mirror of
https://github.com/morgan9e/systemd
synced 2026-04-15 00:47:10 +09:00
- drop unnecessary SYNTHETIC_ERRNO() when the logger does not propagate error code, - drop unnecessary '%m' in error message when the error code is specified with SYNTHETIC_ERRNO(), - add missing full stop at the end of log message, - use RET_GATHER(), - add missing ", ignoring.", - upeercase the first letter, etc., etc...
1744 lines
78 KiB
C
1744 lines
78 KiB
C
/* SPDX-License-Identifier: LGPL-2.1-or-later */
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#include <sys/file.h>
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#if HAVE_OPENSSL
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#include <openssl/err.h>
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#endif
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#include "sd-id128.h"
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#include "blockdev-util.h"
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#include "capability-util.h"
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#include "chattr-util.h"
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#include "constants.h"
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#include "copy.h"
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#include "creds-util.h"
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#include "efi-api.h"
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#include "env-util.h"
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#include "fd-util.h"
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#include "fileio.h"
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#include "format-util.h"
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#include "fs-util.h"
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#include "io-util.h"
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#include "memory-util.h"
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#include "mkdir-label.h"
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#include "openssl-util.h"
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#include "parse-util.h"
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#include "path-util.h"
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#include "random-util.h"
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#include "recurse-dir.h"
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#include "sparse-endian.h"
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#include "stat-util.h"
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#include "tmpfile-util.h"
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#include "tpm2-util.h"
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#include "user-util.h"
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#include "varlink.h"
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#define PUBLIC_KEY_MAX (UINT32_C(1024) * UINT32_C(1024))
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bool credential_name_valid(const char *s) {
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/* We want that credential names are both valid in filenames (since that's our primary way to pass
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* them around) and as fdnames (which is how we might want to pass them around eventually) */
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return filename_is_valid(s) && fdname_is_valid(s);
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}
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bool credential_glob_valid(const char *s) {
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const char *e, *a;
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size_t n;
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/* Checks if a credential glob expression is valid. Note that this is more restrictive than
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* fnmatch()! We only allow trailing asterisk matches for now (simply because we want some freedom
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* with automatically extending the pattern in a systematic way to cover for unit instances getting
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* per-instance credentials or similar. Moreover, credential globbing expressions are also more
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* restrictive then credential names: we don't allow *, ?, [, ] in them (except for the asterisk
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* match at the end of the string), simply to not allow ambiguity. After all, we want the flexibility
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* to one day add full globbing should the need arise. */
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if (isempty(s))
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return false;
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/* Find first glob (or NUL byte) */
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n = strcspn(s, "*?[]");
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e = s + n;
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/* For now, only allow asterisk wildcards, and only at the end of the string. If it's anything else, refuse. */
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if (isempty(e))
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return credential_name_valid(s);
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if (!streq(e, "*")) /* only allow trailing "*", no other globs */
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return false;
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if (n == 0) /* Explicitly allow the complete wildcard. */
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return true;
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if (n > NAME_MAX + strlen(e)) /* before we make a copy on the stack, let's check this is not overly large */
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return false;
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/* Make a copy of the string without the '*' suffix */
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a = strndupa_safe(s, n);
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return credential_name_valid(a);
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}
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static int get_credentials_dir_internal(const char *envvar, const char **ret) {
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const char *e;
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assert(ret);
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e = secure_getenv(envvar);
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if (!e)
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return -ENXIO;
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if (!path_is_absolute(e) || !path_is_normalized(e))
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return -EINVAL;
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*ret = e;
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return 0;
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}
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int get_credentials_dir(const char **ret) {
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return get_credentials_dir_internal("CREDENTIALS_DIRECTORY", ret);
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}
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int get_encrypted_credentials_dir(const char **ret) {
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return get_credentials_dir_internal("ENCRYPTED_CREDENTIALS_DIRECTORY", ret);
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}
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int open_credentials_dir(void) {
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const char *d;
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int r;
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r = get_credentials_dir(&d);
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if (r < 0)
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return r;
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return RET_NERRNO(open(d, O_CLOEXEC|O_DIRECTORY));
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}
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int read_credential(const char *name, void **ret, size_t *ret_size) {
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_cleanup_free_ char *fn = NULL;
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const char *d;
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int r;
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assert(ret);
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if (!credential_name_valid(name))
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return -EINVAL;
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r = get_credentials_dir(&d);
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if (r < 0)
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return r;
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fn = path_join(d, name);
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if (!fn)
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return -ENOMEM;
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return read_full_file_full(
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AT_FDCWD, fn,
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UINT64_MAX, SIZE_MAX,
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READ_FULL_FILE_SECURE,
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NULL,
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(char**) ret, ret_size);
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}
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int read_credential_with_decryption(const char *name, void **ret, size_t *ret_size) {
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_cleanup_(iovec_done_erase) struct iovec ret_iovec = {};
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_cleanup_(erase_and_freep) void *data = NULL;
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_cleanup_free_ char *fn = NULL;
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size_t sz = 0;
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const char *d;
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int r;
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/* Just like read_credential() but will also look for encrypted credentials. Note that services only
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* receive decrypted credentials, hence use read_credential() for those. This helper here is for
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* generators, i.e. code that runs outside of service context, and thus has no decrypted credentials
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* yet.
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*
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* Note that read_credential_harder_and_warn() logs on its own, while read_credential() does not!
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* (It's a lot more complex and error prone given its TPM2 connectivity, and is generally called from
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* generators only where logging is OK).
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*
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* Error handling is also a bit different: if we can't find a credential we'll return 0 and NULL
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* pointers/zero size, rather than -ENXIO/-ENOENT. */
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if (!credential_name_valid(name))
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return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid credential name: %s", name);
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r = read_credential(name, ret, ret_size);
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if (r >= 0)
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return 1; /* found */
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if (!IN_SET(r, -ENXIO, -ENOENT))
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return log_error_errno(r, "Failed read unencrypted credential '%s': %m", name);
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r = get_encrypted_credentials_dir(&d);
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if (r == -ENXIO)
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goto not_found;
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if (r < 0)
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return log_error_errno(r, "Failed to determine encrypted credentials directory: %m");
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fn = path_join(d, name);
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if (!fn)
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return log_oom();
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r = read_full_file_full(
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AT_FDCWD, fn,
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UINT64_MAX, SIZE_MAX,
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READ_FULL_FILE_SECURE,
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NULL,
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(char**) &data, &sz);
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if (r == -ENOENT)
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goto not_found;
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if (r < 0)
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return log_error_errno(r, "Failed to read encrypted credential data: %m");
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if (geteuid() != 0)
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r = ipc_decrypt_credential(
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name,
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now(CLOCK_REALTIME),
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getuid(),
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&IOVEC_MAKE(data, sz),
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CREDENTIAL_ANY_SCOPE,
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&ret_iovec);
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else
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r = decrypt_credential_and_warn(
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name,
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now(CLOCK_REALTIME),
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/* tpm2_device= */ NULL,
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/* tpm2_signature_path= */ NULL,
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getuid(),
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&IOVEC_MAKE(data, sz),
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CREDENTIAL_ANY_SCOPE,
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&ret_iovec);
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if (r < 0)
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return r;
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if (ret)
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*ret = TAKE_PTR(ret_iovec.iov_base);
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if (ret_size)
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*ret_size = ret_iovec.iov_len;
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return 1; /* found */
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not_found:
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if (ret)
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*ret = NULL;
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if (ret_size)
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*ret_size = 0;
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return 0; /* not found */
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}
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int read_credential_strings_many_internal(
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const char *first_name, char **first_value,
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...) {
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_cleanup_free_ void *b = NULL;
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bool all = true;
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int r, ret = 0;
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/* Reads a bunch of credentials into the specified buffers. If the specified buffers are already
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* non-NULL frees them if a credential is found. Only supports string-based credentials
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* (i.e. refuses embedded NUL bytes).
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*
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* 0 is returned when some or all credentials are missing.
