From 113236754315de718857edea23d7aaa513bbe5cf Mon Sep 17 00:00:00 2001 From: Ali Polatel Date: Tue, 9 Sep 2025 16:28:02 +0200 Subject: [PATCH] magic: recognize syd encrypted files Documentation: https://man.exherbo.org/syd.7.html#Crypt_Sandboxing Signed-off-by: Ali Polatel --- magic/Magdir/syd | 37 +++++++++++++++++++++++++++++++++++++ magic/Makefile.am | 1 + 2 files changed, 38 insertions(+) create mode 100644 magic/Magdir/syd diff --git a/magic/Magdir/syd b/magic/Magdir/syd new file mode 100644 index 00000000..0203d6f8 --- /dev/null +++ b/magic/Magdir/syd @@ -0,0 +1,37 @@ +#------------------------------------------------------------------------------ +# $File: syd,v $ +# syd: file(1) magic for syd(1) encrypted files +# +# From: Ali Polatel +# Documentation: https://man.exherbo.org/syd.7.html#Crypt_Sandboxing +# No defined extension yet; files are recognized by magic header only. +# +# Layout: +# 0..3 : "\x7fSYD" +# 4 : version byte (current API: 3) +# 5..36 : HMAC (32 bytes, SHA256) +# 37..52 : IV (16 bytes) +# 53.. : ciphertext (AES-256-CTR) +#------------------------------------------------------------------------------ + +# Header and version +0 string \x7fSYD SYD encrypted file +>4 ubyte x \b, version %u + +# Version 3: algorithm + HMAC/IV as hex blobs + ciphertext size +>>4 ubyte =3 \b, AES-256-CTR; HMAC-SHA256: +>>>5 belong x \b%08x +>>>9 belong x \b%08x +>>>13 belong x \b%08x +>>>17 belong x \b%08x +>>>21 belong x \b%08x +>>>25 belong x \b%08x +>>>29 belong x \b%08x +>>>33 belong x \b%08x +>>>37 belong x \b, IV:%08x +>>>41 belong x \b%08x +>>>45 belong x \b%08x +>>>49 belong x \b%08x +>>>-0 offset-53 x \b, ciphertext %llu bytes + +# End of syd diff --git a/magic/Makefile.am b/magic/Makefile.am index 0a99b836..49241d5b 100644 --- a/magic/Makefile.am +++ b/magic/Makefile.am @@ -304,6 +304,7 @@ $(MAGIC_FRAGMENT_DIR)/statistics \ $(MAGIC_FRAGMENT_DIR)/subtitle \ $(MAGIC_FRAGMENT_DIR)/sun \ $(MAGIC_FRAGMENT_DIR)/svf \ +$(MAGIC_FRAGMENT_DIR)/syd \ $(MAGIC_FRAGMENT_DIR)/sylk \ $(MAGIC_FRAGMENT_DIR)/symbos \ $(MAGIC_FRAGMENT_DIR)/sysex \ -- 2.51.0