The SHA algorithms are necessary to measure configuration information into
the TPM as early as possible before using the values. This implementation
uses the established approach of #including the SHA libraries directly in
the code since the compressed kernel is not uncompressed at this point.
The SHA code here has its origins in the code from the main kernel. That
code could not be pulled directly into the setup portion of the compressed
kernel because of other dependencies it pulls in. The result is this is a
modified copy of that code that still leverages the core SHA algorithms.
Signed-off-by: Daniel P. Smith
Signed-off-by: Ross Philipson
---
arch/x86/boot/compressed/Makefile | 4 +
arch/x86/boot/compressed/early_sha1.c | 104
arch/x86/boot/compressed/early_sha1.h | 17 +++
arch/x86/boot/compressed/early_sha256.c | 6 +
arch/x86/boot/compressed/early_sha512.c | 6 +
include/linux/sha512.h | 21
lib/sha1.c | 4 +
lib/sha512.c| 209
8 files changed, 371 insertions(+)
create mode 100644 arch/x86/boot/compressed/early_sha1.c
create mode 100644 arch/x86/boot/compressed/early_sha1.h
create mode 100644 arch/x86/boot/compressed/early_sha256.c
create mode 100644 arch/x86/boot/compressed/early_sha512.c
create mode 100644 include/linux/sha512.h
create mode 100644 lib/sha512.c
diff --git a/arch/x86/boot/compressed/Makefile
b/arch/x86/boot/compressed/Makefile
index ff7894f..0fd84b9 100644
--- a/arch/x86/boot/compressed/Makefile
+++ b/arch/x86/boot/compressed/Makefile
@@ -96,6 +96,10 @@ vmlinux-objs-$(CONFIG_ACPI) += $(obj)/acpi.o
vmlinux-objs-$(CONFIG_EFI_MIXED) += $(obj)/efi_thunk_$(BITS).o
efi-obj-$(CONFIG_EFI_STUB) = $(objtree)/drivers/firmware/efi/libstub/lib.a
+vmlinux-objs-$(CONFIG_SECURE_LAUNCH) += $(obj)/early_sha1.o
+vmlinux-objs-$(CONFIG_SECURE_LAUNCH_SHA256) += $(obj)/early_sha256.o
+vmlinux-objs-$(CONFIG_SECURE_LAUNCH_SHA512) += $(obj)/early_sha512.o
+
# The compressed kernel is built with -fPIC/-fPIE so that a boot loader
# can place it anywhere in memory and it will still run. However, since
# it is executed as-is without any ELF relocation processing performed
diff --git a/arch/x86/boot/compressed/early_sha1.c
b/arch/x86/boot/compressed/early_sha1.c
new file mode 100644
index 000..198c46d
--- /dev/null
+++ b/arch/x86/boot/compressed/early_sha1.c
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates.
+ * Copyright (c) 2020 Apertus Solutions, LLC.
+ */
+
+#include
+#include
+#include
+#include
+#include
+
+#include "early_sha1.h"
+
+#define SHA1_DISABLE_EXPORT
+#include "../../../../lib/sha1.c"
+
+/* The SHA1 implementation in lib/sha1.c was written to get the workspace
+ * buffer as a parameter. This wrapper function provides a container
+ * around a temporary workspace that is cleared after the transform completes.
+ */
+static void __sha_transform(u32 *digest, const char *data)
+{
+ u32 ws[SHA1_WORKSPACE_WORDS];
+
+ sha1_transform(digest, data, ws);
+
+ memset(ws, 0, sizeof(ws));
+ /*
+* As this is cryptographic code, prevent the memset 0 from being
+* optimized out potentially leaving secrets in memory.
+*/
+ wmb();
+
+}
+
+void early_sha1_init(struct sha1_state *sctx)
+{
+ sha1_init(sctx->state);
+ sctx->count = 0;
+}
+
+void early_sha1_update(struct sha1_state *sctx,
+ const u8 *data,
+ unsigned int len)
+{
+ unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
+
+ sctx->count += len;
+
+ if (likely((partial + len) >= SHA1_BLOCK_SIZE)) {
+ int blocks;
+
+ if (partial) {
+ int p = SHA1_BLOCK_SIZE - partial;
+
+ memcpy(sctx->buffer + partial, data, p);
+ data += p;
+ len -= p;
+
+ __sha_transform(sctx->state, sctx->buffer);
+ }
+
+ blocks = len / SHA1_BLOCK_SIZE;
+ len %= SHA1_BLOCK_SIZE;
+
+ if (blocks) {
+ while (blocks--) {
+ __sha_transform(sctx->state, data);
+ data += SHA1_BLOCK_SIZE;
+ }
+ }
+ partial = 0;
+ }
+
+ if (len)
+ memcpy(sctx->buffer + partial, data, len);
+}
+
+void early_sha1_final(struct sha1_state *sctx, u8 *out)
+{
+ const int bit_offset = SHA1_BLOCK_SIZE - sizeof(__be64);
+ __be64 *bits = (__be64 *)(sctx->buffer + bit_offset);
+ __be32 *digest = (__be32 *)out;
+ unsigned int partial = sctx->count % SHA1_BLOCK_SIZE;
+ int i;
+
+ sctx->buffer[partial++] = 0x80;
+ if (partial > bit_offset) {
+ memset(sctx->buffer +