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*/
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if (!first_name)
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return 0;
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r = read_credential(first_name, &b, NULL);
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if (r == -ENXIO) /* No creds passed at all? Bail immediately. */
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return 0;
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if (r == -ENOENT)
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all = false;
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else if (r < 0)
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RET_GATHER(ret, r);
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else
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free_and_replace(*first_value, b);
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va_list ap;
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va_start(ap, first_value);
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for (;;) {
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_cleanup_free_ void *bb = NULL;
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const char *name;
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char **value;
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name = va_arg(ap, const char *);
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if (!name)
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break;
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value = ASSERT_PTR(va_arg(ap, char **));
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r = read_credential(name, &bb, NULL);
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if (r == -ENOENT)
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all = false;
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else if (r < 0)
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RET_GATHER(ret, r);
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else
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free_and_replace(*value, bb);
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}
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va_end(ap);
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return ret < 0 ? ret : all;
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}
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int read_credential_bool(const char *name) {
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_cleanup_free_ void *data = NULL;
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int r;
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r = read_credential(name, &data, NULL);
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if (r < 0)
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return IN_SET(r, -ENXIO, -ENOENT) ? 0 : r;
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return parse_boolean(data);
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}
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int get_credential_user_password(const char *username, char **ret_password, bool *ret_is_hashed) {
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_cleanup_(erase_and_freep) char *creds_password = NULL;
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_cleanup_free_ char *cn = NULL;
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int r;
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/* Try to pick up the password for this account via the credentials logic */
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cn = strjoin("passwd.hashed-password.", username);
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if (!cn)
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return -ENOMEM;
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r = read_credential(cn, (void**) &creds_password, NULL);
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if (r == -ENOENT) {
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free(cn);
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cn = strjoin("passwd.plaintext-password.", username);
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if (!cn)
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return -ENOMEM;
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r = read_credential(cn, (void**) &creds_password, NULL);
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if (r < 0)
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log_debug_errno(r, "Couldn't read credential '%s', ignoring: %m", cn);
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else
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*ret_is_hashed = false;
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} else if (r < 0)
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log_debug_errno(r, "Couldn't read credential '%s', ignoring: %m", cn);
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else
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*ret_is_hashed = true;
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*ret_password = TAKE_PTR(creds_password);
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return r;
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}
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#if HAVE_OPENSSL
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#define CREDENTIAL_HOST_SECRET_SIZE 4096
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static const sd_id128_t credential_app_id =
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SD_ID128_MAKE(d3,ac,ec,ba,0d,ad,4c,df,b8,c9,38,15,28,93,6c,58);
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struct credential_host_secret_format {
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/* The hashed machine ID of the machine this belongs to. Why? We want to ensure that each machine
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* gets its own secret, even if people forget to flush out this secret file. Hence we bind it to the
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* machine ID, for which there's hopefully a better chance it will be flushed out. We use a hashed
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* machine ID instead of the literal one, because it's trivial to, and it might be a good idea not
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* being able to directly associate a secret key file with a host. */
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sd_id128_t machine_id;
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/* The actual secret key */
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uint8_t data[CREDENTIAL_HOST_SECRET_SIZE];
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} _packed_;
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static void warn_not_encrypted(int fd, CredentialSecretFlags flags, const char *dirname, const char *filename) {
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int r;
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assert(fd >= 0);
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assert(dirname);
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assert(filename);
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if (!FLAGS_SET(flags, CREDENTIAL_SECRET_WARN_NOT_ENCRYPTED))
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return;
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r = fd_is_encrypted(fd);
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if (r < 0)
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log_debug_errno(r, "Failed to determine if credential secret file '%s/%s' is encrypted.",
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dirname, filename);
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else if (r == 0)
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log_warning("Credential secret file '%s/%s' is not located on encrypted media, using anyway.",
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dirname, filename);
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}
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static int make_credential_host_secret(
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int dfd,
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const sd_id128_t machine_id,
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CredentialSecretFlags flags,
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const char *dirname,
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const char *fn,
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struct iovec *ret) {
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_cleanup_free_ char *t = NULL;
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_cleanup_close_ int fd = -EBADF;
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int r;
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assert(dfd >= 0);
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assert(fn);
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fd = open_tmpfile_linkable_at(dfd, fn, O_CLOEXEC|O_WRONLY, &t);
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if (fd < 0)
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return log_debug_errno(fd, "Failed to create temporary file for credential host secret: %m");
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r = chattr_secret(fd, 0);
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if (r < 0)
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log_debug_errno(r, "Failed to set file attributes for secrets file, ignoring: %m");
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struct credential_host_secret_format buf = {
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.machine_id = machine_id,
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};
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CLEANUP_ERASE(buf);
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r = crypto_random_bytes(buf.data, sizeof(buf.data));
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if (r < 0)
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goto fail;
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r = loop_write(fd, &buf, sizeof(buf));
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if (r < 0)
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goto fail;
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if (fchmod(fd, 0400) < 0) {
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r = -errno;
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goto fail;
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}
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if (fsync(fd) < 0) {
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r = -errno;
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goto fail;
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}
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warn_not_encrypted(fd, flags, dirname, fn);
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|
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r = link_tmpfile_at(fd, dfd, t, fn, LINK_TMPFILE_SYNC);
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if (r < 0) {
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log_debug_errno(r, "Failed to link host key into place: %m");
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goto fail;
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}
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if (ret) {
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void *copy;
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copy = memdup(buf.data, sizeof(buf.data));
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if (!copy)
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return -ENOMEM;
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*ret = IOVEC_MAKE(copy, sizeof(buf.data));
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}
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return 0;
|
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|
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fail:
|
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if (t && unlinkat(dfd, t, 0) < 0)
|
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log_debug_errno(errno, "Failed to remove temporary credential key: %m");
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||
|
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return r;
|
||
}
|
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|
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int get_credential_host_secret(CredentialSecretFlags flags, struct iovec *ret) {
|
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_cleanup_free_ char *_dirname = NULL, *_filename = NULL;
|
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_cleanup_close_ int dfd = -EBADF;
|
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sd_id128_t machine_id;
|
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const char *dirname, *filename;
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int r;
|
||
|
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r = sd_id128_get_machine_app_specific(credential_app_id, &machine_id);
|
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if (r < 0)
|
||
return r;
|
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|
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const char *e = secure_getenv("SYSTEMD_CREDENTIAL_SECRET");
|
||
if (e) {
|
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if (!path_is_normalized(e))
|
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return -EINVAL;
|
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if (!path_is_absolute(e))
|
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return -EINVAL;
|
||
|
||
r = path_extract_directory(e, &_dirname);
|
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if (r < 0)
|
||
return r;
|
||
|
||
r = path_extract_filename(e, &_filename);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
dirname = _dirname;
|
||
filename = _filename;
|
||
} else {
|
||
dirname = "/var/lib/systemd";
|
||
filename = "credential.secret";
|
||
}
|
||
|
||
assert(dirname);
|
||
assert(filename);
|
||
|
||
mkdir_parents(dirname, 0755);
|
||
dfd = open_mkdir_at(AT_FDCWD, dirname, O_CLOEXEC, 0755);
|
||
if (dfd < 0)
|
||
return log_debug_errno(dfd, "Failed to create or open directory '%s': %m", dirname);
|
||
|
||
if (FLAGS_SET(flags, CREDENTIAL_SECRET_FAIL_ON_TEMPORARY_FS)) {
|
||
r = fd_is_temporary_fs(dfd);
|
||
if (r < 0)
|
||
return log_debug_errno(r, "Failed to check directory '%s': %m", dirname);
|
||
if (r > 0)
|
||
return log_debug_errno(SYNTHETIC_ERRNO(ENOMEDIUM),
|
||
"Directory '%s' is on a temporary file system, refusing.", dirname);
|
||
}
|
||
|
||
for (unsigned attempt = 0;; attempt++) {
|
||
_cleanup_(erase_and_freep) struct credential_host_secret_format *f = NULL;
|
||
_cleanup_close_ int fd = -EBADF;
|
||
size_t l = 0;
|
||
ssize_t n = 0;
|
||
struct stat st;
|
||
|
||
if (attempt >= 3) /* Somebody is playing games with us */
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EIO),
|
||
"All attempts to create secret store in %s failed.", dirname);
|
||
|
||
fd = openat(dfd, filename, O_CLOEXEC|O_RDONLY|O_NOCTTY|O_NOFOLLOW);
|
||
if (fd < 0) {
|
||
if (errno != ENOENT || !FLAGS_SET(flags, CREDENTIAL_SECRET_GENERATE))
|
||
return log_debug_errno(errno,
|
||
"Failed to open %s/%s: %m", dirname, filename);
|
||
|
||
|
||
r = make_credential_host_secret(dfd, machine_id, flags, dirname, filename, ret);
|
||
if (r == -EEXIST) {
|
||
log_debug_errno(r, "Credential secret %s/%s appeared while we were creating it, rereading.",
|
||
dirname, filename);
|
||
continue;
|
||
}
|
||
if (r < 0)
|
||
return log_debug_errno(r, "Failed to create credential secret %s/%s: %m",
|
||
dirname, filename);
|
||
return 0;
|
||
}
|
||
|
||
if (fstat(fd, &st) < 0)
|
||
return log_debug_errno(errno, "Failed to stat %s/%s: %m", dirname, filename);
|
||
|
||
r = stat_verify_regular(&st);
|
||
if (r < 0)
|
||
return log_debug_errno(r, "%s/%s is not a regular file: %m", dirname, filename);
|
||
if (st.st_nlink == 0) /* Deleted by now, try again */
|
||
continue;
|
||
if (st.st_nlink > 1)
|
||
/* Our deletion check won't work if hardlinked somewhere else */
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
|
||
"%s/%s has too many links, refusing.",
|
||
dirname, filename);
|
||
if ((st.st_mode & 07777) != 0400)
|
||
/* Don't use file if not 0400 access mode */
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
|
||
"%s/%s has permissive access mode, refusing.",
|
||
dirname, filename);
|
||
l = st.st_size;
|
||
if (l < offsetof(struct credential_host_secret_format, data) + 1)
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EINVAL),
|
||
"%s/%s is too small, refusing.", dirname, filename);
|
||
if (l > 16*1024*1024)
|
||
return log_debug_errno(SYNTHETIC_ERRNO(E2BIG),
|
||
"%s/%s is too big, refusing.", dirname, filename);
|
||
|
||
f = malloc(l+1);
|
||
if (!f)
|
||
return log_oom_debug();
|
||
|
||
n = read(fd, f, l+1);
|
||
if (n < 0)
|
||
return log_debug_errno(errno,
|
||
"Failed to read %s/%s: %m", dirname, filename);
|
||
if ((size_t) n != l) /* What? The size changed? */
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EIO),
|
||
"Failed to read %s/%s.", dirname, filename);
|
||
|
||
if (sd_id128_equal(machine_id, f->machine_id)) {
|
||
size_t sz;
|
||
|
||
warn_not_encrypted(fd, flags, dirname, filename);
|
||
|
||
sz = l - offsetof(struct credential_host_secret_format, data);
|
||
assert(sz > 0);
|
||
|
||
if (ret) {
|
||
void *copy;
|
||
|
||
assert(sz <= sizeof(f->data)); /* Ensure we don't read past f->data bounds */
|
||
|
||
copy = memdup(f->data, sz);
|
||
if (!copy)
|
||
return log_oom_debug();
|
||
|
||
*ret = IOVEC_MAKE(copy, sz);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
/* Hmm, this secret is from somewhere else. Let's delete the file. Let's first acquire a lock
|
||
* to ensure we are the only ones accessing the file while we delete it. */
|
||
|
||
if (flock(fd, LOCK_EX) < 0)
|
||
return log_debug_errno(errno,
|
||
"Failed to flock %s/%s: %m", dirname, filename);
|
||
|
||
/* Before we delete it check that the file is still linked into the file system */
|
||
if (fstat(fd, &st) < 0)
|
||
return log_debug_errno(errno, "Failed to stat %s/%s: %m", dirname, filename);
|
||
if (st.st_nlink == 0) /* Already deleted by now? */
|
||
continue;
|
||
if (st.st_nlink != 1) /* Safety check, someone is playing games with us */
|
||
return log_debug_errno(SYNTHETIC_ERRNO(EPERM),
|
||
"%s/%s unexpectedly has too many links.",
|
||
dirname, filename);
|
||
if (unlinkat(dfd, filename, 0) < 0)
|
||
return log_debug_errno(errno, "Failed to unlink %s/%s: %m", dirname, filename);
|
||
|
||
/* And now try again */
|
||
}
|
||
}
|
||
|
||
/* Construction is like this:
|
||
*
|
||
* A symmetric encryption key is derived from:
|
||
*
|
||
* 1. Either the "host" key (a key stored in /var/lib/credential.secret)
|
||
*
|
||
* 2. A key generated by letting the TPM2 calculate an HMAC hash of some nonce we pass to it, keyed
|
||
* by a key derived from its internal seed key.
