[PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Tobias Hagelborn]

Move the signature file into place only after it is successfully signed.
This to avoid race and corrupted .sig files in cases multiple onging
builds write to a shared sstate-cache dir.

Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
---
 meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
index 613dab8561..868846cdc5 100644
--- a/meta/lib/oe/gpg_sign.py
+++ b/meta/lib/oe/gpg_sign.py
@@ -5,11 +5,12 @@
 #
 
 """Helper module for GPG signing"""
-import os
 
 import bb
-import subprocess
+import os
 import shlex
+import subprocess
+import tempfile
 
 class LocalSigner(object):
     """Class for handling local (on the build host) signing"""
@@ -73,8 +74,6 @@ class LocalSigner(object):
             cmd += ['--homedir', self.gpg_path]
         if armor:
             cmd += ['--armor']
-        if output_suffix:
-            cmd += ['-o', input_file + "." + output_suffix]
         if use_sha256:
             cmd += ['--digest-algo', "SHA256"]
 
@@ -83,19 +82,25 @@ class LocalSigner(object):
         if self.gpg_version > (2,1,):
             cmd += ['--pinentry-mode', 'loopback']
 
-        cmd += [input_file]
-
         try:
             if passphrase_file:
                 with open(passphrase_file) as fobj:
                     passphrase = fobj.readline();
 
-            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
-            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
+            output_file = input_file + "." + (output_suffix or 'sig')
+            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
+                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
+                cmd += ['-o', tmp_file]
+
+                cmd += [input_file]
+
+                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
 
-            if job.returncode:
-                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
+                if job.returncode:
+                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
 
+                os.rename(tmp_file, output_file)
         except IOError as e:
             bb.error("IO error (%s): %s" % (e.errno, e.strerror))
             raise Exception("Failed to sign '%s'" % input_file)
-- 
2.30.2

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Richard Purdie]

On Thu, 2023-03-23 at 11:08 +0100, Tobias Hagelborn wrote:
> Move the signature file into place only after it is successfully signed.
> This to avoid race and corrupted .sig files in cases multiple onging
> builds write to a shared sstate-cache dir.
> 
> Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
> ---
>  meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
>  1 file changed, 15 insertions(+), 10 deletions(-)
> 
> diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
> index 613dab8561..868846cdc5 100644
> --- a/meta/lib/oe/gpg_sign.py
> +++ b/meta/lib/oe/gpg_sign.py
> @@ -5,11 +5,12 @@
>  #
>  
>  """Helper module for GPG signing"""
> -import os
>  
>  import bb
> -import subprocess
> +import os
>  import shlex
> +import subprocess
> +import tempfile
>  
>  class LocalSigner(object):
>      """Class for handling local (on the build host) signing"""
> @@ -73,8 +74,6 @@ class LocalSigner(object):
>              cmd += ['--homedir', self.gpg_path]
>          if armor:
>              cmd += ['--armor']
> -        if output_suffix:
> -            cmd += ['-o', input_file + "." + output_suffix]
>          if use_sha256:
>              cmd += ['--digest-algo', "SHA256"]
>  
> @@ -83,19 +82,25 @@ class LocalSigner(object):
>          if self.gpg_version > (2,1,):
>              cmd += ['--pinentry-mode', 'loopback']
>  
> -        cmd += [input_file]
> -
>          try:
>              if passphrase_file:
>                  with open(passphrase_file) as fobj:
>                      passphrase = fobj.readline();
>  
> -            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> -            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> +            output_file = input_file + "." + (output_suffix or 'sig')

This doesn't match the behaviour of output_suffix as used above where
it defaults to None. This forces it to a default of "sig" instead?

If that intentional that should be in the commit message.


> +            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
> +                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
> +                cmd += ['-o', tmp_file]
> +
> +                cmd += [input_file]
> +
> +                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> +                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
>  
> -            if job.returncode:
> -                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> +                if job.returncode:
> +                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
>  
> +                os.rename(tmp_file, output_file)
>          except IOError as e:
>              bb.error("IO error (%s): %s" % (e.errno, e.strerror))
>              raise Exception("Failed to sign '%s'" % input_file)

Cheers,

Richard

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Richard Purdie]

