The following commit has been merged into the x86/sgx branch of tip: Commit-ID: 5f0ce664d8c6c160ce4333e809545a8a57fe2baf Gitweb: https://git.kernel.org/tip/5f0ce664d8c6c160ce4333e809545a8a57fe2baf Author: Jarkko Sakkinen <jarkko@xxxxxxxxxx> AuthorDate: Mon, 15 Nov 2021 10:35:16 -08:00 Committer: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> CommitterDate: Mon, 15 Nov 2021 11:34:01 -08:00 selftests/sgx: Make data measurement for an enclave segment optional 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@xxxxxxxxxx> Signed-off-by: Reinette Chatre <reinette.chatre@xxxxxxxxx> Signed-off-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Acked-by: Dave Hansen <dave.hansen@xxxxxxxxxxxxxxx> Link: https://lkml.kernel.org/r/625b6fe28fed76275e9238ec4e15ec3c0d87de81.1636997631.git.reinette.chatre@xxxxxxxxx --- 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(-) diff --git a/tools/testing/selftests/sgx/load.c b/tools/testing/selftests/sgx/load.c index 5605474..f1be789 100644 --- a/tools/testing/selftests/sgx/load.c +++ b/tools/testing/selftests/sgx/load.c @@ -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++; } diff --git a/tools/testing/selftests/sgx/main.h b/tools/testing/selftests/sgx/main.h index 452d11d..aebc69e 100644 --- a/tools/testing/selftests/sgx/main.h +++ b/tools/testing/selftests/sgx/main.h @@ -12,6 +12,7 @@ struct encl_segment { size_t size; unsigned int prot; unsigned int flags; + bool measure; }; struct encl { diff --git a/tools/testing/selftests/sgx/sigstruct.c b/tools/testing/selftests/sgx/sigstruct.c index 202a96f..50c5ab1 100644 --- a/tools/testing/selftests/sgx/sigstruct.c +++ b/tools/testing/selftests/sgx/sigstruct.c @@ -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;
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