diff options
author | Yawning Angel <yawning@torproject.org> | 2014-08-17 17:11:03 +0000 |
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committer | Yawning Angel <yawning@torproject.org> | 2014-08-17 17:11:03 +0000 |
commit | 339c63f0c8cd4374f6fa26484498eb6fa91b7bca (patch) | |
tree | edef1bebc1a40a653b2b9f0bd02f53c8c4923ac3 /drbg | |
parent | 8a3eb4b30965975951a92dde8f68ce17cb08ac8e (diff) |
Massive cleanup/code reorg.
* Changed obfs4proxy to be more like obfsproxy in terms of design,
including being an easy framework for developing new TCP/IP style
pluggable transports.
* Added support for also acting as an obfs2/obfs3 client or bridge
as a transition measure (and because the code itself is trivial).
* Massively cleaned up the obfs4 and related code to be easier to
read, and more idiomatic Go-like in style.
* To ease deployment, obfs4proxy will now autogenerate the node-id,
curve25519 keypair, and drbg seed if none are specified, and save
them to a JSON file in the pt_state directory (Fixes Tor bug #12605).
Diffstat (limited to 'drbg')
-rw-r--r-- | drbg/hash_drbg.go | 147 |
1 files changed, 0 insertions, 147 deletions
diff --git a/drbg/hash_drbg.go b/drbg/hash_drbg.go deleted file mode 100644 index c94902a..0000000 --- a/drbg/hash_drbg.go +++ /dev/null @@ -1,147 +0,0 @@ -/* - * Copyright (c) 2014, Yawning Angel <yawning at torproject dot org> - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or without - * modification, are permitted provided that the following conditions are met: - * - * * Redistributions of source code must retain the above copyright notice, - * this list of conditions and the following disclaimer. - * - * * Redistributions in binary form must reproduce the above copyright notice, - * this list of conditions and the following disclaimer in the documentation - * and/or other materials provided with the distribution. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" - * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE - * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE - * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR - * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF - * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS - * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN - * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE - * POSSIBILITY OF SUCH DAMAGE. - */ - -// Package drbg implements a minimalistic DRBG based off SipHash-2-4 in OFB -// mode. -package drbg - -import ( - "encoding/base64" - "encoding/binary" - "fmt" - "hash" - - "github.com/dchest/siphash" - - "git.torproject.org/pluggable-transports/obfs4.git/csrand" -) - -// Size is the length of the HashDrbg output. -const Size = siphash.Size - -// SeedLength is the length of the HashDrbg seed. -const SeedLength = 16 + Size - -// Seed is the initial state for a HashDrbg. It consists of a SipHash-2-4 -// key, and 8 bytes of initial data. -type Seed [SeedLength]byte - -// Bytes returns a pointer to the raw HashDrbg seed. -func (seed *Seed) Bytes() *[SeedLength]byte { - return (*[SeedLength]byte)(seed) -} - -// Base64 returns the Base64 representation of the seed. -func (seed *Seed) Base64() string { - return base64.StdEncoding.EncodeToString(seed.Bytes()[:]) -} - -// NewSeed returns a Seed initialized with the runtime CSPRNG. -func NewSeed() (seed *Seed, err error) { - seed = new(Seed) - err = csrand.Bytes(seed.Bytes()[:]) - if err != nil { - return nil, err - } - - return -} - -// SeedFromBytes creates a Seed from the raw bytes, truncating to SeedLength as -// appropriate. -func SeedFromBytes(src []byte) (seed *Seed, err error) { - if len(src) < SeedLength { - return nil, InvalidSeedLengthError(len(src)) - } - - seed = new(Seed) - copy(seed.Bytes()[:], src) - - return -} - -// SeedFromBase64 creates a Seed from the Base64 representation, truncating to -// SeedLength as appropriate. -func SeedFromBase64(encoded string) (seed *Seed, err error) { - var raw []byte - raw, err = base64.StdEncoding.DecodeString(encoded) - if err != nil { - return nil, err - } - - return SeedFromBytes(raw) -} - -// InvalidSeedLengthError is the error returned when the seed provided to the -// DRBG is an invalid length. -type InvalidSeedLengthError int - -func (e InvalidSeedLengthError) Error() string { - return fmt.Sprintf("invalid seed length: %d", int(e)) -} - -// HashDrbg is a CSDRBG based off of SipHash-2-4 in OFB mode. -type HashDrbg struct { - sip hash.Hash64 - ofb [Size]byte -} - -// NewHashDrbg makes a HashDrbg instance based off an optional seed. The seed -// is truncated to SeedLength. -func NewHashDrbg(seed *Seed) *HashDrbg { - drbg := new(HashDrbg) - drbg.sip = siphash.New(seed.Bytes()[:16]) - copy(drbg.ofb[:], seed.Bytes()[16:]) - - return drbg -} - -// Int63 returns a uniformly distributed random integer [0, 1 << 63). -func (drbg *HashDrbg) Int63() int64 { - block := drbg.NextBlock() - ret := binary.BigEndian.Uint64(block) - ret &= (1<<63 - 1) - - return int64(ret) -} - -// Seed does nothing, call NewHashDrbg if you want to reseed. -func (drbg *HashDrbg) Seed(seed int64) { - // No-op. -} - -// NextBlock returns the next 8 byte DRBG block. -func (drbg *HashDrbg) NextBlock() []byte { - drbg.sip.Write(drbg.ofb[:]) - copy(drbg.ofb[:], drbg.sip.Sum(nil)) - - ret := make([]byte, Size) - copy(ret, drbg.ofb[:]) - return ret -} - -/* vim :set ts=4 sw=4 sts=4 noet : */ |