| 2021-03-25 12:59:51 |
Dimitri John Ledkov |
bug |
|
|
added bug |
| 2021-03-25 13:00:00 |
Dimitri John Ledkov |
bug task added |
|
sbsigntool (Ubuntu) |
|
| 2021-03-25 13:01:27 |
Dimitri John Ledkov |
description |
launchpad signing shimaa64.efi fails to validate
mktemp -d
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK |
launchpad signing shimaa64.efi fails to validate
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK |
|
| 2021-03-25 13:05:32 |
Dimitri John Ledkov |
description |
launchpad signing shimaa64.efi fails to validate
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK |
launchpad signing shimaa64.efi fails to validate
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 14:10:06 |
Dimitri John Ledkov |
description |
launchpad signing shimaa64.efi fails to validate
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 14:10:13 |
Dimitri John Ledkov |
nominated for series |
|
Ubuntu Bionic |
|
| 2021-03-25 14:10:13 |
Dimitri John Ledkov |
bug task added |
|
sbsigntool (Ubuntu Bionic) |
|
| 2021-03-25 14:10:22 |
Dimitri John Ledkov |
sbsigntool (Ubuntu): status |
New |
Fix Released |
|
| 2021-03-25 14:12:26 |
Dimitri John Ledkov |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 14:13:16 |
Dimitri John Ledkov |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.
signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 14:23:16 |
Dimitri John Ledkov |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Signatures produced by sbsign in bionic, must be able to verify with pesigcheck
* Existing signatures generated by launchpad should fail validation
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Test that pesigcheck fails too
openssl x509 -outform der -out 15.3-0ubuntu1~ppa1/control/uefi.der -in 15.3-0ubuntu1~ppa1/control/uefi.crt
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.signed -c 15.3-0ubuntu1~ppa1/control/uefi.der
pesigcheck: "15.3-0ubuntu1~ppa1/shimaa64.efi.signed" is invalid.
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
pesigcheck -i 15.3-0ubuntu1~ppa1/shimaa64.efi.signed -c /var/lib/shim-signed/mok/MOK.der
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Copy the signed binary & cert to focal, and check that sbverify verifies them.
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 14:54:03 |
Dimitri John Ledkov |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
...
Signature verification failed
Is the correct output
# Generate new key on bionic, resign using new sbsigntool, and check that it is now all good:
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Copy the signed binary & cert to focal, and check that sbverify verifies them.
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# install old sbsign
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Verification will pass with old sbsign, but it is wrong.
# Generate new key on bionic
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
cp 15.3-0ubuntu1~ppa1/shimaa64.efi old-sbsign.efi
cp 15.3-0ubuntu1~ppa1/shimaa64.efi new-sbsign.efi
# self-sign the binary using the old sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem old-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach old-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in old-sbsign-signature.p7c -print | grep -A5 messageDi
# upgrade to new sbsign
# check that verifcation now fails
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
should now fail.
# self-sign with new sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem new-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach new-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in new-sbsign-signature.p7c -print | grep -A5 messageDi
# Also detach the launchpad signature and print digest
sbattach --detach lp-sbsign-signature.p7c 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
openssl pkcs7 -inform der -in lp-sbsign-signature.p7c -print | grep -A5 messageDi
The correct digest is, which should be in the new-sbsign-signature.p7c:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 6a 83 1f 9e cb 7a 68 7f-17 c0 9d 81 c0 j....zh......
000d - 6b 17 b2 c3 1c d7 ed b5-b3 89 49 a3 c1 k.........I..
001a - 8d 75 59 d3 b3 11 .uY...
The wrong digest is, which is in lp & old sbsign signatures:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 2a c3 bb e6 20 27 6b b2-58 f8 8d 50 eb *... 'k.X..P.
000d - 1e 88 68 a3 12 08 7a 1d-27 e5 42 e6 0e ..h...z.'.B..
001a - e4 24 9a 5c 0a 92 .$.\..
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 16:30:06 |
Łukasz Zemczak |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# install old sbsign
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Verification will pass with old sbsign, but it is wrong.
# Generate new key on bionic
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
cp 15.3-0ubuntu1~ppa1/shimaa64.efi old-sbsign.efi
cp 15.3-0ubuntu1~ppa1/shimaa64.efi new-sbsign.efi
# self-sign the binary using the old sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem old-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach old-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in old-sbsign-signature.p7c -print | grep -A5 messageDi
# upgrade to new sbsign
# check that verifcation now fails
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
should now fail.
# self-sign with new sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem new-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach new-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in new-sbsign-signature.p7c -print | grep -A5 messageDi
# Also detach the launchpad signature and print digest
sbattach --detach lp-sbsign-signature.p7c 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
openssl pkcs7 -inform der -in lp-sbsign-signature.p7c -print | grep -A5 messageDi
The correct digest is, which should be in the new-sbsign-signature.p7c:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 6a 83 1f 9e cb 7a 68 7f-17 c0 9d 81 c0 j....zh......
