add a verify_checksum function

git-svn-id: svn://tug.org/texlive/trunk@40432 c570f23f-e606-0410-a88d-b1316a301751

1 files changed, 53 insertions, 0 deletions

diff --git a/Master/tlpkg/TeXLive/TLUtils.pm b/Master/tlpkg/TeXLive/TLUtils.pm
index 6fafd4e5806..ea196963172 100644
--- a/Master/tlpkg/TeXLive/TLUtils.pm
+++ b/Master/tlpkg/TeXLive/TLUtils.pm
@@ -100,6 +100,7 @@ C<TeXLive::TLUtils> -- utilities used in TeX Live infrastructure
   TeXLive::TLUtils::give_ctan_mirror_base();
   TeXLive::TLUtils::tlmd5($path);
   TeXLive::TLUtils::tlchecksum($path);
+  TeXLive::TLUtils::verify_checksum($file, $checksum);
   TeXLive::TLUtils::compare_tlpobjs($tlpA, $tlpB);
   TeXLive::TLUtils::compare_tlpdbs($tlpdbA, $tlpdbB);
   TeXLive::TLUtils::report_tlpdb_differences(\%ret);
@@ -175,6 +176,7 @@ BEGIN {
     &extract_mirror_entry
     &tlmd5
     &tlchecksum
+    &verify_checksum
     &wsystem
     &xsystem
     &run_cmd
@@ -3604,6 +3606,57 @@ sub tlchecksum {
   }
 }
 
+=pod
+
+=item C<< verify_checksum ($file, $checksum) >>
+
+Verifies the checksum of the (already downloaded) file against
+C<$checksum> (which can be a remote URL).
+
+Returns 1 on success, and a pair of 0 and a warning otherwise.
+
+=cut
+
+sub verify_checksum {
+  my ($file, $checksum) = @_;
+  ddebug("verify_checksum: remote path of digest = $checksum\n");
+  my $local_digest;
+  my $remote_digest;
+  my ($cs_fh, $cs_file);
+  my $ret = 1;
+  if ($checksum =~ m,^(http|ftp)://,) {
+    ($cs_fh, $cs_file) = tempfile();
+    # now $cs_fh filehandle is open, the file created
+    # TLUtils::download_file will just overwrite what is there
+    # on windows that doesn't work, so we close the fh immediately
+    # this creates a short loophole, but much better than before anyway
+    close($cs_fh);
+    $ret = download_file($checksum, $cs_file);
+  } else {
+    $cs_file = $checksum;
+  }
+  if ($ret && (-r "$cs_file")) {
+    open $cs_fh "<$cs_file" or return(0, "file not found");
+    if (read ($cs_fh, $remote_digest, $ChecksumLength) != $ChecksumLength) {
+      return(0, "read error");
+    } else {
+      close($cs_fh);
+      ddebug("found remote digest: $remote_digest\n");
+    }
+  } else {
+    return(0, "digest not found");
+  }
+  my $local_digest = tlchecksum($file);
+  ddebug("local_digest = $local_digest\n");
+  if ($local_digest eq $remote_digest) {
+    debug("checksum of local copy identical with remote hash\n");
+    return(1);
+  } else {
+    return(0, "checksum error");
+  }
+  return(0, "not reachable");
+}
+
 #
 # compare_tlpobjs 
 # returns a hash