Extract the necessary functions from sha256 into a PBL headder and add a
verification function to the PBL. The function will be called before the
individual architectures decompress functions is run.
Signed-off-by: Rouven Czerwinski <r.czerwinski@xxxxxxxxxxxxxx>
---
crypto/Makefile | 2 ++
crypto/sha2.c | 11 +++++++----
include/crypto/pbl-sha.h | 13 +++++++++++++
include/pbl.h | 2 ++
pbl/Kconfig | 9 +++++++++
pbl/decomp.c | 39 +++++++++++++++++++++++++++++++++++++++
6 files changed, 72 insertions(+), 4 deletions(-)
create mode 100644 include/crypto/pbl-sha.h
diff --git a/crypto/Makefile b/crypto/Makefile
index 3402f57..d6fb74a 100644
--- a/crypto/Makefile
+++ b/crypto/Makefile
@@ -8,6 +8,8 @@ obj-$(CONFIG_DIGEST_MD5_GENERIC) += md5.o
obj-$(CONFIG_DIGEST_SHA1_GENERIC) += sha1.o
obj-$(CONFIG_DIGEST_SHA224_GENERIC) += sha2.o
obj-$(CONFIG_DIGEST_SHA256_GENERIC) += sha2.o
+pbl-$(CONFIG_PBL_VERIFY_PIGGY) += sha2.o
+pbl-$(CONFIG_PBL_VERIFY_PIGGY) += digest.o
obj-$(CONFIG_DIGEST_SHA384_GENERIC) += sha4.o
obj-$(CONFIG_DIGEST_SHA512_GENERIC) += sha4.o
diff --git a/crypto/sha2.c b/crypto/sha2.c
index c62ddb8..3947a09 100644
--- a/crypto/sha2.c
+++ b/crypto/sha2.c
@@ -27,6 +27,7 @@
#include <crypto/sha.h>
#include <crypto/internal.h>
+#include <crypto/pbl-sha.h>
static inline u32 Ch(u32 x, u32 y, u32 z)
{
@@ -232,7 +233,7 @@ static int sha224_init(struct digest *desc)
return 0;
}
-static int sha256_init(struct digest *desc)
+int sha256_init(struct digest *desc)
{
struct sha256_state *sctx = digest_ctx(desc);
sctx->state[0] = SHA256_H0;
@@ -248,7 +249,7 @@ static int sha256_init(struct digest *desc)
return 0;
}
-static int sha256_update(struct digest *desc, const void *data,
+int sha256_update(struct digest *desc, const void *data,
unsigned long len)
{
struct sha256_state *sctx = digest_ctx(desc);
@@ -280,7 +281,7 @@ static int sha256_update(struct digest *desc, const void *data,
return 0;
}
-static int sha256_final(struct digest *desc, u8 *out)
+int sha256_final(struct digest *desc, u8 *out)
{
struct sha256_state *sctx = digest_ctx(desc);
__be32 *dst = (__be32 *)out;
@@ -348,7 +349,7 @@ static int sha224_digest_register(void)
}
device_initcall(sha224_digest_register);
-static struct digest_algo m256 = {
+struct digest_algo m256 = {
.base = {
.name = "sha256",
.driver_name = "sha256-generic",
@@ -365,6 +366,7 @@ static struct digest_algo m256 = {
.ctx_length = sizeof(struct sha256_state),
};
+#ifndef __PBL__
static int sha256_digest_register(void)
{
if (!IS_ENABLED(CONFIG_SHA256))
@@ -373,3 +375,4 @@ static int sha256_digest_register(void)
return digest_algo_register(&m256);
}
coredevice_initcall(sha256_digest_register);
+#endif /* __PBL__ */
diff --git a/include/crypto/pbl-sha.h b/include/crypto/pbl-sha.h
new file mode 100644
index 0000000..7d323ab
--- /dev/null
+++ b/include/crypto/pbl-sha.h
@@ -0,0 +1,13 @@
+/* SPDX-License-Identifier: GPL-2.0 */
+#ifndef __PBL_SHA_H_
+
+#define __PBL_SHA_H_
+
+#include <digest.h>
+#include <types.h>
+
+int sha256_init(struct digest *desc);
+int sha256_update(struct digest *desc, const void *data, unsigned long len);
+int sha256_final(struct digest *desc, u8 *out);
+
+#endif /* __PBL-SHA_H_ */
diff --git a/include/pbl.h b/include/pbl.h
index 787bd82..1917a76 100644
--- a/include/pbl.h
+++ b/include/pbl.h
@@ -11,6 +11,8 @@ extern unsigned long free_mem_ptr;
extern unsigned long free_mem_end_ptr;
void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len);
+int pbl_barebox_verify(void *compressed_start, unsigned int len, void *hash,
+ unsigned int hash_len);
#ifdef __PBL__
#define IN_PBL 1
diff --git a/pbl/Kconfig b/pbl/Kconfig
index f2250dd..5e7ee06 100644
--- a/pbl/Kconfig
+++ b/pbl/Kconfig
@@ -44,6 +44,15 @@ config PBL_RELOCATABLE
This option only inflluences the PBL image. See RELOCATABLE to also make
the real image relocatable.
+config PBL_VERIFY_PIGGY
+ depends on ARM
+ bool
+ help
+ Use a PBL builtin sha256sum to verify the piggydata before decompression.
+ WARNING: your board will not boot if a mismatch is detected, enable DEBUG_LL
+ to see the builtin and calculated hash.
+ This effectively locks a given PBL to the matching main barebox.
+
config IMAGE_COMPRESSION
bool
depends on HAVE_IMAGE_COMPRESSION
diff --git a/pbl/decomp.c b/pbl/decomp.c
index 72a1623..ef713a6 100644
--- a/pbl/decomp.c
+++ b/pbl/decomp.c
@@ -6,6 +6,10 @@
*/
#include <common.h>
+#include <crypto/sha.h>
+#include <crypto/pbl-sha.h>
+#include <digest.h>
+#include <asm/sections.h>
#include <pbl.h>
#include <debug_ll.h>
@@ -54,3 +58,38 @@ void pbl_barebox_uncompress(void *dest, void *compressed_start, unsigned int len
NULL, NULL,
dest, NULL, errorfn);
}
+
+int pbl_barebox_verify(void *compressed_start, unsigned int len, void *hash,
+ unsigned int hash_len)
+{
+ struct sha256_state sha_state = { 0 };
+ struct digest d = { .ctx = &sha_state };
+ char computed_hash[SHA256_DIGEST_SIZE];
+ int i;
+ char *char_hash = hash;
+
+ if (hash_len != SHA256_DIGEST_SIZE)
+ return -1;
+
+ sha256_init(&d);
+ sha256_update(&d, compressed_start, len);
+ sha256_final(&d, computed_hash);
+ if (IS_ENABLED(CONFIG_DEBUG_LL)) {
+ putc_ll('C');
+ putc_ll('H');
+ putc_ll('\n');
+ for (i = 0; i < SHA256_DIGEST_SIZE; i++) {
+ puthex_ll(computed_hash[i]);
+ putc_ll('\n');
+ }
+ putc_ll('I');
+ putc_ll('H');
+ putc_ll('\n');
+ for (i = 0; i < SHA256_DIGEST_SIZE; i++) {
+ puthex_ll(char_hash[i]);
+ putc_ll('\n');
+ }
+ }
+
+ return memcmp(hash, computed_hash, SHA256_DIGEST_SIZE);
+}
--
git-series 0.9.1
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