|
||
*
|
||
* 3. The concatenation of the above.
|
||
*
|
||
* 4. Or a fixed "empty" key. This will not provide confidentiality or authenticity, of course, but is
|
||
* useful to encode credentials for the initrd on TPM-less systems, where we simply have no better
|
||
* concept to bind things to. Note that decryption of a key set up like this will be refused on
|
||
* systems that have a TPM and have SecureBoot enabled.
|
||
*
|
||
* The above is hashed with SHA256 which is then used as encryption key for AES256-GCM. The encrypted
|
||
* credential is a short (unencrypted) header describing which of the three keys to use, the IV to use for
|
||
* AES256-GCM and some more meta information (sizes of certain objects) that is strictly speaking redundant,
|
||
* but kinda nice to have since we can have a more generic parser. If the TPM2 key is used this is followed
|
||
* by another (unencrypted) header, with information about the TPM2 policy used (specifically: the PCR mask
|
||
* to bind against, and a hash of the resulting policy — the latter being redundant, but speeding up things a
|
||
* bit, since we can more quickly refuse PCR state), followed by a sealed/exported TPM2 HMAC key. This is
|
||
* then followed by the encrypted data, which begins with a metadata header (which contains validity
|
||
* timestamps as well as the credential name), followed by the actual credential payload. The file ends in
|
||
* the AES256-GCM tag. To make things simple, the AES256-GCM AAD covers the main and the TPM2 header in
|
||
* full. This means the whole file is either protected by AAD, or is ciphertext, or is the tag. No
|
||
* unprotected data is included.
|
||
*/
|
||
|
||
struct _packed_ encrypted_credential_header {
|
||
sd_id128_t id;
|
||
le32_t key_size;
|
||
le32_t block_size;
|
||
le32_t iv_size;
|
||
le32_t tag_size;
|
||
uint8_t iv[];
|
||
/* Followed by NUL bytes until next 8 byte boundary */
|
||
};
|
||
|
||
struct _packed_ tpm2_credential_header {
|
||
le64_t pcr_mask; /* Note that the spec for PC Clients only mandates 24 PCRs, and that's what systems
|
||
* generally have. But keep the door open for more. */
|
||
le16_t pcr_bank; /* For now, either TPM2_ALG_SHA256 or TPM2_ALG_SHA1 */
|
||
le16_t primary_alg; /* Primary key algorithm (either TPM2_ALG_RSA or TPM2_ALG_ECC for now) */
|
||
le32_t blob_size;
|
||
le32_t policy_hash_size;
|
||
uint8_t policy_hash_and_blob[];
|
||
/* Followed by NUL bytes until next 8 byte boundary */
|
||
};
|
||
|
||
struct _packed_ tpm2_public_key_credential_header {
|
||
le64_t pcr_mask; /* PCRs used for the public key PCR policy (usually just PCR 11, i.e. the unified kernel) */
|
||
le32_t size; /* Size of DER public key */
|
||
uint8_t data[]; /* DER public key */
|
||
/* Followed by NUL bytes until next 8 byte boundary */
|
||
};
|
||
|
||
struct _packed_ scoped_credential_header {
|
||
le64_t flags; /* SCOPE_HASH_DATA_BASE_FLAGS for now */
|
||
};
|
||
|
||
/* This header is encrypted */
|
||
struct _packed_ metadata_credential_header {
|
||
le64_t timestamp;
|
||
le64_t not_after;
|
||
le32_t name_size;
|
||
char name[];
|
||
/* Followed by NUL bytes until next 8 byte boundary */
|
||
};
|
||
|
||
struct _packed_ scoped_hash_data {
|
||
le64_t flags; /* copy of the scoped_credential_header.flags */
|
||
le32_t uid;
|
||
sd_id128_t machine_id;
|
||
char username[]; /* followed by the username */
|
||
/* Later on we might want to extend this: with a cgroup path to allow per-app secrets, and with the user's $HOME encryption key */
|
||
};
|
||
|
||
enum {
|
||
/* Flags for scoped_hash_data.flags and scoped_credential_header.flags */
|
||
SCOPE_HASH_DATA_HAS_UID = 1 << 0,
|
||
SCOPE_HASH_DATA_HAS_MACHINE = 1 << 1,
|
||
SCOPE_HASH_DATA_HAS_USERNAME = 1 << 2,
|
||
|
||
SCOPE_HASH_DATA_BASE_FLAGS = SCOPE_HASH_DATA_HAS_UID | SCOPE_HASH_DATA_HAS_USERNAME | SCOPE_HASH_DATA_HAS_MACHINE,
|
||
};
|
||
|
||
/* Some generic limit for parts of the encrypted credential for which we don't know the right size ahead of
|
||
* time, but where we are really sure it won't be larger than this. Should be larger than any possible IV,
|
||
* padding, tag size and so on. This is purely used for early filtering out of invalid sizes. */
|
||
#define CREDENTIAL_FIELD_SIZE_MAX (16U*1024U)
|
||
|
||
static int sha256_hash_host_and_tpm2_key(
|
||
const struct iovec *host_key,
|
||
const struct iovec *tpm2_key,
|
||
uint8_t ret[static SHA256_DIGEST_LENGTH]) {
|
||
|
||
_cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *md = NULL;
|
||
unsigned l;
|
||
|
||
assert(iovec_is_valid(host_key));
|
||
assert(iovec_is_valid(tpm2_key));
|
||
assert(ret);
|
||
|
||
/* Combines the host key and the TPM2 HMAC hash into a SHA256 hash value we'll use as symmetric encryption key. */
|
||
|
||
md = EVP_MD_CTX_new();
|
||
if (!md)
|
||
return log_oom();
|
||
|
||
if (EVP_DigestInit_ex(md, EVP_sha256(), NULL) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initial SHA256 context.");
|
||
|
||
if (iovec_is_set(host_key) && EVP_DigestUpdate(md, host_key->iov_base, host_key->iov_len) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to hash host key.");
|
||
|
||
if (iovec_is_set(tpm2_key) && EVP_DigestUpdate(md, tpm2_key->iov_base, tpm2_key->iov_len) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to hash TPM2 key.");
|
||
|
||
assert(EVP_MD_CTX_size(md) == SHA256_DIGEST_LENGTH);
|
||
|
||
if (EVP_DigestFinal_ex(md, ret, &l) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finalize SHA256 hash.");
|
||
|
||
assert(l == SHA256_DIGEST_LENGTH);
|
||
return 0;
|
||
}
|
||
|
||
static int mangle_uid_into_key(
|
||
uid_t uid,
|
||
uint8_t md[static SHA256_DIGEST_LENGTH]) {
|
||
|
||
sd_id128_t mid;
|
||
int r;
|
||
|
||
assert(uid_is_valid(uid));
|
||
assert(md);
|
||
|
||
/* If we shall encrypt for a specific user, we HMAC() a structure with the user's credentials
|
||
* (specifically, UID, user name, machine ID) with the key we'd otherwise use for system credentials,
|
||
* and use the resulting hash as actual encryption key. */
|
||
|
||
errno = 0;
|
||
struct passwd *pw = getpwuid(uid);
|
||
if (!pw)
|
||
return log_error_errno(
|
||
IN_SET(errno, 0, ENOENT) ? SYNTHETIC_ERRNO(ESRCH) : errno,
|
||
"Failed to resolve UID " UID_FMT ": %m", uid);
|
||
|
||
r = sd_id128_get_machine(&mid);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to read machine ID: %m");
|
||
|
||
size_t sz = offsetof(struct scoped_hash_data, username) + strlen(pw->pw_name) + 1;
|
||
_cleanup_free_ struct scoped_hash_data *d = malloc0(sz);
|
||
if (!d)
|
||
return log_oom();
|
||
|
||
d->flags = htole64(SCOPE_HASH_DATA_BASE_FLAGS);
|
||
d->uid = htole32(uid);
|
||
d->machine_id = mid;
|
||
|
||
strcpy(d->username, pw->pw_name);
|
||
|
||
_cleanup_(erase_and_freep) void *buf = NULL;
|
||
size_t buf_size = 0;
|
||
r = openssl_hmac_many(
|
||
"sha256",
|
||
md, SHA256_DIGEST_LENGTH,
|
||
&IOVEC_MAKE(d, sz), 1,
|
||
&buf, &buf_size);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
assert(buf_size == SHA256_DIGEST_LENGTH);
|
||
memcpy(md, buf, buf_size);
|
||
|
||
return 0;
|
||
}
|
||
|
||
int encrypt_credential_and_warn(
|
||
sd_id128_t with_key,
|
||
const char *name,
|
||
usec_t timestamp,
|
||
usec_t not_after,
|
||
const char *tpm2_device,
|
||
uint32_t tpm2_hash_pcr_mask,
|
||
const char *tpm2_pubkey_path,
|
||
uint32_t tpm2_pubkey_pcr_mask,
|
||
uid_t uid,
