commit d0fbcd5e403b4cb1cf73b2a02ac4e624f9fef1a0 · veryroundbird.house/core

+70

crypto/verify.go

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       package crypto

     

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       import (

     

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       	"bytes"

     

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       	"crypto/sha256"

     

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       	"encoding/base64"

     

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       	"fmt"

     

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       	"strings"

     

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       	"github.com/hiddeco/sshsig"

     

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       	"golang.org/x/crypto/ssh"

     

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       	"tangled.sh/tangled.sh/core/types"

     

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       )

     

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       func VerifySignature(pubKey, signature, payload []byte) (error, bool) {

     

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       	pub, _, _, _, err := ssh.ParseAuthorizedKey(pubKey)

     

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       	if err != nil {

     

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       		return fmt.Errorf("failed to parse public key: %w", err), false

     

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       	}

     

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       	sig, err := sshsig.Unarmor(signature)

     

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       	if err != nil {

     

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       		return fmt.Errorf("failed to parse signature: %w", err), false

     

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       	}

     

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       	buf := bytes.NewBuffer(payload)

     

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       	sshsig.Verify(buf, sig, pub, sshsig.HashSHA256, "git")

     

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       	return err, err == nil

     

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       }

     

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       // VerifyCommitSignature reconstructs the payload used to sign a commit. This is

     

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       // essentially the git cat-file output but without the gpgsig header.

     

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       //

     

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       // Caveats: signature verification will fail on commits with more than one parent,

     

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       // i.e. merge commits, because types.NiceDiff doesn't carry more than one Parent field

     

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       // and we are unable to reconstruct the payload correctly.

     

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       //

     

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       // Ideally this should directly operate on an *object.Commit.

     

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       func VerifyCommitSignature(pubKey string, commit types.NiceDiff) (error, bool) {

     

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       	signature := commit.Commit.PGPSignature

     

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       	author := bytes.NewBuffer([]byte{})

     

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       	committer := bytes.NewBuffer([]byte{})

     

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       	commit.Commit.Author.Encode(author)

     

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       	commit.Commit.Committer.Encode(committer)

     

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       	payload := strings.Builder{}

     

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       	fmt.Fprintf(&payload, "tree %s\n", commit.Commit.Tree)

     

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       	fmt.Fprintf(&payload, "parent %s\n", commit.Commit.Parent)

     

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       	fmt.Fprintf(&payload, "author %s\n", author.String())

     

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       	fmt.Fprintf(&payload, "committer %s\n", committer.String())

     

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       	if commit.Commit.ChangedId != "" {

     

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       		fmt.Fprintf(&payload, "change-id %s\n", commit.Commit.ChangedId)

     

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       	}

     

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       	fmt.Fprintf(&payload, "\n%s", commit.Commit.Message)

     

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       	return VerifySignature([]byte(pubKey), []byte(signature), []byte(payload.String()))

     

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       }

     

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       // SSHFingerprint computes the fingerprint of the supplied ssh pubkey.

     

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       func SSHFingerprint(pubKey string) (string, error) {

     

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       	pk, _, _, _, err := ssh.ParseAuthorizedKey([]byte(pubKey))

     

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       	if err != nil {

     

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       		return "", err

     

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       	}

     

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       	hash := sha256.Sum256(pk.Marshal())

     

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       	return "SHA256:" + base64.StdEncoding.EncodeToString(hash[:]), nil

     

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       }

+2 -1

go.mod

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       	github.com/go-git/go-git/v5 v5.14.0

     

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       	github.com/google/uuid v1.6.0

     

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       	github.com/gorilla/sessions v1.4.0

     

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       	github.com/hiddeco/sshsig v0.2.0

     

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       	github.com/ipfs/go-cid v0.5.0

     

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       	github.com/lestrrat-go/jwx/v2 v2.1.6

     

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       	github.com/mattn/go-sqlite3 v1.14.24

     
···

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       	github.com/urfave/cli/v3 v3.3.3

     

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       	github.com/whyrusleeping/cbor-gen v0.3.1

     

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       	github.com/yuin/goldmark v1.4.13

     

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       	golang.org/x/crypto v0.38.0

     

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       	golang.org/x/net v0.39.0

     

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       	golang.org/x/xerrors v0.0.0-20240903120638-7835f813f4da

     

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       	tangled.sh/icyphox.sh/atproto-oauth v0.0.0-20250526154904-3906c5336421

     
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       	go.uber.org/atomic v1.11.0 // indirect

     

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       	go.uber.org/multierr v1.11.0 // indirect

     

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       	go.uber.org/zap v1.27.0 // indirect

     

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       	golang.org/x/crypto v0.38.0 // indirect

     

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       	golang.org/x/exp v0.0.0-20250408133849-7e4ce0ab07d0 // indirect

     

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       	golang.org/x/sync v0.13.0 // indirect

     

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       	golang.org/x/sys v0.33.0 // indirect

go.sum

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       github.com/hashicorp/golang-lru/v2 v2.0.7/go.mod h1:QeFd9opnmA6QUJc5vARoKUSoFhyfM2/ZepoAG6RGpeM=

     

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       github.com/hexops/gotextdiff v1.0.3 h1:gitA9+qJrrTCsiCl7+kh75nPqQt1cx4ZkudSTLoUqJM=

     

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       github.com/hexops/gotextdiff v1.0.3/go.mod h1:pSWU5MAI3yDq+fZBTazCSJysOMbxWL1BSow5/V2vxeg=

     

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       github.com/hiddeco/sshsig v0.2.0 h1:gMWllgKCITXdydVkDL+Zro0PU96QI55LwUwebSwNTSw=

     

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       github.com/hiddeco/sshsig v0.2.0/go.mod h1:nJc98aGgiH6Yql2doqH4CTBVHexQA40Q+hMMLHP4EqE=

     

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       github.com/hpcloud/tail v1.0.0/go.mod h1:ab1qPbhIpdTxEkNHXyeSf5vhxWSCs/tWer42PpOxQnU=

     

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       github.com/ianlancetaylor/demangle v0.0.0-20200824232613-28f6c0f3b639/go.mod h1:aSSvb/t6k1mPoxDqO4vJh6VOCGPwU4O0C2/Eqndh1Sc=

     

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       github.com/ipfs/bbloom v0.0.4 h1:Gi+8EGJ2y5qiD5FbsbpX/TMNcJw8gSqr7eyjHa4Fhvs=