add hash file

1 files changed, 10 insertions, 0 deletions

diff --git a/internal/util/crypto.go b/internal/util/crypto.go
index 2a29628..a8c8fac 100644
--- a/internal/util/crypto.go
+++ b/internal/util/crypto.go
@@ -4,8 +4,10 @@ import (
 	"crypto"
 	"crypto/ed25519"
 	"fmt"
+	"io/ioutil"
 
 	"git.sigsum.org/sigsum-go/pkg/hex"
+	"git.sigsum.org/sigsum-go/pkg/types"
 )
 
 func SignerFromHex(s string) (crypto.Signer, error) {
@@ -18,3 +20,11 @@ func SignerFromHex(s string) (crypto.Signer, error) {
 	}
 	return ed25519.PrivateKey(b), nil
 }
+
+func FileHash(path string) (*types.Hash, error) {
+	b, err := ioutil.ReadFile(path)
+	if err != nil {
+		return nil, fmt.Errorf("util: read file %s: %v", path, err)
+	}
+	return types.HashFn(b), nil
+}