Adding upstream version 255.4.upstream/255.4

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1085 insertions, 0 deletions

diff --git a/src/boot/measure.c b/src/boot/measure.c
new file mode 100644
index 0000000..5c5071e
--- /dev/null
+++ b/src/boot/measure.c
@@ -0,0 +1,1085 @@
+/* SPDX-License-Identifier: LGPL-2.1-or-later */
+
+#include <getopt.h>
+#include <unistd.h>
+
+#include "alloc-util.h"
+#include "build.h"
+#include "efi-loader.h"
+#include "fd-util.h"
+#include "fileio.h"
+#include "hexdecoct.h"
+#include "json.h"
+#include "main-func.h"
+#include "memstream-util.h"
+#include "openssl-util.h"
+#include "parse-argument.h"
+#include "parse-util.h"
+#include "pretty-print.h"
+#include "sha256.h"
+#include "terminal-util.h"
+#include "tpm2-pcr.h"
+#include "tpm2-util.h"
+#include "uki.h"
+#include "verbs.h"
+
+/* Tool for pre-calculating expected TPM PCR values based on measured resources. This is intended to be used
+ * to pre-calculate suitable values for PCR 11, the way sd-stub measures into it. */
+
+static char *arg_sections[_UNIFIED_SECTION_MAX] = {};
+static char **arg_banks = NULL;
+static char *arg_tpm2_device = NULL;
+static char *arg_private_key = NULL;
+static char *arg_public_key = NULL;
+static JsonFormatFlags arg_json_format_flags = JSON_FORMAT_PRETTY_AUTO|JSON_FORMAT_COLOR_AUTO|JSON_FORMAT_OFF;
+static PagerFlags arg_pager_flags = 0;
+static bool arg_current = false;
+static char **arg_phase = NULL;
+static char *arg_append = NULL;
+
+STATIC_DESTRUCTOR_REGISTER(arg_banks, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_tpm2_device, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_private_key, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_public_key, freep);
+STATIC_DESTRUCTOR_REGISTER(arg_phase, strv_freep);
+STATIC_DESTRUCTOR_REGISTER(arg_append, freep);
+
+static void free_sections(char*(*sections)[_UNIFIED_SECTION_MAX]) {
+        for (UnifiedSection c = 0; c < _UNIFIED_SECTION_MAX; c++)
+                free((*sections)[c]);
+}
+
+STATIC_DESTRUCTOR_REGISTER(arg_sections, free_sections);
+
+static int help(int argc, char *argv[], void *userdata) {
+        _cleanup_free_ char *link = NULL;
+        int r;
+
+        r = terminal_urlify_man("systemd-measure", "1", &link);
+        if (r < 0)
+                return log_oom();
+
+        printf("%1$s  [OPTIONS...] COMMAND ...\n"
+               "\n%5$sPre-calculate and sign PCR hash for a unified kernel image (UKI).%6$s\n"
+               "\n%3$sCommands:%4$s\n"
+               "  status                 Show current PCR values\n"
+               "  calculate              Calculate expected PCR values\n"
+               "  sign                   Calculate and sign expected PCR values\n"
+               "\n%3$sOptions:%4$s\n"
+               "  -h --help              Show this help\n"
+               "     --version           Print version\n"
+               "     --no-pager          Do not pipe output into a pager\n"
+               "  -c --current           Use current PCR values\n"
+               "     --phase=PHASE       Specify a boot phase to sign for\n"
+               "     --bank=DIGEST       Select TPM bank (SHA1, SHA256, SHA384, SHA512)\n"
+               "     --tpm2-device=PATH  Use specified TPM2 device\n"
+               "     --private-key=KEY   Private key (PEM) to sign with\n"
+               "     --public-key=KEY    Public key (PEM) to validate against\n"
+               "     --json=MODE         Output as JSON\n"
+               "  -j                     Same as --json=pretty on tty, --json=short otherwise\n"
+               "     --append=PATH       Load specified JSON signature, and append new signature to it\n"
+               "\n%3$sUKI PE Section Options:%4$s                                         %3$sUKI PE Section%4$s\n"
+               "     --linux=PATH        Path to Linux kernel image file        %7$s .linux\n"
+               "     --osrel=PATH        Path to os-release file                %7$s .osrel\n"
+               "     --cmdline=PATH      Path to file with kernel command line  %7$s .cmdline\n"
+               "     --initrd=PATH       Path to initrd image file              %7$s .initrd\n"
+               "     --splash=PATH       Path to splash bitmap file             %7$s .splash\n"
+               "     --dtb=PATH          Path to Devicetree file                %7$s .dtb\n"
+               "     --uname=PATH        Path to 'uname -r' file                %7$s .uname\n"
+               "     --sbat=PATH         Path to SBAT file                      %7$s .sbat\n"
+               "     --pcrpkey=PATH      Path to public key for PCR signatures  %7$s .pcrpkey\n"
+               "\nSee the %2$s for details.\n",
+               program_invocation_short_name,
+               link,
+               ansi_underline(),
+               ansi_normal(),
+               ansi_highlight(),
+               ansi_normal(),
+               special_glyph(SPECIAL_GLYPH_ARROW_RIGHT));
+
+        return 0;
+}
+
+static char *normalize_phase(const char *s) {
+        _cleanup_strv_free_ char **l = NULL;
+
+        /* Let's normalize phase expressions. We split the series of colon-separated words up, then remove
+         * all empty ones, and glue them back together again. In other words we remove duplicate ":", as well
+         * as leading and trailing ones. */
+
+        l = strv_split(s, ":"); /* Split series of words */
+        if (!l)
+                return NULL;
+
+        /* Remove all empty words and glue things back together */
