Commit graph

6 commits

Author SHA1 Message Date
Eelco Dolstra f3dc231250 * Removed the `id' attribute hack.
* Formalise the notion of fixed-output derivations, i.e., derivations
  for which a cryptographic hash of the output is known in advance.
  Changes to such derivations should not propagate upwards through the
  dependency graph.  Previously this was done by specifying the hash
  component of the output path through the `id' attribute, but this is
  insecure since you can lie about it (i.e., you can specify any hash
  and then produce a completely different output).  Now the
  responsibility for checking the output is moved from the builder to
  Nix itself.

  A fixed-output derivation can be created by specifying the
  `outputHash' and `outputHashAlgo' attributes, the latter taking
  values `md5', `sha1', and `sha256', and the former specifying the
  actual hash in hexadecimal or in base-32 (auto-detected by looking
  at the length of the attribute value).  MD5 is included for
  compatibility but should be considered deprecated.

* Removed the `drvPath' pseudo-attribute in derivation results.  It's
  no longer necessary.

* Cleaned up the support for multiple output paths in derivation store
  expressions.  Each output now has a unique identifier (e.g., `out',
  `devel', `docs').  Previously there was no way to tell output paths
  apart at the store expression level.

* `nix-hash' now has a flag `--base32' to specify that the hash should
  be printed in base-32 notation.

* `fetchurl' accepts parameters `sha256' and `sha1' in addition to
  `md5'.

* `nix-prefetch-url' now prints out a SHA-1 hash in base-32.  (TODO: a
  flag to specify the hash.)
2005-01-17 16:55:19 +00:00
Eelco Dolstra d58a11e019 * Shorten SHA-256 hashes used in store path name generation to 160
bits, then encode them in a radix-32 representation (using digits
  and letters except e, o, u, and t).  This produces store paths like
  /nix/store/4i0zb0z7f88mwghjirkz702a71dcfivn-aterm-2.3.1.  The nice
  thing about this is that the hash part of the file name is still 32
  characters, as before with MD5.

  (Of course, shortening SHA-256 to 160 bits makes it no better than
  SHA-160 in theory, but hopefully it's a bit more resistant to
  attacks; it's certainly a lot slower.)
2005-01-14 16:04:03 +00:00
Eelco Dolstra 63791eb05b * Add SHA-256.
* Tests for the various hashes.
2005-01-14 12:03:04 +00:00
Eelco Dolstra 7e8961f720 * Added SHA-1 support. nix-hash' now has an option --type sha1' to
select SHA-1 hashing.
2005-01-13 17:39:26 +00:00
Eelco Dolstra 078e20885e * Help text for all (non-script) programs, so no more:
$ nix-instantiate --help
error: unknown flag `--help`
Try `nix-instantiate --help' for more information.

:-)
2003-12-01 15:55:05 +00:00
Eelco Dolstra 53e376d836 * Refactored the source tree. 2003-10-20 09:20:11 +00:00
Renamed from src/nix-hash.cc (Browse further)