Enforce Cid security rules for getting and adding blocks

License: MIT
Signed-off-by: Jakub Sztandera <kubuxu@protonmail.ch>

blockservice/blockservice.go

@@ -10,6 +10,7 @@ import (
 	"io"
 
 	exchange "github.com/ipfs/go-ipfs/exchange"
+	"github.com/ipfs/go-ipfs/removeme/verifcid"
 
 	logging "gx/ipfs/QmRb5jh8z2E8hMGN2tkvs1yHynUanqnZ3UeKwgN1i9P1F8/go-log"
 	blockstore "gx/ipfs/QmTVDM4LCSUMFNQzbDLL9zQwp8usE6QHymFdh3h8vL9v6b/go-ipfs-blockstore"
@@ -130,6 +131,11 @@ func NewSession(ctx context.Context, bs BlockService) *Session {
 // TODO pass a context into this if the remote.HasBlock is going to remain here.
 func (s *blockService) AddBlock(o blocks.Block) error {
 	c := o.Cid()
+	// hash security
+	err := verifcid.ValidateCid(c)
+	if err != nil {
+		return err
+	}
 	if s.checkFirst {
 		if has, err := s.blockstore.Has(c); has || err != nil {
 			return err
@@ -149,6 +155,13 @@ func (s *blockService) AddBlock(o blocks.Block) error {
 }
 
 func (s *blockService) AddBlocks(bs []blocks.Block) error {
+	//hash security
+	for _, b := range bs {
+		err := verifcid.ValidateCid(b.Cid())
+		if err != nil {
+			return err
+		}
+	}
 	var toput []blocks.Block
 	if s.checkFirst {
 		toput = make([]blocks.Block, 0, len(bs))
@@ -189,10 +202,15 @@ func (s *blockService) GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block,
 		f = s.exchange
 	}
 
-	return getBlock(ctx, c, s.blockstore, f)
+	return getBlock(ctx, c, s.blockstore, f) //hash security
 }
 
 func getBlock(ctx context.Context, c *cid.Cid, bs blockstore.Blockstore, f exchange.Fetcher) (blocks.Block, error) {
+	err := verifcid.ValidateCid(c)
+	if err != nil {
+		return nil, err
+	}
+
 	block, err := bs.Get(c)
 	if err == nil {
 		return block, nil
@@ -224,11 +242,18 @@ func getBlock(ctx context.Context, c *cid.Cid, bs blockstore.Blockstore, f excha
 // the returned channel.
 // NB: No guarantees are made about order.
 func (s *blockService) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan blocks.Block {
-	return getBlocks(ctx, ks, s.blockstore, s.exchange)
+	return getBlocks(ctx, ks, s.blockstore, s.exchange) //hash security
 }
 
 func getBlocks(ctx context.Context, ks []*cid.Cid, bs blockstore.Blockstore, f exchange.Fetcher) <-chan blocks.Block {
 	out := make(chan blocks.Block)
+	for _, c := range ks {
+		// hash security
+		if err := verifcid.ValidateCid(c); err != nil {
+			log.Errorf("unsafe CID (%s) passed to blockService.GetBlocks: %s", c, err)
+		}
+	}
+
 	go func() {
 		defer close(out)
 		var misses []*cid.Cid
@@ -285,12 +310,12 @@ type Session struct {
 
 // GetBlock gets a block in the context of a request session
 func (s *Session) GetBlock(ctx context.Context, c *cid.Cid) (blocks.Block, error) {
-	return getBlock(ctx, c, s.bs, s.ses)
+	return getBlock(ctx, c, s.bs, s.ses) // hash security
 }
 
 // GetBlocks gets blocks in the context of a request session
 func (s *Session) GetBlocks(ctx context.Context, ks []*cid.Cid) <-chan blocks.Block {
-	return getBlocks(ctx, ks, s.bs, s.ses)
+	return getBlocks(ctx, ks, s.bs, s.ses) // hash security
 }
 
 var _ BlockGetter = (*Session)(nil)

core/builder.go

@@ -15,6 +15,7 @@ import (
 	dag "github.com/ipfs/go-ipfs/merkledag"
 	resolver "github.com/ipfs/go-ipfs/path/resolver"
 	pin "github.com/ipfs/go-ipfs/pin"
+	"github.com/ipfs/go-ipfs/removeme/verifbs"
 	repo "github.com/ipfs/go-ipfs/repo"
 	cfg "github.com/ipfs/go-ipfs/repo/config"
 	uio "github.com/ipfs/go-ipfs/unixfs/io"
@@ -170,7 +171,9 @@ func setupNode(ctx context.Context, n *IpfsNode, cfg *BuildCfg) error {
 		TempErrFunc: isTooManyFDError,
 	}
 
