heads/patches/coreboot-4.8.1/0000-measuredboot.patch
Patrick Rudolph 28d3b7c89c
patches/coreboot-4.8.1: Measure firmware into PCR2 (#793)
As part of migration to coreboot 4.12, which includes measured boot
without additional patches, measure all parts of the firmware and the
payload into PCR2.

The same is done in coreboot 4.12. This commit ensures that boards not
migrated yet will show the same behaviour.

TODO: Update heads-wiki.

Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
2020-08-11 17:54:59 -04:00

477 lines
13 KiB
Diff

diff --git ./src/Kconfig ./src/Kconfig
index 99a704d..004b4a7 100644
--- ./src/Kconfig
+++ ./src/Kconfig
@@ -260,6 +260,21 @@ config BOOTSPLASH_FILE
The path and filename of the file to use as graphical bootsplash
screen. The file format has to be jpg.
+config MEASURED_BOOT
+ bool "Enable TPM measured boot"
+ default n
+ select TPM
+ depends on MAINBOARD_HAS_LPC_TPM
+ depends on !VBOOT
+ help
+ Enable this option to measure the bootblock, romstage and
+ CBFS files into TPM PCRs. This does not verify these values
+ (that is the job of something like vboot), but makes it possible
+ for the payload to validate the boot path and allow something
+ like Heads to attest to the user that the system is likely safe.
+
+ You probably want to say N.
+
endmenu
menu "Mainboard"
diff --git ./src/drivers/pc80/tpm/romstage.c ./src/drivers/pc80/tpm/romstage.c
index b8e4705..7732e66 100644
--- ./src/drivers/pc80/tpm/romstage.c
+++ ./src/drivers/pc80/tpm/romstage.c
@@ -48,6 +48,12 @@ static const struct {
static const struct {
u8 buffer[12];
+} tpm2_startup_cmd = {
+ {0x80, 0x01, 0x0, 0x0, 0x0, 0xc, 0x0, 0x0, 0x01, 0x44, 0x0, 0x0 }
+};
+
+static const struct {
+ u8 buffer[12];
} tpm_deactivate_cmd = {
{0x0, 0xc1, 0x0, 0x0, 0x0, 0xc, 0x0, 0x0, 0x0, 0x99, 0x0, 0x3 }
};
@@ -229,9 +235,15 @@ void init_tpm(int s3resume)
return;
}
} else {
- printk(BIOS_SPEW, "TPM: Startup\n");
- result = TlclSendReceive(tpm_startup_cmd.buffer,
- response, sizeof(response));
+ if (IS_ENABLED(CONFIG_TPM2)) {
+ printk(BIOS_SPEW, "TPM2: Startup\n");
+ result = TlclSendReceive(tpm2_startup_cmd.buffer,
+ response, sizeof(response));
+ } else {
+ printk(BIOS_SPEW, "TPM: Startup\n");
+ result = TlclSendReceive(tpm_startup_cmd.buffer,
+ response, sizeof(response));
+ }
}
tis_close();
diff --git ./src/drivers/pc80/tpm/tis.c ./src/drivers/pc80/tpm/tis.c
index 3549173..11fc027 100644
--- ./src/drivers/pc80/tpm/tis.c
+++ ./src/drivers/pc80/tpm/tis.c
@@ -125,10 +125,11 @@ static const struct device_name atmel_devices[] = {
static const struct device_name infineon_devices[] = {
{0x000b, "SLB9635 TT 1.2"},
- {0x001a, "SLB9660 TT 1.2"},
#if IS_ENABLED(CONFIG_TPM2)
+ {0x001a, "SLB9665 TT 2.0"},
{0x001b, "SLB9670 TT 2.0"},
#else
+ {0x001a, "SLB9660 TT 1.2"},
{0x001b, "SLB9670 TT 1.2"},
#endif
{0xffff}
diff --git ./src/include/program_loading.h ./src/include/program_loading.h
index 7aba302..879c26e 100644
--- ./src/include/program_loading.h
+++ ./src/include/program_loading.h
@@ -24,6 +24,8 @@ enum {
/* Last segment of program. Can be used to take different actions for
* cache maintenance of a program load. */
SEG_FINAL = 1 << 0,
+ /* Indicate that the program segment should not be measured */
+ SEG_NO_MEASURE = 1 << 1,
};
// The prog_type is a bit mask, so that in searches one can find, e.g.,
diff --git ./src/lib/cbfs.c ./src/lib/cbfs.c
index 87ab387..708d321 100644
--- ./src/lib/cbfs.c
+++ ./src/lib/cbfs.c
@@ -70,7 +70,13 @@ void *cbfs_boot_map_with_leak(const char *name, uint32_t type, size_t *size)
if (size != NULL)
*size = fsize;
- return rdev_mmap(&fh.data, 0, fsize);
+ void * buffer = rdev_mmap(&fh.data, 0, fsize);
+
+#ifndef __SMM__
+ prog_segment_loaded((uintptr_t)buffer, fsize, 0);
+#endif
+
+ return buffer;
}
int cbfs_locate_file_in_region(struct cbfsf *fh, const char *region_name,
@@ -98,7 +104,8 @@ size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
return 0;
if (rdev_readat(rdev, buffer, offset, in_size) != in_size)
return 0;
- return in_size;
+ out_size = in_size;
+ break;
case CBFS_COMPRESS_LZ4:
