diff --git a/fs/cifs/Kconfig b/fs/cifs/Kconfig index 034f00f21390..afeefe79c25e 100644 --- a/fs/cifs/Kconfig +++ b/fs/cifs/Kconfig @@ -146,6 +146,15 @@ config CIFS_DEBUG2 option can be turned off unless you are debugging cifs problems. If unsure, say N. +config CIFS_DEBUG_DUMP_KEYS + bool "Dump encryption keys for offline decryption (Unsafe)" + depends on CIFS_DEBUG && CIFS_SMB2 + help + Enabling this will dump the encryption and decryption keys + used to communicate on an encrypted share connection on the + console. This allows Wireshark to decrypt and dissect + encrypted network captures. Enable this carefully. + config CIFS_DFS_UPCALL bool "DFS feature support" depends on CIFS && KEYS diff --git a/fs/cifs/smb2transport.c b/fs/cifs/smb2transport.c index c69ec96e92ac..67367cf1f8cd 100644 --- a/fs/cifs/smb2transport.c +++ b/fs/cifs/smb2transport.c @@ -335,9 +335,31 @@ generate_smb3signingkey(struct cifs_ses *ses, if (rc) return rc; - return generate_key(ses, ptriplet->decryption.label, - ptriplet->decryption.context, - ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE); + rc = generate_key(ses, ptriplet->decryption.label, + ptriplet->decryption.context, + ses->smb3decryptionkey, SMB3_SIGN_KEY_SIZE); + + if (rc) + return rc; + +#ifdef CONFIG_CIFS_DEBUG_DUMP_KEYS + cifs_dbg(VFS, "%s: dumping generated AES session keys\n", __func__); + /* + * The session id is opaque in terms of endianness, so we can't + * print it as a long long. we dump it as we got it on the wire + */ + cifs_dbg(VFS, "Session Id %*ph\n", (int)sizeof(ses->Suid), + &ses->Suid); + cifs_dbg(VFS, "Session Key %*ph\n", + SMB2_NTLMV2_SESSKEY_SIZE, ses->auth_key.response); + cifs_dbg(VFS, "Signing Key %*ph\n", + SMB3_SIGN_KEY_SIZE, ses->smb3signingkey); + cifs_dbg(VFS, "ServerIn Key %*ph\n", + SMB3_SIGN_KEY_SIZE, ses->smb3encryptionkey); + cifs_dbg(VFS, "ServerOut Key %*ph\n", + SMB3_SIGN_KEY_SIZE, ses->smb3decryptionkey); +#endif + return rc; } int