cryptenroll: support listing and wiping tokens

meson.build

@@ -2434,13 +2434,18 @@ if conf.get('HAVE_LIBCRYPTSETUP') == 1
 
         systemd_cryptenroll_sources = files('''
                 src/cryptenroll/cryptenroll-fido2.h
+                src/cryptenroll/cryptenroll-list.c
+                src/cryptenroll/cryptenroll-list.h
                 src/cryptenroll/cryptenroll-password.c
                 src/cryptenroll/cryptenroll-password.h
                 src/cryptenroll/cryptenroll-pkcs11.h
                 src/cryptenroll/cryptenroll-recovery.c
                 src/cryptenroll/cryptenroll-recovery.h
                 src/cryptenroll/cryptenroll-tpm2.h
+                src/cryptenroll/cryptenroll-wipe.c
+                src/cryptenroll/cryptenroll-wipe.h
                 src/cryptenroll/cryptenroll.c
+                src/cryptenroll/cryptenroll.h
 '''.split())
 
         if conf.get('HAVE_P11KIT') == 1 and conf.get('HAVE_OPENSSL') == 1

src/cryptenroll/cryptenroll-list.c

@@ -0,0 +1,126 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "cryptenroll-list.h"
+#include "cryptenroll.h"
+#include "format-table.h"
+#include "parse-util.h"
+
+int list_enrolled(struct crypt_device *cd) {
+
+        struct keyslot_metadata {
+                int slot;
+                const char *type;
+        } *keyslot_metadata = NULL;
+        size_t n_keyslot_metadata = 0, n_keyslot_metadata_allocated = 0;
+        _cleanup_(table_unrefp) Table *t = NULL;
+        int slot_max, r;
+        TableCell *cell;
+
+        assert(cd);
+
+        /* First step, find out all currently used slots */
+        assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+        for (int slot = 0; slot < slot_max; slot++) {
+                crypt_keyslot_info status;
+
+                status = crypt_keyslot_status(cd, slot);
+                if (!IN_SET(status, CRYPT_SLOT_ACTIVE, CRYPT_SLOT_ACTIVE_LAST))
+                        continue;
+
+                if (!GREEDY_REALLOC(keyslot_metadata, n_keyslot_metadata_allocated, n_keyslot_metadata+1))
+                        return log_oom();
+
+                keyslot_metadata[n_keyslot_metadata++] = (struct keyslot_metadata) {
+                        .slot = slot,
+                };
+        }
+
+        /* Second step, enumerate through all tokens, and update the slot table, indicating what kind of
+         * token they are assigned to */
+        for (int token = 0; token < LUKS2_TOKENS_MAX; token++) {
+                _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+                const char *type;
+                JsonVariant *w, *z;
+                EnrollType et;
+
+                r = cryptsetup_get_token_as_json(cd, token, NULL, &v);
+                if (IN_SET(r, -ENOENT, -EINVAL))
+                        continue;
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to read JSON token data off disk, ignoring: %m");
+                        continue;
+                }
+
+                w = json_variant_by_key(v, "type");
+                if (!w || !json_variant_is_string(w)) {
+                        log_warning("Token JSON data lacks type field, ignoring.");
+                        continue;
+                }
+
+                et = luks2_token_type_from_string(json_variant_string(w));
+                if (et < 0)
+                        type = "other";
+                else
+                        type = enroll_type_to_string(et);
+
+                w = json_variant_by_key(v, "keyslots");
+                if (!w || !json_variant_is_array(w)) {
+                        log_warning("Token JSON data lacks keyslots field, ignoring.");
+                        continue;
+                }
+
+                JSON_VARIANT_ARRAY_FOREACH(z, w) {
+                        unsigned u;
+
+                        if (!json_variant_is_string(z)) {
+                                log_warning("Token JSON data's keyslot field is not an array of strings, ignoring.");
+                                continue;
+                        }
+
+                        r = safe_atou(json_variant_string(z), &u);
+                        if (r < 0) {
+                                log_warning_errno(r, "Token JSON data's keyslot filed is not an integer formatted as string, ignoring.");
+                                continue;
+                        }
+
+                        for (size_t i = 0; i < n_keyslot_metadata; i++) {
+                                if ((unsigned) keyslot_metadata[i].slot != u)
+                                        continue;
+
+                                if (keyslot_metadata[i].type) /* Slot claimed multiple times? */
+                                        keyslot_metadata[i].type = POINTER_MAX;
+                                else
+                                        keyslot_metadata[i].type = type;
+                        }
+                }
+        }
+
+        /* Finally, create a table out of it all */
+        t = table_new("slot", "type");
+        if (!t)
+                return log_oom();
+
+        assert_se(cell = table_get_cell(t, 0, 0));
+        (void) table_set_align_percent(t, cell, 100);
+
+        for (size_t i = 0; i < n_keyslot_metadata; i++) {
+                r = table_add_many(
+                                t,
+                                TABLE_INT, keyslot_metadata[i].slot,
+                                TABLE_STRING, keyslot_metadata[i].type == POINTER_MAX ? "conflict" :
+                                              keyslot_metadata[i].type ?: "password");
+                if (r < 0)
+                        return table_log_add_error(r);
+        }
+
+        if (table_get_rows(t) <= 1) {
+                log_info("No slots found.");
+                return 0;
+        }
+
+        r = table_print(t, stdout);
+        if (r < 0)
+                return log_error_errno(r, "Failed to show slot table: %m");
+
+        return 0;
+}

