This patch introduced SNAPSHOT_SIG_HASH config for user to select which
hash algorithm will be used during signature generation of snapshot.
v2:
Add define check of oCONFIG_SNAPSHOT_VERIFICATION in snapshot.c before
declare pkey_hash().
Reviewed-by: Jiri Kosina <jkosina@xxxxxxx>
Signed-off-by: Lee, Chun-Yi <jlee@xxxxxxxx>
---
kernel/power/Kconfig | 46 ++++++++++++++++++++++++++++++++++++++++++++++
kernel/power/snapshot.c | 27 ++++++++++++++++++++++-----
2 files changed, 68 insertions(+), 5 deletions(-)
diff --git a/kernel/power/Kconfig b/kernel/power/Kconfig
index b592d88..79b34fa 100644
--- a/kernel/power/Kconfig
+++ b/kernel/power/Kconfig
@@ -78,6 +78,52 @@ config SNAPSHOT_VERIFICATION
dependent on UEFI environment. EFI bootloader should generate the
key-pair.
+choice
+ prompt "Which hash algorithm should snapshot be signed with?"
+ depends on SNAPSHOT_VERIFICATION
+ help
+ This determines which sort of hashing algorithm will be used during
+ signature generation of snapshot. This algorithm _must_ be built into
+ the kernel directly so that signature verification can take place.
+ It is not possible to load a signed snapshot containing the algorithm
+ to check the signature on that module.
+
+config SNAPSHOT_SIG_SHA1
+ bool "Sign modules with SHA-1"
+ select CRYPTO_SHA1
+ select CRYPTO_SHA1_SSSE3 if X86_64
+
+config SNAPSHOT_SIG_SHA224
+ bool "Sign modules with SHA-224"
+ select CRYPTO_SHA256
+ select CRYPTO_SHA256_SSSE3 if X86_64
+
+config SNAPSHOT_SIG_SHA256
+ bool "Sign modules with SHA-256"
+ select CRYPTO_SHA256
+ select CRYPTO_SHA256_SSSE3 if X86_64
+
+config SNAPSHOT_SIG_SHA384
+ bool "Sign modules with SHA-384"
+ select CRYPTO_SHA512
+ select CRYPTO_SHA512_SSSE3 if X86_64
+
+config SNAPSHOT_SIG_SHA512
+ bool "Sign modules with SHA-512"
+ select CRYPTO_SHA512
+ select CRYPTO_SHA512_SSSE3 if X86_64
+
+endchoice
+
+config SNAPSHOT_SIG_HASH
+ string
+ depends on SNAPSHOT_VERIFICATION
+ default "sha1" if SNAPSHOT_SIG_SHA1
+ default "sha224" if SNAPSHOT_SIG_SHA224
+ default "sha256" if SNAPSHOT_SIG_SHA256
+ default "sha384" if SNAPSHOT_SIG_SHA384
+ default "sha512" if SNAPSHOT_SIG_SHA512
+
config PM_STD_PARTITION
string "Default resume partition"
depends on HIBERNATION
diff --git a/kernel/power/snapshot.c b/kernel/power/snapshot.c
index b9c6a8a..f02e351 100644
--- a/kernel/power/snapshot.c
+++ b/kernel/power/snapshot.c
@@ -1042,12 +1042,29 @@ static inline void copy_data_page(unsigned long dst_pfn, unsigned long src_pfn)
}
#endif /* CONFIG_HIGHMEM */
-#define SNAPSHOT_HASH "sha256"
+#ifdef CONFIG_SNAPSHOT_VERIFICATION
+static const char *snapshot_hash = CONFIG_SNAPSHOT_SIG_HASH;
+
+static int pkey_hash(void)
+{
+ int i, ret;
+
+ ret = -1;
+ for (i = 0; i < PKEY_HASH__LAST; i++) {
+ if (!strcmp(pkey_hash_algo[i], snapshot_hash)) {
+ ret = i;
+ break;
+ }
+ }
+
+ return ret;
+}
/*
* Signature of snapshot for check.
*/
static u8 signature[SIG_LENG];
+#endif
static int
copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
@@ -1068,7 +1085,7 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
ret = -ENOMEM;
if (!capable(CAP_COMPROMISE_KERNEL)) {
- tfm = crypto_alloc_shash(SNAPSHOT_HASH, 0, 0);
+ tfm = crypto_alloc_shash(snapshot_hash, 0, 0);
if (IS_ERR(tfm)) {
pr_err("IS_ERR(tfm): %ld", PTR_ERR(tfm));
return PTR_ERR(tfm);
@@ -1145,7 +1162,7 @@ copy_data_pages(struct memory_bitmap *copy_bm, struct memory_bitmap *orig_bm)
goto error_key;
}
- pks = generate_signature(s4_sign_key, digest, PKEY_HASH_SHA256, false);
+ pks = generate_signature(s4_sign_key, digest, pkey_hash(), false);
if (IS_ERR(pks)) {
pr_err("Generate signature fail: %lx", PTR_ERR(pks));
ret = PTR_ERR(pks);
@@ -2499,7 +2516,7 @@ int snapshot_verify_signature(u8 *digest, size_t digest_size)
pr_err("PM: Allocate public key signature fail!");
return -ENOMEM;
}
- pks->pkey_hash_algo = PKEY_HASH_SHA256;
+ pks->pkey_hash_algo = pkey_hash();
pks->digest = digest;
pks->digest_size = digest_size;
@@ -2547,7 +2564,7 @@ int snapshot_image_verify(void)
if (!h_buf)
return 0;
- tfm = crypto_alloc_shash(SNAPSHOT_HASH, 0, 0);
+ tfm = crypto_alloc_shash(snapshot_hash, 0, 0);
if (IS_ERR(tfm)) {
pr_err("IS_ERR(tfm): %ld", PTR_ERR(tfm));
return PTR_ERR(tfm);
--
1.6.4.2
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