On Wed, 2023-03-29 at 23:33 +0100, Richard Purdie via
lists.openembedded.org wrote:
> On Thu, 2023-03-23 at 11:08 +0100, Tobias Hagelborn wrote:
> > Move the signature file into place only after it is successfully signed.
> > This to avoid race and corrupted .sig files in cases multiple onging
> > builds write to a shared sstate-cache dir.
> > 
> > Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
> > ---
> >  meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
> >  1 file changed, 15 insertions(+), 10 deletions(-)
> > 
> > diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
> > index 613dab8561..868846cdc5 100644
> > --- a/meta/lib/oe/gpg_sign.py
> > +++ b/meta/lib/oe/gpg_sign.py
> > @@ -5,11 +5,12 @@
> >  #
> >  
> >  """Helper module for GPG signing"""
> > -import os
> >  
> >  import bb
> > -import subprocess
> > +import os
> >  import shlex
> > +import subprocess
> > +import tempfile
> >  
> >  class LocalSigner(object):
> >      """Class for handling local (on the build host) signing"""
> > @@ -73,8 +74,6 @@ class LocalSigner(object):
> >              cmd += ['--homedir', self.gpg_path]
> >          if armor:
> >              cmd += ['--armor']
> > -        if output_suffix:
> > -            cmd += ['-o', input_file + "." + output_suffix]
> >          if use_sha256:
> >              cmd += ['--digest-algo', "SHA256"]
> >  
> > @@ -83,19 +82,25 @@ class LocalSigner(object):
> >          if self.gpg_version > (2,1,):
> >              cmd += ['--pinentry-mode', 'loopback']
> >  
> > -        cmd += [input_file]
> > -
> >          try:
> >              if passphrase_file:
> >                  with open(passphrase_file) as fobj:
> >                      passphrase = fobj.readline();
> >  
> > -            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > -            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > +            output_file = input_file + "." + (output_suffix or 'sig')
> 
> This doesn't match the behaviour of output_suffix as used above where
> it defaults to None. This forces it to a default of "sig" instead?
> 
> If that intentional that should be in the commit message.
> 
> 
> > +            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
> > +                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
> > +                cmd += ['-o', tmp_file]
> > +
> > +                cmd += [input_file]
> > +
> > +                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > +                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> >  
> > -            if job.returncode:
> > -                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > +                if job.returncode:
> > +                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> >  
> > +                os.rename(tmp_file, output_file)
> >          except IOError as e:
> >              bb.error("IO error (%s): %s" % (e.errno, e.strerror))
> >              raise Exception("Failed to sign '%s'" % input_file)

I've been struggling to confirm it but have now done so. This does
cause an oe-selftest failure as here:

https://autobuilder.yoctoproject.org/typhoon/#/builders/80/builds/4950/steps/14/logs/stdio


i.e. from

oe-selftest -r runtime_test.TestImage.test_testimage_dnf

Cheers,

Richard

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Tobias Hagelborn]

[-- Attachment #1: Type: text/plain, Size: 4117 bytes --]

Thanks for the test feedback Richard!

I have not run the oe selftest properly on this one and will look in to the self-test results.
(We have not used the signed rpm part for instance)

Cheers
Tobias

________________________________
From: Richard Purdie <richard.purdie@linuxfoundation.org>
Sent: Thursday, March 30, 2023 11:10 AM
To: Tobias Hagelborn <Tobias.Hagelborn@axis.com>; openembedded-core@lists.openembedded.org <openembedded-core@lists.openembedded.org>
Subject: Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

