Merge pull request #34628 from DaanDeMeyer/measure

Rework TEST-86-MULTI-PROFILE-UKI + associated bugfixes

mkosi.conf

@@ -33,9 +33,8 @@ CacheDirectory=build/mkosi.cache
 BuildSourcesEphemeral=yes
 Incremental=yes
 
-# TODO: Remove when TEST-70-TPM doesn't fail in an image with signed PCRs anymore.
 [Validation]
-SignExpectedPcr=no
+SignExpectedPcr=yes
 
 [Content]
 ExtraTrees=

mkosi.uki-profiles/profile1.conf

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+[UKIProfile]
+Profile=
+        ID=profile1
+        TITLE=Profile Two
+Cmdline=testprofile1=1

mkosi.uki-profiles/profile2.conf

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: LGPL-2.1-or-later
+
+[UKIProfile]
+Profile=
+        ID=profile2
+        TITLE=Profile Two
+Cmdline=testprofile2=1

src/boot/measure.c

@@ -16,6 +16,7 @@
 #include "openssl-util.h"
 #include "parse-argument.h"
 #include "parse-util.h"
+#include "pe-binary.h"
 #include "pretty-print.h"
 #include "sha256.h"
 #include "strv.h"
@@ -517,6 +518,38 @@ static int measure_kernel(PcrState *pcr_states, size_t n) {
                         m += sz;
                 }
 
+                if (c == UNIFIED_SECTION_LINUX) {
+                        _cleanup_free_ PeHeader *pe_header = NULL;
+
+                        r = pe_load_headers(fd, /*ret_dos_header=*/ NULL, &pe_header);
+                        if (r < 0)
+                                log_warning_errno(r, "Failed to parse kernel image file '%s', ignoring: %m", arg_sections[c]);
+                        else if (m < pe_header->optional.SizeOfImage) {
+                                memzero(buffer, BUFFER_SIZE);
+
+                                /* Our EFI stub measures VirtualSize bytes of the .linux section into PCR 11.
+                                 * Notably, VirtualSize can be larger than the section's size on disk. In
+                                 * that case the extra space is initialized with zeros, so the stub ends up
+                                 * measuring a bunch of zeros. To accomodate this, we have to measure the
+                                 * same number of zeros here. We opt to measure extra zeros here instead of
+                                 * modifying the stub to only measure the number of bytes on disk as we want
+                                 * newer ukify + systemd-measure to work with older versions of the stub and
+                                 * as of 6.12 the kernel image's VirtualSize won't be larger than its size on
+                                 * disk anymore (see https://github.com/systemd/systemd/issues/34578#issuecomment-2382459515).
+                                 */
+
+                                while (m < pe_header->optional.SizeOfImage) {
+                                        uint64_t sz = MIN(BUFFER_SIZE, pe_header->optional.SizeOfImage - m);
+
+                                        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 */

src/cryptenroll/cryptenroll-tpm2.c

@@ -78,8 +78,6 @@ static int search_policy_hash(
                                         j++;
                                 }
 
-                                assert(j == n_policy_hash);
-
                                 if (match) /* Found entry with the exact same set of hashes */
                                         return keyslot;
                         }

src/pcrlock/pehash.c

@@ -216,10 +216,24 @@ int uki_hash(int fd,
                 if (EVP_DigestInit_ex(mdctx, md, NULL) != 1)
                         return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Failed to allocate message digest.");
 
-                r = hash_file(fd, mdctx, section->PointerToRawData, section->VirtualSize);
+                r = hash_file(fd, mdctx, section->PointerToRawData, MIN(section->VirtualSize, section->SizeOfRawData));
                 if (r < 0)
                         return r;
 
