ecdsa 0.14

tl;dr:

• support for Brainpool curves
• better test coverage, fixed bugs found by it
• support for compressed point representation

Bug fixes:

• Strict checking of DER requirements when parsing SEQUENCE, INTEGER,
  OBJECT IDENTIFIER and BITSTRING objects.
• DER parsers now consistently raise UnexpectedDER exception on malformed DER
  encoded byte strings.
• Make sure that both malformed and invalid signatures raise BadSignatureError.
• Ensure that all SigningKey and VerifyingKey methods that should accept
  bytes-like objects actually do accept them (also avoid copying input strings).
• Make SigningKey.sign_digest_deterministic use default object hashfunc when
  none was provided.
• encode_integer now works for large integers.
• Make encode_oid and remove_object correctly handle OBJECT IDENTIFIERs
  with large second subidentifier and padding in encoded subidentifiers.

New features:

• Deterministic signature methods now accept extra_entropy parameter to further
  randomise the selection of k (the nonce) for signature, as specified in
  RFC6979.
• Recovery of public key from signature is now supported.
• Support for SEC1/X9.62 formatted keys, all three encodings are supported:
  "uncompressed", "compressed" and "hybrid". Both string, and PEM/DER will
  automatically accept them, if the size of the key matches the curve.
• Benchmarking application now provides performance numbers that are easier to
  compare against OpenSSL.
• Support for all Brainpool curves (non-twisted).

New API:

• CurveFp: __str__ is now supported.
• SigningKey.sign_deterministic, SigningKey.sign_digest_deterministic and
  generate_k: extra_entropy parameter was added
• Signature.recover_public_keys was added
• VerifyingKey.from_public_key_recovery and
• VerifyingKey.from_public_key_recovery_with_digest were added
• VerifyingKey.to_string: encoding parameter was added
• VerifyingKey.to_der and SigningKey.to_der: point_encoding parameter was
  added.
• encode_bitstring: unused parameter was added
• remove_bitstring: expect_unused parameter was added
• SECP256k1 is now part of curves * import
• Curves: __repr__ is now supported
• VerifyingKey: __repr__ is now supported

Deprecations:

• Python 2.5 is not supported any more - dead code removal.
• from ecdsa.keys import * will now import only objects defined in that module.
• Trying to decode a malformed point using VerifyingKey.from_string
  will rise now the MalformedPointError exception (that inherits from
  AssertionError but is not it).
• Multiple functions in numbertheory are considered deprecated: phi,
  carmichael, carmichael_of_factorized, carmichael_of_ppower,
  order_mod, largest_factor_relatively_prime, kinda_order_mod. They will
  now emit DeprecationWarning when used. Run the application or test suite
  with -Wd option or with PYTHONWARNINGS=default environment variable to
  verify if those methods are not used. They will be removed completely in a
  future release.
• encode_bitstring and decode_bitstring expect the number of unused
  bits to be passed as an argument now. They will emit DeprecationWarning
  if they are used in the deprecated way.
• modular_exp: will emit DeprecationWarning

Hardening:

• Deterministic signatures now verify that the signature won't leak private
  key through very unlikely selection of k value (the nonce).
• Nonce bit size hiding was added (hardening against Minerva attack). Please
  note that it DOES NOT make library secure against side channel attacks (timing
  attacks).

Performance:

• The public key in key generation is not verified twice now, making key
  generation and private key reading about 33% faster.
• Microoptimisation to inverse_mod function, increasing performance by about
  40% for all operations.

Maintenance:

• Extended test coverage to newer python versions.
• Fixes to examples in README.md: correct commands, more correct code (now works
  on Python 3).
• Stopped bundling six
• Moved sources into src subdirectory
• Made benchmarking script standalone (runnable either with tox -e speed, or
  after installation, with python speed.py)
• Now test coverage reported to coveralls is branch coverage, not line coverage
• Autodetection of curves supported by OpenSSL (test suite compatibility with
  Fedora OpenSSL package).
• More readable error messages (exceptions) in der module.
• Documentation to VerifyingKey, SigningKey and signature encoder/decoder
  functions added.
• Added measuring and verifying condition coverage to Continuous Integration.
• Big clean-up of the test suite, use pytest parametrisation and hypothesis
  for better test coverage and more precise failure reporting.
• Use platform-provided math.gcd, when provided.