On Wed, 2023-03-29 at 23:33 +0100, Richard Purdie via
lists.openembedded.org wrote:
> On Thu, 2023-03-23 at 11:08 +0100, Tobias Hagelborn wrote:
> > Move the signature file into place only after it is successfully signed.
> > This to avoid race and corrupted .sig files in cases multiple onging
> > builds write to a shared sstate-cache dir.
> >
> > Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
> > ---
> >  meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
> >  1 file changed, 15 insertions(+), 10 deletions(-)
> >
> > diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
> > index 613dab8561..868846cdc5 100644
> > --- a/meta/lib/oe/gpg_sign.py
> > +++ b/meta/lib/oe/gpg_sign.py
> > @@ -5,11 +5,12 @@
> >  #
> >
> >  """Helper module for GPG signing"""
> > -import os
> >
> >  import bb
> > -import subprocess
> > +import os
> >  import shlex
> > +import subprocess
> > +import tempfile
> >
> >  class LocalSigner(object):
> >      """Class for handling local (on the build host) signing"""
> > @@ -73,8 +74,6 @@ class LocalSigner(object):
> >              cmd += ['--homedir', self.gpg_path]
> >          if armor:
> >              cmd += ['--armor']
> > -        if output_suffix:
> > -            cmd += ['-o', input_file + "." + output_suffix]
> >          if use_sha256:
> >              cmd += ['--digest-algo', "SHA256"]
> >
> > @@ -83,19 +82,25 @@ class LocalSigner(object):
> >          if self.gpg_version > (2,1,):
> >              cmd += ['--pinentry-mode', 'loopback']
> >
> > -        cmd += [input_file]
> > -
> >          try:
> >              if passphrase_file:
> >                  with open(passphrase_file) as fobj:
> >                      passphrase = fobj.readline();
> >
> > -            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > -            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > +            output_file = input_file + "." + (output_suffix or 'sig')
>
> This doesn't match the behaviour of output_suffix as used above where
> it defaults to None. This forces it to a default of "sig" instead?
>
> If that intentional that should be in the commit message.
>
>
> > +            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
> > +                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
> > +                cmd += ['-o', tmp_file]
> > +
> > +                cmd += [input_file]
> > +
> > +                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > +                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> >
> > -            if job.returncode:
> > -                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > +                if job.returncode:
> > +                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> >
> > +                os.rename(tmp_file, output_file)
> >          except IOError as e:
> >              bb.error("IO error (%s): %s" % (e.errno, e.strerror))
> >              raise Exception("Failed to sign '%s'" % input_file)

I've been struggling to confirm it but have now done so. This does
cause an oe-selftest failure as here:

https://autobuilder.yoctoproject.org/typhoon/#/builders/80/builds/4950/steps/14/logs/stdio


i.e. from

oe-selftest -r runtime_test.TestImage.test_testimage_dnf

Cheers,

Richard



[-- Attachment #2: Type: text/html, Size: 8448 bytes --]

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Alexandre Belloni]

On 30/03/2023 10:10:21+0100, Richard Purdie wrote:
> On Wed, 2023-03-29 at 23:33 +0100, Richard Purdie via
> lists.openembedded.org wrote:
> > On Thu, 2023-03-23 at 11:08 +0100, Tobias Hagelborn wrote:
> > > Move the signature file into place only after it is successfully signed.
> > > This to avoid race and corrupted .sig files in cases multiple onging
> > > builds write to a shared sstate-cache dir.
> > > 
> > > Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
> > > ---
> > >  meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
> > >  1 file changed, 15 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
> > > index 613dab8561..868846cdc5 100644
> > > --- a/meta/lib/oe/gpg_sign.py
> > > +++ b/meta/lib/oe/gpg_sign.py
> > > @@ -5,11 +5,12 @@
> > >  #
> > >  
> > >  """Helper module for GPG signing"""
> > > -import os
> > >  
> > >  import bb
> > > -import subprocess
> > > +import os
> > >  import shlex
> > > +import subprocess
> > > +import tempfile
> > >  
> > >  class LocalSigner(object):
> > >      """Class for handling local (on the build host) signing"""
> > > @@ -73,8 +74,6 @@ class LocalSigner(object):
> > >              cmd += ['--homedir', self.gpg_path]
> > >          if armor:
> > >              cmd += ['--armor']
> > > -        if output_suffix:
> > > -            cmd += ['-o', input_file + "." + output_suffix]
> > >          if use_sha256:
> > >              cmd += ['--digest-algo', "SHA256"]
> > >  
> > > @@ -83,19 +82,25 @@ class LocalSigner(object):
> > >          if self.gpg_version > (2,1,):
> > >              cmd += ['--pinentry-mode', 'loopback']
> > >  
> > > -        cmd += [input_file]
> > > -
> > >          try:
> > >              if passphrase_file:
> > >                  with open(passphrase_file) as fobj:
> > >                      passphrase = fobj.readline();
> > >  
> > > -            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > > -            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > > +            output_file = input_file + "." + (output_suffix or 'sig')
> > 
> > This doesn't match the behaviour of output_suffix as used above where
> > it defaults to None. This forces it to a default of "sig" instead?
> > 
> > If that intentional that should be in the commit message.
> > 
> > 
> > > +            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
> > > +                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
> > > +                cmd += ['-o', tmp_file]
> > > +
> > > +                cmd += [input_file]
> > > +
> > > +                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > > +                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > >  
> > > -            if job.returncode:
> > > -                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > > +                if job.returncode:
> > > +                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > >  
> > > +                os.rename(tmp_file, output_file)
> > >          except IOError as e:
> > >              bb.error("IO error (%s): %s" % (e.errno, e.strerror))
> > >              raise Exception("Failed to sign '%s'" % input_file)
> 
> I've been struggling to confirm it but have now done so. This does
> cause an oe-selftest failure as here:
> 
> https://autobuilder.yoctoproject.org/typhoon/#/builders/80/builds/4950/steps/14/logs/stdio
> 
> 
> i.e. from
> 
> oe-selftest -r runtime_test.TestImage.test_testimage_dnf
> 

