chiark / gitweb /
load-fragment: speed up parsing by using a perfect hash table with configuration...
[elogind.git] / src / cryptsetup.c
index 22312477d2587ade1aed77e88e55aa16bbb80f27..c0caf9a93035e38155cf88f0196721471066ee7a 100644 (file)
 ***/
 
 #include <string.h>
+#include <errno.h>
+#include <sys/mman.h>
+#include <mntent.h>
+
+#include <libcryptsetup.h>
+#include <libudev.h>
 
 #include "log.h"
 #include "util.h"
+#include "strv.h"
+#include "ask-password-api.h"
+#include "def.h"
+
+static const char *opt_type = NULL; /* LUKS1 or PLAIN */
+static char *opt_cipher = NULL;
+static unsigned opt_key_size = 0;
+static char *opt_hash = NULL;
+static unsigned opt_tries = 0;
+static bool opt_readonly = false;
+static bool opt_verify = false;
+static usec_t opt_timeout = DEFAULT_TIMEOUT_USEC;
+
+/* Options Debian's crypttab knows we don't:
+
+    offset=
+    skip=
+    precheck=
+    check=
+    checkargs=
+    noearly=
+    loud=
+    keyscript=
+*/
+
+static int parse_one_option(const char *option) {
+        assert(option);
+
+        /* Handled outside of this tool */
+        if (streq(option, "noauto"))
+                return 0;
+
+        if (startswith(option, "cipher=")) {
+                char *t;
+
+                if (!(t = strdup(option+7)))
+                        return -ENOMEM;
+
+                free(opt_cipher);
+                opt_cipher = t;
+
+        } else if (startswith(option, "size=")) {
+
+                if (safe_atou(option+5, &opt_key_size) < 0) {
+                        log_error("size= parse failure, ignoring.");
+                        return 0;
+                }
+
+        } else if (startswith(option, "hash=")) {
+                char *t;
+
+                if (!(t = strdup(option+5)))
+                        return -ENOMEM;
+
+                free(opt_hash);
+                opt_hash = t;
+
+        } else if (startswith(option, "tries=")) {
+
+                if (safe_atou(option+6, &opt_tries) < 0) {
+                        log_error("tries= parse failure, ignoring.");
+                        return 0;
+                }
+
+        } else if (streq(option, "readonly"))
+                opt_readonly = true;
+        else if (streq(option, "verify"))
+                opt_verify = true;
+        else if (streq(option, "luks"))
+                opt_type = CRYPT_LUKS1;
+        else if (streq(option, "plain") ||
+                 streq(option, "swap") ||
+                 streq(option, "tmp"))
+                opt_type = CRYPT_PLAIN;
+        else if (startswith(option, "timeout=")) {
+
+                if (parse_usec(option+8, &opt_timeout) < 0) {
+                        log_error("timeout= parse failure, ignoring.");
+                        return 0;
+                }
+
+        } else
+                log_error("Encountered unknown /etc/crypttab option '%s', ignoring.", option);
+
+        return 0;
+}
+
+static int parse_options(const char *options) {
+        char *state;
+        char *w;
+        size_t l;
+
+        assert(options);
+
+        FOREACH_WORD_SEPARATOR(w, l, options, ",", state) {
+                char *o;
+                int r;
+
+                if (!(o = strndup(w, l)))
+                        return -ENOMEM;
+
+                r = parse_one_option(o);
+                free(o);
+
+                if (r < 0)
+                        return r;
+        }
+
+        return 0;
+}
+
+static void log_glue(int level, const char *msg, void *usrptr) {
+        log_debug("%s", msg);
+}
+
+static char *disk_description(const char *path) {
+        struct udev *udev = NULL;
+        struct udev_device *device = NULL;
+        struct stat st;
+        char *description = NULL;
+        const char *model;
+
+        assert(path);
+
+        if (stat(path, &st) < 0)
+                return NULL;
+
+        if (!S_ISBLK(st.st_mode))
+                return NULL;
+
+        if (!(udev = udev_new()))
+                return NULL;
+
+        if (!(device = udev_device_new_from_devnum(udev, 'b', st.st_rdev)))
+                goto finish;
+
+        if ((model = udev_device_get_property_value(device, "ID_MODEL_FROM_DATABASE")) ||
+            (model = udev_device_get_property_value(device, "ID_MODEL")) ||
+            (model = udev_device_get_property_value(device, "DM_NAME")))
+                description = strdup(model);
+
+finish:
+        if (device)
+                udev_device_unref(device);
+
+        if (udev)
+                udev_unref(udev);
+
+        return description;
+}
+
+static char *disk_mount_point(const char *label) {
+        char *mp = NULL, *device = NULL;
+        FILE *f = NULL;
+        struct mntent *m;
+
+        /* Yeah, we don't support native systemd unit files here for now */
+
+        if (asprintf(&device, "/dev/mapper/%s", label) < 0)
+                goto finish;
+
+        if (!(f = setmntent("/etc/fstab", "r")))
+                goto finish;
+
+        while ((m = getmntent(f)))
+                if (path_equal(m->mnt_fsname, device)) {
+                        mp = strdup(m->mnt_dir);
+                        break;
+                }
+
+finish:
+        if (f)
+                endmntent(f);
+
+        free(device);
+
+        return mp;
+}
+
+static int help(void) {
+
+        printf("%s attach VOLUME SOURCEDEVICE [PASSWORD] [OPTIONS]\n"
+               "%s detach VOLUME\n\n"
+               "Attaches or detaches an encrypted block device.\n",
+               program_invocation_short_name,
+               program_invocation_short_name);
+
+        return 0;
+}
 
