1): &{Namespace",
-		NamespaceFormat(1<<16 - 1): "unknown Namespace: unknown NamespaceFormat: 65535",
-	}
-	tests := append(test_cases_namespace(t), testCaseSerialize{
-		description: "valid: unknown Namespace",
-		item: Namespace{
-			Format: NamespaceFormat(1<<16 - 1),
-		},
-	})
-	for _, table := range tests {
-		namespace, ok := table.item.(Namespace)
-		if !ok {
-			t.Fatalf("must cast to Namespace in test %q", table.description)
-		}
-
-		prefix, ok := wantPrefix[namespace.Format]
-		if !ok {
-			t.Fatalf("must have prefix for StFormat %v in test %q", namespace.Format, table.description)
-		}
-		if got, want := namespace.String(), prefix; !strings.HasPrefix(got, want) {
-			t.Errorf("got %q but wanted prefix %q in test %q", got, want, table.description)
-		}
-	}
-}
-
-func TestFingerprint(t *testing.T) {
-	for _, table := range []struct {
-		description string
-		namespace   *Namespace
-		wantErr     bool
-		wantFpr     [NamespaceFingerprintSize]byte
-	}{
-		{
-			description: "invalid: no fingerprint for type",
-			namespace: &Namespace{
-				Format: NamespaceFormatReserved,
-			},
-			wantErr: true,
-		},
-		{
-			description: "valid: ed25519_v1",
-			namespace:   mustInitNamespaceEd25519V1(t, 0xaf),
-			wantFpr: func() (ret [NamespaceFingerprintSize]byte) {
-				for i, _ := range ret {
-					ret[i] = 0xaf
-				}
-				return
-			}(),
-		},
-	} {
-		fpr, err := table.namespace.Fingerprint()
-		if got, want := err != nil, table.wantErr; got != want {
-			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
-		}
-		if err != nil {
-			continue
-		}
-		if got, want := *fpr, table.wantFpr; !bytes.Equal(got[:], want[:]) {
-			t.Errorf("got fpr %v but wanted %v in test %q", got, want, table.description)
-		}
-	}
-}
-
-func TestVerify(t *testing.T) {
-	var tests []testCaseNamespace
-	tests = append(tests, test_cases_verify(t)...)
-	tests = append(tests, test_cases_verify_ed25519v1(t)...)
-	for _, table := range tests {
-		err := table.namespace.Verify(table.msg, table.sig)
-		if got, want := err != nil, table.wantErr; got != want {
-			t.Errorf("got error=%v but wanted %v in test %q: %v", got, want, table.description, err)
-		}
-	}
-}
-
-func TestNewNamespaceEd25519V1(t *testing.T) {
-	size := 32 // verification key size
-	for _, table := range []struct {
-		description string
-		vk          []byte
-		wantErr     bool
-	}{
-		{
-			description: "invalid",
-			vk:          make([]byte, size+1),
-			wantErr:     true,
-		},
-		{
-			description: "valid",
-			vk:          make([]byte, size),
-		},
-	} {
-		n, err := NewNamespaceEd25519V1(table.vk)
-		if got, want := err != nil, table.wantErr; got != want {
-			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
-		}
-		if err != nil {
-			continue
-		}
-		if got, want := n.Format, NamespaceFormatEd25519V1; got != want {
-			t.Errorf("got namespace format %v but wanted %v in test %q", got, want, table.description)
-			continue
-		}
-		if got, want := n.Ed25519V1.Namespace[:], table.vk; !bytes.Equal(got, want) {
-			t.Errorf("got namespace %X but wanted %X in test %q", got, want, table.description)
-		}
-	}
-}
-
-// testCaseNamespace is a common test case used for Namespace.Verify() tests
-type testCaseNamespace struct {
-	description string
-	namespace   *Namespace
-	msg, sig    []byte
-	wantErr     bool
-}
-
-// test_cases_verify returns basic namespace.Verify() tests
-func test_cases_verify(t *testing.T) []testCaseNamespace {
-	return []testCaseNamespace{
-		{
-			description: "test_cases_verify: invalid: unsupported namespace",
-			namespace:   &Namespace{Format: NamespaceFormatReserved},
-			msg:         []byte("msg"),
-			sig:         []byte("sig"),
-			wantErr:     true,
-		},
-	}
-}
-
-// test_cases_verify_ed25519v1 returns ed25519_v1 Namespace.Verify() tests
-func test_cases_verify_ed25519v1(t *testing.T) []testCaseNamespace {
-	testEd25519Sk := [64]byte{230, 122, 195, 152, 194, 195, 147, 153, 80, 120, 153, 79, 102, 27, 52, 187, 136, 218, 150, 234, 107, 9, 167, 4, 92, 21, 11, 113, 42, 29, 129, 69, 75, 60, 249, 150, 229, 93, 75, 32, 103, 126, 244, 37, 53, 182, 68, 82, 249, 109, 49, 94, 10, 19, 146, 244, 58, 191, 169, 107, 78, 37, 45, 210}
-	testEd25519Vk := [32]byte{75, 60, 249, 150, 229, 93, 75, 32, 103, 126, 244, 37, 53, 182, 68, 82, 249, 109, 49, 94, 10, 19, 146, 244, 58, 191, 169, 107, 78, 37, 45, 210}
-	return []testCaseNamespace{
-		{
-			description: "test_cases_verify_ed25519v1: invalid: sk signed message, but vk is not for sk",
-			namespace: &Namespace{
-				Format: NamespaceFormatEd25519V1,
-				Ed25519V1: &Ed25519V1{
-					Namespace: [32]byte{},
-				},
-			},
-			msg:     []byte("message"),
-			sig:     ed25519.Sign(ed25519.PrivateKey(testEd25519Sk[:]), []byte("message")),
-			wantErr: true,
-		},
-		{
-			description: "test_cases_verify_ed25519v1: invalid: vk is for sk, but sk did not sign message",
-			namespace: &Namespace{
-				Format: NamespaceFormatEd25519V1,
-				Ed25519V1: &Ed25519V1{
-					Namespace: testEd25519Vk,
-				},
-			},
-			msg:     []byte("some message"),
-			sig:     ed25519.Sign(ed25519.PrivateKey(testEd25519Sk[:]), []byte("another message")),
-			wantErr: true,
-		},
-		{
-			description: "test_cases_verify_ed25519v1: valid",
-			namespace: &Namespace{
-				Format: NamespaceFormatEd25519V1,
-				Ed25519V1: &Ed25519V1{
-					Namespace: testEd25519Vk,
-				},
-			},
-			msg: []byte("message"),
-			sig: ed25519.Sign(ed25519.PrivateKey(testEd25519Sk[:]), []byte("message")),
-		},
-	}
-}
-