src/cryptenroll/cryptenroll-list.h

@@ -0,0 +1,6 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "cryptsetup-util.h"
+
+int list_enrolled(struct crypt_device *cd);

src/cryptenroll/cryptenroll-wipe.c

@@ -0,0 +1,445 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include "cryptenroll-wipe.h"
+#include "cryptenroll.h"
+#include "json.h"
+#include "memory-util.h"
+#include "parse-util.h"
+#include "set.h"
+#include "sort-util.h"
+
+static int find_all_slots(struct crypt_device *cd, Set *wipe_slots, Set *keep_slots) {
+        int slot_max;
+
+        assert(cd);
+        assert(wipe_slots);
+        assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+
+        /* Finds all currently assigned slots, and adds them to 'wipe_slots', except if listed already in 'keep_slots' */
+
+        for (int slot = 0; slot < slot_max; slot++) {
+                crypt_keyslot_info status;
+
+                /* No need to check this slot if we already know we want to wipe it or definitely keep it. */
+                if (set_contains(keep_slots, INT_TO_PTR(slot)) ||
+                    set_contains(wipe_slots, INT_TO_PTR(slot)))
+                        continue;
+
+                status = crypt_keyslot_status(cd, slot);
+                if (!IN_SET(status, CRYPT_SLOT_ACTIVE, CRYPT_SLOT_ACTIVE_LAST))
+                        continue;
+
+                if (set_put(wipe_slots, INT_TO_PTR(slot)) < 0)
+                        return log_oom();
+        }
+
+        return 0;
+}
+
+static int find_empty_passphrase_slots(struct crypt_device *cd, Set *wipe_slots, Set *keep_slots) {
+        size_t vks;
+        int r, slot_max;
+
+        assert(cd);
+        assert(wipe_slots);
+        assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+
+        /* Finds all slots with an empty passphrase assigned (i.e. "") and adds them to 'wipe_slots', except
+         * if listed already in 'keep_slots' */
+
+        r = crypt_get_volume_key_size(cd);
+        if (r <= 0)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to determine LUKS volume key size");
+        vks = (size_t) r;
+
+        for (int slot = 0; slot < slot_max; slot++) {
+                _cleanup_(erase_and_freep) char *vk = NULL;
+                crypt_keyslot_info status;
+
+                /* No need to check this slot if we already know we want to wipe it or definitely keep it. */
+                if (set_contains(keep_slots, INT_TO_PTR(slot)) ||
+                    set_contains(wipe_slots, INT_TO_PTR(slot)))
+                        continue;
+
+                status = crypt_keyslot_status(cd, slot);
+                if (!IN_SET(status, CRYPT_SLOT_ACTIVE, CRYPT_SLOT_ACTIVE_LAST))
+                        continue;
+
+                vk = malloc(vks);
+                if (!vk)
+                        return log_oom();
+
+                r = crypt_volume_key_get(cd, slot, vk, &vks, "", 0);
+                if (r < 0) {
+                        log_debug_errno(r, "Failed to acquire volume key from slot %i with empty password, ignoring: %m", slot);
+                        continue;
+                }
+
+                if (set_put(wipe_slots, INT_TO_PTR(r)) < 0)
+                        return log_oom();
+        }
+
+        return 0;
+}
+
+static int find_slots_by_mask(
+                struct crypt_device *cd,
+                Set *wipe_slots,
+                Set *keep_slots,
+                unsigned by_mask) {
+
+        _cleanup_(set_freep) Set *listed_slots = NULL;
+        int r;
+
+        assert(cd);
+        assert(wipe_slots);
+
+        if (by_mask == 0)
+                return 0;
+
+        /* Find all slots that are associated with a token of a type in the specified token type mask */
+
+        for (int token = 0; token < LUKS2_TOKENS_MAX; token++) {
+                _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+                JsonVariant *w, *z;
+                EnrollType t;
+
+                r = cryptsetup_get_token_as_json(cd, token, NULL, &v);
+                if (IN_SET(r, -ENOENT, -EINVAL))
+                        continue;
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to read JSON token data off disk, ignoring: %m");
+                        continue;
+                }
+
+                w = json_variant_by_key(v, "type");
+                if (!w || !json_variant_is_string(w)) {
+                        log_warning("Token JSON data lacks type field, ignoring.");
+                        continue;
+                }
+
+                t = luks2_token_type_from_string(json_variant_string(w));
+
+                w = json_variant_by_key(v, "keyslots");