 int main(int argc, char *argv[]) {
-        int r = EXIT_SUCCESS;
+        int r = EXIT_FAILURE;
+        struct crypt_device *cd = NULL;
+        char **passwords = NULL, *truncated_cipher = NULL;
+        const char *cipher = NULL, *cipher_mode = NULL, *hash = NULL, *name = NULL;
+        char *description = NULL, *name_buffer = NULL, *mount_point = NULL;
+        unsigned keyfile_size = 0;
+
+        if (argc <= 1) {
+                help();
+                return EXIT_SUCCESS;
+        }
 
         if (argc < 3) {
                 log_error("This program requires at least two arguments.");
                 return EXIT_FAILURE;
         }
 
-        log_set_target(LOG_TARGET_SYSLOG_OR_KMSG);
+        log_set_target(LOG_TARGET_AUTO);
         log_parse_environment();
         log_open();
 
-        if (streq(argv[1], "create")) {
+        if (streq(argv[1], "attach")) {
+                uint32_t flags = 0;
+                int k;
+                unsigned try;
+                const char *key_file = NULL;
+                usec_t until;
+                crypt_status_info status;
+
+                /* Arguments: systemd-cryptsetup attach VOLUME SOURCE-DEVICE [PASSWORD] [OPTIONS] */
 
-        } else if (streq(argv[1], "format")) {
+                if (argc < 4) {
+                        log_error("attach requires at least two arguments.");
+                        goto finish;
+                }
 
+                if (argc >= 5 &&
+                    argv[4][0] &&
+                    !streq(argv[4], "-") &&
+                    !streq(argv[4], "none")) {
 
