var my_public_key = curve25519(my_secret); var shared_secret = curve25519(my_secret, public_key);
As in curve25519-donna, some bits in the private key are altered to harden the operation of the function. If you need the private key to be unmodified for your protocol, use
Private and public keys are represented by arrays of 16-bit values, starting from the least significant ones:
key = arr + arr × 2^16 + arr × 2^32 + … + arr × 2^(16 × 15)
For consistency and conformance testing, you can run the script
test-curve25519.coffee under tests/
The output should be identical to
test-curve25519.c from the reference
Among the contributors, in no particular order:
Graydon Hoare: suggested clamping the private key by default for increased safety and uniformity with other implementations.
liliakai: spotted an unused argument in some of the functions
Guy Kloss: performance improvements through bit-shift operations
If you are one of the contributors and want to add yourself or change the information here, please do submit a pull request.
Copyright and MIT licensing
Copyright (c) 2007, 2013, 2014 Michele Bini
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.