+        return strv_join(strv_remove(l, ""), ":");
+}
+
+static int parse_argv(int argc, char *argv[]) {
+        enum {
+                ARG_VERSION = 0x100,
+                ARG_NO_PAGER,
+                _ARG_SECTION_FIRST,
+                ARG_LINUX = _ARG_SECTION_FIRST,
+                ARG_OSREL,
+                ARG_CMDLINE,
+                ARG_INITRD,
+                ARG_SPLASH,
+                ARG_DTB,
+                ARG_UNAME,
+                ARG_SBAT,
+                _ARG_PCRSIG, /* the .pcrsig section is not input for signing, hence not actually an argument here */
+                _ARG_SECTION_LAST,
+                ARG_PCRPKEY = _ARG_SECTION_LAST,
+                ARG_BANK,
+                ARG_PRIVATE_KEY,
+                ARG_PUBLIC_KEY,
+                ARG_TPM2_DEVICE,
+                ARG_JSON,
+                ARG_PHASE,
+                ARG_APPEND,
+        };
+
+        static const struct option options[] = {
+                { "help",        no_argument,       NULL, 'h'             },
+                { "no-pager",    no_argument,       NULL, ARG_NO_PAGER    },
+                { "version",     no_argument,       NULL, ARG_VERSION     },
+                { "linux",       required_argument, NULL, ARG_LINUX       },
+                { "osrel",       required_argument, NULL, ARG_OSREL       },
+                { "cmdline",     required_argument, NULL, ARG_CMDLINE     },
+                { "initrd",      required_argument, NULL, ARG_INITRD      },
+                { "splash",      required_argument, NULL, ARG_SPLASH      },
+                { "dtb",         required_argument, NULL, ARG_DTB         },
+                { "uname",       required_argument, NULL, ARG_UNAME       },
+                { "sbat",        required_argument, NULL, ARG_SBAT        },
+                { "pcrpkey",     required_argument, NULL, ARG_PCRPKEY     },
+                { "current",     no_argument,       NULL, 'c'             },
+                { "bank",        required_argument, NULL, ARG_BANK        },
+                { "tpm2-device", required_argument, NULL, ARG_TPM2_DEVICE },
+                { "private-key", required_argument, NULL, ARG_PRIVATE_KEY },
+                { "public-key",  required_argument, NULL, ARG_PUBLIC_KEY  },
+                { "json",        required_argument, NULL, ARG_JSON        },
+                { "phase",       required_argument, NULL, ARG_PHASE       },
+                { "append",      required_argument, NULL, ARG_APPEND      },
+                {}
+        };
+
+        int c, r;
+
+        assert(argc >= 0);
+        assert(argv);
+
+        /* Make sure the arguments list and the section list, stays in sync */
+        assert_cc(_ARG_SECTION_FIRST + _UNIFIED_SECTION_MAX == _ARG_SECTION_LAST + 1);
+
+        while ((c = getopt_long(argc, argv, "hjc", options, NULL)) >= 0)
+                switch (c) {
+
+                case 'h':
+                        help(0, NULL, NULL);
+                        return 0;
+
+                case ARG_VERSION:
+                        return version();
+
+                case ARG_NO_PAGER:
+                        arg_pager_flags |= PAGER_DISABLE;
+                        break;
+
+                case _ARG_SECTION_FIRST..._ARG_SECTION_LAST: {
+                        UnifiedSection section = c - _ARG_SECTION_FIRST;
+
+                        r = parse_path_argument(optarg, /* suppress_root= */ false, arg_sections + section);
+                        if (r < 0)
+                                return r;
+                        break;
+                }
+
+                case 'c':
+                        arg_current = true;
+                        break;
+
+                case ARG_BANK: {
+                        const EVP_MD *implementation;
+
+                        implementation = EVP_get_digestbyname(optarg);
+                        if (!implementation)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unknown bank '%s', refusing.", optarg);
+
+                        if (strv_extend(&arg_banks, EVP_MD_name(implementation)) < 0)
+                                return log_oom();
+
+                        break;
+                }
+
+                case ARG_PRIVATE_KEY:
+                        r = parse_path_argument(optarg, /* suppress_root= */ false, &arg_private_key);
+                        if (r < 0)
+                                return r;
+
+                        break;
+
+                case ARG_PUBLIC_KEY:
+                        r = parse_path_argument(optarg, /* suppress_root= */ false, &arg_public_key);
+                        if (r < 0)
+                                return r;
+
+                        break;
+
+                case ARG_TPM2_DEVICE: {
+                        _cleanup_free_ char *device = NULL;
+
+                        if (streq(optarg, "list"))
+                                return tpm2_list_devices();
+
+                        if (!streq(optarg, "auto")) {
+                                device = strdup(optarg);
+                                if (!device)
+                                        return log_oom();
+                        }
+
+                        free_and_replace(arg_tpm2_device, device);
+                        break;
+                }
+
+                case 'j':
+                        arg_json_format_flags = JSON_FORMAT_PRETTY_AUTO|JSON_FORMAT_COLOR_AUTO;
+                        break;
+
+                case ARG_JSON:
+                        r = parse_json_argument(optarg, &arg_json_format_flags);
+                        if (r <= 0)
+                                return r;
+
+                        break;
+
+                case ARG_PHASE: {
+                        char *n;
+
+                        n = normalize_phase(optarg);
+                        if (!n)
+                                return log_oom();
+
+                        r = strv_consume(&arg_phase, TAKE_PTR(n));
+                        if (r < 0)
+                                return r;
+
+                        break;
+                }
+
+                case ARG_APPEND:
+                        r = parse_path_argument(optarg, /* suppress_root= */ false, &arg_append);
+                        if (r < 0)
+                                return r;
+
+                        break;
+
+                case '?':
+                        return -EINVAL;
+
+                default:
+                        assert_not_reached();
+                }
+
+        if (strv_isempty(arg_banks)) {
+                /* If no banks are specifically selected, pick all known banks */
+                arg_banks = strv_new("SHA1", "SHA256", "SHA384", "SHA512");
+                if (!arg_banks)
+                        return log_oom();
+        }
+
+        strv_sort(arg_banks);
+        strv_uniq(arg_banks);
+
+        if (arg_current)
+                for (UnifiedSection us = 0; us < _UNIFIED_SECTION_MAX; us++)
+                        if (arg_sections[us])
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "The --current switch cannot be used in combination with --linux= and related switches.");
+
+        if (strv_isempty(arg_phase)) {
+                /* If no phases are specifically selected, pick everything from the beginning of the initrd
+                 * to the beginning of shutdown. */
+                if (strv_extend_strv(&arg_phase,
+                                     STRV_MAKE("enter-initrd",
+                                               "enter-initrd:leave-initrd",
+                                               "enter-initrd:leave-initrd:sysinit",
+                                               "enter-initrd:leave-initrd:sysinit:ready"),
+                                     /* filter_duplicates= */ false) < 0)
+                        return log_oom();
+        } else {
+                strv_sort(arg_phase);
+                strv_uniq(arg_phase);
+        }
+
+        _cleanup_free_ char *j = NULL;
+        j = strv_join(arg_phase, ", ");
+        if (!j)
+                return log_oom();
+
+        log_debug("Measuring boot phases: %s", j);
+        return 1;
+}
+
+/* The PCR 11 state for one specific bank */
+typedef struct PcrState {
+        char *bank;
+        const EVP_MD *md;
+        void *value;
+        size_t value_size;
+        void *saved_value; /* A copy of the original value we calculated, used by pcr_states_save()/pcr_states_restore() to come later back to */
+} PcrState;
+
+static void pcr_state_free_all(PcrState **pcr_state) {
+        assert(pcr_state);
+
+        if (!*pcr_state)
+                return;
+
+        for (size_t i = 0; (*pcr_state)[i].value; i++) {
+                free((*pcr_state)[i].bank);
+                free((*pcr_state)[i].value);
+                free((*pcr_state)[i].saved_value);
+        }
+
+        *pcr_state = mfree(*pcr_state);
+}
+
+static void evp_md_ctx_free_all(EVP_MD_CTX **md[]) {
+        assert(md);
+
+        if (!*md)
+                return;
+
+        for (size_t i = 0; (*md)[i]; i++)
+                EVP_MD_CTX_free((*md)[i]);
+
+        *md = mfree(*md);
+}
+
+static int pcr_state_extend(PcrState *pcr_state, const void *data, size_t sz) {
+        _cleanup_(EVP_MD_CTX_freep) EVP_MD_CTX *mc = NULL;
+        unsigned value_size;
+
+        assert(pcr_state);
+        assert(data || sz == 0);
+        assert(pcr_state->md);
+        assert(pcr_state->value);
+        assert(pcr_state->value_size > 0);
+
+        /* Extends a (virtual) PCR by the given data */
+
+        mc = EVP_MD_CTX_new();
+        if (!mc)
+                return log_oom();
+
+        if (EVP_DigestInit_ex(mc, pcr_state->md, NULL) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to initialize %s context.", pcr_state->bank);
+
+        /* First thing we do, is hash the old PCR value */
+        if (EVP_DigestUpdate(mc, pcr_state->value, pcr_state->value_size) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to run digest.");
+
+        /* Then, we hash the new data */
+        if (EVP_DigestUpdate(mc, data, sz) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to run digest.");
+
+        if (EVP_DigestFinal_ex(mc, pcr_state->value, &value_size) != 1)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finalize hash context.");
+
+        assert(value_size == pcr_state->value_size);
+        return 0;
+}
+
+#define BUFFER_SIZE (16U * 1024U)
+
+static int measure_kernel(PcrState *pcr_states, size_t n) {
+        _cleanup_free_ void *buffer = NULL;
+        int r;
+
+        assert(n > 0);
+        assert(pcr_states);
+
+        /* Virtually measures the components of a unified kernel image into PCR 11 */
+
+        if (arg_current) {
+                /* Shortcut things, if we should just use the current PCR value */
+
+                for (size_t i = 0; i < n; i++) {
+                        _cleanup_free_ char *p = NULL, *s = NULL;
+                        _cleanup_free_ void *v = NULL;
+                        size_t sz;
+