-        } else if (streq(argv[1], "remove")) {
+                        if (!path_is_absolute(argv[4]))
+                                log_error("Password file path %s is not absolute. Ignoring.", argv[4]);
+                        else
+                                key_file = argv[4];
+                }
+
+                if (argc >= 6 && argv[5][0] && !streq(argv[5], "-"))
+                        parse_options(argv[5]);
+
+                /* A delicious drop of snake oil */
+                mlockall(MCL_FUTURE);
+
+                description = disk_description(argv[3]);
+                mount_point = disk_mount_point(argv[2]);
+
+                if (description && streq(argv[2], description)) {
+                        /* If the description string is simply the
+                         * volume name, then let's not show this
+                         * twice */
+                        free(description);
+                        description = NULL;
+                }
+
+                if (mount_point && description)
+                        asprintf(&name_buffer, "%s (%s) on %s", description, argv[2], mount_point);
+                else if (mount_point)
+                        asprintf(&name_buffer, "%s on %s", argv[2], mount_point);
+                else if (description)
+                        asprintf(&name_buffer, "%s (%s)", description, argv[2]);
+
+                name = name_buffer ? name_buffer : argv[2];
+
+                if ((k = crypt_init(&cd, argv[3]))) {
+                        log_error("crypt_init() failed: %s", strerror(-k));
+                        goto finish;
+                }
+
+                crypt_set_log_callback(cd, log_glue, NULL);
+
+                status = crypt_status(cd, argv[2]);
+                if (status == CRYPT_ACTIVE || status == CRYPT_BUSY) {
+                        log_info("Volume %s already active.", argv[2]);
+                        r = EXIT_SUCCESS;
+                        goto finish;
+                }
+
+                if (opt_readonly)
+                        flags |= CRYPT_ACTIVATE_READONLY;
+
+                if (opt_timeout > 0)
+                        until = now(CLOCK_MONOTONIC) + opt_timeout;
+                else
+                        until = 0;
+
+                opt_tries = opt_tries > 0 ? opt_tries : 3;
+                opt_key_size = (opt_key_size > 0 ? opt_key_size : 256);
+                hash = opt_hash ? opt_hash : "ripemd160";
+
+                if (opt_cipher) {
+                        size_t l;
+
+                        l = strcspn(opt_cipher, "-");
+
+                        if (!(truncated_cipher = strndup(opt_cipher, l))) {
+                                log_error("Out of memory");
+                                goto finish;
+                        }
+
+                        cipher = truncated_cipher;
+                        cipher_mode = opt_cipher[l] ? opt_cipher+l+1 : "plain";
+                } else {
+                        cipher = "aes";
+                        cipher_mode = "cbc-essiv:sha256";
+                }
+
+                for (try = 0; try < opt_tries; try++) {
+                        bool pass_volume_key = false;
+
+                        strv_free(passwords);
+                        passwords = NULL;
+
+                        if (!key_file) {
+                                char *text;
+                                char **p;
+
+                                if (asprintf(&text, "Please enter passphrase for disk %s!", name) < 0) {
+                                        log_error("Out of memory");
+                                        goto finish;
+                                }
+
+                                k = ask_password_auto(text, "drive-harddisk", until, try == 0 && !opt_verify, &passwords);
+                                free(text);
+
+                                if (k < 0) {
+                                        log_error("Failed to query password: %s", strerror(-k));
+                                        goto finish;
+                                }
+
+                                if (opt_verify) {
+                                        char **passwords2 = NULL;
+
+                                        assert(strv_length(passwords) == 1);
+
+                                        if (asprintf(&text, "Please enter passphrase for disk %s! (verification)", name) < 0) {
+                                                log_error("Out of memory");
+                                                goto finish;
+                                        }
+
+                                        k = ask_password_auto(text, "drive-harddisk", until, false, &passwords2);
+                                        free(text);
+
+                                        if (k < 0) {
+                                                log_error("Failed to query verification password: %s", strerror(-k));
+                                                goto finish;
+                                        }
+
+                                        assert(strv_length(passwords2) == 1);
+
+                                        if (!streq(passwords[0], passwords2[0])) {
+                                                log_warning("Passwords did not match, retrying.");
+                                                strv_free(passwords2);
+                                                continue;
+                                        }