-func mustInitNamespaceEd25519V1(t *testing.T, initByte byte) *Namespace {
-	t.Helper()
-	buf := make([]byte, 32)
-	for i := 0; i < len(buf); i++ {
-		buf[i] = initByte
-	}
-	ns, err := NewNamespaceEd25519V1(buf)
-	if err != nil {
-		t.Fatalf("must make Ed25519v1 namespace: %v", err)
-	}
-	return ns
-}
diff --git a/types/serialize.go b/types/serialize.go
deleted file mode 100644
index fd93336..0000000
--- a/types/serialize.go
+++ /dev/null
@@ -1,50 +0,0 @@
-package types
-
-import (
-	"fmt"
-
-	"github.com/google/certificate-transparency-go/tls"
-)
-
-const (
-	HashSizeV1 = 32
-)
-
-// GetProofByHashV1 is a serializable get-proof-by-hash request
-type GetProofByHashV1 struct {
-	Hash     [HashSizeV1]byte
-	TreeSize uint64
-}
-
-// GetConsistencyProofV1 is a serializable get-consistency-proof request
-type GetConsistencyProofV1 struct {
-	First  uint64
-	Second uint64
-}
-
-// GetEntriesV1 is a serializable get-entries request
-type GetEntriesV1 struct {
-	Start uint64
-	End   uint64
-}
-
-// Marshal marshals a TLS-encodable structure
-func Marshal(item interface{}) ([]byte, error) {
-	serialized, err := tls.Marshal(item)
-	if err != nil {
-		return nil, fmt.Errorf("tls.Marshal: %v", err)
-	}
-	return serialized, nil
-}
-
-// Unmarshal unmarshals a TLS-encoded structure
-func Unmarshal(serialized []byte, out interface{}) error {
-	extra, err := tls.Unmarshal(serialized, out)
-	if err != nil {
-		return fmt.Errorf("tls.Unmarshal: %v", err)
-	}
-	if len(extra) > 0 {
-		return fmt.Errorf("tls.Unmarshal: extra data: %X", extra)
-	}
-	return nil
-}
diff --git a/types/serialize_test.go b/types/serialize_test.go
deleted file mode 100644
index a06effe..0000000
--- a/types/serialize_test.go
+++ /dev/null
@@ -1,736 +0,0 @@
-package types
-
-import (
-	"bytes"
-	"testing"
-
-	"encoding/binary"
-)
-
-// testCaseSerialize is a common test case used for ST log types
-type testCaseSerialize struct {
-	description string
-	item        interface{}
-	wantErr     bool
-	wantBytes   []byte // only used if no error and not equal to nil
-}
-
-// TestMarshalUnmarshal tests that valid ST log structures can be marshalled and
-// then unmarshalled without error, and that invalid ST log structures cannot be
-// marshalled.  If wantBytes is non-nil the marshalled result must also match.
-func TestMarshalUnmarshal(t *testing.T) {
-	var tests []testCaseSerialize
-	tests = append(tests, test_cases_stitemlist(t)...)
-	tests = append(tests, test_cases_stitem(t)...)
-	tests = append(tests, test_cases_sthv1(t)...)
-	tests = append(tests, test_cases_costhv1(t)...)
-	tests = append(tests, test_cases_cpv1(t)...)
-	tests = append(tests, test_cases_ipv1(t)...)
-	tests = append(tests, test_cases_signed_checksumv1(t)...)
-	tests = append(tests, test_cases_checksumv1(t)...)
-	tests = append(tests, test_cases_thv1(t)...)
-	tests = append(tests, test_cases_nh(t)...)
-	tests = append(tests, test_cases_sigv1(t)...)
-	tests = append(tests, test_cases_namespace(t)...)
-	tests = append(tests, test_cases_ed25519v1(t)...)
-	tests = append(tests, test_cases_requests(t)...)
-	for _, table := range tests {
-		b, err := Marshal(table.item)
-		if got, want := err != nil, table.wantErr; got != want {
-			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
-		}
-		if err != nil {
-			continue // nothing to unmarshal
-		}
-		if got, want := b, table.wantBytes; want != nil && !bytes.Equal(got, want) {
-			t.Errorf("got bytes \n%v\n\tbut wanted\n%v\n\t in test %q: %v", got, want, table.description, err)
-		}
-
-		switch table.item.(type) {
-		case StItemList:
-			var item StItemList
-			err = Unmarshal(b, &item)
-		case StItem:
-			var item StItem
-			err = Unmarshal(b, &item)
-		case SignedTreeHeadV1:
-			var item SignedTreeHeadV1
-			err = Unmarshal(b, &item)
-		case CosignedTreeHeadV1:
-			var item CosignedTreeHeadV1
-			err = Unmarshal(b, &item)
-		case ConsistencyProofV1:
-			var item ConsistencyProofV1
-			err = Unmarshal(b, &item)
-		case InclusionProofV1:
-			var item InclusionProofV1
-			err = Unmarshal(b, &item)
-		case SignedChecksumV1:
-			var item SignedChecksumV1
-			err = Unmarshal(b, &item)
-		case ChecksumV1:
-			var item ChecksumV1
-			err = Unmarshal(b, &item)
-		case TreeHeadV1:
-			var item TreeHeadV1
-			err = Unmarshal(b, &item)
-		case NodeHash:
-			var item NodeHash
-			err = Unmarshal(b, &item)
-		case SignatureV1:
-			var item SignatureV1
-			err = Unmarshal(b, &item)
-		case Namespace:
-			var item Namespace
-			err = Unmarshal(b, &item)
-		case Ed25519V1:
-			var item Ed25519V1
-			err = Unmarshal(b, &item)
-		case GetProofByHashV1:
-			var item GetProofByHashV1
-			err = Unmarshal(b, &item)
-		case GetConsistencyProofV1:
-			var item GetConsistencyProofV1
-			err = Unmarshal(b, &item)
-		case GetEntriesV1:
-			var item GetEntriesV1
-			err = Unmarshal(b, &item)
-		default:
-			t.Errorf("unhandled type in test %q", table.description)
-		}
-		if err != nil {
-			t.Errorf("unmarshal failed but wanted success in test %q: %v", table.description, err)
-		}
-	}
-}
-
-// TestUnmarshalStItem tests that invalid StItems cannot be unmarshalled
-func TestUnmarshalStItem(t *testing.T) {
-	tests := test_cases_stitem(t)[1:] // skip reserved type
-	for _, table := range tests {
-		description := table.description[7:] // skip "valid: " prefix
-		b, err := Marshal(table.item)
-		if err != nil {
-			t.Fatalf("must marshal in test %q: %v", description, err)
-		}
-
-		var item StItem
-		if err := Unmarshal(append(b[:], []byte{0}...), &item); err == nil {