000d - 6b 17 b2 c3 1c d7 ed b5-b3 89 49 a3 c1 k.........I..
001a - 8d 75 59 d3 b3 11 .uY...
The wrong digest is, which is in lp & old sbsign signatures:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 2a c3 bb e6 20 27 6b b2-58 f8 8d 50 eb *... 'k.X..P.
000d - 1e 88 68 a3 12 08 7a 1d-27 e5 42 e6 0e ..h...z.'.B..
001a - e4 24 9a 5c 0a 92 .$.\..
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# install old sbsign
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Verification will pass with old sbsign, but it is wrong.
# Generate new key on bionic
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
cp 15.3-0ubuntu1~ppa1/shimaa64.efi old-sbsign.efi
cp 15.3-0ubuntu1~ppa1/shimaa64.efi new-sbsign.efi
# self-sign the binary using the old sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem old-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach old-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in old-sbsign-signature.p7c -print | grep -A5 messageDi
# upgrade to new sbsign
# check that verifcation now fails
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
should now fail.
# self-sign with new sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem new-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach new-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in new-sbsign-signature.p7c -print | grep -A5 messageDi
# Also detach the launchpad signature and print digest
sbattach --detach lp-sbsign-signature.p7c 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
openssl pkcs7 -inform der -in lp-sbsign-signature.p7c -print | grep -A5 messageDi
The correct digest is, which should be in the new-sbsign-signature.p7c:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 6a 83 1f 9e cb 7a 68 7f-17 c0 9d 81 c0 j....zh......
000d - 6b 17 b2 c3 1c d7 ed b5-b3 89 49 a3 c1 k.........I..
001a - 8d 75 59 d3 b3 11 .uY...
The wrong digest is, which is in lp & old sbsign signatures:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 2a c3 bb e6 20 27 6b b2-58 f8 8d 50 eb *... 'k.X..P.
000d - 1e 88 68 a3 12 08 7a 1d-27 e5 42 e6 0e ..h...z.'.B..
001a - e4 24 9a 5c 0a 92 .$.\..
* Additionally to that, check that existing bionic x64 binaries still verify correctly. I.e. grub / kernel.
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 16:31:00 |
Łukasz Zemczak |
sbsigntool (Ubuntu Bionic): status |
New |
Fix Committed |
|
| 2021-03-25 16:31:02 |
Łukasz Zemczak |
bug |
|
|
added subscriber Ubuntu Stable Release Updates Team |
| 2021-03-25 16:31:05 |
Łukasz Zemczak |
bug |
|
|
added subscriber SRU Verification |
| 2021-03-25 16:31:10 |
Łukasz Zemczak |
tags |
|
verification-needed verification-needed-bionic |
|
| 2021-03-25 16:55:02 |
Dimitri John Ledkov |
description |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# install old sbsign
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Verification will pass with old sbsign, but it is wrong.
# Generate new key on bionic
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
cp 15.3-0ubuntu1~ppa1/shimaa64.efi old-sbsign.efi
cp 15.3-0ubuntu1~ppa1/shimaa64.efi new-sbsign.efi
# self-sign the binary using the old sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem old-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach old-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in old-sbsign-signature.p7c -print | grep -A5 messageDi
# upgrade to new sbsign
# check that verifcation now fails
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
should now fail.
# self-sign with new sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem new-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach new-sbsign-signature.p7c old-sbsign.efi
openssl pkcs7 -inform der -in new-sbsign-signature.p7c -print | grep -A5 messageDi
# Also detach the launchpad signature and print digest
sbattach --detach lp-sbsign-signature.p7c 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
openssl pkcs7 -inform der -in lp-sbsign-signature.p7c -print | grep -A5 messageDi
The correct digest is, which should be in the new-sbsign-signature.p7c:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 6a 83 1f 9e cb 7a 68 7f-17 c0 9d 81 c0 j....zh......
000d - 6b 17 b2 c3 1c d7 ed b5-b3 89 49 a3 c1 k.........I..
001a - 8d 75 59 d3 b3 11 .uY...
The wrong digest is, which is in lp & old sbsign signatures:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 2a c3 bb e6 20 27 6b b2-58 f8 8d 50 eb *... 'k.X..P.
000d - 1e 88 68 a3 12 08 7a 1d-27 e5 42 e6 0e ..h...z.'.B..
001a - e4 24 9a 5c 0a 92 .$.\..
* Additionally to that, check that existing bionic x64 binaries still verify correctly. I.e. grub / kernel.
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
[Impact]
* Calculating the hash of the binary is ill defined if there are gaps in sections, or sections are not aligned to ensure that signature table is aligned.
