diff options
| -rw-r--r-- | internal/fusefrontend/node_openbackingdir.go | 68 | ||||
| -rw-r--r-- | internal/fusefrontend/root_node.go | 60 |
2 files changed, 60 insertions, 68 deletions
diff --git a/internal/fusefrontend/node_openbackingdir.go b/internal/fusefrontend/node_openbackingdir.go deleted file mode 100644 index 733c239..0000000 --- a/internal/fusefrontend/node_openbackingdir.go +++ /dev/null @@ -1,68 +0,0 @@ -package fusefrontend - -import ( - "path/filepath" - "strings" - "syscall" - - "github.com/rfjakob/gocryptfs/internal/nametransform" - "github.com/rfjakob/gocryptfs/internal/syscallcompat" -) - -// openBackingDir opens the parent ciphertext directory of plaintext path -// "relPath". It returns the dirfd (opened with O_PATH) and the encrypted -// basename. -// -// The caller should then use Openat(dirfd, cName, ...) and friends. -// For convenience, if relPath is "", cName is going to be ".". -// -// openBackingDir is secure against symlink races by using Openat and -// ReadDirIVAt. -func (rn *RootNode) openBackingDir(relPath string) (dirfd int, cName string, err error) { - dirRelPath := nametransform.Dir(relPath) - // With PlaintextNames, we don't need to read DirIVs. Easy. - if rn.args.PlaintextNames { - dirfd, err = syscallcompat.OpenDirNofollow(rn.args.Cipherdir, dirRelPath) - if err != nil { - return -1, "", err - } - // If relPath is empty, cName is ".". - cName = filepath.Base(relPath) - return dirfd, cName, nil - } - // Open cipherdir (following symlinks) - dirfd, err = syscall.Open(rn.args.Cipherdir, syscall.O_DIRECTORY|syscallcompat.O_PATH, 0) - if err != nil { - return -1, "", err - } - // If relPath is empty, cName is ".". - if relPath == "" { - return dirfd, ".", nil - } - // Walk the directory tree - parts := strings.Split(relPath, "/") - for i, name := range parts { - iv, err := nametransform.ReadDirIVAt(dirfd) - if err != nil { - syscall.Close(dirfd) - return -1, "", err - } - cName, err = rn.nameTransform.EncryptAndHashName(name, iv) - if err != nil { - syscall.Close(dirfd) - return -1, "", err - } - // Last part? We are done. - if i == len(parts)-1 { - break - } - // Not the last part? Descend into next directory. - dirfd2, err := syscallcompat.Openat(dirfd, cName, syscall.O_NOFOLLOW|syscall.O_DIRECTORY|syscallcompat.O_PATH, 0) - syscall.Close(dirfd) - if err != nil { - return -1, "", err - } - dirfd = dirfd2 - } - return dirfd, cName, nil -} diff --git a/internal/fusefrontend/root_node.go b/internal/fusefrontend/root_node.go index 2689e05..cf23169 100644 --- a/internal/fusefrontend/root_node.go +++ b/internal/fusefrontend/root_node.go @@ -2,6 +2,8 @@ package fusefrontend import ( "os" + "path/filepath" + "strings" "sync" "sync/atomic" "syscall" @@ -185,3 +187,61 @@ func (rn *RootNode) openWriteOnlyFile(dirfd int, cName string, newFlags int) (rw }() return syscallcompat.Openat(dirfd, cName, newFlags, 0) } + +// openBackingDir opens the parent ciphertext directory of plaintext path +// "relPath". It returns the dirfd (opened with O_PATH) and the encrypted +// basename. +// +// The caller should then use Openat(dirfd, cName, ...) and friends. +// For convenience, if relPath is "", cName is going to be ".". +// +// openBackingDir is secure against symlink races by using Openat and +// ReadDirIVAt. +func (rn *RootNode) openBackingDir(relPath string) (dirfd int, cName string, err error) { + dirRelPath := nametransform.Dir(relPath) + // With PlaintextNames, we don't need to read DirIVs. Easy. + if rn.args.PlaintextNames { + dirfd, err = syscallcompat.OpenDirNofollow(rn.args.Cipherdir, dirRelPath) + if err != nil { + return -1, "", err + } + // If relPath is empty, cName is ".". + cName = filepath.Base(relPath) + return dirfd, cName, nil + } + // Open cipherdir (following symlinks) + dirfd, err = syscall.Open(rn.args.Cipherdir, syscall.O_DIRECTORY|syscallcompat.O_PATH, 0) + if err != nil { + return -1, "", err + } + // If relPath is empty, cName is ".". + if relPath == "" { + return dirfd, ".", nil + } + // Walk the directory tree + parts := strings.Split(relPath, "/") + for i, name := range parts { + iv, err := nametransform.ReadDirIVAt(dirfd) + if err != nil { + syscall.Close(dirfd) + return -1, "", err + } + cName, err = rn.nameTransform.EncryptAndHashName(name, iv) + if err != nil { + syscall.Close(dirfd) + return -1, "", err + } + // Last part? We are done. + if i == len(parts)-1 { + break + } + // Not the last part? Descend into next directory. + dirfd2, err := syscallcompat.Openat(dirfd, cName, syscall.O_NOFOLLOW|syscall.O_DIRECTORY|syscallcompat.O_PATH, 0) + syscall.Close(dirfd) + if err != nil { + return -1, "", err + } + dirfd = dirfd2 + } + return dirfd, cName, nil +} |