|
||
const struct iovec *input,
|
||
CredentialFlags flags,
|
||
struct iovec *ret) {
|
||
|
||
_cleanup_(iovec_done) struct iovec tpm2_blob = {}, tpm2_policy_hash = {}, iv = {}, pubkey = {};
|
||
_cleanup_(iovec_done_erase) struct iovec tpm2_key = {}, output = {}, host_key = {};
|
||
_cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL;
|
||
_cleanup_free_ struct metadata_credential_header *m = NULL;
|
||
uint16_t tpm2_pcr_bank = 0, tpm2_primary_alg = 0;
|
||
struct encrypted_credential_header *h;
|
||
int ksz, bsz, ivsz, tsz, added, r;
|
||
uint8_t md[SHA256_DIGEST_LENGTH];
|
||
const EVP_CIPHER *cc;
|
||
sd_id128_t id;
|
||
size_t p, ml;
|
||
|
||
assert(iovec_is_valid(input));
|
||
assert(ret);
|
||
|
||
if (!sd_id128_in_set(with_key,
|
||
_CRED_AUTO,
|
||
_CRED_AUTO_INITRD,
|
||
_CRED_AUTO_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST,
|
||
CRED_AES256_GCM_BY_HOST_SCOPED,
|
||
CRED_AES256_GCM_BY_TPM2_HMAC,
|
||
CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED,
|
||
CRED_AES256_GCM_BY_NULL))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid key type: " SD_ID128_FORMAT_STR, SD_ID128_FORMAT_VAL(with_key));
|
||
|
||
if (name && !credential_name_valid(name))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Invalid credential name: %s", name);
|
||
|
||
if (not_after != USEC_INFINITY && timestamp != USEC_INFINITY && not_after < timestamp)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Credential is invalidated before it is valid (" USEC_FMT " < " USEC_FMT ").", not_after, timestamp);
|
||
|
||
if (DEBUG_LOGGING) {
|
||
char buf[FORMAT_TIMESTAMP_MAX];
|
||
|
||
if (name)
|
||
log_debug("Including credential name '%s' in encrypted credential.", name);
|
||
if (timestamp != USEC_INFINITY)
|
||
log_debug("Including timestamp '%s' in encrypted credential.", format_timestamp(buf, sizeof(buf), timestamp));
|
||
if (not_after != USEC_INFINITY)
|
||
log_debug("Including not-after timestamp '%s' in encrypted credential.", format_timestamp(buf, sizeof(buf), not_after));
|
||
}
|
||
|
||
if (sd_id128_in_set(with_key,
|
||
_CRED_AUTO_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED)) {
|
||
if (!uid_is_valid(uid))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Scoped credential selected, but no UID specified.");
|
||
} else
|
||
uid = UID_INVALID;
|
||
|
||
if (sd_id128_in_set(with_key,
|
||
_CRED_AUTO,
|
||
_CRED_AUTO_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST,
|
||
CRED_AES256_GCM_BY_HOST_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED)) {
|
||
|
||
r = get_credential_host_secret(
|
||
CREDENTIAL_SECRET_GENERATE|
|
||
CREDENTIAL_SECRET_WARN_NOT_ENCRYPTED|
|
||
(sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_SCOPED) ? CREDENTIAL_SECRET_FAIL_ON_TEMPORARY_FS : 0),
|
||
&host_key);
|
||
if (r == -ENOMEDIUM && sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_SCOPED))
|
||
log_debug_errno(r, "Credential host secret location on temporary file system, not using.");
|
||
else if (r < 0)
|
||
return log_error_errno(r, "Failed to determine local credential host secret: %m");
|
||
}
|
||
|
||
#if HAVE_TPM2
|
||
bool try_tpm2;
|
||
if (sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_INITRD, _CRED_AUTO_SCOPED)) {
|
||
/* If automatic mode is selected lets see if a TPM2 it is present. If we are running in a
|
||
* container tpm2_support will detect this, and will return a different flag combination of
|
||
* TPM2_SUPPORT_FULL, effectively skipping the use of TPM2 when inside one. */
|
||
|
||
try_tpm2 = tpm2_support() == TPM2_SUPPORT_FULL;
|
||
if (!try_tpm2)
|
||
log_debug("System lacks TPM2 support or running in a container, not attempting to use TPM2.");
|
||
} else
|
||
try_tpm2 = sd_id128_in_set(with_key,
|
||
CRED_AES256_GCM_BY_TPM2_HMAC,
|
||
CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED);
|
||
|
||
if (try_tpm2) {
|
||
if (sd_id128_in_set(with_key,
|
||
_CRED_AUTO,
|
||
_CRED_AUTO_INITRD,
|
||
_CRED_AUTO_SCOPED,
|
||
CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK,
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED)) {
|
||
|
||
/* Load public key for PCR policies, if one is specified, or explicitly requested */
|
||
|
||
r = tpm2_load_pcr_public_key(tpm2_pubkey_path, &pubkey.iov_base, &pubkey.iov_len);
|
||
if (r < 0) {
|
||
if (tpm2_pubkey_path || r != -ENOENT || !sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_INITRD, _CRED_AUTO_SCOPED))
|
||
return log_error_errno(r, "Failed read TPM PCR public key: %m");
|
||
|
||
log_debug_errno(r, "Failed to read TPM2 PCR public key, proceeding without: %m");
|
||
}
|
||
}
|
||
|
||
if (!iovec_is_set(&pubkey))
|
||
tpm2_pubkey_pcr_mask = 0;
|
||
|
||
_cleanup_(tpm2_context_unrefp) Tpm2Context *tpm2_context = NULL;
|
||
r = tpm2_context_new_or_warn(tpm2_device, &tpm2_context);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
r = tpm2_get_best_pcr_bank(tpm2_context, tpm2_hash_pcr_mask | tpm2_pubkey_pcr_mask, &tpm2_pcr_bank);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Could not find best pcr bank: %m");
|
||
|
||
TPML_PCR_SELECTION tpm2_hash_pcr_selection;
|
||
tpm2_tpml_pcr_selection_from_mask(tpm2_hash_pcr_mask, tpm2_pcr_bank, &tpm2_hash_pcr_selection);
|
||
|
||
_cleanup_free_ Tpm2PCRValue *tpm2_hash_pcr_values = NULL;
|
||
size_t tpm2_n_hash_pcr_values;
|
||
r = tpm2_pcr_read(tpm2_context, &tpm2_hash_pcr_selection, &tpm2_hash_pcr_values, &tpm2_n_hash_pcr_values);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Could not read PCR values: %m");
|
||
|
||
TPM2B_PUBLIC public;
|
||
if (iovec_is_set(&pubkey)) {
|
||
r = tpm2_tpm2b_public_from_pem(pubkey.iov_base, pubkey.iov_len, &public);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Could not convert public key to TPM2B_PUBLIC: %m");
|
||
}
|
||
|
||
TPM2B_DIGEST tpm2_policy = TPM2B_DIGEST_MAKE(NULL, TPM2_SHA256_DIGEST_SIZE);
|
||
r = tpm2_calculate_sealing_policy(
|
||
tpm2_hash_pcr_values,
|
||
tpm2_n_hash_pcr_values,
|
||
iovec_is_set(&pubkey) ? &public : NULL,
|
||
/* use_pin= */ false,
|
||
/* pcrlock_policy= */ NULL,
|
||
&tpm2_policy);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Could not calculate sealing policy digest: %m");
|
||
|
||
r = tpm2_seal(tpm2_context,
|
||
/* seal_key_handle= */ 0,
|
||
&tpm2_policy,
|
||
/* pin= */ NULL,
|
||
&tpm2_key,
|
||
&tpm2_blob,
|
||
&tpm2_primary_alg,
|
||
/* ret_srk= */ NULL);
|
||
if (r < 0) {
|
||
if (sd_id128_equal(with_key, _CRED_AUTO_INITRD))
|
||
log_warning("TPM2 present and used, but we didn't manage to talk to it. Credential will be refused if SecureBoot is enabled.");
|
||
else if (!sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_SCOPED))
|
||
return log_error_errno(r, "Failed to seal to TPM2: %m");
|
||
|
||
log_notice_errno(r, "TPM2 sealing didn't work, continuing without TPM2: %m");
|
||
}
|
||
|
||
if (!iovec_memdup(&IOVEC_MAKE(tpm2_policy.buffer, tpm2_policy.size), &tpm2_policy_hash))
|
||
return log_oom();
|
||
|
||
assert(tpm2_blob.iov_len <= CREDENTIAL_FIELD_SIZE_MAX);
|
||
assert(tpm2_policy_hash.iov_len <= CREDENTIAL_FIELD_SIZE_MAX);
|
||
}
|
||
#endif
|
||
|
||
if (sd_id128_in_set(with_key, _CRED_AUTO, _CRED_AUTO_INITRD, _CRED_AUTO_SCOPED)) {
|
||
/* Let's settle the key type in auto mode now. */
|
||
|
||
if (iovec_is_set(&host_key) && iovec_is_set(&tpm2_key))
|
||
id = iovec_is_set(&pubkey) ? (sd_id128_equal(with_key, _CRED_AUTO_SCOPED) ?
