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authorDaniel J Walsh <dwalsh@redhat.com>2018-07-08 07:55:30 -0400
committerAtomic Bot <atomic-devel@projectatomic.io>2018-07-19 18:43:32 +0000
commit98703eb204923f06555605c648fc165a55214520 (patch)
treea407bae8b3489d4f9b0f0d0f228658bbfe95a38e /vendor/github.com/ulikunitz/xz/format.go
parentc020db8cd21cb221cfbe36b264e0ec02999596ed (diff)
downloadpodman-98703eb204923f06555605c648fc165a55214520.tar.gz
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Vendor in latest code for storage,image, buildah
vendor in containers/storage vendor in containers/image vendor in projectatomic/buildah Signed-off-by: Daniel J Walsh <dwalsh@redhat.com> Closes: #1114 Approved by: mheon
Diffstat (limited to 'vendor/github.com/ulikunitz/xz/format.go')
-rw-r--r--vendor/github.com/ulikunitz/xz/format.go728
1 files changed, 728 insertions, 0 deletions
diff --git a/vendor/github.com/ulikunitz/xz/format.go b/vendor/github.com/ulikunitz/xz/format.go
new file mode 100644
index 000000000..798159c6c
--- /dev/null
+++ b/vendor/github.com/ulikunitz/xz/format.go
@@ -0,0 +1,728 @@
+// Copyright 2014-2017 Ulrich Kunitz. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package xz
+
+import (
+ "bytes"
+ "crypto/sha256"
+ "errors"
+ "fmt"
+ "hash"
+ "hash/crc32"
+ "io"
+
+ "github.com/ulikunitz/xz/lzma"
+)
+
+// allZeros checks whether a given byte slice has only zeros.
+func allZeros(p []byte) bool {
+ for _, c := range p {
+ if c != 0 {
+ return false
+ }
+ }
+ return true
+}
+
+// padLen returns the length of the padding required for the given
+// argument.
+func padLen(n int64) int {
+ k := int(n % 4)
+ if k > 0 {
+ k = 4 - k
+ }
+ return k
+}
+
+/*** Header ***/
+
+// headerMagic stores the magic bytes for the header
+var headerMagic = []byte{0xfd, '7', 'z', 'X', 'Z', 0x00}
+
+// HeaderLen provides the length of the xz file header.
+const HeaderLen = 12
+
+// Constants for the checksum methods supported by xz.
+const (
+ CRC32 byte = 0x1
+ CRC64 = 0x4
+ SHA256 = 0xa
+)
+
+// errInvalidFlags indicates that flags are invalid.
+var errInvalidFlags = errors.New("xz: invalid flags")
+
+// verifyFlags returns the error errInvalidFlags if the value is
+// invalid.
+func verifyFlags(flags byte) error {
+ switch flags {
+ case CRC32, CRC64, SHA256:
+ return nil
+ default:
+ return errInvalidFlags
+ }
+}
+
+// flagstrings maps flag values to strings.
+var flagstrings = map[byte]string{
+ CRC32: "CRC-32",
+ CRC64: "CRC-64",
+ SHA256: "SHA-256",
+}
+
+// flagString returns the string representation for the given flags.
+func flagString(flags byte) string {
+ s, ok := flagstrings[flags]
+ if !ok {
+ return "invalid"
+ }
+ return s
+}
+
+// newHashFunc returns a function that creates hash instances for the
+// hash method encoded in flags.
+func newHashFunc(flags byte) (newHash func() hash.Hash, err error) {
+ switch flags {
+ case CRC32:
+ newHash = newCRC32
+ case CRC64:
+ newHash = newCRC64
+ case SHA256:
+ newHash = sha256.New
+ default:
+ err = errInvalidFlags
+ }
+ return
+}
+
+// header provides the actual content of the xz file header: the flags.
+type header struct {
+ flags byte
+}
+
+// Errors returned by readHeader.
+var errHeaderMagic = errors.New("xz: invalid header magic bytes")
+
+// ValidHeader checks whether data is a correct xz file header. The
+// length of data must be HeaderLen.
+func ValidHeader(data []byte) bool {
+ var h header
+ err := h.UnmarshalBinary(data)
+ return err == nil
+}
+
+// String returns a string representation of the flags.
+func (h header) String() string {
+ return flagString(h.flags)
+}
+
+// UnmarshalBinary reads header from the provided data slice.
