74f0c84fa4
Noteable additions: - `redefines-builtin-id` forbid variable names that shadow go builtins - `empty-lines` remove unnecessary empty lines that `gofumpt` does not remove for some reason - `superfluous-else` eliminate more superfluous `else` branches Rules are also sorted alphabetically and I cleaned up various parts of `.golangci.yml`.
537 lines
17 KiB
Go
537 lines
17 KiB
Go
// Copyright 2021 The Gitea Authors. All rights reserved.
|
|
// SPDX-License-Identifier: MIT
|
|
|
|
package asymkey
|
|
|
|
import (
|
|
"context"
|
|
"fmt"
|
|
"hash"
|
|
"strings"
|
|
|
|
"code.gitea.io/gitea/models/db"
|
|
repo_model "code.gitea.io/gitea/models/repo"
|
|
user_model "code.gitea.io/gitea/models/user"
|
|
"code.gitea.io/gitea/modules/git"
|
|
"code.gitea.io/gitea/modules/log"
|
|
"code.gitea.io/gitea/modules/setting"
|
|
|
|
"github.com/keybase/go-crypto/openpgp/packet"
|
|
)
|
|
|
|
// __________________ ________ ____ __.
|
|
// / _____/\______ \/ _____/ | |/ _|____ ___.__.
|
|
// / \ ___ | ___/ \ ___ | <_/ __ < | |
|
|
// \ \_\ \| | \ \_\ \ | | \ ___/\___ |
|
|
// \______ /|____| \______ / |____|__ \___ > ____|
|
|
// \/ \/ \/ \/\/
|
|
// _________ .__ __
|
|
// \_ ___ \ ____ _____ _____ |__|/ |_
|
|
// / \ \/ / _ \ / \ / \| \ __\
|
|
// \ \___( <_> ) Y Y \ Y Y \ || |
|
|
// \______ /\____/|__|_| /__|_| /__||__|
|
|
// \/ \/ \/
|
|
// ____ ____ .__ _____.__ __ .__
|
|
// \ \ / /___________|__|/ ____\__| ____ _____ _/ |_|__| ____ ____
|
|
// \ Y // __ \_ __ \ \ __\| |/ ___\\__ \\ __\ |/ _ \ / \
|
|
// \ /\ ___/| | \/ || | | \ \___ / __ \| | | ( <_> ) | \
|
|
// \___/ \___ >__| |__||__| |__|\___ >____ /__| |__|\____/|___| /
|
|
// \/ \/ \/ \/
|
|
|
|
// This file provides functions relating commit verification
|
|
|
|
// CommitVerification represents a commit validation of signature
|
|
type CommitVerification struct {
|
|
Verified bool
|
|
Warning bool
|
|
Reason string
|
|
SigningUser *user_model.User
|
|
CommittingUser *user_model.User
|
|
SigningEmail string
|
|
SigningKey *GPGKey
|
|
SigningSSHKey *PublicKey
|
|
TrustStatus string
|
|
}
|
|
|
|
// SignCommit represents a commit with validation of signature.
|
|
type SignCommit struct {
|
|
Verification *CommitVerification
|
|
*user_model.UserCommit
|
|
}
|
|
|
|
const (
|
|
// BadSignature is used as the reason when the signature has a KeyID that is in the db
|
|
// but no key that has that ID verifies the signature. This is a suspicious failure.
|
|
BadSignature = "gpg.error.probable_bad_signature"
|
|
// BadDefaultSignature is used as the reason when the signature has a KeyID that matches the
|
|
// default Key but is not verified by the default key. This is a suspicious failure.
|
|
BadDefaultSignature = "gpg.error.probable_bad_default_signature"
|
|
// NoKeyFound is used as the reason when no key can be found to verify the signature.
|
|
NoKeyFound = "gpg.error.no_gpg_keys_found"
|
|
)
|
|
|
|
// ParseCommitsWithSignature checks if signaute of commits are corresponding to users gpg keys.