-			t.Errorf("unmarshal suceeded with one extra byte in test %q", description)
-		}
-		if err := Unmarshal(b[:len(b)-1], &item); err == nil {
-			t.Errorf("unmarshal suceeded with one byte short in test %q", description)
-		}
-		if err := Unmarshal(append(b[:], b[:]...), &item); err == nil {
-			t.Errorf("unmarshal succeeded with appended StItem in test %q", description)
-		}
-		if err := Unmarshal([]byte{0}, &item); err == nil {
-			t.Errorf("unmarshal succeeded with a single byte in test %q", description)
-		}
-	}
-}
-
-// test_cases_stitemlist returns test cases for the StItemList type
-func test_cases_stitemlist(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	return []testCaseSerialize{
-		testCaseSerialize{
-			description: "test_cases_stitemlist: valid: StItemList: empty",
-			item:        StItemList{},
-			wantBytes:   []byte{0x00, 0x00, 0x00, 0x00},
-		}, // skip max len check because it is huge
-		testCaseSerialize{
-			description: "test_cases_stitemlist: valid: mixed content",
-			item:        testStItemList,
-			wantBytes:   testStItemListBytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_stitem returns test cases for the different StItem types
-func test_cases_stitem(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	return []testCaseSerialize{
-		{
-			description: "invalid: StItem: reserved",
-			item:        testStItemReserved,
-			wantErr:     true,
-		},
-		{
-			description: "valid: StItem: signed_tree_head_v1",
-			item:        testStItemSignedTreeHeadV1,
-			wantBytes:   testStItemSignedTreeHeadV1Bytes,
-		},
-		{
-			description: "valid: StItem: cosigned_tree_head_v1",
-			item:        testStItemCosignedTreeHeadV1,
-			wantBytes:   testStItemCosignedTreeHeadV1Bytes,
-		},
-		{
-			description: "valid: StItem: consistency_proof_v1",
-			item:        testStItemConsistencyProofV1,
-			wantBytes:   testStItemConsistencyProofV1Bytes,
-		},
-		{
-			description: "valid: StItem: inclusion_proof_v1",
-			item:        testStItemInclusionProofV1,
-			wantBytes:   testStItemInclusionProofV1Bytes,
-		},
-		{
-			description: "valid: StItem: signed_checksum_v1",
-			item:        testStItemSignedChecksumV1,
-			wantBytes:   testStItemSignedChecksumV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_sthv1 returns test cases for the SignedTreeHeadV1 structure
-func test_cases_sthv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	return []testCaseSerialize{
-		{
-			description: "valid: testSignedTreeHeadV1",
-			item:        testSignedTreeHeadV1,
-			wantBytes:   testSignedTreeHeadV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_costhv1 returns test cases for the CosignedTreeHeadV1 structure
-func test_cases_costhv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	return []testCaseSerialize{
-		{
-			description: "test_cases_costhv1: valid: min",
-			item: CosignedTreeHeadV1{
-				SignedTreeHead: testSignedTreeHeadV1,
-				Cosignatures:   make([]SignatureV1, 0),
-			},
-		}, // skipping "valid: max" because it is huge
-		{
-			description: "test_cases_costhv1: testCosignedTreeHeadV1",
-			item:        testCosignedTreeHeadV1,
-			wantBytes:   testCosignedTreeHeadV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_cpv1 returns test cases for the ConsistencyProofV1 structure
-func test_cases_cpv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	max := 65535 // max consistency proof
-	return []testCaseSerialize{
-		{
-			description: "test_cases_cpv1: invalid: >max",
-			item: ConsistencyProofV1{
-				LogId:     testNamespace,
-				TreeSize1: 0,
-				TreeSize2: 0,
-				ConsistencyPath: func() []NodeHash {
-					var path []NodeHash
-					for sum := 0; sum < max+1; sum += 1 + len(testNodeHash.Data) {
-						path = append(path, testNodeHash)
-					}
-					return path
-				}(),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_cpv1: valid: min",
-			item: ConsistencyProofV1{
-				LogId:           testNamespace,
-				TreeSize1:       0,
-				TreeSize2:       0,
-				ConsistencyPath: make([]NodeHash, 0),
-			},
-		},
-		{
-			description: "test_cases_cpv1: valid: testConsistencyProofV1",
-			item:        testConsistencyProofV1,
-			wantBytes:   testConsistencyProofV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_ipv1 returns test cases for the InclusionProofV1 structure
-func test_cases_ipv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	max := 65535 // max inclusion proof
-	return []testCaseSerialize{
-		{
-			description: "test_cases_ipv1: invalid: >max",
-			item: InclusionProofV1{
-				LogId:     testNamespace,
-				TreeSize:  0,
-				LeafIndex: 0,
-				InclusionPath: func() []NodeHash {
-					var path []NodeHash
-					for sum := 0; sum < max+1; sum += 1 + len(testNodeHash.Data) {
-						path = append(path, testNodeHash)
-					}
-					return path
-				}(),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_ipv1: valid: min",
-			item: InclusionProofV1{
-				LogId:         testNamespace,
-				TreeSize:      0,
-				LeafIndex:     0,
-				InclusionPath: make([]NodeHash, 0),
-			},
-		},
-		{
-			description: "test_cases_ipv1: valid: testInclusionProofV1",
-			item:        testInclusionProofV1,
-			wantBytes:   testInclusionProofV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_signed_checksumv1 returns test cases for the SignedChecksumV1 structure
-func test_cases_signed_checksumv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	return []testCaseSerialize{
-		{
-			description: "test_cases_signed_checksumv1: valid: testSignedChecksumV1",
