diff options
Diffstat (limited to 'plumbing')
| -rw-r--r-- | plumbing/format/packfile/delta_test.go | 24 | ||||
| -rw-r--r-- | plumbing/format/packfile/patch_delta.go | 77 |
2 files changed, 85 insertions, 16 deletions
diff --git a/plumbing/format/packfile/delta_test.go b/plumbing/format/packfile/delta_test.go index 9ee3499..42b777a 100644 --- a/plumbing/format/packfile/delta_test.go +++ b/plumbing/format/packfile/delta_test.go @@ -1,7 +1,6 @@ package packfile import ( - "fmt" "math/rand" . "gopkg.in/check.v1" @@ -86,9 +85,28 @@ func (s *DeltaSuite) TestAddDelta(c *C) { baseBuf := genBytes(t.base) targetBuf := genBytes(t.target) delta := DiffDelta(baseBuf, targetBuf) - result := PatchDelta(baseBuf, delta) + result, err := PatchDelta(baseBuf, delta) - c.Log(fmt.Printf("Executing test case: %s\n", t.description)) + c.Log("Executing test case:", t.description) + c.Assert(err, IsNil) c.Assert(result, DeepEquals, targetBuf) } } + +func (s *DeltaSuite) TestIncompleteDelta(c *C) { + for _, t := range s.testCases { + c.Log("Incomplete delta on:", t.description) + baseBuf := genBytes(t.base) + targetBuf := genBytes(t.target) + delta := DiffDelta(baseBuf, targetBuf) + delta = delta[:len(delta)-2] + result, err := PatchDelta(baseBuf, delta) + c.Assert(err, NotNil) + c.Assert(result, IsNil) + } + + // check nil input too + result, err := PatchDelta(nil, nil) + c.Assert(err, NotNil) + c.Assert(result, IsNil) +} diff --git a/plumbing/format/packfile/patch_delta.go b/plumbing/format/packfile/patch_delta.go index 840f840..976cabc 100644 --- a/plumbing/format/packfile/patch_delta.go +++ b/plumbing/format/packfile/patch_delta.go @@ -1,6 +1,7 @@ package packfile import ( + "errors" "io/ioutil" "gopkg.in/src-d/go-git.v4/plumbing" @@ -30,7 +31,11 @@ func ApplyDelta(target, base plumbing.EncodedObject, delta []byte) error { return err } - dst := PatchDelta(src, delta) + dst, err := PatchDelta(src, delta) + if err != nil { + return err + } + target.SetSize(int64(len(dst))) if _, err := w.Write(dst); err != nil { @@ -40,15 +45,22 @@ func ApplyDelta(target, base plumbing.EncodedObject, delta []byte) error { return nil } +var ( + ErrInvalidDelta = errors.New("invalid delta") + ErrDeltaCmd = errors.New("wrong delta command") +) + // PatchDelta returns the result of applying the modification deltas in delta to src. -func PatchDelta(src, delta []byte) []byte { +// An error will be returned if delta is corrupted (ErrDeltaLen) or an action command +// is not copy from source or copy from delta (ErrDeltaCmd). +func PatchDelta(src, delta []byte) ([]byte, error) { if len(delta) < deltaSizeMin { - return nil + return nil, ErrInvalidDelta } srcSz, delta := decodeLEB128(delta) if srcSz != uint(len(src)) { - return nil + return nil, ErrInvalidDelta } targetSz, delta := decodeLEB128(delta) @@ -57,12 +69,25 @@ func PatchDelta(src, delta []byte) []byte { var dest []byte var cmd byte for { + if len(delta) == 0 { + return nil, ErrInvalidDelta + } + cmd = delta[0] delta = delta[1:] if isCopyFromSrc(cmd) { var offset, sz uint - offset, delta = decodeOffset(cmd, delta) - sz, delta = decodeSize(cmd, delta) + var err error + offset, delta, err = decodeOffset(cmd, delta) + if err != nil { + return nil, err + } + + sz, delta, err = decodeSize(cmd, delta) + if err != nil { + return nil, err + } + if invalidSize(sz, targetSz) || invalidOffsetSize(offset, sz, srcSz) { break @@ -72,13 +97,18 @@ func PatchDelta(src, delta []byte) []byte { } else if isCopyFromDelta(cmd) { sz := uint(cmd) // cmd is the size itself if invalidSize(sz, targetSz) { - break + return nil, ErrInvalidDelta + } + + if uint(len(delta)) < sz { + return nil, ErrInvalidDelta } + dest = append(dest, delta[0:sz]...) remainingTargetSz -= sz delta = delta[sz:] } else { - return nil + return nil, ErrDeltaCmd } if remainingTargetSz <= 0 { @@ -86,7 +116,7 @@ func PatchDelta(src, delta []byte) []byte { } } - return dest + return dest, nil } // Decodes a number encoded as an unsigned LEB128 at the start of some @@ -124,39 +154,60 @@ func isCopyFromDelta(cmd byte) bool { return (cmd&0x80) == 0 && cmd != 0 } -func decodeOffset(cmd byte, delta []byte) (uint, []byte) { +func decodeOffset(cmd byte, delta []byte) (uint, []byte, error) { var offset uint if (cmd & 0x01) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } offset = uint(delta[0]) delta = delta[1:] } if (cmd & 0x02) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } offset |= uint(delta[0]) << 8 delta = delta[1:] } if (cmd & 0x04) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } offset |= uint(delta[0]) << 16 delta = delta[1:] } if (cmd & 0x08) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } offset |= uint(delta[0]) << 24 delta = delta[1:] } - return offset, delta + return offset, delta, nil } -func decodeSize(cmd byte, delta []byte) (uint, []byte) { +func decodeSize(cmd byte, delta []byte) (uint, []byte, error) { var sz uint if (cmd & 0x10) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } sz = uint(delta[0]) delta = delta[1:] } if (cmd & 0x20) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } sz |= uint(delta[0]) << 8 delta = delta[1:] } if (cmd & 0x40) != 0 { + if len(delta) == 0 { + return 0, nil, ErrInvalidDelta + } sz |= uint(delta[0]) << 16 delta = delta[1:] } @@ -164,7 +215,7 @@ func decodeSize(cmd byte, delta []byte) (uint, []byte) { sz = 0x10000 } - return sz, delta + return sz, delta, nil } func invalidSize(sz, targetSz uint) bool { |