v2v: ova: support SHA256 hashes in manifest

The OVF standard allows the use of SHA256 hashes in the manifest file.
Adding support for this.

One of the tests was updated to put SHA256 into manifest file.

Signed-off-by: Tomáš Golembiovský <tgolembi@redhat.com>

test-data/guestfs-hashsums.sh

@@ -41,3 +41,16 @@ do_sha1 ()
       ;;
   esac
 }
+
+do_sha256 ()
+{
+  case "$(uname)" in
+    Linux)
+      sha256sum "$1" | awk '{print $1}'
+      ;;
+    *)
+      echo "$0: unknown method to calculate SHA256 of file on $(uname)"
+      exit 1
+      ;;
+  esac
+}

v2v/input_ova.ml

@@ -133,7 +133,7 @@ object
 
     (* Read any .mf (manifest) files and verify sha1. *)
     let mf = find_files exploded ".mf" in
-    let rex = Str.regexp "SHA1(\\(.*\\))= \\([0-9a-fA-F]+\\)\r?" in
+    let rex = Str.regexp "\\(SHA1\\|SHA256\\)(\\(.*\\))= \\([0-9a-fA-F]+\\)\r?" in
     List.iter (
       fun mf ->
         debug "processing manifest %s" mf;
@@ -142,13 +142,14 @@ object
         let rec loop () =
           let line = input_line chan in
           if Str.string_match rex line 0 then (
-            let disk = Str.matched_group 1 line in
-            let expected = Str.matched_group 2 line in
-            let csum = Checksums.SHA1 expected in
+            let mode = Str.matched_group 1 line in
+            let disk = Str.matched_group 2 line in
+            let expected = Str.matched_group 3 line in
+            let csum = Checksums.of_string mode expected in
             try Checksums.verify_checksum csum (mf_folder // disk)
             with Checksums.Mismatched_checksum (_, actual) ->
-              error (f_"checksum of disk %s does not match manifest %s (actual sha1(%s) = %s, expected sha1 (%s) = %s)")
-                disk mf disk actual disk expected;
+              error (f_"checksum of disk %s does not match manifest %s (actual %s(%s) = %s, expected %s(%s) = %s)")
+                disk mf mode disk actual mode disk expected;
           )
           else
             warning (f_"unable to parse line from manifest file: %S") line

v2v/test-v2v-i-ova.sh

@@ -57,8 +57,8 @@ qemu-img convert $f -O vmdk $d/$vmdk
 cp $ovf $d/$ovf
 sha1=`do_sha1 $d/$ovf`
 echo "SHA1($ovf)= $sha1" > $d/$mf
-sha1=`do_sha1 $d/$vmdk`
-echo "SHA1($vmdk)= $sha1" >> $d/$mf
+sha256=`do_sha256 $d/$vmdk`
+echo "SHA256($vmdk)= $sha256" >> $d/$mf
 
 pushd .
 cd $d