-			item:        testSignedChecksumV1,
-			wantBytes:   testSignedChecksumV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_checksumv1 returns test cases for the ChecksumV1 structure
-func test_cases_checksumv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	minIdentifier, maxIdentifier, identifier := 1, 128, []byte("foobar-1-2-3")
-	minChecksum, maxChecksum, checksum := 1, 64, make([]byte, 32)
-	return []testCaseSerialize{
-		{
-			description: "test_cases_checksumv1: invalid: identifier: min",
-			item: ChecksumV1{
-				Identifier: make([]byte, minIdentifier-1),
-				Checksum:   checksum,
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_checksumv1: invalid: identifier: max",
-			item: ChecksumV1{
-				Identifier: make([]byte, maxIdentifier+1),
-				Checksum:   checksum,
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_checksumv1: invalid: checksum: min",
-			item: ChecksumV1{
-				Identifier: identifier,
-				Checksum:   make([]byte, minChecksum-1),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_checksumv1: invalid: checksum: max",
-			item: ChecksumV1{
-				Identifier: identifier,
-				Checksum:   make([]byte, maxChecksum+1),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_checksumv1: valid: testChecksumV1",
-			item:        testChecksumV1,
-			wantBytes:   testChecksumV1Bytes,
-		},
-	}
-}
-
-// test_cases_thv1 returns test cases for the TreeHeadV1 structure
-func test_cases_thv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	min, max := 0, 1<<16-1 // extensions min and max
-	return []testCaseSerialize{
-		{
-			description: "test_cases_thv1: invalid: max",
-			item: TreeHeadV1{
-				Timestamp: 0,
-				TreeSize:  0,
-				RootHash:  testNodeHash,
-				Extension: make([]byte, max+1),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_thv1: valid: min",
-			item: TreeHeadV1{
-				Timestamp: 0,
-				TreeSize:  0,
-				RootHash:  testNodeHash,
-				Extension: make([]byte, min),
-			},
-		},
-		{
-			description: "test_cases_thv1: valid: max",
-			item: TreeHeadV1{
-				Timestamp: 0,
-				TreeSize:  0,
-				RootHash:  testNodeHash,
-				Extension: make([]byte, max),
-			},
-		},
-		{
-			description: "test_cases_thv1: valid: testTreeHeadV1",
-			item:        testTreeHeadV1,
-			wantBytes:   testTreeHeadV1Bytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_nh returns test cases for the NodeHash structure
-func test_cases_nh(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	min, max := 32, 1<<8-1 // NodeHash min and max
-	return []testCaseSerialize{
-		{
-			description: "test_cases_nh: invalid: min",
-			item:        NodeHash{make([]byte, min-1)},
-			wantErr:     true,
-		},
-		{
-			description: "test_cases_nh: invalid: max",
-			item:        NodeHash{make([]byte, max+1)},
-			wantErr:     true,
-		},
-		{
-			description: "test_cases_nh: valid: min",
-			item:        NodeHash{make([]byte, min)},
-		},
-		{
-			description: "test_cases_nh: valid: max",
-			item:        NodeHash{make([]byte, max)},
-		},
-		{
-			description: "test_cases_nh: valid: testNodeHash",
-			item:        testNodeHash,
-			wantBytes:   testNodeHashBytes,
-		}, // other invalid bounds are already tested in subtypes
-	}
-}
-
-// test_cases_sigv1 returns test cases for the SignatureV1 structure
-func test_cases_sigv1(t *testing.T) []testCaseSerialize {
-	t.Helper()
-	min, max := 1, 1<<16-1 // signature min and max
-	return []testCaseSerialize{
-		{
-			description: "test_cases_sigv1: invalid: min",
-			item: SignatureV1{
-				Namespace: testNamespace,
-				Signature: make([]byte, min-1),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_sigv1: invalid: max",
-			item: SignatureV1{
-				Namespace: testNamespace,
-				Signature: make([]byte, max+1),
-			},
-			wantErr: true,
-		},
-		{
-			description: "test_cases_sigv1: valid: min",
-			item: SignatureV1{
-				Namespace: testNamespace,
-				Signature: make([]byte, min),
-			},
-		},
-		{
-			description: "test_cases_sigv1: valid: max",
-			item: SignatureV1{
-				Namespace: testNamespace,
-				Signature: make([]byte, max),
-			},
-		},
-		{
-			description: "test_cases_sigV1: valid: testSignatureV1",
-			item:        testSignatureV1,
-			wantBytes:   testSignatureV1Bytes,
-		},
-	}
-}
-
-// test_cases_namespace returns test cases for the different Namespace types.
-func test_cases_namespace(t *testing.T) []testCaseSerialize {
-	return []testCaseSerialize{
-		{
-			description: "invalid: Namespace: reserved",
-			item:        testNamespaceReserved,
-			wantErr:     true,
-		},
-		{
-			description: "valid: Namespace: ed25519_v1",
-			item:        testNamespaceEd25519V1,
-			wantBytes:   testNamespaceEd25519V1Bytes,
-		},
-	}
-}
-
-// test_cases_ed25519v1 returns test cases for the Ed25519V1 structure
-func test_cases_ed25519v1(t *testing.T) []testCaseSerialize {
-	return []testCaseSerialize{
-		{
-			description: "valid: testNamespaceEd25519V1",
-			item:        testEd25519V1,
-			wantBytes:   testEd25519V1Bytes,
-		},
-	}
-}
-
-// test_cases_requests returns test cases for proof request types
-func test_cases_requests(t *testing.T) []testCaseSerialize {
-	return []testCaseSerialize{
-		{
-			description: "valid: GetProofByHashV1",
-			item: GetProofByHashV1{
-				Hash:     [HashSizeV1]byte{},
-				TreeSize: 16909060,
-			},
-			wantBytes: bytes.Join([][]byte{
-				make([]byte, 32), // hash
-				[]byte{0x00, 0x00, 0x00, 0x00, 0x1, 0x2, 0x3, 0x4}, // tree size
-			}, nil),
-		},
-		{
