| Message ID | 20240911122911.1381864-2-roberto.sassu@huaweicloud.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | KEYS: Add support for PGP keys and signatures | expand |
On Wed Sep 11, 2024 at 3:28 PM EEST, Roberto Sassu wrote: > From: Roberto Sassu <roberto.sassu@huawei.com> > > Introduce the new function to get the number of bits and bytes from an MPI. > > Signed-off-by: Roberto Sassu <roberto.sassu@huawei.com> > Signed-off-by: David Howells <dhowells@redhat.com> > --- > include/linux/mpi.h | 2 ++ > lib/crypto/mpi/mpicoder.c | 33 ++++++++++++++++++++++++++------- > 2 files changed, 28 insertions(+), 7 deletions(-) > > diff --git a/include/linux/mpi.h b/include/linux/mpi.h > index eb0d1c1db208..a7dd4c9d8120 100644 > --- a/include/linux/mpi.h > +++ b/include/linux/mpi.h > @@ -90,6 +90,8 @@ enum gcry_mpi_format { > }; > > MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); > +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, > + unsigned int *nbits_arg, unsigned int *nbytes_arg); "_arg" - what is the point of this? > MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); > int mpi_fromstr(MPI val, const char *str); > MPI mpi_scanval(const char *string); > diff --git a/lib/crypto/mpi/mpicoder.c b/lib/crypto/mpi/mpicoder.c > index 3cb6bd148fa9..92447a1c8bf9 100644 > --- a/lib/crypto/mpi/mpicoder.c > +++ b/lib/crypto/mpi/mpicoder.c > @@ -79,22 +79,41 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) > } > EXPORT_SYMBOL_GPL(mpi_read_raw_data); > > -MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) > +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, > + unsigned int *nbits_arg, unsigned int *nbytes_arg) > { > const uint8_t *buffer = xbuffer; > - unsigned int nbits, nbytes; > - MPI val; > + unsigned int nbits; > > - if (*ret_nread < 2) > - return ERR_PTR(-EINVAL); > + if (ret_nread < 2) > + return -EINVAL; > nbits = buffer[0] << 8 | buffer[1]; > > if (nbits > MAX_EXTERN_MPI_BITS) { > pr_info("MPI: mpi too large (%u bits)\n", nbits); > - return ERR_PTR(-EINVAL); > + return -EINVAL; > } > > - nbytes = DIV_ROUND_UP(nbits, 8); > + if (nbits_arg) > + *nbits_arg = nbits; > + if (nbytes_arg) > + *nbytes_arg = DIV_ROUND_UP(nbits, 8); > + > + return 0; > +} > +EXPORT_SYMBOL_GPL(mpi_key_length); > + > +MPI mpi_read_from_buffer(const void *xbuffer, unsigned int *ret_nread) > +{ > + const uint8_t *buffer = xbuffer; > + unsigned int nbytes; > + MPI val; > + int ret; > + > + ret = mpi_key_length(xbuffer, *ret_nread, NULL, &nbytes); > + if (ret < 0) > + return ERR_PTR(ret); > + > if (nbytes + 2 > *ret_nread) { > pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", > nbytes, *ret_nread); BR, Jarkko
diff --git a/include/linux/mpi.h b/include/linux/mpi.h index eb0d1c1db208..a7dd4c9d8120 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -90,6 +90,8 @@ enum gcry_mpi_format { }; MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, + unsigned int *nbits_arg, unsigned int *nbytes_arg); MPI mpi_read_from_buffer(const void *buffer, unsigned *ret_nread); int mpi_fromstr(MPI val, const char *str); MPI mpi_scanval(const char *string); diff --git a/lib/crypto/mpi/mpicoder.c b/lib/crypto/mpi/mpicoder.c index 3cb6bd148fa9..92447a1c8bf9 100644 --- a/lib/crypto/mpi/mpicoder.c +++ b/lib/crypto/mpi/mpicoder.c @@ -79,22 +79,41 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) } EXPORT_SYMBOL_GPL(mpi_read_raw_data); -MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, + unsigned int *nbits_arg, unsigned int *nbytes_arg) { const uint8_t *buffer = xbuffer; - unsigned int nbits, nbytes; - MPI val; + unsigned int nbits; - if (*ret_nread < 2) - return ERR_PTR(-EINVAL); + if (ret_nread < 2) + return -EINVAL; nbits = buffer[0] << 8 | buffer[1]; if (nbits > MAX_EXTERN_MPI_BITS) { pr_info("MPI: mpi too large (%u bits)\n", nbits); - return ERR_PTR(-EINVAL); + return -EINVAL; } - nbytes = DIV_ROUND_UP(nbits, 8); + if (nbits_arg) + *nbits_arg = nbits; + if (nbytes_arg) + *nbytes_arg = DIV_ROUND_UP(nbits, 8); + + return 0; +} +EXPORT_SYMBOL_GPL(mpi_key_length); + +MPI mpi_read_from_buffer(const void *xbuffer, unsigned int *ret_nread) +{ + const uint8_t *buffer = xbuffer; + unsigned int nbytes; + MPI val; + int ret; + + ret = mpi_key_length(xbuffer, *ret_nread, NULL, &nbytes); + if (ret < 0) + return ERR_PTR(ret); + if (nbytes + 2 > *ret_nread) { pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", nbytes, *ret_nread);