mirror of https://github.com/ethereum/go-ethereum
Remove multihash from Swarm bzz:// for Feeds (#18175)
Javier Peletier
6 years ago
committed by
Anton Evangelatov
parent
0699287440
commit
2714e8f091
@ -1,92 +0,0 @@ |
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// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package multihash |
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import ( |
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"bytes" |
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"encoding/binary" |
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"errors" |
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"fmt" |
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) |
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const ( |
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defaultMultihashLength = 32 |
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defaultMultihashTypeCode = 0x1b |
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) |
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var ( |
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multihashTypeCode uint8 |
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MultihashLength = defaultMultihashLength |
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) |
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func init() { |
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multihashTypeCode = defaultMultihashTypeCode |
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MultihashLength = defaultMultihashLength |
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} |
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// check if valid swarm multihash
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func isSwarmMultihashType(code uint8) bool { |
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return code == multihashTypeCode |
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} |
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// GetMultihashLength returns the digest length of the provided multihash
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// It will fail if the multihash is not a valid swarm mulithash
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func GetMultihashLength(data []byte) (int, int, error) { |
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cursor := 0 |
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typ, c := binary.Uvarint(data) |
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if c <= 0 { |
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return 0, 0, errors.New("unreadable hashtype field") |
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} |
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if !isSwarmMultihashType(uint8(typ)) { |
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return 0, 0, fmt.Errorf("hash code %x is not a swarm hashtype", typ) |
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} |
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cursor += c |
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hashlength, c := binary.Uvarint(data[cursor:]) |
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if c <= 0 { |
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return 0, 0, errors.New("unreadable length field") |
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} |
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cursor += c |
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// we cheekily assume hashlength < maxint
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inthashlength := int(hashlength) |
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if len(data[c:]) < inthashlength { |
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return 0, 0, errors.New("length mismatch") |
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} |
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return inthashlength, cursor, nil |
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} |
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// FromMulithash returns the digest portion of the multihash
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// It will fail if the multihash is not a valid swarm multihash
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func FromMultihash(data []byte) ([]byte, error) { |
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hashLength, _, err := GetMultihashLength(data) |
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if err != nil { |
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return nil, err |
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} |
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return data[len(data)-hashLength:], nil |
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} |
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// ToMulithash wraps the provided digest data with a swarm mulithash header
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func ToMultihash(hashData []byte) []byte { |
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buf := bytes.NewBuffer(nil) |
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b := make([]byte, 8) |
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c := binary.PutUvarint(b, uint64(multihashTypeCode)) |
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buf.Write(b[:c]) |
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c = binary.PutUvarint(b, uint64(len(hashData))) |
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buf.Write(b[:c]) |
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buf.Write(hashData) |
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return buf.Bytes() |
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} |
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@ -1,53 +0,0 @@ |
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// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
|
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// it under the terms of the GNU Lesser General Public License as published by
|
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// the Free Software Foundation, either version 3 of the License, or
|
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// (at your option) any later version.
|
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//
|
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// The go-ethereum library is distributed in the hope that it will be useful,
|
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package multihash |
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import ( |
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"bytes" |
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"math/rand" |
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"testing" |
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) |
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// parse multihash, and check that invalid multihashes fail
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func TestCheckMultihash(t *testing.T) { |
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hashbytes := make([]byte, 32) |
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c, err := rand.Read(hashbytes) |
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if err != nil { |
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t.Fatal(err) |
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} else if c < 32 { |
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t.Fatal("short read") |
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} |
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expected := ToMultihash(hashbytes) |
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l, hl, _ := GetMultihashLength(expected) |
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if l != 32 { |
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t.Fatalf("expected length %d, got %d", 32, l) |
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} else if hl != 2 { |
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t.Fatalf("expected header length %d, got %d", 2, hl) |
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} |
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if _, _, err := GetMultihashLength(expected[1:]); err == nil { |
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t.Fatal("expected failure on corrupt header") |
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} |
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if _, _, err := GetMultihashLength(expected[:len(expected)-2]); err == nil { |
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t.Fatal("expected failure on short content") |
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} |
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dh, _ := FromMultihash(expected) |
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if !bytes.Equal(dh, hashbytes) { |
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t.Fatalf("expected content hash %x, got %x", hashbytes, dh) |
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} |
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} |
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