2.7.0

New features

• Added syntax for record updates (see #399 for details of implemented and planned features).

• Updated the :browse command to list module parameters (issue #586).

• Added support for test vector creation (the :dumptests command). This feature computes a list of random inputs and outputs for the given expression of function type and saves it to a file. This is useful for generating tests from a trusted Cryptol specification to apply to an implementation written in another language.

Breaking changes

• Removed the [x..] construct from the language (issue #574). It was shorthand for [x..2^^n-1] for a bit vector of size n, which was often not what the user intended. Users should instead write either [x..y] or [x...], to construct a smaller range or a lazy sequence, respectively.

• Renamed the value-level width function to length, and generalized its type (issue #550). It does not behave identically to the type-level width operator, which led to confusion. The name length matches more closely with similar functions in other languages.

Bug fixes

• Improved type checking performance of decimal literals.

• Improved type checking of /^ and %^ (issues #581, #582).

• Improved performance of sequence updates with the update primitive (issue #579).

• Fixed elapsed time printed by :prove and :sat (issue #572).

• Fixed SMT-Lib formulas generated for right shifts (issue #566).

• Fixed crash when importing non-parameterized modules with the backtick prefix (issue #565).

• Improved performance of symbolic execution for Z n (issue #554).

• Fixed interpretation of the satNum option so finding multiple solutions doesn't run forever (issue #553).

• Improved type checking of the length function (issue #548).

• Improved error message when trying to prove properties in parameterized modules (issue #545).

• Stopped warning about defaulting at the REPL when warnDefaulting is set to false (issue #543).

• Fixed builds on non-x86 architectures (issue #542).

• Made browsing of interactively-bound identifiers work better (issue #538).

• Fixed a bug that allowed changing the semantics of the _ # _ pattern and the - and ~ operators by creating local definitions of functions that they expand to (issue #568).

• Closed issues #498, #547, #551, #562, and #563.

Solver versions

Cryptol can interact with a variety of external SMT solvers to support the :prove and :sat commands, and requires Z3 for its type checker. Many versions of these solvers will work correctly, but for Yices and Z3 we recommend the following specific versions.

• Z3 4.7.1
• Yices 2.6.1

For Yices, this is the latest version at the time of this writing. For Z3, it is not, and the latest versions (4.8.x) include changes that cause some examples that previously succeeded to time out when type checking.

2.6.0

This release includes several significant language additions, including unbounded integers and parameterized modules, along with many smaller improvements and bug fixes.

Added

• Cryptol now has types for unbounded integers (Integer) and, relatedly, integers modulo a constant value (Z n), which can be used for more natural encodings of many public-key algorithms, among many other use cases.

• Modules can now take types and values (including functions) as parameters. Importing modules can instantiate these parameters, and proofs about parameterized modules can leave parameters abstract (and therefore prove properties for all possible concrete parameters).

• Constraint synonyms can be used to group together collections of commonly-used constraints.

• Signed operations now exist for arithmetic (/$ and %$), comparison (>$, <$, <=$, and >=$), and shifting (>>$).

• Operations for chaining arithmetic now exist. The carry function returns True if addition of its arguments would result in unsigned overflow, the scarry function does the same for signed overflow, and the sborrow function checks for overflow on signed subtraction.

• The new type operators /^ and %^ perform ceiling division and modulus, respectively. These can be particularly useful in computing the number of fixed-size blocks needed to store a message of a
  particular size, for instance, or conversely to compute the amount of padding needed to fill up an integral number of blocks.

• The new type operator != allows the constraint that two types are not equal.

• The experimental new :extract-coq command will export the currently-defined environment in a form usable with the Coq definition of Cryptol's operational semantics.

• The new :ast command prints out the internal form of the AST for a given expression.

• Underscores are allowed in numeric literals, and can be used to group digits for greater readability.

Changed

• The Cryptol::Extras module has been merged with the Prelude, now that it type-checks more quickly. Removing a Cryptol::Extras import should be enough to get older modules to work with this release.