+                if (section->SizeOfRawData < section->VirtualSize) {
+                        uint8_t zeroes[1024] = {};
+                        size_t remaining = section->VirtualSize - section->SizeOfRawData;
+
+                        while (remaining > 0) {
+                                size_t sz = MIN(sizeof(zeroes), remaining);
+
+                                if (EVP_DigestUpdate(mdctx, zeroes, sz) != 1)
+                                        return log_debug_errno(SYNTHETIC_ERRNO(ENOTRECOVERABLE), "Unable to hash data.");
+
+                                remaining -= sz;
+                        }
+                }
+
                 hashes[i] = malloc(hsz);
                 if (!hashes[i])
                         return log_oom_debug();

test/TEST-86-MULTI-PROFILE-UKI/meson.build

@@ -6,6 +6,5 @@ integration_tests += [
                 'storage' : 'persistent',
                 'vm' : true,
                 'firmware' : 'auto',
-                'enabled' : false,
         },
 ]

test/units/TEST-70-TPM2.pcrlock.sh

@@ -86,7 +86,7 @@ echo -n hoho >/tmp/pcrlockpwd
 chmod 0600 /tmp/pcrlockpwd
 cryptsetup luksFormat -q --pbkdf pbkdf2 --pbkdf-force-iterations 1000 --use-urandom "$img" /tmp/pcrlockpwd
 
-systemd-cryptenroll --unlock-key-file=/tmp/pcrlockpwd --tpm2-device=auto --tpm2-pcrlock=/var/lib/systemd/pcrlock.json --wipe-slot=tpm2 "$img"
+systemd-cryptenroll --unlock-key-file=/tmp/pcrlockpwd --tpm2-device=auto --tpm2-pcrlock=/var/lib/systemd/pcrlock.json --tpm2-public-key= --wipe-slot=tpm2 "$img"
 systemd-cryptsetup attach pcrlock "$img" - tpm2-device=auto,tpm2-pcrlock=/var/lib/systemd/pcrlock.json,headless
 systemd-cryptsetup detach pcrlock
 
@@ -136,7 +136,7 @@ systemd-cryptenroll --unlock-tpm2-device=auto --tpm2-device=auto --tpm2-pcrlock=
 "$SD_MEASURE" sign --current --bank=sha256 --private-key="$img".private.pem --public-key="$img".public.pem --phase=: | tee "$img".pcrsign
 SYSTEMD_CRYPTSETUP_USE_TOKEN_MODULE=0 systemd-cryptsetup attach pcrlock "$img" - "tpm2-device=auto,tpm2-pcrlock=/var/lib/systemd/pcrlock.json,tpm2-signature=$img.pcrsign,headless"
 systemd-cryptsetup detach pcrlock
-systemd-cryptenroll --unlock-key-file=/tmp/pcrlockpwd --tpm2-device=auto --tpm2-pcrlock=/var/lib/systemd/pcrlock.json --wipe-slot=tpm2 "$img"
+systemd-cryptenroll --unlock-key-file=/tmp/pcrlockpwd --tpm2-device=auto --tpm2-pcrlock=/var/lib/systemd/pcrlock.json --tpm2-public-key= --wipe-slot=tpm2 "$img"
 rm "$img".public.pem "$img".private.pem "$img".pcrsign
 
 # Now use the root fs support, i.e. make the tool write a copy of the pcrlock

test/units/TEST-86-MULTI-PROFILE-UKI.sh

@@ -25,57 +25,42 @@ fi
 echo "CURRENT EVENT LOG + PCRS:"
 /usr/lib/systemd/systemd-pcrlock
 
-if test ! -f /run/systemd/stub/profile; then
-    openssl genpkey -algorithm RSA -pkeyopt rsa_keygen_bits:2048 -out /root/pcrsign.private.pem
-    openssl rsa -pubout -in /root/pcrsign.private.pem -out /root/pcrsign.public.pem
+test -f /run/systemd/stub/profile
 
-    ukify build --extend="$CURRENT_UKI" --output=/tmp/extended0.efi --profile='ID=profile0
-TITLE="Profile Zero"' --measure-base="$CURRENT_UKI" --pcr-private-key=/root/pcrsign.private.pem --pcr-public-key=/root/pcrsign.public.pem --pcr-banks=sha256,sha384,sha512
+# shellcheck source=/dev/null
+. /run/systemd/stub/profile
 
