2.16

This security release fixes memory-safety vulnerabilities when processing
untrusted files. Users are strongly encouraged to upgrade.

Security fixes

• fixed heap overflow when extracting script signature blocks larger than
  2 GiB (thanks to Lucidsec for reporting the issue)
• fixed buffer overflows in script UTF conversions on 32-bit builds, and
  out-of-bounds reads in scripts with odd UTF-16 sizes or signature blocks
  at the start of the file
• fixed double free and invalid memory reads when verifying malformed
  PKCS#7 content with OpenSSL older than 3.5 (thanks to smaeljaish771 for
  reporting the double free)
• fixed use-after-free and double free of CRLs embedded in signatures;
  these CRLs can be added to signed files without invalidating signatures
• fixed invalid pointer use with non-signedData Authenticode timestamp
  responses, MSI signatures, and "-spc" or "-certs" files
• fixed crashes on signatures or nested signatures with missing PKCS#7
  content (thanks to Małgorzata Olszówka)
• fixed invalid pointer dereferences when processing malformed catalog
  members, PE page hashes, or PKCS#7 certificate files without certificates
• fixed process memory disclosure into output files when PE or CAB
  signature offsets overlap headers, and out-of-bounds reads when parsing
  PE headers near the end of files approaching 4 GiB
• fixed out-of-bounds reads and possible memory disclosure with truncated
  CAB headers or unterminated cabinet names; malformed names are also
  rejected during digest calculation (thanks to Małgorzata Olszówka)
• fixed out-of-bounds reads in truncated MSI files and invalid sector
  references, and stack exhaustion with long directory chains or deeply
  nested storages
• fixed stack buffer overflow with oversized "-readpass" files on Windows,
  and buffer underflow with "-askpass" input starting with a NUL character
• enabled ASLR in prebuilt Linux binaries through static PIE, and added
  build metadata

Other user-visible changes

• fixed corrupted output and failed verification when signing MSI files
  with empty or nested storages, or signing/removing signatures when the
  output has no streams smaller than 4 KiB
• fixed replacing or removing duplicate MSI DigitalSignature streams
• fixed opening MSI files whose directory starts at the first sector, and
  spurious sector-chain errors when reading MSI streams
• fixed crashes and invalid output on memory allocation failures during
  MSI signing and script UTF conversion
• fixed "remove-signature" reporting success and keeping truncated output
  for CAB files with corrupted headers
• fixed "-askpass" truncating passwords not terminated with a newline
• made warnings about ignored file-format options consistent and removed
  duplicate warnings
• included license files in prebuilt binary archives

Downloads

Source and tested binaries are included for Linux (x86-64 and ARM64),
Windows (x86-64 and ARM64), and macOS (x86-64).

The macOS ARM64 binary is not included: GitHub could not allocate a hosted
runner, and that job never started. All five included binary build/test jobs
passed. Publication was not delayed further because the security fixes are
already public. The source is available for building on macOS ARM64.

Verifying downloads

Every archive, BUILDINFO.json, and SHA256SUMS.txt has an ASCII-armored
detached GPG signature (.asc), signed with Michał Trojnara's key:

AC91 5EA3 0645 D9D3 D4DA E4FE B104 8932 DD3A AAA3

Using a trusted copy of this public key, authenticate the checksum manifest
before checking the downloaded files:

gpg --verify SHA256SUMS.txt.asc SHA256SUMS.txt
sha256sum -c SHA256SUMS.txt

Individual archives can also be verified directly, for example:

gpg --verify osslsigncode-2.16.tar.gz.asc osslsigncode-2.16.tar.gz

BUILDINFO.json records the source commit, workflow commit, successful binary
jobs, and GitHub artifact digests. The workflow stopped before its attestation
job, so this release uses GPG signatures, not GitHub artifact attestations.