Commit Graph

6 Commits

Author SHA1 Message Date
Werner Koch 434a641d40
agent: Add "ephemeral" Assuan option.
* agent/agent.h (struct ephemeral_private_key_s): New.
(struct server_control_s): Add ephemeral_mode and ephemeral_keys.
(GENKEY_FLAG_NO_PROTECTION, GENKEY_FLAG_PRESET): New.
* agent/genkey.c (clear_ephemeral_keys): New.
(store_key): Add arg ctrl and implement ephemeral_mode.  Change all
callers.
(agent_genkey): Replace args no_protection and preset by a generic new
flags arg.
* agent/findkey.c (wipe_and_fclose): New.
(agent_write_private_key): Add arg ctrl and implement ephemeral_mode.
Change all callers.
(agent_update_private_key): Ditto
(read_key_file): Ditto.
(agent_key_available): Ditto.
* agent/command-ssh.c (card_key_available): Do not update display s/n
in ephemeral mode.  This is however enver triggred.
* agent/gpg-agent.c (agent_deinit_default_ctrl): Cleanup ephemeral
keys.
* agent/command.c (cmd_genkey): Use the new flags instead of separate
vars.
(cmd_readkey): Create a shadow key only in non-ephemeral_mode.
(cmd_getinfo): Add sub-command "ephemeral".
(option_handler): Add option "ephemeral".
--

The idea here that a session can be switched in an ephemeral mode
which does not store or read keys from disk but keeps them local to
the session.

GnuPG-bug-id: 6944
2024-01-22 16:49:54 +01:00
NIIBE Yutaka 9909f622f6
agent: fix tpm2d keytotpm handling
* agent/divert-tpm2.c (agent_write_tpm2_shadow_key): Call
agent_delete_key before agent_write_private_key.  Recover
from an error.

--

Cherry-picked from master commit of:
	eda3997b43

Fixes-commit: a1015bf2fc
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2023-10-06 09:51:33 +09:00
Werner Koch 13013ec1c0
agent: Create and use Token entries to track the display s/n.
* agent/findkey.c (agent_write_private_key): Add arg dispserialno and
update the token.
(agent_write_shadow_key): Add arg dispserialno and adjust all callers.
--

GnuPG-bug-id: 6135

Note that this has been forward ported from 2.2
2023-05-26 11:59:46 +02:00
NIIBE Yutaka 6a37240cf2 agent: Move confirmation handling into findkey.c.
* agent/agent.h (divert_tpm2_pksign, divert_tpm2_pkdecrypt): Fix API.
(divert_pksign, divert_pkdecrypt): Likewise.
* agent/divert-scd.c (ask_for_card): Remove.
(divert_pksign, divert_pkdecrypt): Don't call ask_for_card.
* agent/divert-tpm2.c (divert_tpm2_pksign, divert_tpm2_pkdecrypt):
Remove DESC_TEXT argument.
* agent/findkey.c (prompt_for_card): New (was: ask_for_card).
(agent_key_from_file): Call prompt_for_card when it's a key
on card.
* agent/pkdecrypt.c (agent_pkdecrypt): Follow the change of API.
* agent/pksign.c (agent_pksign_do): Likewise.

--

Signed-off-by: NIIBE Yutaka <gniibe@fsij.org>
2022-05-20 13:43:08 +09:00
James Bottomley 92b601fcee
gpg: Add new command keytotpm to convert a private key to TPM format
* agent/command.c (cmd_keytotpm): New.
(agent/command.c): Register new command KEYTOTPM.
* g10/call-agent.c (agent_keytotpm): New.
* g10/keyedit.c (cmdKEYTOTPM): New command "keytotpm".
(keyedit_menu): Implement.

--

The plumbing is done in two parts: the agent is modified to understand
a KEYTOTPM assuan command taking the key grip as an argument.  This
simply obtains the key s expression and calls the existing writeky
diversion to the tpm2daemon.  The daemon reponds with the TPM
conversion of the key and that key is then stored in the keyfile as a
shadowed-private-key with "tpm2-v1" type.

To effect the conversion, all the user does from gpg --edit-key is
select which private key they wish to move (or move the primary if no
key is selected) and type keytotpm.  The conversion to TPM form is
instantaneous and once converted, the actual key cannot be recovered,
meaning that if you want your gpg key to move to a new laptop you must
keep an unconverted backup copy in a safe location.

When you do a list command, all TPM keys show up as

     card-no: TPM-Protected

The key is stored encrypted to the TPM2 storage seed and since each
TPM has a unique seed, only the single TPM contained in your laptop
can now read the key.  This means you cannot simply copy the shadowed
key file over to a new laptop, you must copy over the backup copy and
then convert it to TPM form on the new laptop.

To decomission your laptop, execute a tssclear command which
regenerates the storage seed and effectively shreds all keys.  Note
when you have done this *every* TPM2 shadowed private key becomes
unreadable by any TPM and all are effectively destroyed.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Very minor cosmetic changes.

Signed-off-by: Werner Koch <wk@gnupg.org>
2021-03-10 13:34:18 +01:00
James Bottomley 1f995b9ba4
agent: Add new shadow key type and functions to call tpm2daemon
* agent/call-tpm2d.c: New.
* divert-tpm2.c: New.
* agent/Makefile.am: Add new files.
* agent/agent.h (DAEMON_TPM2D): New.  Add stub fucntions.
* agent/call-daemon.c (GNUPG_MODULE_NAME_TPM2DAEMON): New.
* agent/command.c (do_one_keyinfo): Handle tpmv2.
* agent/gpg-agent.c (oTpm2daemonProgram): New.
(opts): New option --tpm2daemon-program.
(parse_rereadable_options): Handle option.
* agent/pkdecrypt.c (agent_pkdecrypt): Divert to tpm2d.
(agent_pksign_do): Ditto.
---

A new shadow key type: "tpm2-v1" is introduced signalling that the
shadowed key is handled by the tpm2daemon.  A function to identify
this type is introduced and diversions to the tpm2daemon functions are
conditioned on this function for pkign and pkdecrypt where the same
diversions to scd are currently done.  The (info) field of the
shadowed key stores the actual TPM key.  The TPM key is encrypted so
only the physical TPM it was created on can read it (so no special
protection is required for the info filed), but if the (info) field
becomes corrupt or damaged, the key will be lost (unlike the token
case, where the key is actually moved inside the token).

Note, this commit adds handling for existing TPM format shadow keys,
but there is still no way to create them.

Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>

Additional changes:
* Add ChangeLog entries.
* Some minor indentation fixes.
* agent/Makefile.am (gpg_agent_SOURCES): Change to make distcheck
  work.
* agent/agent.h [!HAVE_LIBTSS]: Do not return -EINVAL but an
  gpg_error_t.  Mark args as unused.
* agent/protect.c (agent_is_tpm2_key): Free BUF.

Signed-off-by: Werner Koch <wk@gnupg.org>
2021-03-10 13:23:05 +01:00