1 files changed, 144 insertions, 0 deletions
diff --git a/src/cryptsetup/cryptsetup-pkcs11.c b/src/cryptsetup/cryptsetup-pkcs11.c
new file mode 100644
index 0000000..50db46f
--- /dev/null
+++ b/src/cryptsetup/cryptsetup-pkcs11.c
@@ -0,0 +1,144 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <fcntl.h>
+#include <unistd.h>
+#include <sys/stat.h>
+
+#include <p11-kit/p11-kit.h>
+#include <p11-kit/uri.h>
+
+#include "alloc-util.h"
+#include "ask-password-api.h"
+#include "cryptsetup-pkcs11.h"
+#include "cryptsetup-keyfile.h"
+#include "escape.h"
+#include "fd-util.h"
+#include "format-util.h"
+#include "macro.h"
+#include "memory-util.h"
+#include "pkcs11-util.h"
+#include "stat-util.h"
+#include "strv.h"
+
+struct pkcs11_callback_data {
+        const char *friendly_name;
+        usec_t until;
+        void *encrypted_key;
+        size_t encrypted_key_size;
+        void *decrypted_key;
+        size_t decrypted_key_size;
+        bool free_encrypted_key;
+};
+
+static void pkcs11_callback_data_release(struct pkcs11_callback_data *data) {
+        free(data->decrypted_key);
+
+        if (data->free_encrypted_key)
+                free(data->encrypted_key);
+}
+
+static int pkcs11_callback(
+                CK_FUNCTION_LIST *m,
+                CK_SESSION_HANDLE session,
+                CK_SLOT_ID slot_id,
+                const CK_SLOT_INFO *slot_info,
+                const CK_TOKEN_INFO *token_info,
+                P11KitUri *uri,
+                void *userdata) {
+
+        struct pkcs11_callback_data *data = userdata;
+        CK_OBJECT_HANDLE object;
+        int r;
+
+        assert(m);
+        assert(slot_info);
+        assert(token_info);
+        assert(uri);
+        assert(data);
+
+        /* Called for every token matching our URI */
+
+        r = pkcs11_token_login(
+                        m,
+                        session,
+                        slot_id,
+                        token_info,
+                        data->friendly_name,
+                        "drive-harddisk",
+                        "pkcs11-pin",
+                        data->until,
+                        NULL);
+        if (r < 0)
+                return r;
+
+        /* We are likely called during early boot, where entropy is scarce. Mix some data from the PKCS#11
+         * token, if it supports that. It should be cheap, given that we already are talking to it anyway and
+         * shouldn't hurt. */
+        (void) pkcs11_token_acquire_rng(m, session);
+
+        r = pkcs11_token_find_private_key(m, session, uri, &object);
+        if (r < 0)
+                return r;
+
+        r = pkcs11_token_decrypt_data(
+                        m,
+                        session,
+                        object,
+                        data->encrypted_key,
+                        data->encrypted_key_size,
+                        &data->decrypted_key,
+                        &data->decrypted_key_size);
+        if (r < 0)
+                return r;
+
+        return 0;
+}
+
+int decrypt_pkcs11_key(
+                const char *friendly_name,
+                const char *pkcs11_uri,
+                const char *key_file,         /* We either expect key_file and associated parameters to be set (for file keys) … */
+                size_t key_file_size,
+                uint64_t key_file_offset,
+                const void *key_data,         /* … or key_data and key_data_size (for literal keys) */
+                size_t key_data_size,
+                usec_t until,
+                void **ret_decrypted_key,
+                size_t *ret_decrypted_key_size) {
+
+        _cleanup_(pkcs11_callback_data_release) struct pkcs11_callback_data data = {
+                .friendly_name = friendly_name,
+                .until = until,
+        };
+        int r;
+
+        assert(friendly_name);
+        assert(pkcs11_uri);
+        assert(key_file || key_data);
+        assert(ret_decrypted_key);
+        assert(ret_decrypted_key_size);
+
+        /* The functions called here log about all errors, except for EAGAIN which means "token not found right now" */
+
+        if (key_data) {
+                data.encrypted_key = (void*) key_data;
+                data.encrypted_key_size = key_data_size;
+
+                data.free_encrypted_key = false;
+        } else {
+                r = load_key_file(key_file, NULL, key_file_size, key_file_offset, &data.encrypted_key, &data.encrypted_key_size);
+                if (r < 0)
+                        return r;
+
+                data.free_encrypted_key = true;
+        }
+
+        r = pkcs11_find_token(pkcs11_uri, pkcs11_callback, &data);
+        if (r < 0)
+                return r;
+
+        *ret_decrypted_key = TAKE_PTR(data.decrypted_key);
+        *ret_decrypted_key_size = data.decrypted_key_size;
+
+        return 0;
+}