+func (h *header) UnmarshalBinary(data []byte) error {
+ // header length
+ if len(data) != HeaderLen {
+ return errors.New("xz: wrong file header length")
+ }
+
+ // magic header
+ if !bytes.Equal(headerMagic, data[:6]) {
+ return errHeaderMagic
+ }
+
+ // checksum
+ crc := crc32.NewIEEE()
+ crc.Write(data[6:8])
+ if uint32LE(data[8:]) != crc.Sum32() {
+ return errors.New("xz: invalid checksum for file header")
+ }
+
+ // stream flags
+ if data[6] != 0 {
+ return errInvalidFlags
+ }
+ flags := data[7]
+ if err := verifyFlags(flags); err != nil {
+ return err
+ }
+
+ h.flags = flags
+ return nil
+}
+
+// MarshalBinary generates the xz file header.
+func (h *header) MarshalBinary() (data []byte, err error) {
+ if err = verifyFlags(h.flags); err != nil {
+ return nil, err
+ }
+
+ data = make([]byte, 12)
+ copy(data, headerMagic)
+ data[7] = h.flags
+
+ crc := crc32.NewIEEE()
+ crc.Write(data[6:8])
+ putUint32LE(data[8:], crc.Sum32())
+
+ return data, nil
+}
+
+/*** Footer ***/
+
+// footerLen defines the length of the footer.
+const footerLen = 12
+
+// footerMagic contains the footer magic bytes.
+var footerMagic = []byte{'Y', 'Z'}
+
+// footer represents the content of the xz file footer.
+type footer struct {
+ indexSize int64
+ flags byte
+}
+
+// String prints a string representation of the footer structure.
+func (f footer) String() string {
+ return fmt.Sprintf("%s index size %d", flagString(f.flags), f.indexSize)
+}
+
+// Minimum and maximum for the size of the index (backward size).
+const (
+ minIndexSize = 4
+ maxIndexSize = (1 << 32) * 4
+)
+
+// MarshalBinary converts footer values into an xz file footer. Note
+// that the footer value is checked for correctness.
+func (f *footer) MarshalBinary() (data []byte, err error) {
+ if err = verifyFlags(f.flags); err != nil {
+ return nil, err
+ }
+ if !(minIndexSize <= f.indexSize && f.indexSize <= maxIndexSize) {
+ return nil, errors.New("xz: index size out of range")
+ }
+ if f.indexSize%4 != 0 {
+ return nil, errors.New(
+ "xz: index size not aligned to four bytes")
+ }
+
+ data = make([]byte, footerLen)
+
+ // backward size (index size)
+ s := (f.indexSize / 4) - 1
+ putUint32LE(data[4:], uint32(s))
+ // flags
+ data[9] = f.flags
+ // footer magic
+ copy(data[10:], footerMagic)
+
+ // CRC-32
+ crc := crc32.NewIEEE()
+ crc.Write(data[4:10])
+ putUint32LE(data, crc.Sum32())
+
+ return data, nil
+}
+
+// UnmarshalBinary sets the footer value by unmarshalling an xz file
+// footer.
+func (f *footer) UnmarshalBinary(data []byte) error {
+ if len(data) != footerLen {
+ return errors.New("xz: wrong footer length")
+ }
+
+ // magic bytes
+ if !bytes.Equal(data[10:], footerMagic) {
+ return errors.New("xz: footer magic invalid")
+ }
+
+ // CRC-32
+ crc := crc32.NewIEEE()
+ crc.Write(data[4:10])
+ if uint32LE(data) != crc.Sum32() {
+ return errors.New("xz: footer checksum error")
+ }
+
+ var g footer
+ // backward size (index size)
+ g.indexSize = (int64(uint32LE(data[4:])) + 1) * 4
+
+ // flags
+ if data[8] != 0 {
+ return errInvalidFlags
+ }
+ g.flags = data[9]
+ if err := verifyFlags(g.flags); err != nil {
+ return err
+ }
+
+ *f = g
+ return nil
+}
+
+/*** Block Header ***/
+
+// blockHeader represents the content of an xz block header.
+type blockHeader struct {
+ compressedSize int64
+ uncompressedSize int64
+ filters []filter
+}
+
+// String converts the block header into a string.