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED : CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK)
|
||
: (sd_id128_equal(with_key, _CRED_AUTO_SCOPED) ?
|
||
CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED : CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC);
|
||
else if (iovec_is_set(&tpm2_key) && !sd_id128_equal(with_key, _CRED_AUTO_SCOPED))
|
||
id = iovec_is_set(&pubkey) ? CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK : CRED_AES256_GCM_BY_TPM2_HMAC;
|
||
else if (iovec_is_set(&host_key))
|
||
id = sd_id128_equal(with_key, _CRED_AUTO_SCOPED) ? CRED_AES256_GCM_BY_HOST_SCOPED : CRED_AES256_GCM_BY_HOST;
|
||
else if (sd_id128_equal(with_key, _CRED_AUTO_INITRD))
|
||
id = CRED_AES256_GCM_BY_NULL;
|
||
else
|
||
return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE),
|
||
"TPM2 not available and host key located on temporary file system, no encryption key available.");
|
||
} else
|
||
id = with_key;
|
||
|
||
if (sd_id128_equal(id, CRED_AES256_GCM_BY_NULL) && !FLAGS_SET(flags, CREDENTIAL_ALLOW_NULL))
|
||
log_warning("Using a null key for encryption and signing. Confidentiality or authenticity will not be provided.");
|
||
|
||
/* Let's now take the host key and the TPM2 key and hash it together, to use as encryption key for the data */
|
||
r = sha256_hash_host_and_tpm2_key(&host_key, &tpm2_key, md);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
if (uid_is_valid(uid)) {
|
||
r = mangle_uid_into_key(uid, md);
|
||
if (r < 0)
|
||
return r;
|
||
}
|
||
|
||
assert_se(cc = EVP_aes_256_gcm());
|
||
|
||
ksz = EVP_CIPHER_key_length(cc);
|
||
assert(ksz == sizeof(md));
|
||
|
||
bsz = EVP_CIPHER_block_size(cc);
|
||
assert(bsz > 0);
|
||
assert((size_t) bsz <= CREDENTIAL_FIELD_SIZE_MAX);
|
||
|
||
ivsz = EVP_CIPHER_iv_length(cc);
|
||
if (ivsz > 0) {
|
||
assert((size_t) ivsz <= CREDENTIAL_FIELD_SIZE_MAX);
|
||
|
||
iv.iov_base = malloc(ivsz);
|
||
if (!iv.iov_base)
|
||
return log_oom();
|
||
|
||
iv.iov_len = ivsz;
|
||
|
||
r = crypto_random_bytes(iv.iov_base, iv.iov_len);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to acquired randomized IV: %m");
|
||
}
|
||
|
||
tsz = 16; /* FIXME: On OpenSSL 3 there is EVP_CIPHER_CTX_get_tag_length(), until then let's hardcode this */
|
||
|
||
context = EVP_CIPHER_CTX_new();
|
||
if (!context)
|
||
return log_error_errno(SYNTHETIC_ERRNO(ENOMEM), "Failed to allocate encryption object: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_EncryptInit_ex(context, cc, NULL, md, iv.iov_base) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize encryption context: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
/* Just an upper estimate */
|
||
output.iov_len =
|
||
ALIGN8(offsetof(struct encrypted_credential_header, iv) + ivsz) +
|
||
ALIGN8(iovec_is_set(&tpm2_key) ? offsetof(struct tpm2_credential_header, policy_hash_and_blob) + tpm2_blob.iov_len + tpm2_policy_hash.iov_len : 0) +
|
||
ALIGN8(iovec_is_set(&pubkey) ? offsetof(struct tpm2_public_key_credential_header, data) + pubkey.iov_len : 0) +
|
||
ALIGN8(uid_is_valid(uid) ? sizeof(struct scoped_credential_header) : 0) +
|
||
ALIGN8(offsetof(struct metadata_credential_header, name) + strlen_ptr(name)) +
|
||
input->iov_len + 2U * (size_t) bsz +
|
||
tsz;
|
||
|
||
output.iov_base = malloc0(output.iov_len);
|
||
if (!output.iov_base)
|
||
return log_oom();
|
||
|
||
h = (struct encrypted_credential_header*) output.iov_base;
|
||
h->id = id;
|
||
h->block_size = htole32(bsz);
|
||
h->key_size = htole32(ksz);
|
||
h->tag_size = htole32(tsz);
|
||
h->iv_size = htole32(ivsz);
|
||
memcpy(h->iv, iv.iov_base, ivsz);
|
||
|
||
p = ALIGN8(offsetof(struct encrypted_credential_header, iv) + ivsz);
|
||
|
||
if (iovec_is_set(&tpm2_key)) {
|
||
struct tpm2_credential_header *t;
|
||
|
||
t = (struct tpm2_credential_header*) ((uint8_t*) output.iov_base + p);
|
||
t->pcr_mask = htole64(tpm2_hash_pcr_mask);
|
||
t->pcr_bank = htole16(tpm2_pcr_bank);
|
||
t->primary_alg = htole16(tpm2_primary_alg);
|
||
t->blob_size = htole32(tpm2_blob.iov_len);
|
||
t->policy_hash_size = htole32(tpm2_policy_hash.iov_len);
|
||
memcpy(t->policy_hash_and_blob, tpm2_blob.iov_base, tpm2_blob.iov_len);
|
||
memcpy(t->policy_hash_and_blob + tpm2_blob.iov_len, tpm2_policy_hash.iov_base, tpm2_policy_hash.iov_len);
|
||
|
||
p += ALIGN8(offsetof(struct tpm2_credential_header, policy_hash_and_blob) + tpm2_blob.iov_len + tpm2_policy_hash.iov_len);
|
||
}
|
||
|
||
if (iovec_is_set(&pubkey)) {
|
||
struct tpm2_public_key_credential_header *z;
|
||
|
||
z = (struct tpm2_public_key_credential_header*) ((uint8_t*) output.iov_base + p);
|
||
z->pcr_mask = htole64(tpm2_pubkey_pcr_mask);
|
||
z->size = htole32(pubkey.iov_len);
|
||
memcpy(z->data, pubkey.iov_base, pubkey.iov_len);
|
||
|
||
p += ALIGN8(offsetof(struct tpm2_public_key_credential_header, data) + pubkey.iov_len);
|
||
}
|
||
|
||
if (uid_is_valid(uid)) {
|
||
struct scoped_credential_header *w;
|
||
|
||
w = (struct scoped_credential_header*) ((uint8_t*) output.iov_base + p);
|
||
w->flags = htole64(SCOPE_HASH_DATA_BASE_FLAGS);
|
||
|
||
p += ALIGN8(sizeof(struct scoped_credential_header));
|
||
}
|
||
|
||
/* Pass the encrypted + TPM2 header + scoped header as AAD */
|
||
if (EVP_EncryptUpdate(context, NULL, &added, output.iov_base, p) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to write AAD data: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
/* Now construct the metadata header */
|
||
ml = strlen_ptr(name);
|
||
m = malloc0(ALIGN8(offsetof(struct metadata_credential_header, name) + ml));
|
||
if (!m)
|
||
return log_oom();
|
||
|
||
m->timestamp = htole64(timestamp);
|
||
m->not_after = htole64(not_after);
|
||
m->name_size = htole32(ml);
|
||
memcpy_safe(m->name, name, ml);
|
||
|
||
/* And encrypt the metadata header */
|
||
if (EVP_EncryptUpdate(context, (uint8_t*) output.iov_base + p, &added, (const unsigned char*) m, ALIGN8(offsetof(struct metadata_credential_header, name) + ml)) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to encrypt metadata header: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
assert(added >= 0);
|
||
assert((size_t) added <= output.iov_len - p);
|
||
p += added;
|
||
|
||
/* Then encrypt the plaintext */
|
||
if (EVP_EncryptUpdate(context, (uint8_t*) output.iov_base + p, &added, input->iov_base, input->iov_len) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to encrypt data: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
assert(added >= 0);
|
||
assert((size_t) added <= output.iov_len - p);
|
||
p += added;
|
||
|
||
/* Finalize */
|
||
if (EVP_EncryptFinal_ex(context, (uint8_t*) output.iov_base + p, &added) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finalize data encryption: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
assert(added >= 0);
|
||
assert((size_t) added <= output.iov_len - p);
|
||
p += added;
|
||
|
||
assert(p <= output.iov_len - tsz);
|
||
|
||
/* Append tag */
|
||
if (EVP_CIPHER_CTX_ctrl(context, EVP_CTRL_GCM_GET_TAG, tsz, (uint8_t*) output.iov_base + p) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to get tag: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
p += tsz;
|
||
assert(p <= output.iov_len);
|
||
output.iov_len = p;
|
||
|
||
if (DEBUG_LOGGING && input->iov_len > 0) {
|
||
size_t base64_size;
|
||
|
||
base64_size = DIV_ROUND_UP(output.iov_len * 4, 3); /* Include base64 size increase in debug output */
|
||
assert(base64_size >= input->iov_len);
|
||
log_debug("Input of %zu bytes grew to output of %zu bytes (+%2zu%%).", input->iov_len, base64_size, base64_size * 100 / input->iov_len - 100);
|
||
}
|
||
|
||
*ret = TAKE_STRUCT(output);
|
||
return 0;
|
||
}
|
||
|
||
int decrypt_credential_and_warn(
|
||
const char *validate_name,
|
||
usec_t validate_timestamp,
|
||
const char *tpm2_device,
|
||
const char *tpm2_signature_path,
|
||
uid_t uid,
|
||
const struct iovec *input,
|
||
CredentialFlags flags,
|
||
struct iovec *ret) {
|
||
|
||
_cleanup_(iovec_done_erase) struct iovec host_key = {}, plaintext = {}, tpm2_key = {};