I realize just now that I forgot to send an email telling exactly that,
sorry!

> Cheers,
> 
> Richard
> 
> 

> 
> -=-=-=-=-=-=-=-=-=-=-=-
> Links: You receive all messages sent to this group.
> View/Reply Online (#179308): https://lists.openembedded.org/g/openembedded-core/message/179308
> Mute This Topic: https://lists.openembedded.org/mt/97797700/3617179
> Group Owner: openembedded-core+owner@lists.openembedded.org
> Unsubscribe: https://lists.openembedded.org/g/openembedded-core/unsub [alexandre.belloni@bootlin.com]
> -=-=-=-=-=-=-=-=-=-=-=-
> 


-- 
Alexandre Belloni, co-owner and COO, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Richard Purdie]

On Thu, 2023-03-30 at 10:10 +0100, Richard Purdie via
lists.openembedded.org wrote:
> On Wed, 2023-03-29 at 23:33 +0100, Richard Purdie via
> lists.openembedded.org wrote:
> > On Thu, 2023-03-23 at 11:08 +0100, Tobias Hagelborn wrote:
> > > Move the signature file into place only after it is successfully signed.
> > > This to avoid race and corrupted .sig files in cases multiple onging
> > > builds write to a shared sstate-cache dir.
> > > 
> > > Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
> > > ---
> > >  meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
> > >  1 file changed, 15 insertions(+), 10 deletions(-)
> > > 
> > > diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
> > > index 613dab8561..868846cdc5 100644
> > > --- a/meta/lib/oe/gpg_sign.py
> > > +++ b/meta/lib/oe/gpg_sign.py
> > > @@ -5,11 +5,12 @@
> > >  #
> > >  
> > >  """Helper module for GPG signing"""
> > > -import os
> > >  
> > >  import bb
> > > -import subprocess
> > > +import os
> > >  import shlex
> > > +import subprocess
> > > +import tempfile
> > >  
> > >  class LocalSigner(object):
> > >      """Class for handling local (on the build host) signing"""
> > > @@ -73,8 +74,6 @@ class LocalSigner(object):
> > >              cmd += ['--homedir', self.gpg_path]
> > >          if armor:
> > >              cmd += ['--armor']
> > > -        if output_suffix:
> > > -            cmd += ['-o', input_file + "." + output_suffix]
> > >          if use_sha256:
> > >              cmd += ['--digest-algo', "SHA256"]
> > >  
> > > @@ -83,19 +82,25 @@ class LocalSigner(object):
> > >          if self.gpg_version > (2,1,):
> > >              cmd += ['--pinentry-mode', 'loopback']
> > >  
> > > -        cmd += [input_file]
> > > -
> > >          try:
> > >              if passphrase_file:
> > >                  with open(passphrase_file) as fobj:
> > >                      passphrase = fobj.readline();
> > >  
> > > -            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > > -            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > > +            output_file = input_file + "." + (output_suffix or 'sig')
> > 
> > This doesn't match the behaviour of output_suffix as used above where
> > it defaults to None. This forces it to a default of "sig" instead?
> > 
> > If that intentional that should be in the commit message.
> > 
> > 
> > > +            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
> > > +                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
> > > +                cmd += ['-o', tmp_file]
> > > +
> > > +                cmd += [input_file]
> > > +
> > > +                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
> > > +                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
> > >  
> > > -            if job.returncode:
> > > -                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > > +                if job.returncode:
> > > +                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
> > >  
> > > +                os.rename(tmp_file, output_file)
> > >          except IOError as e:
> > >              bb.error("IO error (%s): %s" % (e.errno, e.strerror))
> > >              raise Exception("Failed to sign '%s'" % input_file)
> 
> I've been struggling to confirm it but have now done so. This does
> cause an oe-selftest failure as here:
> 
> https://autobuilder.yoctoproject.org/typhoon/#/builders/80/builds/4950/steps/14/logs/stdio
> 
> 
> i.e. from
> 
> oe-selftest -r runtime_test.TestImage.test_testimage_dnf