+func (h blockHeader) String() string {
+ var buf bytes.Buffer
+ first := true
+ if h.compressedSize >= 0 {
+ fmt.Fprintf(&buf, "compressed size %d", h.compressedSize)
+ first = false
+ }
+ if h.uncompressedSize >= 0 {
+ if !first {
+ buf.WriteString(" ")
+ }
+ fmt.Fprintf(&buf, "uncompressed size %d", h.uncompressedSize)
+ first = false
+ }
+ for _, f := range h.filters {
+ if !first {
+ buf.WriteString(" ")
+ }
+ fmt.Fprintf(&buf, "filter %s", f)
+ first = false
+ }
+ return buf.String()
+}
+
+// Masks for the block flags.
+const (
+ filterCountMask = 0x03
+ compressedSizePresent = 0x40
+ uncompressedSizePresent = 0x80
+ reservedBlockFlags = 0x3C
+)
+
+// errIndexIndicator signals that an index indicator (0x00) has been found
+// instead of an expected block header indicator.
+var errIndexIndicator = errors.New("xz: found index indicator")
+
+// readBlockHeader reads the block header.
+func readBlockHeader(r io.Reader) (h *blockHeader, n int, err error) {
+ var buf bytes.Buffer
+ buf.Grow(20)
+
+ // block header size
+ z, err := io.CopyN(&buf, r, 1)
+ n = int(z)
+ if err != nil {
+ return nil, n, err
+ }
+ s := buf.Bytes()[0]
+ if s == 0 {
+ return nil, n, errIndexIndicator
+ }
+
+ // read complete header
+ headerLen := (int(s) + 1) * 4
+ buf.Grow(headerLen - 1)
+ z, err = io.CopyN(&buf, r, int64(headerLen-1))
+ n += int(z)
+ if err != nil {
+ return nil, n, err
+ }
+
+ // unmarshal block header
+ h = new(blockHeader)
+ if err = h.UnmarshalBinary(buf.Bytes()); err != nil {
+ return nil, n, err
+ }
+
+ return h, n, nil
+}
+
+// readSizeInBlockHeader reads the uncompressed or compressed size
+// fields in the block header. The present value informs the function
+// whether the respective field is actually present in the header.
+func readSizeInBlockHeader(r io.ByteReader, present bool) (n int64, err error) {
+ if !present {
+ return -1, nil
+ }
+ x, _, err := readUvarint(r)
+ if err != nil {
+ return 0, err
+ }
+ if x >= 1<<63 {
+ return 0, errors.New("xz: size overflow in block header")
+ }
+ return int64(x), nil
+}
+
+// UnmarshalBinary unmarshals the block header.
+func (h *blockHeader) UnmarshalBinary(data []byte) error {
+ // Check header length
+ s := data[0]
+ if data[0] == 0 {
+ return errIndexIndicator
+ }
+ headerLen := (int(s) + 1) * 4
+ if len(data) != headerLen {
+ return fmt.Errorf("xz: data length %d; want %d", len(data),
+ headerLen)
+ }
+ n := headerLen - 4
+
+ // Check CRC-32
+ crc := crc32.NewIEEE()
+ crc.Write(data[:n])
+ if crc.Sum32() != uint32LE(data[n:]) {
+ return errors.New("xz: checksum error for block header")
+ }
+
+ // Block header flags
+ flags := data[1]
+ if flags&reservedBlockFlags != 0 {
+ return errors.New("xz: reserved block header flags set")
+ }
+
+ r := bytes.NewReader(data[2:n])
+
+ // Compressed size
+ var err error
+ h.compressedSize, err = readSizeInBlockHeader(
+ r, flags&compressedSizePresent != 0)
+ if err != nil {
+ return err
+ }
+
+ // Uncompressed size
+ h.uncompressedSize, err = readSizeInBlockHeader(
+ r, flags&uncompressedSizePresent != 0)
+ if err != nil {
+ return err
+ }
+
+ h.filters, err = readFilters(r, int(flags&filterCountMask)+1)
+ if err != nil {
+ return err
+ }
+
+ // Check padding
+ // Since headerLen is a multiple of 4 we don't need to check
+ // alignment.
+ k := r.Len()
+ // The standard spec says that the padding should have not more
+ // than 3 bytes. However we found paddings of 4 or 5 in the
+ // wild. See https://github.com/ulikunitz/xz/pull/11 and
+ // https://github.com/ulikunitz/xz/issues/15
+ //
+ // The only reasonable approach seems to be to ignore the
+ // padding size. We still check that all padding bytes are zero.