+	//hash security
 	bs := bstore.NewBlockstore(rds)
+	bs = &verifbs.VerifBS{bs}
 
 	opts := bstore.DefaultCacheOpts()
 	conf, err := n.Repo.Config()
@@ -196,8 +199,10 @@ func setupNode(ctx context.Context, n *IpfsNode, cfg *BuildCfg) error {
 	n.Blockstore = bstore.NewGCBlockstore(cbs, n.GCLocker)
 
 	if conf.Experimental.FilestoreEnabled {
+		// hash security
 		n.Filestore = filestore.NewFilestore(bs, n.Repo.FileManager())
 		n.Blockstore = bstore.NewGCBlockstore(n.Filestore, n.GCLocker)
+		n.Blockstore = &verifbs.VerifBSGC{n.Blockstore}
 	}
 
 	rcfg, err := n.Repo.Config()

core/commands/add.go

@@ -258,7 +258,7 @@ You can now check what blocks have been created by:
 			exch = offline.Exchange(addblockstore)
 		}
 
-		bserv := blockservice.New(addblockstore, exch)
+		bserv := blockservice.New(addblockstore, exch) //hash security 001
 		dserv := dag.NewDAGService(bserv)
 
 		outChan := make(chan interface{}, adderOutChanSize)

removeme/verifbs/verifbs.go

+package verifbs
+
+import (
+	"github.com/ipfs/go-ipfs/removeme/verifcid"
+
+	bstore "gx/ipfs/QmTVDM4LCSUMFNQzbDLL9zQwp8usE6QHymFdh3h8vL9v6b/go-ipfs-blockstore"
+	cid "gx/ipfs/QmcZfnkapfECQGcLZaf9B79NRg7cRa9EnZh4LSbkCzwNvY/go-cid"
+	blocks "gx/ipfs/Qmej7nf81hi2x2tvjRBF3mcp74sQyuDH4VMYDGd1YtXjb2/go-block-format"
+)
+
+type VerifBSGC struct {
+	bstore.GCBlockstore
+}
+
+func (bs *VerifBSGC) Put(b blocks.Block) error {
+	if err := verifcid.ValidateCid(b.Cid()); err != nil {
+		return err
+	}
+	return bs.GCBlockstore.Put(b)
+}
+
+func (bs *VerifBSGC) PutMany(blks []blocks.Block) error {
+	for _, b := range blks {
+		if err := verifcid.ValidateCid(b.Cid()); err != nil {
+			return err
+		}
+	}
+	return bs.GCBlockstore.PutMany(blks)
+}
+
+func (bs *VerifBSGC) Get(c *cid.Cid) (blocks.Block, error) {
+	if err := verifcid.ValidateCid(c); err != nil {
+		return nil, err
+	}
+	return bs.GCBlockstore.Get(c)
+}
+
+type VerifBS struct {
+	bstore.Blockstore
+}
+
+func (bs *VerifBS) Put(b blocks.Block) error {
+	if err := verifcid.ValidateCid(b.Cid()); err != nil {
+		return err
+	}
+	return bs.Blockstore.Put(b)
+}
+
+func (bs *VerifBS) PutMany(blks []blocks.Block) error {
+	for _, b := range blks {
+		if err := verifcid.ValidateCid(b.Cid()); err != nil {
+			return err
+		}
+	}
+	return bs.Blockstore.PutMany(blks)
+}
+
+func (bs *VerifBS) Get(c *cid.Cid) (blocks.Block, error) {
+	if err := verifcid.ValidateCid(c); err != nil {
+		return nil, err
+	}
+	return bs.Blockstore.Get(c)
+}

test/sharness/t0050-block.sh

@@ -185,11 +185,11 @@ test_expect_success "block get output looks right" '
 '
 
 test_expect_success "can set multihash type and length on block put" '
-  HASH=$(echo "foooo" | ipfs block put --format=raw --mhtype=sha3 --mhlen=16)
+  HASH=$(echo "foooo" | ipfs block put --format=raw --mhtype=sha3 --mhlen=20)
 '
 
 test_expect_success "output looks good" '
-  test "z25ScPysKoxJBcPxczn9NvuHiZU5" = "$HASH"
+  test "z83bYcqyBkbx5fuNAcvbdv4pr5RYQiEpK" = "$HASH"
 '
 
 test_expect_success "can read block with different hash" '