|
||
_cleanup_(json_variant_unrefp) JsonVariant *signature_json = NULL;
|
||
_cleanup_(EVP_CIPHER_CTX_freep) EVP_CIPHER_CTX *context = NULL;
|
||
struct encrypted_credential_header *h;
|
||
struct metadata_credential_header *m;
|
||
uint8_t md[SHA256_DIGEST_LENGTH];
|
||
bool with_tpm2, with_tpm2_pk, with_host_key, with_null, with_scope;
|
||
const EVP_CIPHER *cc;
|
||
size_t p, hs;
|
||
int r, added;
|
||
|
||
assert(iovec_is_valid(input));
|
||
assert(ret);
|
||
|
||
h = (struct encrypted_credential_header*) input->iov_base;
|
||
|
||
/* The ID must fit in, for the current and all future formats */
|
||
if (input->iov_len < sizeof(h->id))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
with_host_key = sd_id128_in_set(h->id, CRED_AES256_GCM_BY_HOST, CRED_AES256_GCM_BY_HOST_SCOPED, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED);
|
||
with_tpm2_pk = sd_id128_in_set(h->id, CRED_AES256_GCM_BY_TPM2_HMAC_WITH_PK, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED);
|
||
with_tpm2 = sd_id128_in_set(h->id, CRED_AES256_GCM_BY_TPM2_HMAC, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED) || with_tpm2_pk;
|
||
with_null = sd_id128_equal(h->id, CRED_AES256_GCM_BY_NULL);
|
||
with_scope = sd_id128_in_set(h->id, CRED_AES256_GCM_BY_HOST_SCOPED, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_SCOPED, CRED_AES256_GCM_BY_HOST_AND_TPM2_HMAC_WITH_PK_SCOPED);
|
||
|
||
if (!with_host_key && !with_tpm2 && !with_null)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Unknown encryption format, or corrupted data.");
|
||
|
||
if (with_tpm2_pk) {
|
||
r = tpm2_load_pcr_signature(tpm2_signature_path, &signature_json);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to load pcr signature: %m");
|
||
}
|
||
|
||
if (with_null && !FLAGS_SET(flags, CREDENTIAL_ALLOW_NULL)) {
|
||
/* So this is a credential encrypted with a zero length key. We support this to cover for the
|
||
* case where neither a host key not a TPM2 are available (specifically: initrd environments
|
||
* where the host key is not yet accessible and no TPM2 chip exists at all), to minimize
|
||
* different codeflow for TPM2 and non-TPM2 codepaths. Of course, credentials encoded this
|
||
* way offer no confidentiality nor authenticity. Because of that it's important we refuse to
|
||
* use them on systems that actually *do* have a TPM2 chip – if we are in SecureBoot
|
||
* mode. Otherwise an attacker could hand us credentials like this and we'd use them thinking
|
||
* they are trusted, even though they are not. */
|
||
|
||
if (efi_has_tpm2()) {
|
||
if (is_efi_secure_boot())
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG),
|
||
"Credential uses fixed key for fallback use when TPM2 is absent — but TPM2 is present, and SecureBoot is enabled, refusing.");
|
||
|
||
log_warning("Credential uses fixed key for use when TPM2 is absent, but TPM2 is present! Accepting anyway, since SecureBoot is disabled.");
|
||
} else
|
||
log_debug("Credential uses fixed key for use when TPM2 is absent, and TPM2 indeed is absent. Accepting.");
|
||
}
|
||
|
||
if (with_scope) {
|
||
if (!uid_is_valid(uid))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "Encrypted file is scoped to a user, but no user selected.");
|
||
} else {
|
||
/* Refuse to unlock system credentials if user scope is requested. */
|
||
if (uid_is_valid(uid) && !FLAGS_SET(flags, CREDENTIAL_ANY_SCOPE))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "Encrypted file is scoped to the system, but user scope selected.");
|
||
|
||
uid = UID_INVALID;
|
||
}
|
||
|
||
/* Now we know the minimum header size */
|
||
if (input->iov_len < offsetof(struct encrypted_credential_header, iv))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
/* Verify some basic header values */
|
||
if (le32toh(h->key_size) != sizeof(md))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected key size in header.");
|
||
if (le32toh(h->block_size) <= 0 || le32toh(h->block_size) > CREDENTIAL_FIELD_SIZE_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected block size in header.");
|
||
if (le32toh(h->iv_size) > CREDENTIAL_FIELD_SIZE_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "IV size too large.");
|
||
if (le32toh(h->tag_size) != 16) /* FIXME: On OpenSSL 3, let's verify via EVP_CIPHER_CTX_get_tag_length() */
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected tag size in header.");
|
||
|
||
/* Ensure we have space for the full header now (we don't know the size of the name hence this is a
|
||
* lower limit only) */
|
||
if (input->iov_len <
|
||
ALIGN8(offsetof(struct encrypted_credential_header, iv) + le32toh(h->iv_size)) +
|
||
ALIGN8(with_tpm2 ? offsetof(struct tpm2_credential_header, policy_hash_and_blob) : 0) +
|
||
ALIGN8(with_tpm2_pk ? offsetof(struct tpm2_public_key_credential_header, data) : 0) +
|
||
ALIGN8(with_scope ? sizeof(struct scoped_credential_header) : 0) +
|
||
ALIGN8(offsetof(struct metadata_credential_header, name)) +
|
||
le32toh(h->tag_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
p = ALIGN8(offsetof(struct encrypted_credential_header, iv) + le32toh(h->iv_size));
|
||
|
||
if (with_tpm2) {
|
||
#if HAVE_TPM2
|
||
struct tpm2_credential_header* t = (struct tpm2_credential_header*) ((uint8_t*) input->iov_base + p);
|
||
struct tpm2_public_key_credential_header *z = NULL;
|
||
|
||
if (!TPM2_PCR_MASK_VALID(t->pcr_mask))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "TPM2 PCR mask out of range.");
|
||
if (!tpm2_hash_alg_to_string(le16toh(t->pcr_bank)))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "TPM2 PCR bank invalid or not supported");
|
||
if (!tpm2_asym_alg_to_string(le16toh(t->primary_alg)))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "TPM2 primary key algorithm invalid or not supported.");
|
||
if (le32toh(t->blob_size) > CREDENTIAL_FIELD_SIZE_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected TPM2 blob size.");
|
||
if (le32toh(t->policy_hash_size) > CREDENTIAL_FIELD_SIZE_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected TPM2 policy hash size.");
|
||
|
||
/* Ensure we have space for the full TPM2 header now (still don't know the name, and its size
|
||
* though, hence still just a lower limit test only) */
|
||
if (input->iov_len <
|
||
p +
|
||
ALIGN8(offsetof(struct tpm2_credential_header, policy_hash_and_blob) + le32toh(t->blob_size) + le32toh(t->policy_hash_size)) +
|
||
ALIGN8(with_tpm2_pk ? offsetof(struct tpm2_public_key_credential_header, data) : 0) +
|
||
ALIGN8(with_scope ? sizeof(struct scoped_credential_header) : 0) +
|
||
ALIGN8(offsetof(struct metadata_credential_header, name)) +
|
||
le32toh(h->tag_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
p += ALIGN8(offsetof(struct tpm2_credential_header, policy_hash_and_blob) +
|
||
le32toh(t->blob_size) +
|
||
le32toh(t->policy_hash_size));
|
||
|
||
if (with_tpm2_pk) {
|
||
z = (struct tpm2_public_key_credential_header*) ((uint8_t*) input->iov_base + p);
|
||
|
||
if (!TPM2_PCR_MASK_VALID(le64toh(z->pcr_mask)) || le64toh(z->pcr_mask) == 0)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "TPM2 PCR mask out of range.");
|
||
if (le32toh(z->size) > PUBLIC_KEY_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected public key size.");
|
||
|
||
if (input->iov_len <
|
||
p +
|
||
ALIGN8(offsetof(struct tpm2_public_key_credential_header, data) + le32toh(z->size)) +
|
||
ALIGN8(with_scope ? sizeof(struct scoped_credential_header) : 0) +
|
||
ALIGN8(offsetof(struct metadata_credential_header, name)) +
|
||
le32toh(h->tag_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
p += ALIGN8(offsetof(struct tpm2_public_key_credential_header, data) +
|
||
le32toh(z->size));
|
||
}
|
||
|
||
_cleanup_(tpm2_context_unrefp) Tpm2Context *tpm2_context = NULL;
|
||
r = tpm2_context_new(tpm2_device, &tpm2_context);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
// TODO: Add the SRK data to the credential structure so it can be plumbed
|
||
// through and used to verify the TPM session.