+                        if (asprintf(&p, "/sys/class/tpm/tpm0/pcr-%s/%i", pcr_states[i].bank, TPM2_PCR_KERNEL_BOOT) < 0)
+                                return log_oom();
+
+                        r = read_virtual_file(p, 4096, &s, NULL);
+                        if (r == -ENOENT && access("/sys/class/tpm/tpm0/", F_OK) >= 0)
+                                return log_error_errno(r, "TPM device exists, but cannot open '%s'; either the kernel is too old, or selected PCR bank is not supported: %m", p);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to read '%s': %m", p);
+
+                        r = unhexmem(strstrip(s), SIZE_MAX, &v, &sz);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to decode PCR value '%s': %m", s);
+
+                        assert(pcr_states[i].value_size == sz);
+                        memcpy(pcr_states[i].value, v, sz);
+                }
+
+                return 0;
+        }
+
+        buffer = malloc(BUFFER_SIZE);
+        if (!buffer)
+                return log_oom();
+
+        for (UnifiedSection c = 0; c < _UNIFIED_SECTION_MAX; c++) {
+                _cleanup_(evp_md_ctx_free_all) EVP_MD_CTX **mdctx = NULL;
+                _cleanup_close_ int fd = -EBADF;
+                uint64_t m = 0;
+
+                if (!arg_sections[c])
+                        continue;
+
+                fd = open(arg_sections[c], O_RDONLY|O_CLOEXEC);
+                if (fd < 0)
+                        return log_error_errno(errno, "Failed to open '%s': %m", arg_sections[c]);
+
+                /* Allocate one message digest context per bank (NULL terminated) */
+                mdctx = new0(EVP_MD_CTX*, n + 1);
+                if (!mdctx)
+                        return log_oom();
+
+                for (size_t i = 0; i < n; i++) {
+                        mdctx[i] = EVP_MD_CTX_new();
+                        if (!mdctx[i])
+                                return log_oom();
+
+                        if (EVP_DigestInit_ex(mdctx[i], pcr_states[i].md, NULL) != 1)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                                       "Failed to initialize data %s context.", pcr_states[i].bank);
+                }
+
+                for (;;) {
+                        ssize_t sz;
+
+                        sz = read(fd, buffer, BUFFER_SIZE);
+                        if (sz < 0)
+                                return log_error_errno(errno, "Failed to read '%s': %m", arg_sections[c]);
+                        if (sz == 0) /* EOF */
+                                break;
+
+                        for (size_t i = 0; i < n; i++)
+                                if (EVP_DigestUpdate(mdctx[i], buffer, sz) != 1)
+                                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to run digest.");
+
+                        m += sz;
+                }
+
+                fd = safe_close(fd);
+
+                if (m == 0) /* We skip over empty files, the stub does so too */
+                        continue;
+
+                for (size_t i = 0; i < n; i++) {
+                        _cleanup_free_ void *data_hash = NULL;
+                        unsigned data_hash_size;
+
+                        data_hash = malloc(pcr_states[i].value_size);
+                        if (!data_hash)
+                                return log_oom();
+
+                        /* Measure name of section */
+                        if (EVP_Digest(unified_sections[c], strlen(unified_sections[c]) + 1, data_hash, &data_hash_size, pcr_states[i].md, NULL) != 1)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to hash section name with %s.", pcr_states[i].bank);
+
+                        assert(data_hash_size == (unsigned) pcr_states[i].value_size);
+
+                        r = pcr_state_extend(pcr_states + i, data_hash, data_hash_size);
+                        if (r < 0)
+                                return r;
+
+                        /* Retrieve hash of data and measure it */
+                        if (EVP_DigestFinal_ex(mdctx[i], data_hash, &data_hash_size) != 1)
+                                return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Failed to finalize hash context.");
+
+                        assert(data_hash_size == (unsigned) pcr_states[i].value_size);
+
+                        r = pcr_state_extend(pcr_states + i, data_hash, data_hash_size);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        return 0;
+}
+
+static int measure_phase(PcrState *pcr_states, size_t n, const char *phase) {
+        _cleanup_strv_free_ char **l = NULL;
+        int r;
+
+        assert(pcr_states);
+        assert(n > 0);
+
+        /* Measure a phase string into PCR 11. This splits up the "phase" expression at colons, and then
+         * virtually extends each specified word into PCR 11, to model how during boot we measure a series of
+         * words into PCR 11, one for each phase. */
+
+        l = strv_split(phase, ":");
+        if (!l)
+                return log_oom();
+
+        STRV_FOREACH(word, l) {
+                size_t wl;
+
+                if (isempty(*word))
+                        continue;
+
+                wl = strlen(*word);
+
+                for (size_t i = 0; i < n; i++) { /* For each bank */
+                        _cleanup_free_ void *b = NULL;
+                        int bsz;
+
+                        bsz = EVP_MD_size(pcr_states[i].md);
+                        assert(bsz > 0);
+
+                        b = malloc(bsz);
+                        if (!b)
+                                return log_oom();