-    ukify build --extend=/tmp/extended0.efi --output=/tmp/extended1.efi --profile='ID=profile1
-TITLE="Profile One"' --measure-base=/tmp/extended0.efi --cmdline="testprofile1=1 $(cat /proc/cmdline)" --pcr-private-key=/root/pcrsign.private.pem --pcr-public-key=/root/pcrsign.public.pem --pcr-banks=sha256,sha384,sha512
+if [[ "$ID" == "main" ]]; then
+    if [[ -f /root/encrypted.raw ]]; then
+        exit 1
+    fi
 
-    ukify build --extend=/tmp/extended1.efi --output=/tmp/extended2.efi --profile='ID=profile2
-TITLE="Profile Two"' --measure-base=/tmp/extended1.efi --cmdline="testprofile2=1 $(cat /proc/cmdline)" --pcr-private-key=/root/pcrsign.private.pem --pcr-public-key=/root/pcrsign.public.pem --pcr-banks=sha256,sha384,sha512
-
-    echo "EXTENDED UKI:"
-    ukify inspect /tmp/extended2.efi
-    rm /tmp/extended0.efi /tmp/extended1.efi
-    mv /tmp/extended2.efi "$CURRENT_UKI"
-
-    # Prepare a disk image, locked to the PCR measurements of the UKI we just generated
+    # Prepare a disk image, locked to the PCR measurements of the current UKI
     truncate -s 32M /root/encrypted.raw
     echo -n "geheim" >/root/encrypted.secret
     cryptsetup luksFormat -q --pbkdf pbkdf2 --pbkdf-force-iterations 1000 --use-urandom /root/encrypted.raw --key-file=/root/encrypted.secret
-    systemd-cryptenroll --tpm2-device=auto --tpm2-pcrs= --tpm2-public-key=/root/pcrsign.public.pem --unlock-key-file=/root/encrypted.secret /root/encrypted.raw
+    systemd-cryptenroll --tpm2-device=auto --tpm2-pcrs= --unlock-key-file=/root/encrypted.secret /root/encrypted.raw
     rm -f /root/encrypted.secret
+fi
 
+# Validate that with the current profile we can fulfill the PCR 11 policy
+systemd-cryptsetup attach multiprof /root/encrypted.raw - tpm2-device=auto,headless=1
+systemd-cryptsetup detach multiprof
+
+if [[ "$ID" == "main" ]]; then
+    bootctl set-default "$(basename "$CURRENT_UKI")@profile1"
     reboot
     exit 0
+elif [[ "$ID" == "profile1" ]]; then
+    grep testprofile1=1 /proc/cmdline
+    bootctl set-default "$(basename "$CURRENT_UKI")@profile2"
+    reboot
+    exit 0
+elif [[ "$ID" == "profile2" ]]; then
+    grep testprofile2=1 /proc/cmdline
+    rm /root/encrypted.raw
 else
-    # shellcheck source=/dev/null
-    . /run/systemd/stub/profile
-
-    # Validate that with the current profile we can fulfill the PCR 11 policy
-    systemd-cryptsetup attach multiprof /root/encrypted.raw - tpm2-device=auto,headless=1
-    systemd-cryptsetup detach multiprof
-
-    if [ "$ID" = "profile0" ]; then
-        grep -v testprofile /proc/cmdline
-        echo "default $(basename "$CURRENT_UKI")@profile1" >"$(bootctl -p)/loader/loader.conf"
-        reboot
-        exit 0
-    elif [ "$ID" = "profile1" ]; then
-        grep testprofile1=1 /proc/cmdline
-        echo "default $(basename "$CURRENT_UKI")@profile2" >"$(bootctl -p)/loader/loader.conf"
-        reboot
-        exit 0
-    elif [ "$ID" = "profile2" ]; then
-        grep testprofile2=1 /proc/cmdline
-        rm /root/encrypted.raw
-    else
-        exit 1
-    fi
+    exit 1
 fi
 
 touch /testok