|
||
r = tpm2_unseal(tpm2_context,
|
||
le64toh(t->pcr_mask),
|
||
le16toh(t->pcr_bank),
|
||
z ? &IOVEC_MAKE(z->data, le32toh(z->size)) : NULL,
|
||
z ? le64toh(z->pcr_mask) : 0,
|
||
signature_json,
|
||
/* pin= */ NULL,
|
||
/* pcrlock_policy= */ NULL,
|
||
le16toh(t->primary_alg),
|
||
&IOVEC_MAKE(t->policy_hash_and_blob, le32toh(t->blob_size)),
|
||
&IOVEC_MAKE(t->policy_hash_and_blob + le32toh(t->blob_size), le32toh(t->policy_hash_size)),
|
||
/* srk= */ NULL,
|
||
&tpm2_key);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to unseal secret using TPM2: %m");
|
||
#else
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Credential requires TPM2 support, but TPM2 support not available.");
|
||
#endif
|
||
}
|
||
|
||
if (with_scope) {
|
||
struct scoped_credential_header* sh = (struct scoped_credential_header*) ((uint8_t*) input->iov_base + p);
|
||
|
||
if (le64toh(sh->flags) != SCOPE_HASH_DATA_BASE_FLAGS)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Scoped credential with unsupported flags.");
|
||
|
||
if (input->iov_len <
|
||
p +
|
||
sizeof(struct scoped_credential_header) +
|
||
ALIGN8(offsetof(struct metadata_credential_header, name)) +
|
||
le32toh(h->tag_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Encrypted file too short.");
|
||
|
||
p += sizeof(struct scoped_credential_header);
|
||
}
|
||
|
||
if (with_host_key) {
|
||
r = get_credential_host_secret(/* flags= */ 0, &host_key);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to determine local credential key: %m");
|
||
}
|
||
|
||
if (with_null && !FLAGS_SET(flags, CREDENTIAL_ALLOW_NULL))
|
||
log_warning("Warning: using a null key for decryption and authentication. Confidentiality or authenticity are not provided.");
|
||
|
||
sha256_hash_host_and_tpm2_key(&host_key, &tpm2_key, md);
|
||
|
||
if (with_scope) {
|
||
r = mangle_uid_into_key(uid, md);
|
||
if (r < 0)
|
||
return r;
|
||
}
|
||
|
||
assert_se(cc = EVP_aes_256_gcm());
|
||
|
||
/* Make sure cipher expectations match the header */
|
||
if (EVP_CIPHER_key_length(cc) != (int) le32toh(h->key_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected key size in header.");
|
||
if (EVP_CIPHER_block_size(cc) != (int) le32toh(h->block_size))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Unexpected block size in header.");
|
||
|
||
context = EVP_CIPHER_CTX_new();
|
||
if (!context)
|
||
return log_error_errno(SYNTHETIC_ERRNO(ENOMEM), "Failed to allocate decryption object: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_DecryptInit_ex(context, cc, NULL, NULL, NULL) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize decryption context: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_CIPHER_CTX_ctrl(context, EVP_CTRL_GCM_SET_IVLEN, le32toh(h->iv_size), NULL) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to set IV size on decryption context: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_DecryptInit_ex(context, NULL, NULL, md, h->iv) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to set IV and key: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_DecryptUpdate(context, NULL, &added, input->iov_base, p) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to write AAD data: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
plaintext.iov_base = malloc(input->iov_len - p - le32toh(h->tag_size));
|
||
if (!plaintext.iov_base)
|
||
return -ENOMEM;
|
||
|
||
if (EVP_DecryptUpdate(
|
||
context,
|
||
plaintext.iov_base,
|
||
&added,
|
||
(uint8_t*) input->iov_base + p,
|
||
input->iov_len - p - le32toh(h->tag_size)) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to decrypt data: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
assert(added >= 0);
|
||
assert((size_t) added <= input->iov_len - p - le32toh(h->tag_size));
|
||
plaintext.iov_len = added;
|
||
|
||
if (EVP_CIPHER_CTX_ctrl(context, EVP_CTRL_GCM_SET_TAG, le32toh(h->tag_size), (uint8_t*) input->iov_base + input->iov_len - le32toh(h->tag_size)) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to set tag: %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
if (EVP_DecryptFinal_ex(context, (uint8_t*) plaintext.iov_base + plaintext.iov_len, &added) != 1)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Decryption failed (incorrect key?): %s",
|
||
ERR_error_string(ERR_get_error(), NULL));
|
||
|
||
plaintext.iov_len += added;
|
||
|
||
if (plaintext.iov_len < ALIGN8(offsetof(struct metadata_credential_header, name)))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Metadata header incomplete.");
|
||
|
||
m = plaintext.iov_base;
|
||
|
||
if (le64toh(m->timestamp) != USEC_INFINITY &&
|
||
le64toh(m->not_after) != USEC_INFINITY &&
|
||
le64toh(m->timestamp) >= le64toh(m->not_after))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Timestamps of credential are not in order, refusing.");
|
||
|
||
if (le32toh(m->name_size) > CREDENTIAL_NAME_MAX)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Embedded credential name too long, refusing.");
|
||
|
||
hs = ALIGN8(offsetof(struct metadata_credential_header, name) + le32toh(m->name_size));
|
||
if (plaintext.iov_len < hs)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Metadata header incomplete.");
|
||
|
||
if (le32toh(m->name_size) > 0) {
|
||
_cleanup_free_ char *embedded_name = NULL;
|
||
|
||
r = make_cstring(m->name, le32toh(m->name_size), MAKE_CSTRING_REFUSE_TRAILING_NUL, &embedded_name);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Unable to convert embedded credential name to C string: %m");
|
||
|
||
if (!credential_name_valid(embedded_name))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Embedded credential name is not valid, refusing.");
|
||
|
||
if (validate_name && !streq(embedded_name, validate_name)) {
|
||
|
||
r = secure_getenv_bool("SYSTEMD_CREDENTIAL_VALIDATE_NAME");
|
||
if (r < 0 && r != -ENXIO)
|
||
log_debug_errno(r, "Failed to parse $SYSTEMD_CREDENTIAL_VALIDATE_NAME: %m");
|
||
if (r != 0)
|
||
return log_error_errno(SYNTHETIC_ERRNO(EREMOTE), "Embedded credential name '%s' does not match filename '%s', refusing.", embedded_name, validate_name);
|
||
|
||
log_debug("Embedded credential name '%s' does not match expected name '%s', but configured to use credential anyway.", embedded_name, validate_name);
|
||
}
|
||
}
|
||
|
||
if (validate_timestamp != USEC_INFINITY) {
|
||
if (le64toh(m->timestamp) != USEC_INFINITY && le64toh(m->timestamp) > validate_timestamp)
|
||
log_debug("Credential timestamp is from the future, assuming clock skew.");
|
||
|
||
if (le64toh(m->not_after) != USEC_INFINITY && le64toh(m->not_after) < validate_timestamp) {
|
||
|
||
r = secure_getenv_bool("SYSTEMD_CREDENTIAL_VALIDATE_NOT_AFTER");
|
||
if (r < 0 && r != -ENXIO)
|
||
log_debug_errno(r, "Failed to parse $SYSTEMD_CREDENTIAL_VALIDATE_NOT_AFTER: %m");
|
||
if (r != 0)
|
||
return log_error_errno(SYNTHETIC_ERRNO(ESTALE), "Credential's time passed, refusing to use.");
|
||
|
||
log_debug("Credential not-after timestamp has passed, but configured to use credential anyway.");
|
||
}
|
||
}
|
||
|
||
if (ret) {
|
||
_cleanup_(iovec_done_erase) struct iovec without_metadata = {};
|
||
|
||
without_metadata.iov_len = plaintext.iov_len - hs;
|
||
without_metadata.iov_base = memdup_suffix0((uint8_t*) plaintext.iov_base + hs, without_metadata.iov_len);
|
||
if (!without_metadata.iov_base)
|
||
return log_oom();
|
||
|
||
*ret = TAKE_STRUCT(without_metadata);
|
||
}
|
||
|
||
return 0;
|
||
}
|
||
|
||
#else
|
||
|
||
int get_credential_host_secret(CredentialSecretFlags flags, struct iovec *ret) {
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Support for encrypted credentials not available.");
|
||
}
|
||
|
||
int encrypt_credential_and_warn(sd_id128_t with_key, const char *name, usec_t timestamp, usec_t not_after, const char *tpm2_device, uint32_t tpm2_hash_pcr_mask, const char *tpm2_pubkey_path, uint32_t tpm2_pubkey_pcr_mask, uid_t uid, const struct iovec *input, CredentialFlags flags, struct iovec *ret) {
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Support for encrypted credentials not available.");
|
||
}
|
||
|
||
int decrypt_credential_and_warn(const char *validate_name, usec_t validate_timestamp, const char *tpm2_device, const char *tpm2_signature_path, uid_t uid, const struct iovec *input, CredentialFlags flags, struct iovec *ret) {
|
||
return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Support for encrypted credentials not available.");