+
+                        /* First hash the word itself */
+                        if (EVP_Digest(*word, wl, b, NULL, pcr_states[i].md, NULL) != 1)
+                                return log_error_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to hash word '%s'.", *word);
+
+                        /* And then extend the PCR with the resulting hash */
+                        r = pcr_state_extend(pcr_states + i, b, bsz);
+                        if (r < 0)
+                                return r;
+                }
+        }
+
+        return 0;
+}
+
+static int pcr_states_allocate(PcrState **ret) {
+        _cleanup_(pcr_state_free_all) PcrState *pcr_states = NULL;
+        size_t n = 0;
+
+        pcr_states = new0(PcrState, strv_length(arg_banks) + 1);
+        if (!pcr_states)
+                return log_oom();
+
+        /* Allocate a PCR state structure, one for each bank */
+        STRV_FOREACH(d, arg_banks) {
+                const EVP_MD *implementation;
+                _cleanup_free_ void *v = NULL;
+                _cleanup_free_ char *b = NULL;
+                int sz;
+
+                assert_se(implementation = EVP_get_digestbyname(*d)); /* Must work, we already checked while parsing  command line */
+
+                b = strdup(EVP_MD_name(implementation));
+                if (!b)
+                        return log_oom();
+
+                sz = EVP_MD_size(implementation);
+                if (sz <= 0 || sz >= INT_MAX)
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL), "Unexpected digest size: %i", sz);
+
+                v = malloc0(sz); /* initial PCR state is all zeroes */
+                if (!v)
+                        return log_oom();
+
+                pcr_states[n++] = (struct PcrState) {
+                        .bank = ascii_strlower(TAKE_PTR(b)),
+                        .md = implementation,
+                        .value = TAKE_PTR(v),
+                        .value_size = sz,
+                };
+        }
+
+        *ret = TAKE_PTR(pcr_states);
+        return (int) n;
+}
+
+static int pcr_states_save(PcrState *pcr_states, size_t n) {
+        assert(pcr_states);
+        assert(n > 0);
+
+        for (size_t i = 0; i < n; i++) {
+                _cleanup_free_ void *saved = NULL;
+
+                if (!pcr_states[i].value)
+                        continue;
+
+                saved = memdup(pcr_states[i].value, pcr_states[i].value_size);
+                if (!saved)
+                        return log_oom();
+
+                free_and_replace(pcr_states[i].saved_value, saved);
+        }
+
+        return 0;
+}
+
+static void pcr_states_restore(PcrState *pcr_states, size_t n) {
+        assert(pcr_states);
+        assert(n > 0);
+
+        for (size_t i = 0; i < n; i++) {
+
+                assert(pcr_states[i].value);
+                assert(pcr_states[i].saved_value);
+
+                memcpy(pcr_states[i].value, pcr_states[i].saved_value, pcr_states[i].value_size);
+        }
+}
+
+static int verb_calculate(int argc, char *argv[], void *userdata) {
+        _cleanup_(json_variant_unrefp) JsonVariant *w = NULL;
+        _cleanup_(pcr_state_free_all) PcrState *pcr_states = NULL;
+        int r;
+
+        if (!arg_sections[UNIFIED_SECTION_LINUX] && !arg_current)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Either --linux= or --current must be specified, refusing.");
+        if (arg_append)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "The --append= switch is only supported for 'sign', not 'calculate'.");
+
+        assert(!strv_isempty(arg_banks));
+        assert(!strv_isempty(arg_phase));
+
+        r = pcr_states_allocate(&pcr_states);
+        if (r < 0)
+                return r;
+
+        size_t n = r;
+
+        r = measure_kernel(pcr_states, n);
+        if (r < 0)
+                return r;
+
+        /* Save the current state, so that we later can restore to it. This way we can measure the PCR values
+         * for multiple different boot phases without heaving to start from zero each time */
+        r = pcr_states_save(pcr_states, n);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(phase, arg_phase) {
+
+                r = measure_phase(pcr_states, n, *phase);
+                if (r < 0)
+                        return r;
+
+                for (size_t i = 0; i < n; i++) {
+                        if (arg_json_format_flags & JSON_FORMAT_OFF) {
+                                _cleanup_free_ char *hd = NULL;
+
+                                if (i == 0) {
+                                        fflush(stdout);
+                                        fprintf(stderr, "%s# PCR[%i] Phase <%s>%s\n",
+                                                ansi_grey(),
+                                                TPM2_PCR_KERNEL_BOOT,
+                                                isempty(*phase) ? ":" : *phase,
+                                                ansi_normal());
+                                        fflush(stderr);
+                                }
+
+                                hd = hexmem(pcr_states[i].value, pcr_states[i].value_size);
+                                if (!hd)
+                                        return log_oom();
+
+                                printf("%i:%s=%s\n", TPM2_PCR_KERNEL_BOOT, pcr_states[i].bank, hd);
+                        } else {
+                                _cleanup_(json_variant_unrefp) JsonVariant *array = NULL;
+