|
|
func ParseCommitsWithSignature(ctx context.Context, oldCommits []*user_model.UserCommit, repoTrustModel repo_model.TrustModelType, isOwnerMemberCollaborator func(*user_model.User) (bool, error)) []*SignCommit {
|
|
newCommits := make([]*SignCommit, 0, len(oldCommits))
|
|
keyMap := map[string]bool{}
|
|
|
|
for _, c := range oldCommits {
|
|
signCommit := &SignCommit{
|
|
UserCommit: c,
|
|
Verification: ParseCommitWithSignature(ctx, c.Commit),
|
|
}
|
|
|
|
_ = CalculateTrustStatus(signCommit.Verification, repoTrustModel, isOwnerMemberCollaborator, &keyMap)
|
|
|
|
newCommits = append(newCommits, signCommit)
|
|
}
|
|
return newCommits
|
|
}
|
|
|
|
// ParseCommitWithSignature check if signature is good against keystore.
|
|
func ParseCommitWithSignature(ctx context.Context, c *git.Commit) *CommitVerification {
|
|
var committer *user_model.User
|
|
if c.Committer != nil {
|
|
var err error
|
|
// Find Committer account
|
|
committer, err = user_model.GetUserByEmail(ctx, c.Committer.Email) // This finds the user by primary email or activated email so commit will not be valid if email is not
|
|
if err != nil { // Skipping not user for committer
|
|
committer = &user_model.User{
|
|
Name: c.Committer.Name,
|
|
Email: c.Committer.Email,
|
|
}
|
|
// We can expect this to often be an ErrUserNotExist. in the case
|
|
// it is not, however, it is important to log it.
|
|
if !user_model.IsErrUserNotExist(err) {
|
|
log.Error("GetUserByEmail: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.no_committer_account",
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
// If no signature just report the committer
|
|
if c.Signature == nil {
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false, // Default value
|
|
Reason: "gpg.error.not_signed_commit", // Default value
|
|
}
|
|
}
|
|
|
|
// If this a SSH signature handle it differently
|
|
if strings.HasPrefix(c.Signature.Signature, "-----BEGIN SSH SIGNATURE-----") {
|
|
return ParseCommitWithSSHSignature(ctx, c, committer)
|
|
}
|
|
|
|
// Parsing signature
|
|
sig, err := extractSignature(c.Signature.Signature)
|
|
if err != nil { // Skipping failed to extract sign
|
|
log.Error("SignatureRead err: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.extract_sign",
|
|
}
|
|
}
|
|
|
|
keyID := tryGetKeyIDFromSignature(sig)
|
|
defaultReason := NoKeyFound
|
|
|
|
// First check if the sig has a keyID and if so just look at that
|
|
if commitVerification := hashAndVerifyForKeyID(
|
|
ctx,
|
|
sig,
|
|
c.Signature.Payload,
|
|
committer,
|
|
keyID,
|
|
setting.AppName,
|
|
""); commitVerification != nil {
|
|
if commitVerification.Reason == BadSignature {
|
|
defaultReason = BadSignature
|
|
} else {
|
|
return commitVerification
|
|
}
|
|
}
|
|
|
|
// Now try to associate the signature with the committer, if present
|
|
if committer.ID != 0 {
|
|
keys, err := db.Find[GPGKey](ctx, FindGPGKeyOptions{
|
|
OwnerID: committer.ID,
|
|
})
|
|
if err != nil { // Skipping failed to get gpg keys of user
|
|
log.Error("ListGPGKeys: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.failed_retrieval_gpg_keys",
|
|
}
|
|
}
|
|
|
|
if err := GPGKeyList(keys).LoadSubKeys(ctx); err != nil {
|
|
log.Error("LoadSubKeys: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.failed_retrieval_gpg_keys",
|
|
}
|
|
}
|
|
|
|
committerEmailAddresses, _ := user_model.GetEmailAddresses(ctx, committer.ID)
|
|
activated := false
|
|
for _, e := range committerEmailAddresses {
|
|
if e.IsActivated && strings.EqualFold(e.Email, c.Committer.Email) {
|
|
activated = true
|
|
break
|
|
}
|
|
}
|
|
|
|
for _, k := range keys {
|
|
// Pre-check (& optimization) that emails attached to key can be attached to the committer email and can validate
|
|
canValidate := false
|
|
email := ""
|
|
if k.Verified && activated {
|
|
canValidate = true
|
|
email = c.Committer.Email
|
|
}
|
|
if !canValidate {
|
|
for _, e := range k.Emails {
