1 files changed, 52 insertions, 0 deletions
diff --git a/client/verify.go b/client/verify.go
new file mode 100644
index 0000000..c95828c
--- /dev/null
+++ b/client/verify.go
@@ -0,0 +1,52 @@
+package client
+
+import (
+	"fmt"
+	"reflect"
+
+	"github.com/google/trillian/merkle"
+	"github.com/google/trillian/merkle/rfc6962"
+	"github.com/system-transparency/stfe/types"
+)
+
+func VerifySignedTreeHeadV1(namespace *types.Namespace, sth *types.StItem) error {
+	if got, want := &sth.SignedTreeHeadV1.Signature.Namespace, namespace; !reflect.DeepEqual(got, want) {
+		return fmt.Errorf("unexpected log id: %v", want)
+	}
+	th, err := types.Marshal(sth.SignedTreeHeadV1.TreeHead)
+	if err != nil {
+		return fmt.Errorf("Marshal: %v", err)
+	}
+	if err := namespace.Verify(th, sth.SignedTreeHeadV1.Signature.Signature); err != nil {
+		return fmt.Errorf("Verify: %v", err)
+	}
+	return nil
+}
+
+func VerifyConsistencyProofV1(proof, first, second *types.StItem) error {
+	path := make([][]byte, 0, len(proof.ConsistencyProofV1.ConsistencyPath))
+	for _, nh := range proof.ConsistencyProofV1.ConsistencyPath {
+		path = append(path, nh.Data)
+	}
+	return merkle.NewLogVerifier(rfc6962.DefaultHasher).VerifyConsistencyProof(
+		int64(proof.ConsistencyProofV1.TreeSize1),
+		int64(proof.ConsistencyProofV1.TreeSize2),
+		first.SignedTreeHeadV1.TreeHead.RootHash.Data,
+		second.SignedTreeHeadV1.TreeHead.RootHash.Data,
+		path,
+	)
+}
+
+func VerifyInclusionProofV1(proof, sth *types.StItem, leafHash []byte) error {
+	path := make([][]byte, 0, len(proof.InclusionProofV1.InclusionPath))
+	for _, nh := range proof.InclusionProofV1.InclusionPath {
+		path = append(path, nh.Data)
+	}
+	return merkle.NewLogVerifier(rfc6962.DefaultHasher).VerifyInclusionProof(
+		int64(proof.InclusionProofV1.LeafIndex),
+		int64(proof.InclusionProofV1.TreeSize),
+		path,
+		sth.SignedTreeHeadV1.TreeHead.RootHash.Data,
+		leafHash,
+	)
+}