mattermost-community-enterp.../vendor/github.com/bodgit/sevenzip/internal/aes7z/reader.go
Claude ec1f89217a Merge: Complete Mattermost Server with Community Enterprise
Full Mattermost server source with integrated Community Enterprise features.
Includes vendor directory for offline/air-gapped builds.

Structure:
- enterprise-impl/: Enterprise feature implementations
- enterprise-community/: Init files that register implementations
- enterprise/: Bridge imports (community_imports.go)
- vendor/: All dependencies for offline builds

Build (online):
  go build ./cmd/mattermost

Build (offline/air-gapped):
  go build -mod=vendor ./cmd/mattermost

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>
2025-12-17 23:59:07 +09:00

127 lines
2.5 KiB
Go

// Package aes7z implements the 7-zip AES decryption.
package aes7z
import (
"bytes"
"crypto/aes"
"crypto/cipher"
"errors"
"fmt"
"io"
)
var (
errAlreadyClosed = errors.New("aes7z: already closed")
errNeedOneReader = errors.New("aes7z: need exactly one reader")
errInsufficientProperties = errors.New("aes7z: not enough properties")
errNoPasswordSet = errors.New("aes7z: no password set")
errUnsupportedMethod = errors.New("aes7z: unsupported compression method")
)
type readCloser struct {
rc io.ReadCloser
salt, iv []byte
cycles int
cbc cipher.BlockMode
buf bytes.Buffer
}
func (rc *readCloser) Close() error {
if rc.rc == nil {
return errAlreadyClosed
}
if err := rc.rc.Close(); err != nil {
return fmt.Errorf("aes7z: error closing: %w", err)
}
rc.rc = nil
return nil
}
func (rc *readCloser) Password(p string) error {
key, err := calculateKey(p, rc.cycles, rc.salt)
if err != nil {
return err
}
block, err := aes.NewCipher(key)
if err != nil {
return fmt.Errorf("aes7z: error creating cipher: %w", err)
}
rc.cbc = cipher.NewCBCDecrypter(block, rc.iv)
return nil
}
func (rc *readCloser) Read(p []byte) (int, error) {
if rc.rc == nil {
return 0, errAlreadyClosed
}
if rc.cbc == nil {
return 0, errNoPasswordSet
}
var block [aes.BlockSize]byte
for rc.buf.Len() < len(p) {
if _, err := io.ReadFull(rc.rc, block[:]); err != nil {
if errors.Is(err, io.EOF) {
break
}
return 0, fmt.Errorf("aes7z: error reading block: %w", err)
}
rc.cbc.CryptBlocks(block[:], block[:])
_, _ = rc.buf.Write(block[:])
}
n, err := rc.buf.Read(p)
if err != nil && !errors.Is(err, io.EOF) {
err = fmt.Errorf("aes7z: error reading: %w", err)
}
return n, err
}
// NewReader returns a new AES-256-CBC & SHA-256 io.ReadCloser. The Password
// method must be called before attempting to call Read so that the block
// cipher is correctly initialised.
func NewReader(p []byte, _ uint64, readers []io.ReadCloser) (io.ReadCloser, error) {
if len(readers) != 1 {
return nil, errNeedOneReader
}
// Need at least two bytes initially
if len(p) < 2 {
return nil, errInsufficientProperties
}
if p[0]&0xc0 == 0 {
return nil, errUnsupportedMethod
}
rc := new(readCloser)
salt := p[0]>>7&1 + p[1]>>4
iv := p[0]>>6&1 + p[1]&0x0f
if len(p) != int(2+salt+iv) {
return nil, errInsufficientProperties
}
rc.salt = p[2 : 2+salt]
rc.iv = make([]byte, aes.BlockSize)
copy(rc.iv, p[2+salt:])
rc.cycles = int(p[0] & 0x3f)
rc.rc = readers[0]
return rc, nil
}