+                if (!w || !json_variant_is_array(w)) {
+                        log_warning("Token JSON data lacks keyslots field, ignoring.");
+                        continue;
+                }
+
+                JSON_VARIANT_ARRAY_FOREACH(z, w) {
+                        int slot;
+
+                        if (!json_variant_is_string(z)) {
+                                log_warning("Token JSON data's keyslot field is not an array of strings, ignoring.");
+                                continue;
+                        }
+
+                        r = safe_atoi(json_variant_string(z), &slot);
+                        if (r < 0) {
+                                log_warning_errno(r, "Token JSON data's keyslot filed is not an integer formatted as string, ignoring.");
+                                continue;
+                        }
+
+                        if (t >= 0 && (by_mask & (1U << t)) != 0) {
+                                /* Selected by token type */
+                                if (set_put(wipe_slots, INT_TO_PTR(slot)) < 0)
+                                        return log_oom();
+                        } else if ((by_mask & (1U << ENROLL_PASSWORD)) != 0) {
+                                /* If we shall remove all plain password slots, let's maintain a list of
+                                 * slots that are listed in any tokens, since those are *NOT* plain
+                                 * passwords */
+                                if (set_ensure_allocated(&listed_slots, NULL) < 0)
+                                        return log_oom();
+
+                                if (set_put(listed_slots, INT_TO_PTR(slot)) < 0)
+                                        return log_oom();
+                        }
+                }
+        }
+
+        /* "password" slots are those which have no token assigned. If we shall remove those, iterate through
+         * all slots and mark those for wiping that weren't listed in any token */
+        if ((by_mask & (1U << ENROLL_PASSWORD)) != 0) {
+                int slot_max;
+
+                assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+
+                for (int slot = 0; slot < slot_max; slot++) {
+                        crypt_keyslot_info status;
+
+                        /* No need to check this slot if we already know we want to wipe it or definitely keep it. */
+                        if (set_contains(keep_slots, INT_TO_PTR(slot)) ||
+                            set_contains(wipe_slots, INT_TO_PTR(slot)))
+                                continue;
+
+                        if (set_contains(listed_slots, INT_TO_PTR(slot))) /* This has a token, hence is not a password. */
+                                continue;
+
+                        status = crypt_keyslot_status(cd, slot);
+                        if (!IN_SET(status, CRYPT_SLOT_ACTIVE, CRYPT_SLOT_ACTIVE_LAST)) /* Not actually assigned? */
+                                continue;
+
+                        /* Finally, we found a password, add it to the list of slots to wipe */
+                        if (set_put(wipe_slots, INT_TO_PTR(slot)) < 0)
+                                return log_oom();
+                }
+        }
+
+        return 0;
+}
+
+static int find_slot_tokens(struct crypt_device *cd, Set *wipe_slots, Set *keep_slots, Set *wipe_tokens) {
+        int r;
+
+        assert(cd);
+        assert(wipe_slots);
+        assert(keep_slots);
+        assert(wipe_tokens);
+
+        /* Find all tokens matching the slots we want to wipe, so that we can wipe them too. Also, for update
+         * the slots sets according to the token data: add any other slots listed in the tokens we act on. */
+
+        for (int token = 0; token < LUKS2_TOKENS_MAX; token++) {
+                _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+                bool shall_wipe = false;
+                JsonVariant *w, *z;
+
+                r = cryptsetup_get_token_as_json(cd, token, NULL, &v);
+                if (IN_SET(r, -ENOENT, -EINVAL))
+                        continue;
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to read JSON token data off disk, ignoring: %m");
+                        continue;
+                }
+
+                w = json_variant_by_key(v, "keyslots");
+                if (!w || !json_variant_is_array(w)) {
+                        log_warning("Token JSON data lacks keyslots field, ignoring.");
+                        continue;
+                }
+
+                /* Go through the slots associated with this token: if we shall keep any slot of them, the token shall stay too. */