|
||
}
|
||
|
||
#endif
|
||
|
||
int ipc_encrypt_credential(const char *name, usec_t timestamp, usec_t not_after, uid_t uid, const struct iovec *input, CredentialFlags flags, struct iovec *ret) {
|
||
_cleanup_(varlink_unrefp) Varlink *vl = NULL;
|
||
int r;
|
||
|
||
assert(input && iovec_is_valid(input));
|
||
assert(ret);
|
||
|
||
r = varlink_connect_address(&vl, "/run/systemd/io.systemd.Credentials");
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to connect to io.systemd.Credentials: %m");
|
||
|
||
/* Mark anything we get from the service as sensitive, given that it might use a NULL cypher, at least in theory */
|
||
r = varlink_set_input_sensitive(vl);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to enable sensitive Varlink input: %m");
|
||
|
||
/* Create the input data blob object separately, so that we can mark it as sensitive */
|
||
_cleanup_(json_variant_unrefp) JsonVariant *jinput = NULL;
|
||
r = json_build(&jinput, JSON_BUILD_IOVEC_BASE64(input));
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to create input object: %m");
|
||
|
||
json_variant_sensitive(jinput);
|
||
|
||
_cleanup_(json_variant_unrefp) JsonVariant *reply = NULL;
|
||
const char *error_id = NULL;
|
||
r = varlink_callb(vl,
|
||
"io.systemd.Credentials.Encrypt",
|
||
&reply,
|
||
&error_id,
|
||
JSON_BUILD_OBJECT(
|
||
JSON_BUILD_PAIR_CONDITION(name, "name", JSON_BUILD_STRING(name)),
|
||
JSON_BUILD_PAIR("data", JSON_BUILD_VARIANT(jinput)),
|
||
JSON_BUILD_PAIR_CONDITION(timestamp != USEC_INFINITY, "timestamp", JSON_BUILD_UNSIGNED(timestamp)),
|
||
JSON_BUILD_PAIR_CONDITION(not_after != USEC_INFINITY, "notAfter", JSON_BUILD_UNSIGNED(not_after)),
|
||
JSON_BUILD_PAIR_CONDITION(!FLAGS_SET(flags, CREDENTIAL_ANY_SCOPE), "scope", JSON_BUILD_STRING(uid_is_valid(uid) ? "user" : "system")),
|
||
JSON_BUILD_PAIR_CONDITION(uid_is_valid(uid), "uid", JSON_BUILD_UNSIGNED(uid))));
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to call Encrypt() varlink call.");
|
||
if (!isempty(error_id)) {
|
||
if (streq(error_id, "io.systemd.Credentials.NoSuchUser"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "No such user.");
|
||
|
||
return log_error_errno(varlink_error_to_errno(error_id, reply), "Failed to encrypt: %s", error_id);
|
||
}
|
||
|
||
r = json_dispatch(
|
||
reply,
|
||
(const JsonDispatch[]) {
|
||
{ "blob", JSON_VARIANT_STRING, json_dispatch_unbase64_iovec, PTR_TO_SIZE(ret), JSON_MANDATORY },
|
||
{},
|
||
},
|
||
JSON_LOG|JSON_ALLOW_EXTENSIONS,
|
||
/* userdata= */ NULL);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
return 0;
|
||
}
|
||
|
||
int ipc_decrypt_credential(const char *validate_name, usec_t validate_timestamp, uid_t uid, const struct iovec *input, CredentialFlags flags, struct iovec *ret) {
|
||
_cleanup_(varlink_unrefp) Varlink *vl = NULL;
|
||
int r;
|
||
|
||
assert(input && iovec_is_valid(input));
|
||
assert(ret);
|
||
|
||
r = varlink_connect_address(&vl, "/run/systemd/io.systemd.Credentials");
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to connect to io.systemd.Credentials: %m");
|
||
|
||
r = varlink_set_input_sensitive(vl);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to enable sensitive Varlink input: %m");
|
||
|
||
/* Create the input data blob object separately, so that we can mark it as sensitive (it's supposed
|
||
* to be encrypted, but who knows maybe it uses the NULL cypher). */
|
||
_cleanup_(json_variant_unrefp) JsonVariant *jinput = NULL;
|
||
r = json_build(&jinput, JSON_BUILD_IOVEC_BASE64(input));
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to create input object: %m");
|
||
|
||
json_variant_sensitive(jinput);
|
||
|
||
_cleanup_(json_variant_unrefp) JsonVariant *reply = NULL;
|
||
const char *error_id = NULL;
|
||
r = varlink_callb(vl,
|
||
"io.systemd.Credentials.Decrypt",
|
||
&reply,
|
||
&error_id,
|
||
JSON_BUILD_OBJECT(
|
||
JSON_BUILD_PAIR_CONDITION(validate_name, "name", JSON_BUILD_STRING(validate_name)),
|
||
JSON_BUILD_PAIR("blob", JSON_BUILD_VARIANT(jinput)),
|
||
JSON_BUILD_PAIR_CONDITION(validate_timestamp != USEC_INFINITY, "timestamp", JSON_BUILD_UNSIGNED(validate_timestamp)),
|
||
JSON_BUILD_PAIR_CONDITION(!FLAGS_SET(flags, CREDENTIAL_ANY_SCOPE), "scope", JSON_BUILD_STRING(uid_is_valid(uid) ? "user" : "system")),
|
||
JSON_BUILD_PAIR_CONDITION(uid_is_valid(uid), "uid", JSON_BUILD_UNSIGNED(uid))));
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to call Decrypt() varlink call.");
|
||
if (!isempty(error_id)) {
|
||
if (streq(error_id, "io.systemd.Credentials.BadFormat"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EBADMSG), "Bad credential format.");
|
||
if (streq(error_id, "io.systemd.Credentials.NameMismatch"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EREMOTE), "Name in credential doesn't match expectations.");
|
||
if (streq(error_id, "io.systemd.Credentials.TimeMismatch"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(ESTALE), "Outside of credential validity time window.");
|
||
if (streq(error_id, "io.systemd.Credentials.NoSuchUser"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(ESRCH), "No such user.");
|
||
if (streq(error_id, "io.systemd.Credentials.BadScope"))
|
||
return log_error_errno(SYNTHETIC_ERRNO(EMEDIUMTYPE), "Scope mismtach.");
|
||
|
||
return log_error_errno(varlink_error_to_errno(error_id, reply), "Failed to decrypt: %s", error_id);
|
||
}
|
||
|
||
r = json_dispatch(
|
||
reply,
|
||
(const JsonDispatch[]) {
|
||
{ "data", JSON_VARIANT_STRING, json_dispatch_unbase64_iovec, PTR_TO_SIZE(ret), JSON_MANDATORY },
|
||
{},
|
||
},
|
||
JSON_LOG|JSON_ALLOW_EXTENSIONS,
|
||
/* userdata= */ NULL);
|
||
if (r < 0)
|
||
return r;
|
||
|
||
return 0;
|
||
}
|
||
|
||
static int pick_up_credential_one(
|
||
int credential_dir_fd,
|
||
const char *credential_name,
|
||
const PickUpCredential *table_entry) {
|
||
|
||
_cleanup_free_ char *fn = NULL, *target_path = NULL;
|
||
const char *e;
|
||
int r;
|
||
|
||
assert(credential_dir_fd >= 0);
|
||
assert(credential_name);
|
||
assert(table_entry);
|
||
|
||
e = startswith(credential_name, table_entry->credential_prefix);
|
||
if (!e)
|
||
return 0; /* unmatched */
|
||
|
||
fn = strjoin(e, table_entry->filename_suffix);
|
||
if (!fn)
|
||
return log_oom();
|
||
|
||
if (!filename_is_valid(fn))
|
||
return log_warning_errno(SYNTHETIC_ERRNO(EINVAL),
|
||
"Passed credential '%s' would result in invalid filename '%s'.",
|
||
credential_name, fn);
|
||
|
||
r = mkdir_p_label(table_entry->target_dir, 0755);
|
||
if (r < 0)
|
||
return log_warning_errno(r, "Failed to create '%s': %m", table_entry->target_dir);
|
||
|
||
target_path = path_join(table_entry->target_dir, fn);
|
||
if (!target_path)
|
||
return log_oom();
|
||
|
||
r = copy_file_at(
|
||
credential_dir_fd, credential_name,
|
||
AT_FDCWD, target_path,
|
||
/* open_flags= */ 0,
|
||
0644,
|
||
/* flags= */ 0);
|
||
if (r < 0)
|
||
return log_warning_errno(r, "Failed to copy credential %s → file %s: %m",
|
||
credential_name, target_path);
|
||
|
||
log_info("Installed %s from credential.", target_path);
|
||
return 1; /* done */
|
||
}
|
||
|
||
int pick_up_credentials(const PickUpCredential *table, size_t n_table_entry) {
|
||
_cleanup_close_ int credential_dir_fd = -EBADF;
|
||
int r, ret = 0;
|
||
|
||
assert(table);
|
||
assert(n_table_entry > 0);
|
||
|
||
credential_dir_fd = open_credentials_dir();
|
||
if (IN_SET(credential_dir_fd, -ENXIO, -ENOENT)) {
|
||
/* Credential env var not set, or dir doesn't exist. */
|
||
log_debug("No credentials found.");
|
||
return 0;
|
||
}
|
||
if (credential_dir_fd < 0)
|
||
return log_error_errno(credential_dir_fd, "Failed to open credentials directory: %m");
|
||
|
||
_cleanup_free_ DirectoryEntries *des = NULL;
|
||
r = readdir_all(credential_dir_fd, RECURSE_DIR_SORT|RECURSE_DIR_IGNORE_DOT|RECURSE_DIR_ENSURE_TYPE, &des);
|
||
if (r < 0)
|
||
return log_error_errno(r, "Failed to enumerate credentials: %m");
|
||
|
||
FOREACH_ARRAY(i, des->entries, des->n_entries) {
|
||
struct dirent *de = *i;
|
||
|
||
if (de->d_type != DT_REG)
|
||
continue;
|
||
|
||
FOREACH_ARRAY(t, table, n_table_entry) {
|
||
r = pick_up_credential_one(credential_dir_fd, de->d_name, t);
|
||
if (r != 0) {
|
||
RET_GATHER(ret, r);
|
||
break; /* Done, or failed. Let's move to the next credential. */
|
||
}
|
||
}
|
||
}
|
||
|
||
return ret;
|
||
}
|