+                                array = json_variant_ref(json_variant_by_key(w, pcr_states[i].bank));
+
+                                r = json_variant_append_arrayb(
+                                                &array,
+                                                JSON_BUILD_OBJECT(
+                                                                JSON_BUILD_PAIR_CONDITION(!isempty(*phase), "phase", JSON_BUILD_STRING(*phase)),
+                                                                JSON_BUILD_PAIR("pcr", JSON_BUILD_INTEGER(TPM2_PCR_KERNEL_BOOT)),
+                                                                JSON_BUILD_PAIR("hash", JSON_BUILD_HEX(pcr_states[i].value, pcr_states[i].value_size))));
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to append JSON object to array: %m");
+
+                                r = json_variant_set_field(&w, pcr_states[i].bank, array);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to add bank info to object: %m");
+                        }
+                }
+
+                /* Return to the original kernel measurement for the next phase calculation */
+                pcr_states_restore(pcr_states, n);
+        }
+
+        if (!FLAGS_SET(arg_json_format_flags, JSON_FORMAT_OFF)) {
+
+                if (arg_json_format_flags & (JSON_FORMAT_PRETTY|JSON_FORMAT_PRETTY_AUTO))
+                        pager_open(arg_pager_flags);
+
+                json_variant_dump(w, arg_json_format_flags, stdout, NULL);
+        }
+
+        return 0;
+}
+
+static int verb_sign(int argc, char *argv[], void *userdata) {
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        _cleanup_(pcr_state_free_all) PcrState *pcr_states = NULL;
+        _cleanup_(EVP_PKEY_freep) EVP_PKEY *privkey = NULL, *pubkey = NULL;
+        _cleanup_fclose_ FILE *privkeyf = NULL;
+        size_t n;
+        int r;
+
+        if (!arg_sections[UNIFIED_SECTION_LINUX] && !arg_current)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "Either --linux= or --current must be specified, refusing.");
+
+        if (!arg_private_key)
+                return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                       "No private key specified, use --private-key=.");
+
+        assert(!strv_isempty(arg_banks));
+        assert(!strv_isempty(arg_phase));
+
+        if (arg_append) {
+                r = json_parse_file(NULL, arg_append, 0, &v, NULL, NULL);
+                if (r < 0)
+                        return log_error_errno(r, "Failed to parse '%s': %m", arg_append);
+
+                if (!json_variant_is_object(v))
+                        return log_error_errno(SYNTHETIC_ERRNO(EINVAL),
+                                               "File '%s' is not a valid JSON object, refusing.", arg_append);
+        }
+
+        /* When signing we only support JSON output */
+        arg_json_format_flags &= ~JSON_FORMAT_OFF;
+
+        privkeyf = fopen(arg_private_key, "re");
+        if (!privkeyf)
+                return log_error_errno(errno, "Failed to open private key file '%s': %m", arg_private_key);
+
+        privkey = PEM_read_PrivateKey(privkeyf, NULL, NULL, NULL);
+        if (!privkey)
+                return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to parse private key '%s'.", arg_private_key);
+
+        if (arg_public_key) {
+                _cleanup_fclose_ FILE *pubkeyf = NULL;
+
+                pubkeyf = fopen(arg_public_key, "re");
+                if (!pubkeyf)
+                        return log_error_errno(errno, "Failed to open public key file '%s': %m", arg_public_key);
+
+                pubkey = PEM_read_PUBKEY(pubkeyf, NULL, NULL, NULL);
+                if (!pubkey)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO), "Failed to parse public key '%s'.", arg_public_key);
+        } else {
+                _cleanup_(memstream_done) MemStream m = {};
+                FILE *tf;
+
+                /* No public key was specified, let's derive it automatically, if we can */
+
+                tf = memstream_init(&m);
+                if (!tf)
+                        return log_oom();
+
+                if (i2d_PUBKEY_fp(tf, privkey) != 1)
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                               "Failed to extract public key from private key file '%s'.", arg_private_key);
+
+                fflush(tf);
+                rewind(tf);
+
+                if (!d2i_PUBKEY_fp(tf, &pubkey))
+                        return log_error_errno(SYNTHETIC_ERRNO(EIO),
+                                               "Failed to parse extracted public key of private key file '%s'.", arg_private_key);
+        }
+
+        r = pcr_states_allocate(&pcr_states);
+        if (r < 0)
+                return r;
+
+        n = (size_t) r;
+
+        r = measure_kernel(pcr_states, n);
+        if (r < 0)
+                return r;
+
+        r = pcr_states_save(pcr_states, n);
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(phase, arg_phase) {
+
+                r = measure_phase(pcr_states, n, *phase);
+                if (r < 0)
+                        return r;
+
+                for (size_t i = 0; i < n; i++) {
+                        PcrState *p = pcr_states + i;
+
+                        int tpmalg = tpm2_hash_alg_from_string(EVP_MD_name(p->md));
+                        if (tpmalg < 0)
+                                return log_error_errno(tpmalg, "Unsupported PCR bank");
+
+                        Tpm2PCRValue pcr_value = TPM2_PCR_VALUE_MAKE(TPM2_PCR_KERNEL_BOOT,