|
|
if e.IsActivated && strings.EqualFold(e.Email, c.Committer.Email) {
|
|
canValidate = true
|
|
email = e.Email
|
|
break
|
|
}
|
|
}
|
|
}
|
|
if !canValidate {
|
|
continue // Skip this key
|
|
}
|
|
|
|
commitVerification := hashAndVerifyWithSubKeysCommitVerification(sig, c.Signature.Payload, k, committer, committer, email)
|
|
if commitVerification != nil {
|
|
return commitVerification
|
|
}
|
|
}
|
|
}
|
|
|
|
if setting.Repository.Signing.SigningKey != "" && setting.Repository.Signing.SigningKey != "default" && setting.Repository.Signing.SigningKey != "none" {
|
|
// OK we should try the default key
|
|
gpgSettings := git.GPGSettings{
|
|
Sign: true,
|
|
KeyID: setting.Repository.Signing.SigningKey,
|
|
Name: setting.Repository.Signing.SigningName,
|
|
Email: setting.Repository.Signing.SigningEmail,
|
|
}
|
|
if err := gpgSettings.LoadPublicKeyContent(); err != nil {
|
|
log.Error("Error getting default signing key: %s %v", gpgSettings.KeyID, err)
|
|
} else if commitVerification := verifyWithGPGSettings(ctx, &gpgSettings, sig, c.Signature.Payload, committer, keyID); commitVerification != nil {
|
|
if commitVerification.Reason == BadSignature {
|
|
defaultReason = BadSignature
|
|
} else {
|
|
return commitVerification
|
|
}
|
|
}
|
|
}
|
|
|
|
defaultGPGSettings, err := c.GetRepositoryDefaultPublicGPGKey(false)
|
|
if err != nil {
|
|
log.Error("Error getting default public gpg key: %v", err)
|
|
} else if defaultGPGSettings == nil {
|
|
log.Warn("Unable to get defaultGPGSettings for unattached commit: %s", c.ID.String())
|
|
} else if defaultGPGSettings.Sign {
|
|
if commitVerification := verifyWithGPGSettings(ctx, defaultGPGSettings, sig, c.Signature.Payload, committer, keyID); commitVerification != nil {
|
|
if commitVerification.Reason == BadSignature {
|
|
defaultReason = BadSignature
|
|
} else {
|
|
return commitVerification
|
|
}
|
|
}
|
|
}
|
|
|
|
return &CommitVerification{ // Default at this stage
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Warning: defaultReason != NoKeyFound,
|
|
Reason: defaultReason,
|
|
SigningKey: &GPGKey{
|
|
KeyID: keyID,
|
|
},
|
|
}
|
|
}
|
|
|
|
func verifyWithGPGSettings(ctx context.Context, gpgSettings *git.GPGSettings, sig *packet.Signature, payload string, committer *user_model.User, keyID string) *CommitVerification {
|
|
// First try to find the key in the db
|
|
if commitVerification := hashAndVerifyForKeyID(ctx, sig, payload, committer, gpgSettings.KeyID, gpgSettings.Name, gpgSettings.Email); commitVerification != nil {
|
|
return commitVerification
|
|
}
|
|
|
|
// Otherwise we have to parse the key
|
|
ekeys, err := checkArmoredGPGKeyString(gpgSettings.PublicKeyContent)
|
|
if err != nil {
|
|
log.Error("Unable to get default signing key: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.generate_hash",
|
|
}
|
|
}
|
|
for _, ekey := range ekeys {
|
|
pubkey := ekey.PrimaryKey
|
|
content, err := base64EncPubKey(pubkey)
|
|
if err != nil {
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.generate_hash",
|
|
}
|
|
}
|
|
k := &GPGKey{
|
|
Content: content,
|
|
CanSign: pubkey.CanSign(),
|
|
KeyID: pubkey.KeyIdString(),
|
|
}
|
|
for _, subKey := range ekey.Subkeys {
|
|
content, err := base64EncPubKey(subKey.PublicKey)
|
|
if err != nil {
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.generate_hash",
|
|
}
|
|
}
|
|
k.SubsKey = append(k.SubsKey, &GPGKey{
|
|
Content: content,
|
|
CanSign: subKey.PublicKey.CanSign(),
|
|
KeyID: subKey.PublicKey.KeyIdString(),
|
|
})
|
|
}
|
|
if commitVerification := hashAndVerifyWithSubKeysCommitVerification(sig, payload, k, committer, &user_model.User{
|
|
Name: gpgSettings.Name,
|
|
Email: gpgSettings.Email,
|
|
}, gpgSettings.Email); commitVerification != nil {
|
|
return commitVerification
|
|
}
|
|
if keyID == k.KeyID {
|
|
// This is a bad situation ... We have a key id that matches our default key but the signature doesn't match.