I should also mention, this test fails with oe-core's nodistro for
other reasons but does work ok with poky. I filed a bug for that:

https://bugzilla.yoctoproject.org/show_bug.cgi?id=15086

since it was confusing my debugging! You'd therefore need to use poky
for testing your change until we fix that.

Cheers,

Richard

Re: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign

[Tobias Hagelborn]

Some context to this:

We run a shared state-cache and dockerized builds on large servers. Running ~30 builds and ~200 parallel tasks using shared signed-sstate gives this type of error messages (stemming from corruption of the .sig files created):

ERROR: packagegroup-<PACKAGE>-1.0-r0 do_populate_lic: GPG exited with code 2: gpg: signing failed: Bad passphrase

The provided solution with renaming the files into final destination has proven to eliminate the issue.

Cheers
Tobias






From: openembedded-core@lists.openembedded.org <openembedded-core@lists.openembedded.org> on behalf of Tobias Hagelborn <Tobias.Hagelborn@axis.com>
Sent: Thursday, March 23, 2023 11:08 AM
To: openembedded-core@lists.openembedded.org <openembedded-core@lists.openembedded.org>
Subject: [OE-core] [PATCH] lib/oe/gpg_sign.py: Avoid race when creating .sig files in detach_sign 
 
Move the signature file into place only after it is successfully signed.
This to avoid race and corrupted .sig files in cases multiple onging
builds write to a shared sstate-cache dir.

Signed-off-by: Tobias Hagelborn <tobiasha@axis.com>
---
 meta/lib/oe/gpg_sign.py | 25 +++++++++++++++----------
 1 file changed, 15 insertions(+), 10 deletions(-)

diff --git a/meta/lib/oe/gpg_sign.py b/meta/lib/oe/gpg_sign.py
index 613dab8561..868846cdc5 100644
--- a/meta/lib/oe/gpg_sign.py
+++ b/meta/lib/oe/gpg_sign.py
@@ -5,11 +5,12 @@
 #
 
 """Helper module for GPG signing"""
-import os
 
 import bb
-import subprocess
+import os
 import shlex
+import subprocess
+import tempfile
 
 class LocalSigner(object):
     """Class for handling local (on the build host) signing"""
@@ -73,8 +74,6 @@ class LocalSigner(object):
             cmd += ['--homedir', self.gpg_path]
         if armor:
             cmd += ['--armor']
-        if output_suffix:
-            cmd += ['-o', input_file + "." + output_suffix]
         if use_sha256:
             cmd += ['--digest-algo', "SHA256"]
 
@@ -83,19 +82,25 @@ class LocalSigner(object):
         if self.gpg_version > (2,1,):
             cmd += ['--pinentry-mode', 'loopback']
 
-        cmd += [input_file]
-
         try:
             if passphrase_file:
                 with open(passphrase_file) as fobj:
                     passphrase = fobj.readline();
 
-            job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
-            (_, stderr) = job.communicate(passphrase.encode("utf-8"))
+            output_file = input_file + "." + (output_suffix or 'sig')
+            with tempfile.TemporaryDirectory(dir=os.path.dirname(output_file)) as tmp_dir:
+                tmp_file = os.path.join(tmp_dir, os.path.basename(output_file))
+                cmd += ['-o', tmp_file]
+
+                cmd += [input_file]
+
+                job = subprocess.Popen(cmd, stdin=subprocess.PIPE, stderr=subprocess.PIPE)
+                (_, stderr) = job.communicate(passphrase.encode("utf-8"))
 
-            if job.returncode:
-                bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
+                if job.returncode:
+                    bb.fatal("GPG exited with code %d: %s" % (job.returncode, stderr.decode("utf-8")))
 
+                os.rename(tmp_file, output_file)
         except IOError as e:
             bb.error("IO error (%s): %s" % (e.errno, e.strerror))
             raise Exception("Failed to sign '%s'" % input_file)
-- 
2.30.2