NAME

       tthsum ‐ generates or checks TTH message digests

SYNOPSIS

       tthsum [-bhmpvVw] [-c [file]] | [file...]

DESCRIPTION

       tthsum  generates  or  checks  TTH  checksums (roots of the Tiger/THEX hash tree).  The Merkle Hash Tree,
       invented by Ralph Merkle, is a hash construct  that  exhibits  desirable  properties  for  verifying  the
       integrity  of  files and file subranges in an incremental or out‐of‐order fashion.  tthsum uses the Tiger
       hash algorithm, by Ross Anderson and Eli Biham, for both the internal and the leaf nodes.

       The specification of the THEX algorithm is at:
        .  http://tthsum.devs.nu/draft-jchapweske-thex-02.html

       The specification of the Tiger hash algorithm is at:
        .  http://www.cs.technion.ac.il/~biham/Reports/Tiger/

       Normally tthsum generates checksums of all files given to it  as  parameters  and  prints  the  checksums
       followed  by  the  filenames.  If, however, -c is specified, only one filename parameter is allowed. This
       file should contain checksums and filenames to which these checksums refer, and the files listed in  that
       file are checked against the checksums listed there. See option -c for more information.

       If no file is specified data will be read from standard input.

   OPTIONS
       -b     An md5sum compatibility option. It does absolutely nothing.  (md5sum uses -b to treat binary files
              differently from texts files.)

       -c     Check tthsum of all files listed in file against the checksum listed in the same file. The  actual
              format  of  that file is the same as output of tthsum.  That is, each line in the file describes a
              file. A line looks like:

              <TTH CHECKSUM>  <FILENAME>

              So, for example, if a file were created and its message digest calculated like so:

              echo foo > tth-test-file; tthsum tth-test-file

              tthsum would report:

              A2MPPCGS5CPJV6AOAP37ICDCFV3WYU7PBREC6FY  tth-test-file

              See NOTES for more information on the digest file format.

       -m     Use mmap(2) instead of read(2) to read the contents of the files to hash. Normally, using read  is
              cheaper.  This  all  depends  on  system  load,  I/O speed, CPU speed, L1 and/or L2 cache size and
              whatnot.

       -p     Show the progress. Print the percentage of completeness while hashing on  standard  error.  Prints
              file position instead of percentage when the file size is unknown.

       -v     Be verbose. Print filenames when checking (with -c).

       -w     Warn on improperly formatted lines when checking (with -c).

       -h, -V Print  a small help text or the version, respectively, on standard out.  If an unknown combination
              of options is encountered, the small help is printed on standard error and tthsum will return non‐
              zero.

RETURN VALUE

       tthsum  returns  0  if  no  error  occurred or, when checking a digest, if at least one line is formatted
       properly and the TTHs of all properly formatted lines match.  tthsum returns 2 if an unknown  combination
       of options is encountered.  In all other cases will tthsum return 1.

NOTES

       tthsum intentionally uses an interface identical to md5sum.

       tthsum uses BASE32 encoding consisting of the following characters: ABCDEFGHIJKLMNOPQRSTUVWXYZ234567.  It
       will accept lower case letters in the digest input as well.

       tthsum does not accept long options such as --help.

       A digest file format line looks like: <BASE32><SPACES><FILENAME><EOL>.  BASE32 is  a  39  character  long
       BASE32  encoded string.  SPACES is a set of two spaces (0x20).  FILENAME is the name of the file, encoded
       in UTF8 and with all control characters (those below 0x20) encoded as \xNN or \C  C‐style  escapes.  (The
       backslash  is  escaped  as \\ as well. On Windows, backslashes in paths will be translated to slashes for
       compatibility with real operating systems.)  EOL may be CRLF (\r\n), just plain LF (\n) or  even  nothing
       at end‐of‐file.

       If  you  see  warnings  about  an  improper  locale  setup,  check  your LANG and/or LC_CTYPE environment
       variables.  If these are not set properly, tthsum cannot  represent  non‐ASCII  characters  (those  above
       0x7F) in UTF8. See locale(1) for more information or try to set LC_CTYPE to e.g. "en_US".

REPORTING BUGS

       Report bugs to <walter+tthsum@wjd.nu>.

COPYRIGHT

       Copyright    ©    2009    Walter    Doekes.     License    GPLv3+:   GNU   GPL   version   3   or   later
       <http://gnu.org/licenses/gpl.html>
       This is free software: you are free to change and redistribute it.  There is NO WARRANTY, to  the  extent
       permitted by law.

AUTHOR

       tthsum  and  this  manpage  were  written  by Walter Doekes (walter+tthsum@wjd.nu).  The hashing code was
       copied  directly  from  DC++,  an  open  source  peer‐to‐peer  file  sharing  program  by   Jacek   Sieka
       (jacek@creatio.se)  who  had based the hashing code on the one used in BCDC++ (a modified DC++) by Dustin
       Brody (blackclaw@parsoma.net).  After version 1.1.0, the hashing code from the Tiger hash authors is used
       instead, to support big endian architectures and to remove the need for C++ compilers and libraries.  The
       md5sum manpage, written by Juho Vuori (javuori@cc.helsinki.fi), was used as a template. This manpage  was
       proofread by Dustin Brody.

SEE ALSO

       cksfv(1), md5sum(1), sha1sum(1)