+                JSON_VARIANT_ARRAY_FOREACH(z, w) {
+                        int slot;
+
+                        if (!json_variant_is_string(z)) {
+                                log_warning("Token JSON data's keyslot field is not an array of strings, ignoring.");
+                                continue;
+                        }
+
+                        r = safe_atoi(json_variant_string(z), &slot);
+                        if (r < 0) {
+                                log_warning_errno(r, "Token JSON data's keyslot filed is not an integer formatted as string, ignoring.");
+                                continue;
+                        }
+
+                        if (set_contains(keep_slots, INT_TO_PTR(slot))) {
+                                shall_wipe = false;
+                                break; /* If we shall keep this slot, then this is definite: we will keep its token too */
+                        }
+
+                        /* If there's a slot associated with this token that we shall wipe, then remove the
+                         * token too. But we are careful here: let's continue iterating, maybe there's a slot
+                         * that we need to keep, in which case we can reverse the decision again. */
+                        if (set_contains(wipe_slots, INT_TO_PTR(slot)))
+                                shall_wipe = true;
+                }
+
+                /* Go through the slots again, and this time add them to the list of slots to keep/remove */
+                JSON_VARIANT_ARRAY_FOREACH(z, w) {
+                        int slot;
+
+                        if (!json_variant_is_string(z))
+                                continue;
+                        if (safe_atoi(json_variant_string(z), &slot) < 0)
+                                continue;
+
+                        if (set_put(shall_wipe ? wipe_slots : keep_slots, INT_TO_PTR(slot)) < 0)
+                                return log_oom();
+                }
+
+                /* And of course, als remember the tokens to remove. */
+                if (shall_wipe)
+                        if (set_put(wipe_tokens, INT_TO_PTR(token)) < 0)
+                                return log_oom();
+        }
+
+        return 0;
+}
+
+static bool slots_remain(struct crypt_device *cd, Set *wipe_slots, Set *keep_slots) {
+        int slot_max;
+
+        assert(cd);
+        assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+
+        /* Checks if any slots remaining in the LUKS2 header if we remove all slots listed in 'wipe_slots'
+         * (keeping those listed in 'keep_slots') */
+
+        for (int slot = 0; slot < slot_max; slot++) {
+                crypt_keyslot_info status;
+
+                status = crypt_keyslot_status(cd, slot);
+                if (!IN_SET(status, CRYPT_SLOT_ACTIVE, CRYPT_SLOT_ACTIVE_LAST))
+                        continue;
+
+                /* The "keep" set wins if a slot is listed in both sets. This is important so that we can
+                 * safely add a new slot and remove all others of the same type, which in a naive
+                 * implementation might mean we remove what we just added — which we of course don't want. */
+                if (set_contains(keep_slots, INT_TO_PTR(slot)) ||
+                    !set_contains(wipe_slots, INT_TO_PTR(slot)))
+                        return true;
+        }
+
+        return false;
+}
+
+int wipe_slots(struct crypt_device *cd,
+               const int explicit_slots[],
+               size_t n_explicit_slots,
+               WipeScope by_scope,
+               unsigned by_mask,
+               int except_slot) {
+
+        _cleanup_(set_freep) Set *wipe_slots = NULL, *wipe_tokens = NULL, *keep_slots = NULL;
+        _cleanup_free_ int *ordered_slots = NULL, *ordered_tokens = NULL;
+        size_t n_ordered_slots = 0, n_ordered_tokens = 0;
+        int r, slot_max, ret;
+        void *e;
+
+        assert_se(cd);
+
+        /* Shortcut if nothing to wipe. */
+        if (n_explicit_slots == 0 && by_mask == 0 && by_scope == WIPE_EXPLICIT)
+                return 0;
+
+        /* So this is a bit more complicated than I'd wish, but we want support three different axis for wiping slots:
+         *
+         *    1. Wiping by slot indexes
+         *    2. Wiping slots of specified token types
+         *    3. Wiping "all" entries, or entries with an empty password (i.e. "")
+         *
+         * (or any combination of the above)
+         *
+         * Plus: We always want to remove tokens matching the slots.
+         * Plus: We always want to exclude the slots/tokens we just added.
+         */