• Several new type classes now exist: Logic for bitwise logical operations, Zero for the zero primitive, and SignedCmp for signed comparison operations. Some functions with explicit type signatures may now require additional constraints.

• Numeric literals and enumerations can now be used with any type that is a member of the new Literal class, which includes [n], Integer, and Z n.

• Type checker and interpreter performance is generally better. Please report regressions as issues on GitHub.

• The :help command now works with built-in types, commands, and :set options.

• Defaulting warnings and error messages use more meaningful variable names.

• Many bugs have been fixed.

2.5.0

Cryptol 2.5.0

This release includes a re-written interpreter which is generally faster and has fewer strictness-related edge cases, major enhancements to the performance of the type checker, and a variety of smaller additions and bug fixes.

Added

• New update and updates functions provide an efficient, built-in
  way to replace elements of a vector.

• New trace and traceVal functions print messages as they are being
  evaluated, which can be helpful for debugging.

• New short-cutting operators /\, \/ and ==> now exist. The older
  && and || operators are strict, and have higher precedence.

• New experimental :eval command evaluates an expression using
  a reference interpreter, which we created to ultimately serve as the
  official definition of the Cryptol semantics. This interpreter is less
  efficient than the normal one, but written in a very direct style meant
  to clearly describe the meaning of each language construct. For this
  release, the semantics of the reference interpreter are not considered
  final and still subject to change.

• New prover-stats setting in the REPL, when enabled, causes the
  :prove and :sat commands to print information about the time taken
  and prover used to coplete a proof.

• The :help command now shows information about precedence and fixity
  of operators.

• The cryptol executable returns a non-zero exit code when proofs
  fail.

• New prelude function: iterate

• New example: MISTY1

Changed

• The main Cryptol interpreter has been re-written in monadic style,
  which allows much greater control over the order of evaluation, and
  generally improves performance.

• The type-checker has had a major overhaul, improving performance
  dramatically in many cases.

• Overall, performance is generally better.

• New command line option --color makes use of color text output
  configurable.

• With :set ascii=on, the REPL now prints quotation marks around
  strings.

• Cryptol now depends on version 7.0 or greater of the SBV library.

Fixes

• Fix an off by one error in the implementation of split.

• Fix a typo in the implementation of the >> operator.

• Fix the pdiv and pmod primitives in the special case where the
  length of the dividend is less than the degree of the divisor polynomial.

• Fix an issue where literal sequences of bit values were being
  incorrectly reversed.

• Various documentation fixes.

• Close issues #138, #268, #334, #362, #373, #388, #395

2.4.0

Cryptol 2.4.0

This is primarily a maintenance release to support GHC 8.0.1 and drop
support for the GHC 7.8 series, and to roll up a number of smaller
improvements and fixes. Highlights are below, and a comprehensive list
of closed issues is available on GitHub.

Added

• Added convenient aliases to the prelude: a prefix complement
  operator ~, and a base-2 logarithm type alias lg2.
• New library functions in a new module Cryptol::Extras. We
  intend to eventually move these functions into the prelude, but at
  the moment they take too long to typecheck for them to be loaded
  so frequently (tracking this as issue #302).
• A new command line option --command/-c specifies
  commands to be run after the interpreter loads. Multiple commands
  can be specified, and will be run in order. For example:

cryptol Foo.cry --command ':set prover=abc' --command ':prove'

• Added :readByteArray and :writeByteArray to read and
  write raw byte sequences from files, for example:

Cryptol> :writeByteArray /tmp/foo "hello world"
Cryptol> :readByteArray /tmp/foo
Cryptol> it
"hello world"

• Added new examples: A51, Bivium, Trivium, Minilock
• The Windows installer now offers a choice of destination
  directory, and can add the installation directory to the user's
  path.

Changed

• Dropped support for GHC 7.8.4 and earlier.
• The symbolic simulator now takes advantage of an SBV feature that
  can lead to signifcant performance improvements when selecting
  from tables of constant values.
• The random primitive now takes a 256-bit seed, rather than the
  previous 32-bit seed. This avoids inconsistencies between
  platforms with different machine word sizes.
• The splitBy function in the prelude has been removed in favor of
  just using split, which has an identical type.
• Improved documentation and book, notably adding a section about
  using modules, and more syntax details.
• Improved the parser to allow for more flexible use of prefix
  operators.
• Improved formatting of output for several commands and error
  messages.