+ if !allZeros(data[n-k : n]) {
+ return errPadding
+ }
+ return nil
+}
+
+// MarshalBinary marshals the binary header.
+func (h *blockHeader) MarshalBinary() (data []byte, err error) {
+ if !(minFilters <= len(h.filters) && len(h.filters) <= maxFilters) {
+ return nil, errors.New("xz: filter count wrong")
+ }
+ for i, f := range h.filters {
+ if i < len(h.filters)-1 {
+ if f.id() == lzmaFilterID {
+ return nil, errors.New(
+ "xz: LZMA2 filter is not the last")
+ }
+ } else {
+ // last filter
+ if f.id() != lzmaFilterID {
+ return nil, errors.New("xz: " +
+ "last filter must be the LZMA2 filter")
+ }
+ }
+ }
+
+ var buf bytes.Buffer
+ // header size must set at the end
+ buf.WriteByte(0)
+
+ // flags
+ flags := byte(len(h.filters) - 1)
+ if h.compressedSize >= 0 {
+ flags |= compressedSizePresent
+ }
+ if h.uncompressedSize >= 0 {
+ flags |= uncompressedSizePresent
+ }
+ buf.WriteByte(flags)
+
+ p := make([]byte, 10)
+ if h.compressedSize >= 0 {
+ k := putUvarint(p, uint64(h.compressedSize))
+ buf.Write(p[:k])
+ }
+ if h.uncompressedSize >= 0 {
+ k := putUvarint(p, uint64(h.uncompressedSize))
+ buf.Write(p[:k])
+ }
+
+ for _, f := range h.filters {
+ fp, err := f.MarshalBinary()
+ if err != nil {
+ return nil, err
+ }
+ buf.Write(fp)
+ }
+
+ // padding
+ for i := padLen(int64(buf.Len())); i > 0; i-- {
+ buf.WriteByte(0)
+ }
+
+ // crc place holder
+ buf.Write(p[:4])
+
+ data = buf.Bytes()
+ if len(data)%4 != 0 {
+ panic("data length not aligned")
+ }
+ s := len(data)/4 - 1
+ if !(1 < s && s <= 255) {
+ panic("wrong block header size")
+ }
+ data[0] = byte(s)
+
+ crc := crc32.NewIEEE()
+ crc.Write(data[:len(data)-4])
+ putUint32LE(data[len(data)-4:], crc.Sum32())
+
+ return data, nil
+}
+
+// Constants used for marshalling and unmarshalling filters in the xz
+// block header.
+const (
+ minFilters = 1
+ maxFilters = 4
+ minReservedID = 1 << 62
+)
+
+// filter represents a filter in the block header.
+type filter interface {
+ id() uint64
+ UnmarshalBinary(data []byte) error
+ MarshalBinary() (data []byte, err error)
+ reader(r io.Reader, c *ReaderConfig) (fr io.Reader, err error)
+ writeCloser(w io.WriteCloser, c *WriterConfig) (fw io.WriteCloser, err error)
+ // filter must be last filter
+ last() bool
+}
+
+// readFilter reads a block filter from the block header. At this point
+// in time only the LZMA2 filter is supported.
+func readFilter(r io.Reader) (f filter, err error) {
+ br := lzma.ByteReader(r)
+
+ // index
+ id, _, err := readUvarint(br)
+ if err != nil {
+ return nil, err
+ }
+
+ var data []byte
+ switch id {
+ case lzmaFilterID:
+ data = make([]byte, lzmaFilterLen)
+ data[0] = lzmaFilterID
+ if _, err = io.ReadFull(r, data[1:]); err != nil {
+ return nil, err
+ }
+ f = new(lzmaFilter)
+ default:
+ if id >= minReservedID {
+ return nil, errors.New(
+ "xz: reserved filter id in block stream header")
+ }
+ return nil, errors.New("xz: invalid filter id")
+ }
+ if err = f.UnmarshalBinary(data); err != nil {
+ return nil, err
+ }
+ return f, err
+}
+
+// readFilters reads count filters. At this point in time only the count
+// 1 is supported.
+func readFilters(r io.Reader, count int) (filters []filter, err error) {
+ if count != 1 {
+ return nil, errors.New("xz: unsupported filter count")
+ }
+ f, err := readFilter(r)
+ if err != nil {
+ return nil, err
+ }
+ return []filter{f}, err
+}
+
+// writeFilters writes the filters.
