99e0a124cb
This PR is almost a complete rewrite of the ACL system within Consul. It brings the features more in line with other HashiCorp products. Obviously there is quite a bit left to do here but most of it is related docs, testing and finishing the last few commands in the CLI. I will update the PR description and check off the todos as I finish them over the next few days/week. Description At a high level this PR is mainly to split ACL tokens from Policies and to split the concepts of Authorization from Identities. A lot of this PR is mostly just to support CRUD operations on ACLTokens and ACLPolicies. These in and of themselves are not particularly interesting. The bigger conceptual changes are in how tokens get resolved, how backwards compatibility is handled and the separation of policy from identity which could lead the way to allowing for alternative identity providers. On the surface and with a new cluster the ACL system will look very similar to that of Nomads. Both have tokens and policies. Both have local tokens. The ACL management APIs for both are very similar. I even ripped off Nomad's ACL bootstrap resetting procedure. There are a few key differences though. Nomad requires token and policy replication where Consul only requires policy replication with token replication being opt-in. In Consul local tokens only work with token replication being enabled though. All policies in Nomad are globally applicable. In Consul all policies are stored and replicated globally but can be scoped to a subset of the datacenters. This allows for more granular access management. Unlike Nomad, Consul has legacy baggage in the form of the original ACL system. The ramifications of this are: A server running the new system must still support other clients using the legacy system. A client running the new system must be able to use the legacy RPCs when the servers in its datacenter are running the legacy system. The primary ACL DC's servers running in legacy mode needs to be a gate that keeps everything else in the entire multi-DC cluster running in legacy mode. So not only does this PR implement the new ACL system but has a legacy mode built in for when the cluster isn't ready for new ACLs. Also detecting that new ACLs can be used is automatic and requires no configuration on the part of administrators. This process is detailed more in the "Transitioning from Legacy to New ACL Mode" section below.
178 lines
4 KiB
Go
178 lines
4 KiB
Go
// Copyright 2017 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package blake2b
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import (
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"encoding/binary"
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"errors"
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"io"
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)
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// XOF defines the interface to hash functions that
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// support arbitrary-length output.
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type XOF interface {
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// Write absorbs more data into the hash's state. It panics if called
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// after Read.
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io.Writer
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// Read reads more output from the hash. It returns io.EOF if the limit
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// has been reached.
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io.Reader
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// Clone returns a copy of the XOF in its current state.
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Clone() XOF
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// Reset resets the XOF to its initial state.
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Reset()
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}
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// OutputLengthUnknown can be used as the size argument to NewXOF to indicate
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// the the length of the output is not known in advance.
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const OutputLengthUnknown = 0
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// magicUnknownOutputLength is a magic value for the output size that indicates
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// an unknown number of output bytes.
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const magicUnknownOutputLength = (1 << 32) - 1
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// maxOutputLength is the absolute maximum number of bytes to produce when the
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// number of output bytes is unknown.
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const maxOutputLength = (1 << 32) * 64
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// NewXOF creates a new variable-output-length hash. The hash either produce a
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// known number of bytes (1 <= size < 2**32-1), or an unknown number of bytes
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// (size == OutputLengthUnknown). In the latter case, an absolute limit of
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// 256GiB applies.
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//
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// A non-nil key turns the hash into a MAC. The key must between
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// zero and 32 bytes long.
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func NewXOF(size uint32, key []byte) (XOF, error) {
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if len(key) > Size {
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return nil, errKeySize
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}
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if size == magicUnknownOutputLength {
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// 2^32-1 indicates an unknown number of bytes and thus isn't a
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// valid length.
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return nil, errors.New("blake2b: XOF length too large")
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}
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if size == OutputLengthUnknown {
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size = magicUnknownOutputLength
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}
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x := &xof{
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d: digest{
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size: Size,
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keyLen: len(key),
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},
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length: size,
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}
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copy(x.d.key[:], key)
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x.Reset()
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return x, nil
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}
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type xof struct {
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d digest
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length uint32
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remaining uint64
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cfg, root, block [Size]byte
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offset int
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nodeOffset uint32
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readMode bool
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}
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func (x *xof) Write(p []byte) (n int, err error) {
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if x.readMode {
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panic("blake2b: write to XOF after read")
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}
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return x.d.Write(p)
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}
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func (x *xof) Clone() XOF {
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clone := *x
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return &clone
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}
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func (x *xof) Reset() {
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x.cfg[0] = byte(Size)
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binary.LittleEndian.PutUint32(x.cfg[4:], uint32(Size)) // leaf length
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binary.LittleEndian.PutUint32(x.cfg[12:], x.length) // XOF length
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x.cfg[17] = byte(Size) // inner hash size
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x.d.Reset()
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x.d.h[1] ^= uint64(x.length) << 32
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x.remaining = uint64(x.length)
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if x.remaining == magicUnknownOutputLength {
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x.remaining = maxOutputLength
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}
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x.offset, x.nodeOffset = 0, 0
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x.readMode = false
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}
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func (x *xof) Read(p []byte) (n int, err error) {
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if !x.readMode {
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x.d.finalize(&x.root)
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x.readMode = true
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}
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if x.remaining == 0 {
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return 0, io.EOF
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}
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n = len(p)
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if uint64(n) > x.remaining {
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n = int(x.remaining)
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p = p[:n]
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}
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if x.offset > 0 {
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blockRemaining := Size - x.offset
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if n < blockRemaining {
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x.offset += copy(p, x.block[x.offset:])
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x.remaining -= uint64(n)
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return
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}
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copy(p, x.block[x.offset:])
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p = p[blockRemaining:]
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x.offset = 0
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x.remaining -= uint64(blockRemaining)
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}
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for len(p) >= Size {
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binary.LittleEndian.PutUint32(x.cfg[8:], x.nodeOffset)
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x.nodeOffset++
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x.d.initConfig(&x.cfg)
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x.d.Write(x.root[:])
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x.d.finalize(&x.block)
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copy(p, x.block[:])
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p = p[Size:]
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x.remaining -= uint64(Size)
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}
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if todo := len(p); todo > 0 {
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if x.remaining < uint64(Size) {
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x.cfg[0] = byte(x.remaining)
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}
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binary.LittleEndian.PutUint32(x.cfg[8:], x.nodeOffset)
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x.nodeOffset++
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x.d.initConfig(&x.cfg)
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x.d.Write(x.root[:])
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x.d.finalize(&x.block)
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x.offset = copy(p, x.block[:todo])
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x.remaining -= uint64(todo)
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}
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return
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}
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func (d *digest) initConfig(cfg *[Size]byte) {
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d.offset, d.c[0], d.c[1] = 0, 0, 0
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for i := range d.h {
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d.h[i] = iv[i] ^ binary.LittleEndian.Uint64(cfg[i*8:])
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}
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}
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