* This results in sbsign/sbverify to calculate incorrect hash when there are gaps, such as in shimaa64.efi as built on focal with sbat.
* This was fixed in eoan, but launchpad signing service uses sbsign from bionic.
* Thus if binaries have gaps launchpad is producing signatures that are covering the wrong authenticode hash.
[Test Plan]
* Signatures produced by sbsign in bionic, must be able to verify with sbverify from focal or later.
* Old signatures generated by launchpad should fail validation
* Enrolling certificate into db and booting secureboot arm VM must work
ie.
# install old sbsign
# Test old launchpad generated signature, ensure that it fails:
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Verification will pass with old sbsign, but it is wrong.
# Generate new key on bionic
update-secureboot-policy --new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
cp 15.3-0ubuntu1~ppa1/shimaa64.efi old-sbsign.efi
cp 15.3-0ubuntu1~ppa1/shimaa64.efi new-sbsign.efi
# self-sign the binary using the old sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem old-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach old-sbsign-signature.p7c old-sbsign.efi.signed
openssl pkcs7 -inform der -in old-sbsign-signature.p7c -print | grep -A5 messageDi
# upgrade to new sbsign
# check that verifcation now fails
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
should now fail.
# self-sign with new sbsign
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem new-sbsign.efi
# Detach the signature and print the message digest
sbattach --detach new-sbsign-signature.p7c new-sbsign.efi.signed
openssl pkcs7 -inform der -in new-sbsign-signature.p7c -print | grep -A5 messageDi
# Also detach the launchpad signature and print digest
sbattach --detach lp-sbsign-signature.p7c 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
openssl pkcs7 -inform der -in lp-sbsign-signature.p7c -print | grep -A5 messageDi
The correct digest is, which should be in the new-sbsign-signature.p7c:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 6a 83 1f 9e cb 7a 68 7f-17 c0 9d 81 c0 j....zh......
000d - 6b 17 b2 c3 1c d7 ed b5-b3 89 49 a3 c1 k.........I..
001a - 8d 75 59 d3 b3 11 .uY...
The wrong digest is, which is in lp & old sbsign signatures:
object: messageDigest (1.2.840.113549.1.9.4)
set:
OCTET STRING:
0000 - 2a c3 bb e6 20 27 6b b2-58 f8 8d 50 eb *... 'k.X..P.
000d - 1e 88 68 a3 12 08 7a 1d-27 e5 42 e6 0e ..h...z.'.B..
001a - e4 24 9a 5c 0a 92 .$.\..
* Additionally to that, check that existing bionic x64 binaries still verify correctly. I.e. grub / kernel.
[Where problems could occur]
* Existing edk2 OVMF machines in bionic possibly are calculating checksums unpadded, and thus this change will make the new signatures fail to validate in edk2 OVMF. However, the binaries on amd64 do not have gaps and thus have always had correct signatures. arm64 binaries with gaps do not exist in bionic.
[Other Info]
Original bug report:
launchpad signed shimaa64.efi fails to validate on focal
cd $(mktemp -d)
wget http://ppa.launchpad.net/xnox/nonvirt/ubuntu/dists/hirsute/main/signed/shim-arm64/15.3-0ubuntu1~ppa1/signed.tar.gz
tar xvf ./signed.tar.gz
sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification failed
And yet inside bionic-amd64 chroot I get:
# sbverify --cert 15.3-0ubuntu1~ppa1/control/uefi.crt 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
warning: gap in section table:
.data : 0x0007f000 - 0x000b3800,
.sbat : 0x000b4000 - 0x000b5000,
gaps in the section table may result in different checksums
warning: data remaining[740864 vs 800872]: gaps between PE/COFF sections?
Signature verification OK
However,
If in xenial-amd64 I perform
update-secureboot-policy new-key
openssl x509 -inform der -outform pem -in /var/lib/shim-signed/mok/MOK.der -out /var/lib/shim-signed/mok/MOK.pem
sbsign --key /var/lib/shim-signed/mok/MOK.priv --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi
sbverify --cert /var/lib/shim-signed/mok/MOK.pem 15.3-0ubuntu1~ppa1/shimaa64.efi.signed
Signature verification OK
Looks like something is dodgy in sbverify in bionic; i.e. it calculates / signs / verifies wrong hash. |
|
| 2021-03-25 17:05:14 |
Dimitri John Ledkov |
tags |
verification-needed verification-needed-bionic |
verification-done verification-done-bionic |
|
| 2021-03-29 10:02:49 |
Colin Watson |
affects |
launchpad |
lp-signing |
|
| 2021-04-06 22:44:19 |
Launchpad Janitor |
sbsigntool (Ubuntu Bionic): status |
Fix Committed |
Fix Released |
|
| 2021-04-06 22:44:24 |
Brian Murray |
removed subscriber Ubuntu Stable Release Updates Team |
|
|
|