+
+        wipe_slots = set_new(NULL);
+        keep_slots = set_new(NULL);
+        wipe_tokens = set_new(NULL);
+        if (!wipe_slots || !keep_slots || !wipe_tokens)
+                return log_oom();
+
+        /* Let's maintain one set of slots for the slots we definitely want to keep */
+        if (except_slot >= 0)
+                if (set_put(keep_slots, INT_TO_PTR(except_slot)) < 0)
+                        return log_oom();
+
+        assert_se((slot_max = crypt_keyslot_max(CRYPT_LUKS2)) > 0);
+
+        /* Maintain another set of the slots we intend to wipe */
+        for (size_t i = 0; i < n_explicit_slots; i++) {
+                if (explicit_slots[i] >= slot_max)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Slot index %i out of range.", explicit_slots[i]);
+
+                if (set_put(wipe_slots, INT_TO_PTR(explicit_slots[i])) < 0)
+                        return log_oom();
+        }
+
+        /* Now, handle the "all" and "empty passphrase" cases. */
+        switch (by_scope) {
+
+        case WIPE_EXPLICIT:
+                break; /* Nothing to do here */
+
+        case WIPE_ALL:
+                r = find_all_slots(cd, wipe_slots, keep_slots);
+                if (r < 0)
+                        return r;
+
+                break;
+
+        case WIPE_EMPTY_PASSPHRASE:
+                r = find_empty_passphrase_slots(cd, wipe_slots, keep_slots);
+                if (r < 0)
+                        return r;
+
+                break;
+        default:
+                assert_not_reached("Unexpected wipe scope");
+        }
+
+        /* Then add all slots that match a token type */
+        r = find_slots_by_mask(cd, wipe_slots, keep_slots, by_mask);
+        if (r < 0)
+                return r;
+
+        /* And determine tokens that we shall remove */
+        r = find_slot_tokens(cd, wipe_slots, keep_slots, wipe_tokens);
+        if (r < 0)
+                return r;
+
+        /* Safety check: let's make sure that after we are done there's at least one slot remaining */
+        if (!slots_remain(cd, wipe_slots, keep_slots))
+                return log_error_errno(SYNTHETIC_ERRNO(EPERM),
+                                       "Wipe operation would leave no valid slots around, can't allow that, sorry.");
+
+        /* Generated ordered lists of the slots and the tokens to remove */
+        ordered_slots = new(int, set_size(wipe_slots));
+        if (!ordered_slots)
+                return log_oom();
+        SET_FOREACH(e, wipe_slots) {
+                int slot = PTR_TO_INT(e);
+
+                if (set_contains(keep_slots, INT_TO_PTR(slot)))
+                        continue;
+
+                ordered_slots[n_ordered_slots++] = slot;
+        }
+        typesafe_qsort(ordered_slots, n_ordered_slots, cmp_int);
+
+        ordered_tokens = new(int, set_size(wipe_tokens));
+        if (!ordered_tokens)
+                return log_oom();
+        SET_FOREACH(e, wipe_tokens)
+                ordered_tokens[n_ordered_tokens++] = PTR_TO_INT(e);
+        typesafe_qsort(ordered_tokens, n_ordered_tokens, cmp_int);
+
+        if (n_ordered_slots == 0 && n_ordered_tokens == 0) {
+                log_full(except_slot < 0 ? LOG_NOTICE : LOG_DEBUG,
+                         "No slots to remove selected.");
+                return 0;
+        }
+
+        if (DEBUG_LOGGING) {
+                for (size_t i = 0; i < n_ordered_slots; i++)
+                        log_debug("Going to wipe slot %i.", ordered_slots[i]);
+                for (size_t i = 0; i < n_ordered_tokens; i++)
+                        log_debug("Going to wipe token %i.", ordered_tokens[i]);
+        }
+
+        /* Now, let's actually start wiping things. (We go from back to front, to make space at the end
+         * first.) */
+        ret = 0;
+        for (size_t i = n_ordered_slots; i > 0; i--) {
+                r = crypt_keyslot_destroy(cd, ordered_slots[i - 1]);
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to wipe slot %i, continuing: %m", ordered_slots[i - 1]);
+                        if (ret == 0)
+                                ret = r;
+                } else
+                        log_info("Wiped slot %i.", ordered_slots[i - 1]);
+        }
+
+        for (size_t i = n_ordered_tokens; i > 0; i--) {
+                r = crypt_token_json_set(cd, ordered_tokens[i - 1], NULL);
+                if (r < 0) {
+                        log_warning_errno(r, "Failed to wipe token %i, continuing: %m", ordered_tokens[i - 1]);
+                        if (ret == 0)
+                                ret = r;
+                }
+        }
+
+        return ret;
+}