+                                                                     tpmalg,
+                                                                     TPM2B_DIGEST_MAKE(p->value, p->value_size));
+
+                        TPM2B_DIGEST pcr_policy_digest = TPM2B_DIGEST_MAKE(NULL, TPM2_SHA256_DIGEST_SIZE);
+
+                        r = tpm2_calculate_policy_pcr(&pcr_value, 1, &pcr_policy_digest);
+                        if (r < 0)
+                                return log_error_errno(r, "Could not calculate PolicyPCR digest: %m");
+
+                        _cleanup_free_ void *sig = NULL;
+                        size_t ss;
+
+                        r = digest_and_sign(p->md, privkey, pcr_policy_digest.buffer, pcr_policy_digest.size, &sig, &ss);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to sign PCR policy: %m");
+
+                        _cleanup_free_ void *pubkey_fp = NULL;
+                        size_t pubkey_fp_size = 0;
+                        r = pubkey_fingerprint(pubkey, EVP_sha256(), &pubkey_fp, &pubkey_fp_size);
+                        if (r < 0)
+                                return r;
+
+                        _cleanup_(json_variant_unrefp) JsonVariant *a = NULL;
+                        r = tpm2_make_pcr_json_array(UINT64_C(1) << TPM2_PCR_KERNEL_BOOT, &a);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to build JSON PCR mask array: %m");
+
+                        _cleanup_(json_variant_unrefp) JsonVariant *bv = NULL;
+                        r = json_build(&bv, JSON_BUILD_OBJECT(
+                                                       JSON_BUILD_PAIR("pcrs", JSON_BUILD_VARIANT(a)),                                             /* PCR mask */
+                                                       JSON_BUILD_PAIR("pkfp", JSON_BUILD_HEX(pubkey_fp, pubkey_fp_size)),                         /* SHA256 fingerprint of public key (DER) used for the signature */
+                                                       JSON_BUILD_PAIR("pol", JSON_BUILD_HEX(pcr_policy_digest.buffer, pcr_policy_digest.size)),   /* TPM2 policy hash that is signed */
+                                                       JSON_BUILD_PAIR("sig", JSON_BUILD_BASE64(sig, ss))));                                       /* signature data */
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to build JSON object: %m");
+
+                        _cleanup_(json_variant_unrefp) JsonVariant *av = NULL;
+                        av = json_variant_ref(json_variant_by_key(v, p->bank));
+
+                        r = json_variant_append_array_nodup(&av, bv);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to append JSON object: %m");
+
+                        r = json_variant_set_field(&v, p->bank, av);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to add JSON field: %m");
+                }
+
+                /* Return to the original kernel measurement for the next phase calculation */
+                pcr_states_restore(pcr_states, n);
+        }
+
+        if (arg_json_format_flags & (JSON_FORMAT_PRETTY|JSON_FORMAT_PRETTY_AUTO))
+                pager_open(arg_pager_flags);
+
+        json_variant_dump(v, arg_json_format_flags, stdout, NULL);
+
+        return 0;
+}
+
+static int compare_reported_pcr_nr(uint32_t pcr, const char *varname, const char *description) {
+        _cleanup_free_ char *s = NULL;
+        uint32_t v;
+        int r;
+
+        r = efi_get_variable_string(varname, &s);
+        if (r == -ENOENT)
+                return 0;
+        if (r < 0)
+                return log_error_errno(r, "Failed to read EFI variable '%s': %m", varname);
+
+        r = safe_atou32(s, &v);
+        if (r < 0)
+                return log_error_errno(r, "Failed to parse EFI variable '%s': %s", varname, s);
+
+        if (pcr != v)
+                log_warning("PCR number reported by stub for %s (%" PRIu32 ") different from our expectation (%" PRIu32 ").\n"
+                            "The measurements are likely inconsistent.", description, v, pcr);
+
+        return 0;
+}
+
+static int validate_stub(void) {
+        uint64_t features;
+        bool found = false;
+        int r;
+
+        if (tpm2_support() != TPM2_SUPPORT_FULL)
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "Sorry, system lacks full TPM2 support.");
+
+        r = efi_stub_get_features(&features);
+        if (r < 0)
+                return log_error_errno(r, "Unable to get stub features: %m");
+
+        if (!FLAGS_SET(features, EFI_STUB_FEATURE_THREE_PCRS))
+                log_warning("Warning: current kernel image does not support measuring itself, the command line or initrd system extension images.\n"
+                            "The PCR measurements seen are unlikely to be valid.");
+
+        r = compare_reported_pcr_nr(TPM2_PCR_KERNEL_BOOT, EFI_LOADER_VARIABLE(StubPcrKernelImage), "kernel image");
+        if (r < 0)
+                return r;
+
+        r = compare_reported_pcr_nr(TPM2_PCR_KERNEL_CONFIG, EFI_LOADER_VARIABLE(StubPcrKernelParameters), "kernel parameters");
+        if (r < 0)
+                return r;
+
+        r = compare_reported_pcr_nr(TPM2_PCR_SYSEXTS, EFI_LOADER_VARIABLE(StubPcrInitRDSysExts), "initrd system extension images");
+        if (r < 0)
+                return r;
+
+        STRV_FOREACH(bank, arg_banks) {
+                _cleanup_free_ char *b = NULL, *p = NULL;
+
+                b = strdup(*bank);
+                if (!b)
+                        return log_oom();
+
+                if (asprintf(&p, "/sys/class/tpm/tpm0/pcr-%s/", ascii_strlower(b)) < 0)
