Decrypt WiFi AKM 25 after fast transition

asked 2026-01-06 11:28:25 +0000

Lieta gravatar image

Is it possible to decrypt encrypted Wi-Fi frames after fast transition? I have a capture of WiFi fast transition with authentication req/resp and reassociation req/resp. AKM suite is FT using SAE (00 0F AC 19). Pairwise cipher suite is AES (CCM) (00 0F AC 04). I've tried decrypting protected frames by specifying wpa-psk with PMK-R0 and PMK-R1, tk with PTK truncated to 32 and 16 bytes (full PTK is 48 bytes, but the key needs to be 16 or 32 bytes). None of this works - protected frames are not decrypted. Wireshark is compiled from sources from latest commit - 40634e4f14 epan: Unsigned lengths and offsets for the TVB BCD string functions.

Version 4.7.0.

Compile-time info:
 Bit width: 64-bit
  Compiler: GCC 15.2.1 20251211 (Red Hat 15.2.1-5)
      GLib: 2.86.3
 With:
  +brotli                      +Minizip 4.0.10
  +Gcrypt 1.11.1-unknown       +nghttp2 1.66.0
  +GnuTLS 3.8.11 and PKCS#11   +PCRE2 10.47 2025-10-21
  +Kerberos (MIT)              +POSIX capabilities (Linux)
  +libnl 3                     +Qt 6.10.1
  +libpcap                     +QtDBus
  +libsmi 0.5.0                +QtMultimedia
  +libxml2 2.12.10             +Snappy 1.2.2
  +Lua 5.4.8                   +xxhash 0.8.3
  +LZ4 1.10.0                  +zlib 1.3.1.zlib-ng
  +MaxMind                     +Zstandard 1.5.7
 Without:
  -automatic updates  -nghttp3            -zlib-ng

Runtime info:
      OS: Linux 6.17.8-300.fc43.x86_64
     CPU: AMD Ryzen 9 9900X 12-Core Processor (with SSE4.2)
  Memory: 61866 MB of physical memory
    GLib: 2.86.3
  Locale: LC_TYPE=en_US.UTF-8
 Plugins: supported, 24 loaded
 With:
  +brotli 1.2.0                      +nghttp2 1.66.0
  +c-ares 1.34.5                     +PCRE2 10.47 2025-10-21
  +Gcrypt 1.11.1-unknown             +QPA plugin "wayland"
  +GnuTLS 3.8.11                     +Qt 6.10.1
  +HiDPI                             +Wayland
  +libpcap 1.10.5 (with TPACKET_V3)  +xxhash 803
  +libsmi 0.5.0                      +zlib 1.3.1.zlib-ng
  +light display mode                +Zstandard 1.5.7
  +LZ4 1.10.0
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