tvl-depot/tvix/store/protos/pathinfo.go
Florian Klink 8ced43f3c7 feat(tvix/store/protos): validate NarSha256
Change-Id: I016d1b020b04850f0dca68c2ea96643230dada10
Reviewed-on: https://cl.tvl.fyi/c/depot/+/9649
Reviewed-by: Brian McGee <brian@bmcgee.ie>
Tested-by: BuildkiteCI
2023-10-11 15:29:08 +00:00

101 lines
3.3 KiB
Go

package storev1
import (
"bytes"
"crypto/sha256"
"encoding/base64"
"fmt"
"github.com/nix-community/go-nix/pkg/storepath"
)
// Validate performs some checks on the PathInfo struct, returning either the
// StorePath of the root node, or an error.
func (p *PathInfo) Validate() (*storepath.StorePath, error) {
// ensure References has the right number of bytes.
for i, reference := range p.GetReferences() {
if len(reference) != storepath.PathHashSize {
return nil, fmt.Errorf("invalid length of digest at position %d, expected %d, got %d", i, storepath.PathHashSize, len(reference))
}
}
// If there's a Narinfo field populated..
if narInfo := p.GetNarinfo(); narInfo != nil {
// ensure the NarSha256 digest has the correct length.
if len(narInfo.GetNarSha256()) != sha256.Size {
return nil, fmt.Errorf("invalid number of bytes for NarSha256: expected %d, got %d", sha256.Size, len(narInfo.GetNarSha256()))
}
// ensure the number of references matches len(References).
if len(narInfo.GetReferenceNames()) != len(p.GetReferences()) {
return nil, fmt.Errorf("inconsistent number of references: %d (references) vs %d (narinfo)", len(narInfo.GetReferenceNames()), len(p.GetReferences()))
}
// for each ReferenceName…
for i, referenceName := range narInfo.GetReferenceNames() {
// ensure it parses to a store path
storePath, err := storepath.FromString(referenceName)
if err != nil {
return nil, fmt.Errorf("invalid ReferenceName at position %d: %w", i, err)
}
// ensure the digest matches the one at References[i]
if !bytes.Equal(p.GetReferences()[i], storePath.Digest) {
return nil, fmt.Errorf(
"digest in ReferenceName at position %d does not match digest in PathInfo, expected %s, got %s",
i,
base64.StdEncoding.EncodeToString(p.GetReferences()[i]),
base64.StdEncoding.EncodeToString(storePath.Digest),
)
}
}
}
// ensure there is a (root) node present
rootNode := p.GetNode()
if rootNode == nil {
return nil, fmt.Errorf("root node must be set")
}
// for all three node types, ensure the name properly parses to a store path,
// and in case it refers to a digest, ensure it has the right length.
if node := rootNode.GetDirectory(); node != nil {
if len(node.Digest) != 32 {
return nil, fmt.Errorf("invalid digest size for %s, expected %d, got %d", node.Name, 32, len(node.Digest))
}
storePath, err := storepath.FromString(string(node.GetName()))
if err != nil {
return nil, fmt.Errorf("unable to parse %s as StorePath: %w", node.Name, err)
}
return storePath, nil
} else if node := rootNode.GetFile(); node != nil {
if len(node.Digest) != 32 {
return nil, fmt.Errorf("invalid digest size for %s, expected %d, got %d", node.Name, 32, len(node.Digest))
}
storePath, err := storepath.FromString(string(node.GetName()))
if err != nil {
return nil, fmt.Errorf("unable to parse %s as StorePath: %w", node.Name, err)
}
return storePath, nil
} else if node := rootNode.GetSymlink(); node != nil {
storePath, err := storepath.FromString(string(node.GetName()))
if err != nil {
return nil, fmt.Errorf("unable to parse %s as StorePath: %w", node.Name, err)
}
return storePath, nil
} else {
// this would only happen if we introduced a new type
panic("unreachable")
}
}