-			description: "valid: GetConsistencyProofV1",
-			item: GetConsistencyProofV1{
-				First:  0,
-				Second: 16909060,
-			},
-			wantBytes: bytes.Join([][]byte{
-				make([]byte, 8), // first
-				[]byte{0x00, 0x00, 0x00, 0x00, 0x1, 0x2, 0x3, 0x4}, // second
-			}, nil),
-		},
-		{
-			description: "valid: GetEntriesV1",
-			item: GetEntriesV1{
-				Start: 0,
-				End:   16909060,
-			},
-			wantBytes: bytes.Join([][]byte{
-				make([]byte, 8), // start
-				[]byte{0x00, 0x00, 0x00, 0x00, 0x1, 0x2, 0x3, 0x4}, // end
-			}, nil),
-		},
-	}
-}
-
-var (
-	// StItemList
-	testStItemList = StItemList{
-		Items: []StItem{
-			testStItemSignedChecksumV1,
-			testStItemInclusionProofV1,
-			testStItemCosignedTreeHeadV1,
-		},
-	}
-	testStItemListBytes = bytes.Join([][]byte{
-		func() []byte {
-			sum := uint32(len(testStItemSignedChecksumV1Bytes))
-			sum += uint32(len(testStItemInclusionProofV1Bytes))
-			sum += uint32(len(testStItemCosignedTreeHeadV1Bytes))
-			buf := make([]byte, 4)
-			binary.BigEndian.PutUint32(buf, sum)
-			return buf
-		}(), // length specifier list
-		testStItemSignedChecksumV1Bytes,   // first StItem
-		testStItemInclusionProofV1Bytes,   // second StItem
-		testStItemCosignedTreeHeadV1Bytes, // third StItem
-	}, nil)
-
-	// StItem
-	testStItemReserved = StItem{
-		Format: StFormatReserved,
-	}
-
-	testStItemSignedTreeHeadV1 = StItem{
-		Format:           StFormatSignedTreeHeadV1,
-		SignedTreeHeadV1: &testSignedTreeHeadV1,
-	}
-	testStItemSignedTreeHeadV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x01},        // format signed_tree_head_v1
-		testSignedTreeHeadV1Bytes, // SignedTreeHeadV1
-	}, nil)
-
-	testStItemCosignedTreeHeadV1 = StItem{
-		Format:             StFormatCosignedTreeHeadV1,
-		CosignedTreeHeadV1: &testCosignedTreeHeadV1,
-	}
-	testStItemCosignedTreeHeadV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x02},          // format cosigned_tree_head_v1
-		testCosignedTreeHeadV1Bytes, // CosignedTreeHeadV1,
-	}, nil)
-
-	testStItemConsistencyProofV1 = StItem{
-		Format:             StFormatConsistencyProofV1,
-		ConsistencyProofV1: &testConsistencyProofV1,
-	}
-	testStItemConsistencyProofV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x03},          // format consistency_proof_v1
-		testConsistencyProofV1Bytes, // ConsistencyProofV1
-	}, nil)
-
-	testStItemInclusionProofV1 = StItem{
-		Format:           StFormatInclusionProofV1,
-		InclusionProofV1: &testInclusionProofV1,
-	}
-	testStItemInclusionProofV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x04},        // format inclusion_proof_v1
-		testInclusionProofV1Bytes, // InclusionProofV1
-	}, nil)
-
-	testStItemSignedChecksumV1 = StItem{
-		Format:           StFormatSignedChecksumV1,
-		SignedChecksumV1: &testSignedChecksumV1,
-	}
-	testStItemSignedChecksumV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x05},        // format signed_checksum_v1
-		testSignedChecksumV1Bytes, // SignedChecksumV1
-	}, nil)
-
-	// Subtypes used by StItem
-	testSignedTreeHeadV1 = SignedTreeHeadV1{
-		TreeHead:  testTreeHeadV1,
-		Signature: testSignatureV1,
-	}
-	testSignedTreeHeadV1Bytes = bytes.Join([][]byte{
-		testTreeHeadV1Bytes,  // tree head
-		testSignatureV1Bytes, // signature
-	}, nil)
-
-	testCosignedTreeHeadV1 = CosignedTreeHeadV1{
-		SignedTreeHead: testSignedTreeHeadV1,
-		Cosignatures: []SignatureV1{
-			testSignatureV1,
-		},
-	}
-	testCosignedTreeHeadV1Bytes = bytes.Join([][]byte{
-		testSignedTreeHeadV1Bytes,                                 // signed tree head
-		[]byte{0x00, 0x00, 0x00, byte(len(testSignatureV1Bytes))}, // cosignature length specifier
-		testSignatureV1Bytes,                                      // the only cosignature in this list
-	}, nil)
-
-	testConsistencyProofV1 = ConsistencyProofV1{
-		LogId:     testNamespace,
-		TreeSize1: 16909060,
-		TreeSize2: 16909060,
-		ConsistencyPath: []NodeHash{
-			testNodeHash,
-		},
-	}
-	testConsistencyProofV1Bytes = bytes.Join([][]byte{
-		testNamespaceBytes, // log id
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // tree size 1
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // tree size 2
-		[]byte{0x00, byte(len(testNodeHashBytes))},             // consistency path length specifier
-		testNodeHashBytes, // the only node hash in this proof
-	}, nil)
-
-	testInclusionProofV1 = InclusionProofV1{
-		LogId:     testNamespace,
-		TreeSize:  16909060,
-		LeafIndex: 16909060,
-		InclusionPath: []NodeHash{
-			testNodeHash,
-		},
-	}
-	testInclusionProofV1Bytes = bytes.Join([][]byte{
-		testNamespaceBytes, // log id
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // tree size
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // leaf index
-		[]byte{0x00, byte(len(testNodeHashBytes))},             // inclusion path length specifier
-		testNodeHashBytes, // the only node hash in this proof
-	}, nil)
-
-	testSignedChecksumV1 = SignedChecksumV1{
-		Data:      testChecksumV1,
-		Signature: testSignatureV1,
-	}
-	testSignedChecksumV1Bytes = bytes.Join([][]byte{
-		testChecksumV1Bytes,  // data
-		testSignatureV1Bytes, // signature
-	}, nil)
-
-	// Additional subtypes
-	testChecksumV1 = ChecksumV1{
-		Identifier: []byte("foobar-1-2-3"),
-		Checksum:   make([]byte, 32),
-	}
-	testChecksumV1Bytes = bytes.Join([][]byte{
-		[]byte{12},             // identifier length specifier
-		[]byte("foobar-1-2-3"), // identifier
-		[]byte{32},             // checksum length specifier
-		make([]byte, 32),       // checksum
-	}, nil)
-
-	testTreeHeadV1 = TreeHeadV1{