+func writeFilters(w io.Writer, filters []filter) (n int, err error) {
+ for _, f := range filters {
+ p, err := f.MarshalBinary()
+ if err != nil {
+ return n, err
+ }
+ k, err := w.Write(p)
+ n += k
+ if err != nil {
+ return n, err
+ }
+ }
+ return n, nil
+}
+
+/*** Index ***/
+
+// record describes a block in the xz file index.
+type record struct {
+ unpaddedSize int64
+ uncompressedSize int64
+}
+
+// readRecord reads an index record.
+func readRecord(r io.ByteReader) (rec record, n int, err error) {
+ u, k, err := readUvarint(r)
+ n += k
+ if err != nil {
+ return rec, n, err
+ }
+ rec.unpaddedSize = int64(u)
+ if rec.unpaddedSize < 0 {
+ return rec, n, errors.New("xz: unpadded size negative")
+ }
+
+ u, k, err = readUvarint(r)
+ n += k
+ if err != nil {
+ return rec, n, err
+ }
+ rec.uncompressedSize = int64(u)
+ if rec.uncompressedSize < 0 {
+ return rec, n, errors.New("xz: uncompressed size negative")
+ }
+
+ return rec, n, nil
+}
+
+// MarshalBinary converts an index record in its binary encoding.
+func (rec *record) MarshalBinary() (data []byte, err error) {
+ // maximum length of a uvarint is 10
+ p := make([]byte, 20)
+ n := putUvarint(p, uint64(rec.unpaddedSize))
+ n += putUvarint(p[n:], uint64(rec.uncompressedSize))
+ return p[:n], nil
+}
+
+// writeIndex writes the index, a sequence of records.
+func writeIndex(w io.Writer, index []record) (n int64, err error) {
+ crc := crc32.NewIEEE()
+ mw := io.MultiWriter(w, crc)
+
+ // index indicator
+ k, err := mw.Write([]byte{0})
+ n += int64(k)
+ if err != nil {
+ return n, err
+ }
+
+ // number of records
+ p := make([]byte, 10)
+ k = putUvarint(p, uint64(len(index)))
+ k, err = mw.Write(p[:k])
+ n += int64(k)
+ if err != nil {
+ return n, err
+ }
+
+ // list of records
+ for _, rec := range index {
+ p, err := rec.MarshalBinary()
+ if err != nil {
+ return n, err
+ }
+ k, err = mw.Write(p)
+ n += int64(k)
+ if err != nil {
+ return n, err
+ }
+ }
+
+ // index padding
+ k, err = mw.Write(make([]byte, padLen(int64(n))))
+ n += int64(k)
+ if err != nil {
+ return n, err
+ }
+
+ // crc32 checksum
+ putUint32LE(p, crc.Sum32())
+ k, err = w.Write(p[:4])
+ n += int64(k)
+
+ return n, err
+}
+
+// readIndexBody reads the index from the reader. It assumes that the
+// index indicator has already been read.
+func readIndexBody(r io.Reader) (records []record, n int64, err error) {
+ crc := crc32.NewIEEE()
+ // index indicator
+ crc.Write([]byte{0})
+
+ br := lzma.ByteReader(io.TeeReader(r, crc))
+
+ // number of records
+ u, k, err := readUvarint(br)
+ n += int64(k)
+ if err != nil {
+ return nil, n, err
+ }
+ recLen := int(u)
+ if recLen < 0 || uint64(recLen) != u {
+ return nil, n, errors.New("xz: record number overflow")
+ }
+
+ // list of records
+ records = make([]record, recLen)
+ for i := range records {
+ records[i], k, err = readRecord(br)
+ n += int64(k)
+ if err != nil {
+ return nil, n, err
+ }
+ }
+
+ p := make([]byte, padLen(int64(n+1)), 4)
+ k, err = io.ReadFull(br.(io.Reader), p)
+ n += int64(k)
+ if err != nil {
+ return nil, n, err
+ }
+ if !allZeros(p) {
+ return nil, n, errors.New("xz: non-zero byte in index padding")
+ }
+
+ // crc32
+ s := crc.Sum32()
+ p = p[:4]
+ k, err = io.ReadFull(br.(io.Reader), p)
+ n += int64(k)
+ if err != nil {
+ return records, n, err
+ }
+ if uint32LE(p) != s {
+ return nil, n, errors.New("xz: wrong checksum for index")
+ }
+
+ return records, n, nil
+}