@@ -111,7 +111,10 @@ static bool encl_ioc_add_pages(struct encl *encl, struct encl_segment *seg)
ioc.offset = seg->offset;
ioc.length = seg->size;
ioc.secinfo = (unsigned long)&secinfo;
- ioc.flags = SGX_PAGE_MEASURE;
+ if (seg->measure)
+ ioc.flags = SGX_PAGE_MEASURE;
+ else
+ ioc.flags = 0;
rc = ioctl(encl->fd, SGX_IOC_ENCLAVE_ADD_PAGES, &ioc);
if (rc < 0) {
@@ -230,6 +233,7 @@ bool encl_load(const char *path, struct encl *encl)
seg->offset = (phdr->p_offset & PAGE_MASK) - src_offset;
seg->size = (phdr->p_filesz + PAGE_SIZE - 1) & PAGE_MASK;
seg->src = encl->src + seg->offset;
+ seg->measure = true;
j++;
}
@@ -12,6 +12,7 @@ struct encl_segment {
size_t size;
unsigned int prot;
unsigned int flags;
+ bool measure;
};
struct encl {
@@ -296,8 +296,10 @@ static bool mrenclave_segment(EVP_MD_CTX *ctx, struct encl *encl,
if (!mrenclave_eadd(ctx, seg->offset + offset, seg->flags))
return false;
- if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
- return false;
+ if (seg->measure) {
+ if (!mrenclave_eextend(ctx, seg->offset + offset, seg->src + offset))
+ return false;
+ }
}
return true;
For a heap makes sense to leave its contents "unmeasured" in the SGX enclave build process, meaning that they won't contribute to the cryptographic signature (a RSA-3072 signed SHA56 hash) of the enclave. Enclaves are signed blobs where the signature is calculated both from page data and also from "structural properties" of the pages. For instance a page offset of *every* page added to the enclave is hashed. For data, this is optional, not least because hashing a page has a significant contribution to the enclave load time. Thus, where there is no reason to hash, do not. The SGX ioctl interface supports this with SGX_PAGE_MEASURE flag. Only when the flag is *set*, data is measured. Add seg->measure boolean flag to struct encl_segment. Only when the flag is set, include the segment data to the signature (represented by SIGSTRUCT architectural structure). Signed-off-by: Jarkko Sakkinen <jarkko@kernel.org> --- tools/testing/selftests/sgx/load.c | 6 +++++- tools/testing/selftests/sgx/main.h | 1 + tools/testing/selftests/sgx/sigstruct.c | 6 ++++-- 3 files changed, 10 insertions(+), 3 deletions(-)