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Warning: true,
|
|
Reason: BadSignature,
|
|
}
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func verifySign(s *packet.Signature, h hash.Hash, k *GPGKey) error {
|
|
// Check if key can sign
|
|
if !k.CanSign {
|
|
return fmt.Errorf("key can not sign")
|
|
}
|
|
// Decode key
|
|
pkey, err := base64DecPubKey(k.Content)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
return pkey.VerifySignature(h, s)
|
|
}
|
|
|
|
func hashAndVerify(sig *packet.Signature, payload string, k *GPGKey) (*GPGKey, error) {
|
|
// Generating hash of commit
|
|
hash, err := populateHash(sig.Hash, []byte(payload))
|
|
if err != nil { // Skipping as failed to generate hash
|
|
log.Error("PopulateHash: %v", err)
|
|
return nil, err
|
|
}
|
|
// We will ignore errors in verification as they don't need to be propagated up
|
|
err = verifySign(sig, hash, k)
|
|
if err != nil {
|
|
return nil, nil
|
|
}
|
|
return k, nil
|
|
}
|
|
|
|
func hashAndVerifyWithSubKeys(sig *packet.Signature, payload string, k *GPGKey) (*GPGKey, error) {
|
|
verified, err := hashAndVerify(sig, payload, k)
|
|
if err != nil || verified != nil {
|
|
return verified, err
|
|
}
|
|
for _, sk := range k.SubsKey {
|
|
verified, err := hashAndVerify(sig, payload, sk)
|
|
if err != nil || verified != nil {
|
|
return verified, err
|
|
}
|
|
}
|
|
return nil, nil
|
|
}
|
|
|
|
func hashAndVerifyWithSubKeysCommitVerification(sig *packet.Signature, payload string, k *GPGKey, committer, signer *user_model.User, email string) *CommitVerification {
|
|
key, err := hashAndVerifyWithSubKeys(sig, payload, k)
|
|
if err != nil { // Skipping failed to generate hash
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.generate_hash",
|
|
}
|
|
}
|
|
|
|
if key != nil {
|
|
return &CommitVerification{ // Everything is ok
|
|
CommittingUser: committer,
|
|
Verified: true,
|
|
Reason: fmt.Sprintf("%s / %s", signer.Name, key.KeyID),
|
|
SigningUser: signer,
|
|
SigningKey: key,
|
|
SigningEmail: email,
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
func hashAndVerifyForKeyID(ctx context.Context, sig *packet.Signature, payload string, committer *user_model.User, keyID, name, email string) *CommitVerification {
|
|
if keyID == "" {
|
|
return nil
|
|
}
|
|
keys, err := db.Find[GPGKey](ctx, FindGPGKeyOptions{
|
|
KeyID: keyID,
|
|
IncludeSubKeys: true,
|
|
})
|
|
if err != nil {
|
|
log.Error("GetGPGKeysByKeyID: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.failed_retrieval_gpg_keys",
|
|
}
|
|
}
|
|
if len(keys) == 0 {
|
|
return nil
|
|
}
|
|
for _, key := range keys {
|
|
var primaryKeys []*GPGKey
|
|
if key.PrimaryKeyID != "" {
|
|
primaryKeys, err = db.Find[GPGKey](ctx, FindGPGKeyOptions{
|
|
KeyID: key.PrimaryKeyID,
|
|
IncludeSubKeys: true,
|
|
})
|
|
if err != nil {
|
|
log.Error("GetGPGKeysByKeyID: %v", err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.failed_retrieval_gpg_keys",
|
|
}
|
|
}
|
|
}
|
|
|
|
activated, email := checkKeyEmails(ctx, email, append([]*GPGKey{key}, primaryKeys...)...)
