C5: restrict the TLS 1.2 and below cipher list to ECDHE AEAD suites
(ECDHE+AESGCM:ECDHE+CHACHA20, minus NULL/eNULL/MD5/RC4/3DES) instead of
HIGH (which includes CBC), and set SSL_OP_CIPHER_SERVER_PREFERENCE so the
server's order decides the negotiated cipher. Client and server share
create_ssl_ctx, so both are updated.
C7: load the private key through an O_RDONLY|O_NOFOLLOW|O_CLOEXEC fd,
fstat that fd and validate owner/mode (now also rejecting group/other
execute bits), then load from the fd via BIO_new_fd. This removes the
stat-to-load TOCTOU race while keeping the exact-owner/0600 policy.
C8: verify an IP-literal client hostname against the certificate IP SAN
with X509_VERIFY_PARAM_set1_ip_asc instead of SSL_set1_host (a DNS
check), falling back to SSL_set1_host for real names.
Unit tests assert the server-preference option, the absence of CBC/RC4/
3DES suites, and that context creation still succeeds.
- file: open -K dirlink referents via a race-safe relative O_NOFOLLOW walk
from the authorized-root fd instead of re-opening an absolute realpath()
result (removes the intermediate-symlink swap TOCTOU).
- transport_ssh: always single-quote the server path, including --old-args,
so no mode can inject shell metacharacters.
- transport_tls: set SSL_OP_NO_COMPRESSION and (guarded) SSL_OP_NO_RENEGOTIATION.
- credentials: reject --password-file/--early-input with any group/other
permission bit; chmod 0600 the affected test fixtures.
- file_store: export file_store_write_sparse() and remove the verbatim
file.c duplicate.