-		Timestamp: 16909060,
-		TreeSize:  16909060,
-		RootHash:  testNodeHash,
-		Extension: make([]byte, 0),
-	}
-	testTreeHeadV1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // timestamp
-		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04}, // tree size
-		testNodeHashBytes,  // root hash
-		[]byte{0x00, 0x00}, // extension length specifier
-		// no extension
-	}, nil)
-
-	testNodeHash = NodeHash{
-		Data: make([]byte, 32),
-	}
-	testNodeHashBytes = bytes.Join([][]byte{
-		[]byte{32}, // node hash length specifier
-		make([]byte, 32),
-	}, nil)
-
-	testSignatureV1 = SignatureV1{
-		Namespace: testNamespace,
-		Signature: make([]byte, 64),
-	}
-	testSignatureV1Bytes = bytes.Join([][]byte{
-		testNamespaceBytes, // namespace field
-		[]byte{0, 64},      // signature length specifier
-		make([]byte, 64),   // signature
-	}, nil)
-
-	// Namespace
-	testNamespaceReserved = Namespace{
-		Format: NamespaceFormatReserved,
-	}
-
-	testNamespace          = testNamespaceEd25519V1
-	testNamespaceBytes     = testNamespaceEd25519V1Bytes
-	testNamespaceEd25519V1 = Namespace{
-		Format:    NamespaceFormatEd25519V1,
-		Ed25519V1: &testEd25519V1,
-	}
-	testNamespaceEd25519V1Bytes = bytes.Join([][]byte{
-		[]byte{0x00, 0x01}, // format ed25519_v1
-		testEd25519V1Bytes, // Ed25519V1
-	}, nil)
-
-	// Subtypes used by Namespace
-	testEd25519V1 = Ed25519V1{
-		Namespace: [32]byte{},
-	}
-	testEd25519V1Bytes = bytes.Join([][]byte{
-		make([]byte, 32), // namespace, no length specifier because fixed size
-	}, nil)
-)
diff --git a/types/stitem.go b/types/stitem.go
deleted file mode 100644
index 447cad0..0000000
--- a/types/stitem.go
+++ /dev/null
@@ -1,192 +0,0 @@
-package types
-
-import (
-	"fmt"
-
-	"github.com/google/certificate-transparency-go/tls"
-)
-
-// StFormat defines a particular StItem type that is versioned
-type StFormat tls.Enum
-
-const (
-	StFormatReserved           StFormat = 0
-	StFormatSignedTreeHeadV1   StFormat = 1
-	StFormatCosignedTreeHeadV1 StFormat = 2
-	StFormatConsistencyProofV1 StFormat = 3
-	StFormatInclusionProofV1   StFormat = 4
-	StFormatSignedChecksumV1   StFormat = 5
-)
-
-// StItem references a versioned item based on a given format specifier
-type StItem struct {
-	Format             StFormat            `tls:"maxval:65535"`
-	SignedTreeHeadV1   *SignedTreeHeadV1   `tls:"selector:Format,val:1"`
-	CosignedTreeHeadV1 *CosignedTreeHeadV1 `tls:"selector:Format,val:2"`
-	ConsistencyProofV1 *ConsistencyProofV1 `tls:"selector:Format,val:3"`
-	InclusionProofV1   *InclusionProofV1   `tls:"selector:Format,val:4"`
-	SignedChecksumV1   *SignedChecksumV1   `tls:"selector:Format,val:5"`
-}
-
-type StItemList struct {
-	Items []StItem `tls:"minlen:0,maxlen:4294967295"`
-}
-
-type SignedTreeHeadV1 struct {
-	TreeHead  TreeHeadV1
-	Signature SignatureV1
-}
-
-type CosignedTreeHeadV1 struct {
-	SignedTreeHead SignedTreeHeadV1
-	Cosignatures   []SignatureV1 `tls:"minlen:0,maxlen:4294967295"`
-}
-
-type ConsistencyProofV1 struct {
-	LogId           Namespace
-	TreeSize1       uint64
-	TreeSize2       uint64
-	ConsistencyPath []NodeHash `tls:"minlen:0,maxlen:65535"`
-}
-
-type InclusionProofV1 struct {
-	LogId         Namespace
-	TreeSize      uint64
-	LeafIndex     uint64
-	InclusionPath []NodeHash `tls:"minlen:0,maxlen:65535"`
-}
-
-type SignedChecksumV1 struct {
-	Data      ChecksumV1
-	Signature SignatureV1
-}
-
-type ChecksumV1 struct {
-	Identifier []byte `tls:"minlen:1,maxlen:128"`
-	Checksum   []byte `tls:"minlen:1,maxlen:64"`
-}
-
-type TreeHeadV1 struct {
-	Timestamp uint64
-	TreeSize  uint64
-	RootHash  NodeHash
-	Extension []byte `tls:"minlen:0,maxlen:65535"`
-}
-
-type NodeHash struct {
-	Data []byte `tls:"minlen:32,maxlen:255"`
-}
-
-type SignatureV1 struct {
-	Namespace Namespace
-	Signature []byte `tls:"minlen:1,maxlen:65535"`
-}
-
-func (f StFormat) String() string {
-	switch f {
-	case StFormatReserved:
-		return "reserved"
-	case StFormatSignedTreeHeadV1:
-		return "signed_tree_head_v1"
-	case StFormatCosignedTreeHeadV1:
-		return "cosigned_tree_head_v1"
-	case StFormatConsistencyProofV1:
-		return "consistency_proof_v1"
-	case StFormatInclusionProofV1:
-		return "inclusion_proof_v1"
-	case StFormatSignedChecksumV1:
-		return "signed_checksum_v1"
-	default:
-		return fmt.Sprintf("unknown StFormat: %d", f)
-	}
-}
-
-func (i StItem) String() string {
-	switch i.Format {
-	case StFormatReserved:
-		return fmt.Sprintf("Format(%s)", i.Format)
-	case StFormatSignedTreeHeadV1:
-		return fmt.Sprintf("Format(%s): %+v", i.Format, i.SignedTreeHeadV1)
-	case StFormatCosignedTreeHeadV1:
-		return fmt.Sprintf("Format(%s): %+v", i.Format, i.CosignedTreeHeadV1)
-	case StFormatConsistencyProofV1:
-		return fmt.Sprintf("Format(%s): %+v", i.Format, i.ConsistencyProofV1)
-	case StFormatInclusionProofV1:
-		return fmt.Sprintf("Format(%s): %+v", i.Format, i.InclusionProofV1)
-	case StFormatSignedChecksumV1:
-		return fmt.Sprintf("Format(%s): %+v", i.Format, i.SignedChecksumV1)
-	default:
-		return fmt.Sprintf("unknown StItem: %v", i.Format)
-	}
-}
-
-func NewSignedTreeHeadV1(th *TreeHeadV1, sig *SignatureV1) *StItem {
-	return &StItem{
-		Format: StFormatSignedTreeHeadV1,
-		SignedTreeHeadV1: &SignedTreeHeadV1{
-			TreeHead:  *th,
-			Signature: *sig,
-		},
-	}
-}
-
-func NewCosignedTreeHeadV1(sth *SignedTreeHeadV1, cosig []SignatureV1) *StItem {
-	if cosig == nil {
-		cosig = make([]SignatureV1, 0)
-	}
-	return &StItem{
-		Format: StFormatCosignedTreeHeadV1,
