| Subject: | 64 bit issue, calculates incorrect MD5 |
Forwarding from <https://bugs.debian.org/877369>:
-----
Digest::MD5 calculates the wrong MD5 for large scalars:
$ perl -e 'print "\x00" x 1024 x 1024 x 1024 x 9'|md5sum -
97606009c3309d3a0b4b40ae9fadc720 -
$ perl -MDigest::MD5 -E 'say Digest::MD5::md5_hex "\x00" x 1024 x 1024 x 1024 x 9'
e02694e929aec3068ff272bebe0ae0a4
This is likely due to buggy length calculation in MD5.xs, which fails for
large values of "len" (and hasn't changed for 5.26):
ctx->bytes_low += len;
if (ctx->bytes_low < len) /* wrap around */
ctx->bytes_high++;
-----
Note that I couldn't reproduce this myself as I got an out of memory error (on a machine with 16GB of RAM). The problem does not occur when adding the data 1GB at a time using the OO interface.
Digest::MD5 is at 2.54, unmodified by Debian.
Thanks for your work on maintaining Digest::MD5!