account for repoDigests data in power-user json testing

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

cmd/power_user_tasks.go

@@ -1,6 +1,9 @@
 package cmd
 
 import (
+	"crypto"
+	"fmt"
+
 	"github.com/anchore/syft/internal/presenter/poweruser"
 	"github.com/anchore/syft/syft"
 	"github.com/anchore/syft/syft/file"
@@ -80,7 +83,26 @@ func catalogFileDigestTask() (powerUserTask, error) {
 		return nil, nil
 	}
 
-	digestsCataloger, err := file.NewDigestsCataloger(appConfig.FileMetadata.Digests)
+	supportedHashAlgorithms := make(map[string]crypto.Hash)
+	for _, h := range []crypto.Hash{
+		crypto.MD5,
+		crypto.SHA1,
+		crypto.SHA256,
+	} {
+		supportedHashAlgorithms[file.DigestAlgorithmName(h)] = h
+	}
+
+	var hashes []crypto.Hash
+	for _, hashStr := range appConfig.FileMetadata.Digests {
+		name := file.CleanDigestAlgorithmName(hashStr)
+		hashObj, ok := supportedHashAlgorithms[name]
+		if !ok {
+			return nil, fmt.Errorf("unsupported hash algorithm: %s", hashStr)
+		}
+		hashes = append(hashes, hashObj)
+	}
+
+	digestsCataloger, err := file.NewDigestsCataloger(hashes)
 	if err != nil {
 		return nil, err
 	}