-		CosignedTreeHeadV1: &CosignedTreeHeadV1{
-			SignedTreeHead: *sth,
-			Cosignatures:   cosig,
-		},
-	}
-}
-
-func NewConsistencyProofV1(id *Namespace, size1, size2 uint64, path []NodeHash) *StItem {
-	return &StItem{
-		Format: StFormatConsistencyProofV1,
-		ConsistencyProofV1: &ConsistencyProofV1{
-			LogId:           *id,
-			TreeSize1:       size1,
-			TreeSize2:       size2,
-			ConsistencyPath: path,
-		},
-	}
-}
-
-func NewInclusionProofV1(id *Namespace, size, index uint64, path []NodeHash) *StItem {
-	return &StItem{
-		Format: StFormatInclusionProofV1,
-		InclusionProofV1: &InclusionProofV1{
-			LogId:         *id,
-			TreeSize:      size,
-			LeafIndex:     index,
-			InclusionPath: path,
-		},
-	}
-}
-
-func NewSignedChecksumV1(data *ChecksumV1, sig *SignatureV1) *StItem {
-	return &StItem{
-		Format: StFormatSignedChecksumV1,
-		SignedChecksumV1: &SignedChecksumV1{
-			Data:      *data,
-			Signature: *sig,
-		},
-	}
-}
-
-func NewTreeHeadV1(timestamp, size uint64, hash, extension []byte) *TreeHeadV1 {
-	if extension == nil {
-		extension = make([]byte, 0)
-	}
-	return &TreeHeadV1{
-		Timestamp: timestamp,
-		TreeSize:  size,
-		RootHash: NodeHash{
-			Data: hash,
-		},
-		Extension: extension,
-	}
-}
diff --git a/types/stitem_test.go b/types/stitem_test.go
deleted file mode 100644
index 90d6808..0000000
--- a/types/stitem_test.go
+++ /dev/null
@@ -1,64 +0,0 @@
-package types
-
-import (
-	"strings"
-	"testing"
-)
-
-// TestStItemString checks that the String() function prints the right format,
-// and that the body is printed without a nil-pointer panic.
-func TestStItemString(t *testing.T) {
-	wantPrefix := map[StFormat]string{
-		StFormatReserved:           "Format(reserved)",
-		StFormatSignedTreeHeadV1:   "Format(signed_tree_head_v1): &{TreeHead",
-		StFormatCosignedTreeHeadV1: "Format(cosigned_tree_head_v1): &{SignedTreeHead",
-		StFormatConsistencyProofV1: "Format(consistency_proof_v1): &{LogId",
-		StFormatInclusionProofV1:   "Format(inclusion_proof_v1): &{LogId",
-		StFormatSignedChecksumV1:   "Format(signed_checksum_v1): &{Data",
-		StFormat(1<<16 - 1):        "unknown StItem: unknown StFormat: 65535",
-	}
-	tests := append(test_cases_stitem(t), testCaseSerialize{
-		description: "valid: unknown StItem",
-		item: StItem{
-			Format: StFormat(1<<16 - 1),
-		},
-	})
-	for _, table := range tests {
-		item, ok := table.item.(StItem)
-		if !ok {
-			t.Fatalf("must cast to StItem in test %q", table.description)
-		}
-
-		prefix, ok := wantPrefix[item.Format]
-		if !ok {
-			t.Fatalf("must have prefix for StFormat %v in test %q", item.Format, table.description)
-		}
-		if got, want := item.String(), prefix; !strings.HasPrefix(got, want) {
-			t.Errorf("got %q but wanted prefix %q in test %q", got, want, table.description)
-		}
-	}
-}
-
-// TODO: TestNewSignedTreeHeadV1
-func TestNewSignedTreeHeadV1(t *testing.T) {
-}
-
-// TODO: TestNewCosignedTreeHeadV1
-func TestNewCosignedTreeHeadV1(t *testing.T) {
-}
-
-// TODO: TestNewConsistencyProofV1
-func TestNewConsistencyProofV1(t *testing.T) {
-}
-
-// TODO: TestNewInclusionProofV1
-func TestNewInclusionProofV1(t *testing.T) {
-}
-
-// TODO: TestNewSignedChecksumV1
-func TestNewSignedChecksumV1(t *testing.T) {
-}
-
-// TODO: TestNewTreeHeadV1
-func TestNewTreeHeadV1(t *testing.T) {
-}
diff --git a/types/trunnel.go b/types/trunnel.go
new file mode 100644
index 0000000..72ae68d
--- /dev/null
+++ b/types/trunnel.go
@@ -0,0 +1,57 @@
+package types
+
+import (
+	"encoding/binary"
+	"fmt"
+)
+
+const (
+	// MessageSize is the number of bytes in a Trunnel-encoded leaf message
+	MessageSize = 8 + HashSize
+	// LeafSize is the number of bytes in a Trunnel-encoded leaf
+	LeafSize = MessageSize + SignatureSize + HashSize
+)
+
+// Marshal returns a Trunnel-encoded message
+func (m *Message) Marshal() []byte {
+	buf := make([]byte, MessageSize)
+	binary.BigEndian.PutUint64(buf, m.ShardHint)
+	copy(buf[8:], m.Checksum[:])
+	return buf
+}
+
+// Marshal returns a Trunnel-encoded leaf
+func (l *Leaf) Marshal() []byte {
+	buf := l.Message.Marshal()
+	buf = append(buf, l.SigIdent.Signature[:]...)
+	buf = append(buf, l.SigIdent.KeyHash[:]...)
+	return buf
+}
+
+// Marshal returns a Trunnel-encoded tree head
+func (th *TreeHead) Marshal() []byte {
+	buf := make([]byte, 8+8+HashSize)
+	binary.BigEndian.PutUint64(buf[0:8], th.Timestamp)
+	binary.BigEndian.PutUint64(buf[8:16], th.TreeSize)
+	copy(buf[16:], th.RootHash[:])
+	return buf
+}
+
+// Unmarshal parses the Trunnel-encoded buffer as a leaf
+func (l *Leaf) Unmarshal(buf []byte) error {
+	if len(buf) != LeafSize {
+		return fmt.Errorf("invalid leaf size: %v", len(buf))
+	}
+	// Shard hint
+	l.ShardHint = binary.BigEndian.Uint64(buf)
+	offset := 8
+	// Checksum
+	copy(l.Checksum[:], buf[offset:offset+HashSize])
+	offset += HashSize
+	// Signature
+	copy(l.Signature[:], buf[offset:offset+SignatureSize])
+	offset += SignatureSize
+	// KeyHash
+	copy(l.KeyHash[:], buf[offset:])
+	return nil
+}
diff --git a/types/trunnel_test.go b/types/trunnel_test.go
new file mode 100644
index 0000000..0fa7656
--- /dev/null
+++ b/types/trunnel_test.go
@@ -0,0 +1,114 @@
+package types
+
+import (
+	"bytes"
+	"reflect"
+	"testing"
+)
+
+var (
+	testBuffer32 = [32]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31}
+	testBuffer64 = [64]byte{0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63}
+)
+
+func TestMarshalMessage(t *testing.T) {
+	description := "valid: shard hint 72623859790382856, checksum 0x00,0x01,..."