src/cryptenroll/cryptenroll-wipe.h

@@ -0,0 +1,12 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+#include "cryptenroll.h"
+#include "cryptsetup-util.h"
+
+int wipe_slots(struct crypt_device *cd,
+               const int explicit_slots[],
+               size_t n_explicit_slots,
+               WipeScope by_scope,
+               unsigned by_mask,
+               int except_slot);

src/cryptenroll/cryptenroll.c

@@ -4,10 +4,13 @@
 
 #include "ask-password-api.h"
 #include "cryptenroll-fido2.h"
+#include "cryptenroll-list.h"
 #include "cryptenroll-password.h"
 #include "cryptenroll-pkcs11.h"
 #include "cryptenroll-recovery.h"
 #include "cryptenroll-tpm2.h"
+#include "cryptenroll-wipe.h"
+#include "cryptenroll.h"
 #include "cryptsetup-util.h"
 #include "escape.h"
 #include "libfido2-util.h"
@@ -17,32 +20,55 @@
 #include "path-util.h"
 #include "pkcs11-util.h"
 #include "pretty-print.h"
+#include "string-table.h"
 #include "strv.h"
 #include "terminal-util.h"
 #include "tpm2-util.h"
 
-typedef enum EnrollType {
-        ENROLL_PASSWORD,
-        ENROLL_RECOVERY,
-        ENROLL_PKCS11,
-        ENROLL_FIDO2,
-        ENROLL_TPM2,
-        _ENROLL_TYPE_MAX,
-        _ENROLL_TYPE_INVALID = -1,
-} EnrollType;
-
 static EnrollType arg_enroll_type = _ENROLL_TYPE_INVALID;
 static char *arg_pkcs11_token_uri = NULL;
 static char *arg_fido2_device = NULL;
 static char *arg_tpm2_device = NULL;
 static uint32_t arg_tpm2_pcr_mask = UINT32_MAX;
 static char *arg_node = NULL;
+static int *arg_wipe_slots = NULL;
+static size_t arg_n_wipe_slots = 0;
+static WipeScope arg_wipe_slots_scope = WIPE_EXPLICIT;
+static unsigned arg_wipe_slots_mask = 0; /* Bitmask of (1U << EnrollType), for wiping all slots of specific types */
+
+assert_cc(sizeof(arg_wipe_slots_mask) * 8 >= _ENROLL_TYPE_MAX);
 
 STATIC_DESTRUCTOR_REGISTER(arg_pkcs11_token_uri, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_fido2_device, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_tpm2_device, freep);
 STATIC_DESTRUCTOR_REGISTER(arg_node, freep);
 
