From e50ac707316ea6d8059f7036322450727773952d Mon Sep 17 00:00:00 2001 From: Mark Haines Date: Thu, 26 Feb 2015 16:40:56 +0000 Subject: Squashed 'lib/curve25519-donna/' content from commit 28772f3 git-subtree-dir: lib/curve25519-donna git-subtree-split: 28772f37a4b8a57ab9439b9e79b19f9abee686da --- README | 40 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 40 insertions(+) create mode 100644 README (limited to 'README') diff --git a/README b/README new file mode 100644 index 0000000..9adf9be --- /dev/null +++ b/README @@ -0,0 +1,40 @@ +See http://code.google.com/p/curve25519-donna/ for details. + +BUILDING: + +If you run `make`, two .a archives will be built, similar to djb's curve25519 +code. Alternatively, read on: + +The C implementation is contained within curve25519-donna.c. It has no external +dependancies and is BSD licenced. You can copy/include/link it directly in with +your program. Recommended C flags: -O2 + +The x86-64 bit implementation is contained within curve25519-donna-x86-64.c and +curve25519-donna-x86-64.s. Build like this: + +% cpp curve25519-donna-x86-64.s > curve25519-donna-x86-64.s.pp +% as -o curve25519-donna-x86-64.s.o curve25519-donna-x86-64.s.pp +% gcc -O2 -c curve25519-donna-x86-64.c + +Then the two .o files can be linked in + +USAGE: + +The usage is exactly the same as djb's code (as described at +http://cr.yp.to/ecdh.html) expect that the function is called curve25519_donna. + +In short, + +To generate a private key just generate 32 random bytes. + +To generate the public key, just do: + + static const uint8_t basepoint[32] = {9}; + curve25519_donna(mypublic, mysecret, basepoint); + +To generate an agreed key do: + + uint8_t shared_key[32]; + curve25519_donna(shared_key, mysecret, theirpublic); + +And hash the shared_key with a cryptographic hash function before using. -- cgit v1.2.3