+	message := &Message{
+		ShardHint: 72623859790382856,
+		Checksum:  testBuffer32,
+	}
+	want := bytes.Join([][]byte{
+		[]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
+		testBuffer32[:],
+	}, nil)
+	if got := message.Marshal(); !bytes.Equal(got, want) {
+		t.Errorf("got message\n\t%v\nbut wanted\n\t%v\nin test %q\n", got, want, description)
+	}
+}
+
+func TestMarshalLeaf(t *testing.T) {
+	description := "valid: shard hint 72623859790382856, buffers 0x00,0x01,..."
+	leaf := &Leaf{
+		Message: Message{
+			ShardHint: 72623859790382856,
+			Checksum:  testBuffer32,
+		},
+		SigIdent: SigIdent{
+			Signature: testBuffer64,
+			KeyHash:   testBuffer32,
+		},
+	}
+	want := bytes.Join([][]byte{
+		[]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
+		testBuffer32[:], testBuffer64[:], testBuffer32[:],
+	}, nil)
+	if got := leaf.Marshal(); !bytes.Equal(got, want) {
+		t.Errorf("got leaf\n\t%v\nbut wanted\n\t%v\nin test %q\n", got, want, description)
+	}
+}
+
+func TestMarshalTreeHead(t *testing.T) {
+	description := "valid: timestamp 16909060, tree size 72623859790382856, root hash 0x00,0x01,..."
+	th := &TreeHead{
+		Timestamp: 16909060,
+		TreeSize:  72623859790382856,
+		RootHash:  testBuffer32,
+	}
+	want := bytes.Join([][]byte{
+		[]byte{0x00, 0x00, 0x00, 0x00, 0x01, 0x02, 0x03, 0x04},
+		[]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
+		testBuffer32[:],
+	}, nil)
+	if got := th.Marshal(); !bytes.Equal(got, want) {
+		t.Errorf("got tree head\n\t%v\nbut wanted\n\t%v\nin test %q\n", got, want, description)
+	}
+}
+
+func TestUnmarshalLeaf(t *testing.T) {
+	for _, table := range []struct {
+		description string
+		serialized  []byte
+		wantErr     bool
+		want        *Leaf
+	}{
+		{
+			description: "invalid: not enough bytes",
+			serialized:  make([]byte, LeafSize-1),
+			wantErr:     true,
+		},
+		{
+			description: "invalid: too many bytes",
+			serialized:  make([]byte, LeafSize+1),
+			wantErr:     true,
+		},
+		{
+			description: "valid: shard hint 72623859790382856, buffers 0x00,0x01,...",
+			serialized: bytes.Join([][]byte{
+				[]byte{0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08},
+				testBuffer32[:], testBuffer64[:], testBuffer32[:],
+			}, nil),
+			want: &Leaf{
+				Message: Message{
+					ShardHint: 72623859790382856,
+					Checksum:  testBuffer32,
+				},
+				SigIdent: SigIdent{
+					Signature: testBuffer64,
+					KeyHash:   testBuffer32,
+				},
+			},
+		},
+	} {
+		var leaf Leaf
+		err := leaf.Unmarshal(table.serialized)
+		if got, want := err != nil, table.wantErr; got != want {
+			t.Errorf("got error %v but wanted %v in test %q: %v", got, want, table.description, err)
+		}
+		if err != nil {
+			continue // nothing more to check on error
+		}
+		if got, want := &leaf, table.want; !reflect.DeepEqual(got, want) {
+			t.Errorf("got leaf\n\t%v\nbut wanted\n\t%v\nin test %q\n", got, want, table.description)
+		}
+	}
+}
diff --git a/types/types.go b/types/types.go
new file mode 100644
index 0000000..483dac0
--- /dev/null
+++ b/types/types.go
@@ -0,0 +1,73 @@
+package types
+
+import (
+	"crypto/ed25519"
+	"crypto/sha256"
+)
+
+const (
+	HashSize      = sha256.Size
+	SignatureSize = ed25519.SignatureSize
+)
+
+// Leaf is the log's Merkle tree leaf.
+//
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#merkle-tree-leaf
+type Leaf struct {
+	Message
+	SigIdent
+}
+
+// Message is composed of a shard hint and a checksum.  The submitter selects
+// these values to fit the log's shard interval and the opaque data in question.
+type Message struct {
+	ShardHint uint64
+	Checksum  [HashSize]byte
+}
+
+// SigIdent is composed of a signature-signer pair.  The signature is computed
+// over the Trunnel-serialized leaf message.  KeyHash identifies the signer.
+type SigIdent struct {
+	Signature [SignatureSize]byte
+	KeyHash   [HashSize]byte
+}
+
+// SignedTreeHead is composed of a tree head and a list of signature-signer
+// pairs.  Each signature is computed over the Trunnel-serialized tree head.
+//
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#get-tree-head-cosigned
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#get-tree-head-to-sign
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#get-tree-head-latest
+type SignedTreeHead struct {
+	TreeHead
+	SigIdent []SigIdent
+}
+
+// TreeHead is the log's tree head.
+//
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#merkle-tree-head
+type TreeHead struct {
+	Timestamp uint64
+	TreeSize  uint64
+	RootHash  [HashSize]byte
+}
+
+// ConsistencyProof is a consistency proof that proves the log's append-only
+// property.
+//
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#get-consistency-proof
+type ConsistencyProof struct {
+	NewSize uint64
+	OldSize uint64
+	Path    [][HashSize]byte
+}
+
+// InclusionProof is an inclusion proof that proves a leaf is included in the
+// log.
+//
+// Ref: https://github.com/system-transparency/stfe/blob/design/doc/api.md#get-proof-by-hash
+type InclusionProof struct {
+	TreeSize  uint64
+	LeafIndex uint64
+	Path      [][HashSize]byte
+}