+static bool wipe_requested(void) {
+        return arg_n_wipe_slots > 0 ||
+                arg_wipe_slots_scope != WIPE_EXPLICIT ||
+                arg_wipe_slots_mask != 0;
+}
+
+static const char* const enroll_type_table[_ENROLL_TYPE_MAX] = {
+        [ENROLL_PASSWORD] = "password",
+        [ENROLL_RECOVERY] = "recovery",
+        [ENROLL_PKCS11] = "pkcs11",
+        [ENROLL_FIDO2] = "fido2",
+        [ENROLL_TPM2] = "tpm2",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(enroll_type, EnrollType);
+
+static const char *const luks2_token_type_table[_ENROLL_TYPE_MAX] = {
+        /* ENROLL_PASSWORD has no entry here, as slots of this type do not have a token in the LUKS2 header */
+        [ENROLL_RECOVERY] = "systemd-recovery",
+        [ENROLL_PKCS11] = "systemd-pkcs11",
+        [ENROLL_FIDO2] = "systemd-fido2",
+        [ENROLL_TPM2] = "systemd-tpm2",
+};
+
+DEFINE_STRING_TABLE_LOOKUP(luks2_token_type, EnrollType);
+
 static int help(void) {
         _cleanup_free_ char *link = NULL;
         int r;
@@ -65,6 +91,8 @@ static int help(void) {
                "                       Enroll a TPM2 device\n"
                "     --tpm2-pcrs=PCR1,PCR2,PCR3,…\n"
                "                       Specifiy TPM2 PCRs to seal against\n"
+               "     --wipe-slot=SLOT1,SLOT2,…\n"
+               "                       Wipe specified slots\n"
                "\nSee the %s for details.\n"
                , program_invocation_short_name
                , ansi_highlight(), ansi_normal()
@@ -84,6 +112,7 @@ static int parse_argv(int argc, char *argv[]) {
                 ARG_FIDO2_DEVICE,
                 ARG_TPM2_DEVICE,
                 ARG_TPM2_PCRS,
+                ARG_WIPE_SLOT,
         };
 
         static const struct option options[] = {
@@ -95,6 +124,7 @@ static int parse_argv(int argc, char *argv[]) {
                 { "fido2-device",     required_argument, NULL, ARG_FIDO2_DEVICE     },
                 { "tpm2-device",      required_argument, NULL, ARG_TPM2_DEVICE      },
                 { "tpm2-pcrs",        required_argument, NULL, ARG_TPM2_PCRS        },
+                { "wipe-slot",        required_argument, NULL, ARG_WIPE_SLOT        },
                 {}
         };
 
@@ -223,6 +253,60 @@ static int parse_argv(int argc, char *argv[]) {
                         break;
                 }
 
+                case ARG_WIPE_SLOT: {
+                        const char *p = optarg;
+
+                        if (isempty(optarg)) {
+                                arg_wipe_slots_mask = 0;
+                                arg_wipe_slots_scope = WIPE_EXPLICIT;
+                                break;
+                        }
+
+                        for (;;) {
+                                _cleanup_free_ char *slot = NULL;
+                                unsigned n;
+
+                                r = extract_first_word(&p, &slot, ",", EXTRACT_DONT_COALESCE_SEPARATORS);
+                                if (r == 0)
+                                        break;
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to parse slot list: %s", optarg);
+
+                                if (streq(slot, "all"))
+                                        arg_wipe_slots_scope = WIPE_ALL;
+                                else if (streq(slot, "empty")) {
+                                        if (arg_wipe_slots_scope != WIPE_ALL) /* if "all" was specified before, that wins */
+                                                arg_wipe_slots_scope = WIPE_EMPTY_PASSPHRASE;
+                                } else if (streq(slot, "password"))
+                                        arg_wipe_slots_mask = 1U << ENROLL_PASSWORD;
+                                else if (streq(slot, "recovery"))
+                                        arg_wipe_slots_mask = 1U << ENROLL_RECOVERY;
+                                else if (streq(slot, "pkcs11"))
+                                        arg_wipe_slots_mask = 1U << ENROLL_PKCS11;
+                                else if (streq(slot, "fido2"))
+                                        arg_wipe_slots_mask = 1U << ENROLL_FIDO2;
+                                else if (streq(slot, "tpm2"))
+                                        arg_wipe_slots_mask = 1U << ENROLL_TPM2;
+                                else {
+                                        int *a;
+
+                                        r = safe_atou(slot, &n);
+                                        if (r < 0)
+                                                return log_error_errno(r, "Failed to parse slot index: %s", slot);
+                                        if (n > INT_MAX)
+                                                return log_error_errno(SYNTHETIC_ERRNO(ERANGE), "Slot index out of range: %u", n);
+
+                                        a = reallocarray(arg_wipe_slots, sizeof(int), arg_n_wipe_slots + 1);
+                                        if (!a)
+                                                return log_oom();
+
+                                        arg_wipe_slots = a;
+                                        arg_wipe_slots[arg_n_wipe_slots++] = (int) n;
+                                }
+                        }
+                        break;
+                }
+
                 case '?':
                         return -EINVAL;
 