+
+                                        strv_free(passwords2);
+                                }
+
+                                strv_uniq(passwords);
+
+                                STRV_FOREACH(p, passwords) {
+                                        char *c;
+
+                                        if (strlen(*p)+1 >= opt_key_size)
+                                                continue;
+
+                                        /* Pad password if necessary */
+                                        if (!(c = new(char, opt_key_size))) {
+                                                log_error("Out of memory.");
+                                                goto finish;
+                                        }
+
+                                        strncpy(c, *p, opt_key_size);
+                                        free(*p);
+                                        *p = c;
+                                }
+                        }
+
+                        k = 0;
+
+                        if (!opt_type || streq(opt_type, CRYPT_LUKS1))
+                                k = crypt_load(cd, CRYPT_LUKS1, NULL);
+
+                        if ((!opt_type && k < 0) || streq_ptr(opt_type, CRYPT_PLAIN)) {
+                                struct crypt_params_plain params;
+
+                                zero(params);
+                                params.hash = hash;
+
+                                /* In contrast to what the name
+                                 * crypt_setup() might suggest this
+                                 * doesn't actually format anything,
+                                 * it just configures encryption
+                                 * parameters when used for plain
+                                 * mode. */
+                                k = crypt_format(cd, CRYPT_PLAIN,
+                                                 cipher,
+                                                 cipher_mode,
+                                                 NULL,
+                                                 NULL,
+                                                 opt_key_size / 8,
+                                                 &params);
+
+                                pass_volume_key = streq(hash, "plain");
+
+                               /* for CRYPT_PLAIN limit reads
+                                * from keyfile to key length */
+                                keyfile_size = opt_key_size / 8;
+                        }
+
+                        if (k < 0) {
+                                log_error("Loading of cryptographic parameters failed: %s", strerror(-k));
+                                goto finish;
+                        }
+
+                        log_info("Set cipher %s, mode %s, key size %i bits for device %s.",
+                                 crypt_get_cipher(cd),
+                                 crypt_get_cipher_mode(cd),
+                                 crypt_get_volume_key_size(cd)*8,
+                                 argv[3]);
+
+                        if (key_file)
+                                k = crypt_activate_by_keyfile(cd, argv[2], CRYPT_ANY_SLOT, key_file, keyfile_size, flags);
+                        else {
+                                char **p;
+
+                                STRV_FOREACH(p, passwords) {
+
+                                        if (pass_volume_key)
+                                                k = crypt_activate_by_volume_key(cd, argv[2], *p, opt_key_size, flags);
+                                        else
+                                                k = crypt_activate_by_passphrase(cd, argv[2], CRYPT_ANY_SLOT, *p, strlen(*p), flags);
+
+                                        if (k >= 0)
+                                                break;
+                                }
+                        }
+
+                        if (k >= 0)
+                                break;
+
+                        if (k != -EPERM) {
+                                log_error("Failed to activate: %s", strerror(-k));
+                                goto finish;
+                        }
+
+                        log_warning("Invalid passphrase.");
+                }
+
+                if (try >= opt_tries) {
+                        log_error("Too many attempts.");
+                        r = EXIT_FAILURE;
+                        goto finish;
+                }
+
+        } else if (streq(argv[1], "detach")) {
+                int k;
+
+                if ((k = crypt_init_by_name(&cd, argv[2]))) {
+                        log_error("crypt_init() failed: %s", strerror(-k));
+                        goto finish;
+                }
+
+                crypt_set_log_callback(cd, log_glue, NULL);
+
+                if ((k = crypt_deactivate(cd, argv[2])) < 0) {
+                        log_error("Failed to deactivate: %s", strerror(-k));
+                        goto finish;
+                }
 
         } else {
                 log_error("Unknown verb %s.", argv[1]);
                 goto finish;
         }
 
+        r = EXIT_SUCCESS;
+
 finish:
+
+        if (cd)
+                crypt_free(cd);
+
+        free(opt_cipher);
+        free(opt_hash);
+
+        free(truncated_cipher);
+
+        strv_free(passwords);
+
+        free(description);
+        free(mount_point);
+        free(name_buffer);
+
         return r;
 }