+                        return log_oom();
+
+                if (access(p, F_OK) < 0) {
+                        if (errno != ENOENT)
+                                return log_error_errno(errno, "Failed to detect if '%s' exists: %m", b);
+                } else
+                        found = true;
+        }
+
+        if (!found)
+                return log_error_errno(SYNTHETIC_ERRNO(EOPNOTSUPP), "None of the select PCR banks appear to exist.");
+
+        return 0;
+}
+
+static int verb_status(int argc, char *argv[], void *userdata) {
+        static const uint32_t relevant_pcrs[] = {
+                TPM2_PCR_KERNEL_BOOT,
+                TPM2_PCR_KERNEL_CONFIG,
+                TPM2_PCR_SYSEXTS,
+        };
+
+        _cleanup_(json_variant_unrefp) JsonVariant *v = NULL;
+        int r;
+
+        r = validate_stub();
+        if (r < 0)
+                return r;
+
+        for (size_t i = 0; i < ELEMENTSOF(relevant_pcrs); i++) {
+
+                STRV_FOREACH(bank, arg_banks) {
+                        _cleanup_free_ char *b = NULL, *p = NULL, *s = NULL;
+                        _cleanup_free_ void *h = NULL;
+                        size_t l;
+
+                        b = strdup(*bank);
+                        if (!b)
+                                return log_oom();
+
+                        if (asprintf(&p, "/sys/class/tpm/tpm0/pcr-%s/%" PRIu32, ascii_strlower(b), relevant_pcrs[i]) < 0)
+                                return log_oom();
+
+                        r = read_virtual_file(p, 4096, &s, NULL);
+                        if (r == -ENOENT)
+                                continue;
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to read '%s': %m", p);
+
+                        r = unhexmem(strstrip(s), SIZE_MAX, &h, &l);
+                        if (r < 0)
+                                return log_error_errno(r, "Failed to decode PCR value '%s': %m", s);
+
+                        if (arg_json_format_flags & JSON_FORMAT_OFF) {
+                                _cleanup_free_ char *f = NULL;
+
+                                f = hexmem(h, l);
+                                if (!h)
+                                        return log_oom();
+
+                                if (bank == arg_banks) {
+                                        /* before the first line for each PCR, write a short descriptive text to
+                                         * stderr, and leave the primary content on stdout */
+                                        fflush(stdout);
+                                        fprintf(stderr, "%s# PCR[%" PRIu32 "] %s%s%s\n",
+                                                ansi_grey(),
+                                                relevant_pcrs[i],
+                                                tpm2_pcr_index_to_string(relevant_pcrs[i]),
+                                                memeqzero(h, l) ? " (NOT SET!)" : "",
+                                                ansi_normal());
+                                        fflush(stderr);
+                                }
+
+                                printf("%" PRIu32 ":%s=%s\n", relevant_pcrs[i], b, f);
+
+                        } else {
+                                _cleanup_(json_variant_unrefp) JsonVariant *bv = NULL, *a = NULL;
+
+                                r = json_build(&bv,
+                                               JSON_BUILD_OBJECT(
+                                                               JSON_BUILD_PAIR("pcr", JSON_BUILD_INTEGER(relevant_pcrs[i])),
+                                                               JSON_BUILD_PAIR("hash", JSON_BUILD_HEX(h, l))
+                                               )
+                                );
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to build JSON object: %m");
+
+                                a = json_variant_ref(json_variant_by_key(v, b));
+
+                                r = json_variant_append_array(&a, bv);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to append PCR entry to JSON array: %m");
+
+                                r = json_variant_set_field(&v, b, a);
+                                if (r < 0)
+                                        return log_error_errno(r, "Failed to add bank info to object: %m");
+                        }
+                }
+        }
+
+        if (!FLAGS_SET(arg_json_format_flags, JSON_FORMAT_OFF)) {
+                if (arg_json_format_flags & (JSON_FORMAT_PRETTY|JSON_FORMAT_PRETTY_AUTO))
+                        pager_open(arg_pager_flags);
+
+                json_variant_dump(v, arg_json_format_flags, stdout, NULL);
+        }
+
+        return 0;
+}
+
+static int measure_main(int argc, char *argv[]) {
+        static const Verb verbs[] = {
+                { "help",      VERB_ANY, VERB_ANY, 0,            help           },
+                { "status",    VERB_ANY, 1,        VERB_DEFAULT, verb_status    },
+                { "calculate", VERB_ANY, 1,        0,            verb_calculate },
+                { "sign",      VERB_ANY, 1,        0,            verb_sign      },
+                {}
+        };
+
+        return dispatch_verb(argc, argv, verbs, NULL);
+}
+
+static int run(int argc, char *argv[]) {
+        int r;
+
+        log_show_color(true);
+        log_parse_environment();
+        log_open();
+
+        r = parse_argv(argc, argv);
+        if (r <= 0)
+                return r;
+
+        return measure_main(argc, argv);
+}
+
+DEFINE_MAIN_FUNCTION(run);