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| author | Michael Brown <mcb30@ipxe.org> | 2024-03-27 14:28:47 +0000 |
|---|---|---|
| committer | Michael Brown <mcb30@ipxe.org> | 2024-03-27 14:28:47 +0000 |
| commit | 37850e0e854292d074c2d35d18d7bb78d8e6ff85 (patch) | |
| tree | 39b0581719832b892a925706be0af3cbf6768137 | |
| parent | 9bbe77669c6e2b71826449d854f5aa0e2cee7767 (diff) | |
| download | ipxe-37850e0e854292d074c2d35d18d7bb78d8e6ff85.tar.gz | |
[build] Fix build failures with random versions of gccgcmassert
For unknown reasons, miscellaneous versions of gcc seem to struggle
with the static assertions used to ensure the correct layout of the
GCM structures.
Adjust the assertions to use offsetof() rather than direct pointer
comparison, on the basis that offsetof() must be a compile-time
constant value.
Signed-off-by: Michael Brown <mcb30@ipxe.org>
| -rw-r--r-- | src/crypto/gcm.c | 26 | ||||
| -rw-r--r-- | src/include/ipxe/gcm.h | 7 |
2 files changed, 18 insertions, 15 deletions
diff --git a/src/crypto/gcm.c b/src/crypto/gcm.c index a32890d59..b93925d07 100644 --- a/src/crypto/gcm.c +++ b/src/crypto/gcm.c @@ -109,6 +109,9 @@ static union gcm_block gcm_cached_mult[256]; */ static uint16_t gcm_cached_reduce[256]; +/** Offset of a field within GCM context */ +#define gcm_offset( field ) offsetof ( struct gcm_context, field ) + /** * Reverse bits in a byte * @@ -470,17 +473,13 @@ int gcm_setkey ( struct gcm_context *context, const void *key, size_t keylen, */ void gcm_setiv ( struct gcm_context *context, const void *iv, size_t ivlen ) { - /* Sanity check: ensure that memset()s will clear expected state */ - build_assert ( &context->hash < &context->ctr ); - build_assert ( &context->len < &context->ctr ); - build_assert ( &context->ctr < &context->key ); - build_assert ( ( ( void * ) &context->raw_cipher ) > - ( ( void * ) &context->key ) ); - build_assert ( ( ( void * ) context->raw_ctx ) > - ( ( void * ) &context->key ) ); - /* Reset non-key state */ - memset ( context, 0, offsetof ( typeof ( *context ), key ) ); + memset ( context, 0, gcm_offset ( key ) ); + build_assert ( gcm_offset ( key ) > gcm_offset ( hash ) ); + build_assert ( gcm_offset ( key ) > gcm_offset ( len ) ); + build_assert ( gcm_offset ( key ) > gcm_offset ( ctr ) ); + build_assert ( gcm_offset ( key ) < gcm_offset ( raw_cipher ) ); + build_assert ( gcm_offset ( key ) < gcm_offset ( raw_ctx ) ); /* Reset counter */ context->ctr.ctr.value = cpu_to_be32 ( 1 ); @@ -499,7 +498,12 @@ void gcm_setiv ( struct gcm_context *context, const void *iv, size_t ivlen ) { assert ( context->len.len.add == 0 ); /* Reset non-key, non-counter state */ - memset ( context, 0, offsetof ( typeof ( *context ), ctr ) ); + memset ( context, 0, gcm_offset ( ctr ) ); + build_assert ( gcm_offset ( ctr ) > gcm_offset ( hash ) ); + build_assert ( gcm_offset ( ctr ) > gcm_offset ( len ) ); + build_assert ( gcm_offset ( ctr ) < gcm_offset ( key ) ); + build_assert ( gcm_offset ( ctr ) < gcm_offset ( raw_cipher ) ); + build_assert ( gcm_offset ( ctr ) < gcm_offset ( raw_ctx ) ); } DBGC2 ( context, "GCM %p Y[0]:\n", context ); diff --git a/src/include/ipxe/gcm.h b/src/include/ipxe/gcm.h index 4864445d2..2c785a977 100644 --- a/src/include/ipxe/gcm.h +++ b/src/include/ipxe/gcm.h @@ -89,10 +89,9 @@ static int _gcm_name ## _setkey ( void *ctx, const void *key, \ size_t keylen ) { \ struct _gcm_name ## _context *context = ctx; \ build_assert ( _blocksize == sizeof ( context->gcm.key ) ); \ - build_assert ( ( ( void * ) &context->gcm ) == \ - ( ( void * ) context ) ); \ - build_assert ( ( ( void * ) &context->raw ) == \ - ( ( void * ) context->gcm.raw_ctx ) ); \ + build_assert ( offsetof ( typeof ( *context ), gcm ) == 0 ); \ + build_assert ( offsetof ( typeof ( *context ), raw ) == \ + offsetof ( typeof ( *context ), gcm.raw_ctx ) ); \ return gcm_setkey ( &context->gcm, key, keylen, &_raw_cipher ); \ } \ static void _gcm_name ## _setiv ( void *ctx, const void *iv, \ |