From: Roberto Sassu roberto.sassu@huawei.com
euleros inclusion category: feature bugzilla: https://gitee.com/openeuler/kernel/issues/I7QZ2M CVE: NA
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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: Tianxing Zhang zhangtianxing3@huawei.com Reviewed-by: Jason Yan yanaijie@huawei.com Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com Signed-off-by: zhoushuiqing zhoushuiqing2@huawei.com --- include/linux/mpi.h | 4 ++++ lib/mpi/mpicoder.c | 37 +++++++++++++++++++++++++++++++++++++ 2 files changed, 41 insertions(+)
diff --git a/include/linux/mpi.h b/include/linux/mpi.h index eb0d1c1db..68c3a21c8 100644 --- a/include/linux/mpi.h +++ b/include/linux/mpi.h @@ -90,6 +90,10 @@ enum gcry_mpi_format { };
MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes); +#ifdef CONFIG_IMA_DIGEST_LIST +int mpi_key_length(const void *xbuffer, unsigned int ret_nread, + unsigned int *nbits_arg, unsigned int *nbytes_arg); +#endif 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/mpi/mpicoder.c b/lib/mpi/mpicoder.c index 3cb6bd148..ec52d8d0c 100644 --- a/lib/mpi/mpicoder.c +++ b/lib/mpi/mpicoder.c @@ -79,6 +79,42 @@ MPI mpi_read_raw_data(const void *xbuffer, size_t nbytes) } EXPORT_SYMBOL_GPL(mpi_read_raw_data);
+#ifdef CONFIG_IMA_DIGEST_LIST +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; + + 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 -EINVAL; + } + + 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 *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); +#else MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) { const uint8_t *buffer = xbuffer; @@ -95,6 +131,7 @@ MPI mpi_read_from_buffer(const void *xbuffer, unsigned *ret_nread) }
nbytes = DIV_ROUND_UP(nbits, 8); +#endif if (nbytes + 2 > *ret_nread) { pr_info("MPI: mpi larger than buffer nbytes=%u ret_nread=%u\n", nbytes, *ret_nread);