|
|
if !activated {
|
|
continue
|
|
}
|
|
|
|
signer := &user_model.User{
|
|
Name: name,
|
|
Email: email,
|
|
}
|
|
if key.OwnerID != 0 {
|
|
owner, err := user_model.GetUserByID(ctx, key.OwnerID)
|
|
if err == nil {
|
|
signer = owner
|
|
} else if !user_model.IsErrUserNotExist(err) {
|
|
log.Error("Failed to user_model.GetUserByID: %d for key ID: %d (%s) %v", key.OwnerID, key.ID, key.KeyID, err)
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Reason: "gpg.error.no_committer_account",
|
|
}
|
|
}
|
|
}
|
|
commitVerification := hashAndVerifyWithSubKeysCommitVerification(sig, payload, key, committer, signer, email)
|
|
if commitVerification != nil {
|
|
return commitVerification
|
|
}
|
|
}
|
|
// This is a bad situation ... We have a key id that is in our database but the signature doesn't match.
|
|
return &CommitVerification{
|
|
CommittingUser: committer,
|
|
Verified: false,
|
|
Warning: true,
|
|
Reason: BadSignature,
|
|
}
|
|
}
|
|
|
|
// CalculateTrustStatus will calculate the TrustStatus for a commit verification within a repository
|
|
// There are several trust models in Gitea
|
|
func CalculateTrustStatus(verification *CommitVerification, repoTrustModel repo_model.TrustModelType, isOwnerMemberCollaborator func(*user_model.User) (bool, error), keyMap *map[string]bool) error {
|
|
if !verification.Verified {
|
|
return nil
|
|
}
|
|
|
|
// In the Committer trust model a signature is trusted if it matches the committer
|
|
// - it doesn't matter if they're a collaborator, the owner, Gitea or Github
|
|
// NB: This model is commit verification only
|
|
if repoTrustModel == repo_model.CommitterTrustModel {
|
|
// default to "unmatched"
|
|
verification.TrustStatus = "unmatched"
|
|
|
|
// We can only verify against users in our database but the default key will match
|
|
// against by email if it is not in the db.
|
|
if (verification.SigningUser.ID != 0 &&
|
|
verification.CommittingUser.ID == verification.SigningUser.ID) ||
|
|
(verification.SigningUser.ID == 0 && verification.CommittingUser.ID == 0 &&
|
|
verification.SigningUser.Email == verification.CommittingUser.Email) {
|
|
verification.TrustStatus = "trusted"
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Now we drop to the more nuanced trust models...
|
|
verification.TrustStatus = "trusted"
|
|
|
|
if verification.SigningUser.ID == 0 {
|
|
// This commit is signed by the default key - but this key is not assigned to a user in the DB.
|
|
|
|
// However in the repo_model.CollaboratorCommitterTrustModel we cannot mark this as trusted
|
|
// unless the default key matches the email of a non-user.
|
|
if repoTrustModel == repo_model.CollaboratorCommitterTrustModel && (verification.CommittingUser.ID != 0 ||
|
|
verification.SigningUser.Email != verification.CommittingUser.Email) {
|
|
verification.TrustStatus = "untrusted"
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Check we actually have a GPG SigningKey
|
|
var err error
|
|
if verification.SigningKey != nil {
|
|
var isMember bool
|
|
if keyMap != nil {
|
|
var has bool
|
|
isMember, has = (*keyMap)[verification.SigningKey.KeyID]
|
|
if !has {
|
|
isMember, err = isOwnerMemberCollaborator(verification.SigningUser)
|
|
(*keyMap)[verification.SigningKey.KeyID] = isMember
|
|
}
|
|
} else {
|
|
isMember, err = isOwnerMemberCollaborator(verification.SigningUser)
|
|
}
|
|
|
|
if !isMember {
|
|
verification.TrustStatus = "untrusted"
|
|
if verification.CommittingUser.ID != verification.SigningUser.ID {
|
|
// The committing user and the signing user are not the same
|
|
// This should be marked as questionable unless the signing user is a collaborator/team member etc.
|
|
verification.TrustStatus = "unmatched"
|
|
}
|
|
} else if repoTrustModel == repo_model.CollaboratorCommitterTrustModel && verification.CommittingUser.ID != verification.SigningUser.ID {
|
|
// The committing user and the signing user are not the same and our trustmodel states that they must match
|
|
verification.TrustStatus = "unmatched"
|
|
}
|
|
}
|
|
|
|
return err
|
|
}
|