Fixes

• Fixed certain keywords, such as if and else, not appearing as
  tab-completion results.
• Fixed incorrect behavior of shifts and rotates by greater than
  2^63.
• Fixed the prelude not loading when a module specified at the
  command line fails to load.
• Fixed type-correctness of certain generated SMTLIB code from the
  symbolic simulator.
• Fixed a performance regression caused by unnecessarily-parallel
  runtime settings.

2.3.0

Cryptol 2.3.0

General Improvements Made

• Added new typechecker solver and typechecker improvements.

The major feature of this release is a revised constraint solver
for typechecking, and improvements to how the typechecker
generates and propagates constraints. In many cases, the
typechecker will now accept simpler type signatures and require
fewer extraneous "obvious" constraints.

If an existing definition fails to typecheck with the new solver,
try simplifying or eliminating its signature. Some of the
constraints added only to satisfy the earlier typechecker may no
longer be necessary or checkable.

Despite the improvements, we are still aware of some bugs with the
new solver. If you run into trouble, see
the relevant tickets.

• Made the fixity of primitives more consistent with their
  counterparts in other languages.
• Fixed some incorrect strictness in primitives.
• Fixed some pretty-printing bugs that caused commands like :type
  to print results with invalid Cryptol syntax.
• Improved Windows installer, allowing installation to custom
  locations, and adding the executables' directory to the user's
  path.
• Numerous performance and stability fixes.

Features Added

• Added an interpreter option :set tc-solver to allow configuration
  of the SMT solver used during typechecking.
• Added support for docstrings on Cryptol definitions. Docstring
  syntax is the same as block comment syntax, but with more than one
  * opening the block, for example:

/** This is the docstring of foo */
foo x = x + 1

With this example loaded, typing :help foo will display the both
the type and the docstring for foo.

• Added :writeByteArray and :readByteArray interpreter commands
  which allow the interpreter to write values of type [n][8] to a
  file, and then read those values back in (currently binding the
  result to the it variable).
• Added support for UTF-8 in identifiers, and set the locale of the
  interpreter to UTF-8. If you encounter errors reading in your old
  Cryptol files, make sure they are encoded as UTF-8.
• Added experimental cryptol-server executable, which can be built
  by passing -fserver to a Cabal build, or by prefixing a Makefile
  build with CRYPTOL_SERVER=1. The interface to this server is
  very unstable, but to see an example of it in use, see
  pycryptol.

Examples Added

• 3DES
• ChaCha20
• FNV-a1
• SIV (RFC5297)
• Salsa20
• MiniLock (including SHA256, Blake2s, Curve25519, SCrypt, PBKDF2, Salsa20, Poly1305)

Contrib

• Even-Mansour

Puzzles

• Coins
• Fox-Chicken-Corn
• Marble
• NQueens

v2.2.6

Release of version 2.2.6

v2.2.5

Cryptol 2.2.5

This is a minor release:

• Changed to exclude SBV version 5.0, but work with both older and upcoming releases
• Removed the iteSolver option which has soundness issues in older versions of SBV (see LeventErkok/sbv#180)

v2.2.4

Cryptol 2.2.4

This is a minor release:

• Fixed a panic when using :prove and :sat with certain shift primitives (19ce4d4)

v2.2.3

Cryptol 2.2.3

This is a minor release:

• Changed to using SBV 4.3+
• Fixed warnings when building with GHC 7.10.1

v2.2.2

Cryptol 2.2.2

This is a minor release:

• Added an upper bound on sbv to avoid breakage with the new version 4.3 (we're using 4.3 in the development version as of 711ba43)
• Remove vestigial references to the defunct configure script and require Cabal 1.20 (#197)
• Tweak README.md to clarify CVC4 installation requirements

Note that in addition to the binaries posted here, Mac users can now use Homebrew to install both the latest stable release and the latest development version of Cryptol.