distribution/vendor/gopkg.in/square/go-jose.v1/cipher/concat_kdf.go
Derek McGowan a685e3fc98
Replace godep with vndr
Vndr has a simpler configuration and allows pointing to forked
packages. Additionally other docker projects are now using
vndr making vendoring in distribution more consistent.

Updates letsencrypt to use fork.
No longer uses sub-vendored packages.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)
2016-11-23 15:07:06 -08:00

76 lines
1.8 KiB
Go

/*-
* Copyright 2014 Square Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package josecipher
import (
"crypto"
"encoding/binary"
"hash"
"io"
)
type concatKDF struct {
z, info []byte
i uint32
cache []byte
hasher hash.Hash
}
// NewConcatKDF builds a KDF reader based on the given inputs.
func NewConcatKDF(hash crypto.Hash, z, algID, ptyUInfo, ptyVInfo, supPubInfo, supPrivInfo []byte) io.Reader {
buffer := make([]byte, len(algID)+len(ptyUInfo)+len(ptyVInfo)+len(supPubInfo)+len(supPrivInfo))
n := 0
n += copy(buffer, algID)
n += copy(buffer[n:], ptyUInfo)
n += copy(buffer[n:], ptyVInfo)
n += copy(buffer[n:], supPubInfo)
copy(buffer[n:], supPrivInfo)
hasher := hash.New()
return &concatKDF{
z: z,
info: buffer,
hasher: hasher,
cache: []byte{},
i: 1,
}
}
func (ctx *concatKDF) Read(out []byte) (int, error) {
copied := copy(out, ctx.cache)
ctx.cache = ctx.cache[copied:]
for copied < len(out) {
ctx.hasher.Reset()
// Write on a hash.Hash never fails
_ = binary.Write(ctx.hasher, binary.BigEndian, ctx.i)
_, _ = ctx.hasher.Write(ctx.z)
_, _ = ctx.hasher.Write(ctx.info)
hash := ctx.hasher.Sum(nil)
chunkCopied := copy(out[copied:], hash)
copied += chunkCopied
ctx.cache = hash[chunkCopied:]
ctx.i++
}
return copied, nil
}