| 1 | // SPDX-License-Identifier: GPL-2.0 |
|---|---|
| 2 | /* |
| 3 | * Purgatory code running between two kernels. |
| 4 | * |
| 5 | * Copyright IBM Corp. 2018 |
| 6 | * |
| 7 | * Author(s): Philipp Rudo <prudo@linux.vnet.ibm.com> |
| 8 | */ |
| 9 | |
| 10 | #include <linux/kexec.h> |
| 11 | #include <linux/string.h> |
| 12 | #include <crypto/sha2.h> |
| 13 | #include <asm/purgatory.h> |
| 14 | |
| 15 | int verify_sha256_digest(void) |
| 16 | { |
| 17 | struct kexec_sha_region *ptr, *end; |
| 18 | u8 digest[SHA256_DIGEST_SIZE]; |
| 19 | struct sha256_state sctx; |
| 20 | |
| 21 | sha256_init(sctx: &sctx); |
| 22 | end = purgatory_sha_regions + ARRAY_SIZE(purgatory_sha_regions); |
| 23 | |
| 24 | for (ptr = purgatory_sha_regions; ptr < end; ptr++) |
| 25 | sha256_update(sctx: &sctx, data: (uint8_t *)(ptr->start), len: ptr->len); |
| 26 | |
| 27 | sha256_final(sctx: &sctx, out: digest); |
| 28 | |
| 29 | if (memcmp(p: digest, q: purgatory_sha256_digest, size: sizeof(digest))) |
| 30 | return 1; |
| 31 | |
| 32 | return 0; |
| 33 | } |
| 34 |