| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Purgatory code running between two kernels. |
| * |
| * Copyright IBM Corp. 2018 |
| * |
| * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> |
| */ |
| |
| #include <linux/kexec.h> |
| #include <linux/sha256.h> |
| #include <linux/string.h> |
| #include <asm/purgatory.h> |
| |
| int verify_sha256_digest(void) |
| { |
| struct kexec_sha_region *ptr, *end; |
| u8 digest[SHA256_DIGEST_SIZE]; |
| struct sha256_state sctx; |
| |
| sha256_init(&sctx); |
| end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); |
| |
| for (ptr = purgatory_sha_regions; ptr < end; ptr++) |
| sha256_update(&sctx, (uint8_t *)(ptr->start), ptr->len); |
| |
| sha256_final(&sctx, digest); |
| |
| if (memcmp(digest, purgatory_sha256_digest, sizeof(digest))) |
| return 1; |
| |
| return 0; |
| } |
