[PATCH v3] sign-file: Fix incorrect return values check

From: Yusong Gao <a869920004@gmail.com>
To: juergh@proton.me, jarkko@kernel.org
Cc: a869920004@gmail.com, davem@davemloft.net, dhowells@redhat.com,
	dimitri.ledkov@canonical.com, dwmw2@infradead.org,
	herbert@gondor.apana.org.au, keyrings@vger.kernel.org,
	linux-crypto@vger.kernel.org, linux-kernel@vger.kernel.org,
	lists@sapience.com, zohar@linux.ibm.com
Subject: [PATCH v3] sign-file: Fix incorrect return values check
Date: Mon, 27 Nov 2023 02:57:37 +0000	[thread overview]
Message-ID: <20231127025737.451718-1-a869920004@gmail.com> (raw)
In-Reply-To: <20231122082050.7eeea7bd@smeagol>

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On Wed, Nov 22, 2023 at 3:21 PM Juerg Haefliger <juergh@proton.me>
wrote:
>
> On Tue, 21 Nov 2023 03:40:44 +0000
> "Yusong Gao" <a869920004@gmail.com> wrote:
>
> > There are some wrong return values check in sign-file when call
> > OpenSSL
> > API. The ERR() check cond is wrong because of the program only check
> > the
> > return value is < 0 instead of <= 0. For example:
> > 1. CMS_final() return 1 for success or 0 for failure.
> > 2. i2d_CMS_bio_stream() returns 1 for success or 0 for failure.
> > 3. i2d_TYPEbio() return 1 for success and 0 for failure.
> > 4. BIO_free() return 1 for success and 0 for failure.
>
> Good catch! In this case I'd probably be more strict and check for '!=
> 1'.
> See below.
>
> ...Juerg
>
>
> > Link: https://www.openssl.org/docs/manmaster/man3/
> > Fixes: e5a2e3c84782 ("scripts/sign-file.c: Add support for signing
> > with a raw signature")
> >
> > Signed-off-by: Yusong Gao <a869920004@gmail.com>
> > ---
> > V1, V2: Clarify the description of git message.
> > ---
> >  scripts/sign-file.c | 12 ++++++------
> >  1 file changed, 6 insertions(+), 6 deletions(-)
> >
> > diff --git a/scripts/sign-file.c b/scripts/sign-file.c
> > index 598ef5465f82..dcebbcd6bebd 100644
> > --- a/scripts/sign-file.c
> > +++ b/scripts/sign-file.c
> > @@ -322,7 +322,7 @@ int main(int argc, char **argv)
> >                                    CMS_NOSMIMECAP | use_keyid |
> >                                    use_signed_attrs),
> >                   "CMS_add1_signer");
> > -             ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY)
> > < 0,
> > +             ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY)
> > <= 0,
>
> ERR(CMS_final(cms, bm, NULL, CMS_NOCERTS | CMS_BINARY) != 1,
>
>
> >                   "CMS_final");
> >
> >  #else
> > @@ -341,10 +341,10 @@ int main(int argc, char **argv)
> >                       b = BIO_new_file(sig_file_name, "wb");
> >                       ERR(!b, "%s", sig_file_name);
> >  #ifndef USE_PKCS7
> > -                     ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) < 0,
> > +                     ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) <= 0,
>
> ERR(i2d_CMS_bio_stream(b, cms, NULL, 0) != 1,
>
>
> >                           "%s", sig_file_name);
> >  #else
> > -                     ERR(i2d_PKCS7_bio(b, pkcs7) < 0,
> > +                     ERR(i2d_PKCS7_bio(b, pkcs7) <= 0,
>
> ERR(i2d_PKCS7_bio(b, pkcs7) != 1,
>
>
> >                           "%s", sig_file_name);
> >  #endif
> >                       BIO_free(b);
> > @@ -374,9 +374,9 @@ int main(int argc, char **argv)
> >
> >       if (!raw_sig) {
> >  #ifndef USE_PKCS7
> > -             ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) < 0, "%s",
> > dest_name);
> > +             ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) <= 0, "%s",
> > dest_name);
>
>
> ERR(i2d_CMS_bio_stream(bd, cms, NULL, 0) != 1, "%s", dest_name);
>
>
> >  #else
> > -             ERR(i2d_PKCS7_bio(bd, pkcs7) < 0, "%s", dest_name);
> > +             ERR(i2d_PKCS7_bio(bd, pkcs7) <= 0, "%s", dest_name);
>
> ERR(i2d_PKCS7_bio(bd, pkcs7) != 1, "%s", dest_name);
>
>
> >  #endif
> >       } else {
> >               BIO *b;
> > @@ -396,7 +396,7 @@ int main(int argc, char **argv)
> >       ERR(BIO_write(bd, &sig_info, sizeof(sig_info)) < 0, "%s",
> > dest_name);
> >       ERR(BIO_write(bd, magic_number, sizeof(magic_number) - 1) < 0,
> > "%s", dest_name);
> >
> > -     ERR(BIO_free(bd) < 0, "%s", dest_name);
> > +     ERR(BIO_free(bd) <= 0, "%s", dest_name);
>
> ERR(BIO_free(bd) != 1, "%s", dest_name);
>
>
> >
> >       /* Finally, if we're signing in place, replace the original.
> > */
> >       if (replace_orig)
> > --
> > 2.34.1
> >
>

Agreed. Will do.
Thanks for your review.

BR, Yusong Gao