@@ -231,10 +315,6 @@ static int parse_argv(int argc, char *argv[]) {
                 }
         }
 
-        if (arg_enroll_type < 0)
-                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
-                                       "No operation specified, refusing.");
-
         if (optind >= argc)
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
                                        "No block device node specified, refusing.");
@@ -373,7 +453,7 @@ static int run(int argc, char *argv[]) {
         _cleanup_(crypt_freep) struct crypt_device *cd = NULL;
         _cleanup_(erase_and_freep) void *vk = NULL;
         size_t vks;
-        int r;
+        int slot, r;
 
         log_show_color(true);
         log_parse_environment();
@@ -383,37 +463,55 @@ static int run(int argc, char *argv[]) {
         if (r <= 0)
                 return r;
 
-        r = prepare_luks(&cd, &vk, &vks);
+        if (arg_enroll_type < 0)
+                r = prepare_luks(&cd, NULL, NULL); /* No need to unlock device if we don't need the volume key because we don't need to enroll anything */
+        else
+                r = prepare_luks(&cd, &vk, &vks);
         if (r < 0)
                 return r;
 
         switch (arg_enroll_type) {
 
         case ENROLL_PASSWORD:
-                r = enroll_password(cd, vk, vks);
+                slot = enroll_password(cd, vk, vks);
                 break;
 
         case ENROLL_RECOVERY:
-                r = enroll_recovery(cd, vk, vks);
+                slot = enroll_recovery(cd, vk, vks);
                 break;
 
         case ENROLL_PKCS11:
-                r = enroll_pkcs11(cd, vk, vks, arg_pkcs11_token_uri);
+                slot = enroll_pkcs11(cd, vk, vks, arg_pkcs11_token_uri);
                 break;
 
         case ENROLL_FIDO2:
-                r = enroll_fido2(cd, vk, vks, arg_fido2_device);
+                slot = enroll_fido2(cd, vk, vks, arg_fido2_device);
                 break;
 
         case ENROLL_TPM2:
-                r = enroll_tpm2(cd, vk, vks, arg_tpm2_device, arg_tpm2_pcr_mask);
+                slot = enroll_tpm2(cd, vk, vks, arg_tpm2_device, arg_tpm2_pcr_mask);
                 break;
 
+        case _ENROLL_TYPE_INVALID:
+                /* List enrolled slots if we are called without anything to enroll or wipe */
+                if (!wipe_requested())
+                        return list_enrolled(cd);
+
+                /* Only slot wiping selected */
+                return wipe_slots(cd, arg_wipe_slots, arg_n_wipe_slots, arg_wipe_slots_scope, arg_wipe_slots_mask, -1);
+
         default:
                 return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Operation not implemented yet.");
         }
+        if (slot < 0)
+                return slot;
 
-        return r;
+        /* After we completed enrolling, remove user selected slots */
+        r = wipe_slots(cd, arg_wipe_slots, arg_n_wipe_slots, arg_wipe_slots_scope, arg_wipe_slots_mask, slot);
+        if (r < 0)
+                return r;
+
+        return 0;
 }
 
 DEFINE_MAIN_FUNCTION(run);

src/cryptenroll/cryptenroll.h

@@ -0,0 +1,26 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+#pragma once
+
+typedef enum EnrollType {
+        ENROLL_PASSWORD,
+        ENROLL_RECOVERY,
+        ENROLL_PKCS11,
+        ENROLL_FIDO2,
+        ENROLL_TPM2,
+        _ENROLL_TYPE_MAX,
+        _ENROLL_TYPE_INVALID = -1,
+} EnrollType;
+
+typedef enum WipeScope {
+        WIPE_EXPLICIT,          /* only wipe the listed slots */
+        WIPE_ALL,               /* wipe all slots */
+        WIPE_EMPTY_PASSPHRASE,  /* wipe slots with empty passphrases plus listed slots */
+        _WIPE_SCOPE_MAX,
+        _WIPE_SCOPE_INVALID = -1,
+} WipeScope;
+
+const char* enroll_type_to_string(EnrollType t);
+EnrollType enroll_type_from_string(const char *s);
+
+const char* luks2_token_type_to_string(EnrollType t);
+EnrollType luks2_token_type_from_string(const char *s);