if ((ENV_BOOTBLOCK || ENV_VERSTAGE) &&
@@ -116,7 +123,7 @@ size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
timestamp_add_now(TS_START_ULZ4F);
out_size = ulz4fn(compr_start, in_size, buffer, buffer_size);
timestamp_add_now(TS_END_ULZ4F);
- return out_size;
+ break;
case CBFS_COMPRESS_LZMA:
if (ENV_BOOTBLOCK || ENV_VERSTAGE)
@@ -135,11 +142,15 @@ size_t cbfs_load_and_decompress(const struct region_device *rdev, size_t offset,
rdev_munmap(rdev, map);
- return out_size;
+ break;
default:
return 0;
}
+
+ prog_segment_loaded((uintptr_t)buffer, out_size, 0);
+
+ return out_size;
}
static inline int tohex4(unsigned int c)
diff --git ./src/lib/hardwaremain.c ./src/lib/hardwaremain.c
index 6fd55d7..b5b7d91 100644
--- ./src/lib/hardwaremain.c
+++ ./src/lib/hardwaremain.c
@@ -33,6 +33,7 @@
#include <reset.h>
#include <boot/tables.h>
#include <program_loading.h>
+#include <security/tpm/tss.h>
#include <lib.h>
#if IS_ENABLED(CONFIG_HAVE_ACPI_RESUME)
#include <arch/acpi.h>
@@ -545,3 +546,13 @@ void boot_state_current_unblock(void)
{
boot_state_unblock(current_phase.state_id, current_phase.seq);
}
+
+// ramstage measurements go into PCR3 if we are doing measured boot
+void platform_segment_loaded(uintptr_t start, size_t size, int flags)
+{
+ if (IS_ENABLED(CONFIG_MEASURED_BOOT) && !(flags & SEG_NO_MEASURE))
+ {
+ tlcl_measure(2, (const void*) start, size);
+ }
+}
+
diff --git ./src/lib/rmodule.c ./src/lib/rmodule.c
index 66d5120..b50afe7 100644
--- ./src/lib/rmodule.c
+++ ./src/lib/rmodule.c
@@ -198,7 +198,7 @@ int rmodule_load(void *base, struct rmodule *module)
rmodule_clear_bss(module);
prog_segment_loaded((uintptr_t)module->location,
- rmodule_memory_size(module), SEG_FINAL);
+ rmodule_memory_size(module), SEG_FINAL | SEG_NO_MEASURE);
return 0;
}
diff --git ./src/security/tpm/Makefile.inc ./src/security/tpm/Makefile.inc
index 2385635..0743a84 100644
--- ./src/security/tpm/Makefile.inc
+++ ./src/security/tpm/Makefile.inc
@@ -4,6 +4,15 @@ verstage-$(CONFIG_TPM) += tss/tcg-1.2/tss.c
verstage-$(CONFIG_TPM2) += tss/tcg-2.0/tss_marshaling.c
verstage-$(CONFIG_TPM2) += tss/tcg-2.0/tss.c
+ifeq ($(CONFIG_MEASURED_BOOT),y)
+ifneq ($(CONFIG_VBOOT_SEPARATE_VERSTAGE),y)
+romstage-$(CONFIG_TPM) += tss/tcg-1.2/tss.c
+endif
+romstage-$(CONFIG_TPM) += sha1.c
+ramstage-$(CONFIG_TPM) += tss/tcg-1.2/tss.c
+ramstage-$(CONFIG_TPM) += sha1.c
+endif # CONFIG_MEASURED_BOOT
+
ifeq ($(CONFIG_VBOOT_SEPARATE_VERSTAGE),y)
romstage-$(CONFIG_TPM) += tss/tcg-1.2/tss.c
romstage-$(CONFIG_TPM2) += tss/tcg-2.0/tss_marshaling.c
diff --git ./src/security/tpm/sha1.c ./src/security/tpm/sha1.c
new file mode 100644
index 0000000..6b154f8
--- /dev/null
+++ ./src/security/tpm/sha1.c
@@ -0,0 +1,175 @@
+/* Copyright (c) 2010 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ *
+ * SHA-1 implementation largely based on libmincrypt in the the Android
+ * Open Source Project (platorm/system/core.git/libmincrypt/sha.c
+ */
+
+#include <security/tpm/sha1.h>
+#include <string.h>
+
+static uint32_t ror27(uint32_t val)
+{
+ return (val >> 27) | (val << 5);
+}
+static uint32_t ror2(uint32_t val)
+{
+ return (val >> 2) | (val << 30);
+}
+static uint32_t ror31(uint32_t val)
+{
+ return (val >> 31) | (val << 1);
+}
+
+static void sha1_transform(struct sha1_ctx *ctx)
+{
+ uint32_t W[80];
+ register uint32_t A, B, C, D, E;
+ int t;
+
+ A = ctx->state[0];
+ B = ctx->state[1];
+ C = ctx->state[2];
+ D = ctx->state[3];
+ E = ctx->state[4];
+
+#define SHA_F1(A, B, C, D, E, t) \
+ E += ror27(A) + \
+ (W[t] = __builtin_bswap32(ctx->buf.w[t])) + \
+ (D^(B&(C^D))) + 0x5A827999; \
+ B = ror2(B);
+
+ for (t = 0; t < 15; t += 5) {
+ SHA_F1(A, B, C, D, E, t + 0);
+ SHA_F1(E, A, B, C, D, t + 1);
+ SHA_F1(D, E, A, B, C, t + 2);
+ SHA_F1(C, D, E, A, B, t + 3);
+ SHA_F1(B, C, D, E, A, t + 4);
+ }
+ SHA_F1(A, B, C, D, E, t + 0); /* 16th one, t == 15 */
+
+#undef SHA_F1
+
+#define SHA_F1(A, B, C, D, E, t) \
+ E += ror27(A) + \
+ (W[t] = ror31(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16])) + \
+ (D^(B&(C^D))) + 0x5A827999; \
+ B = ror2(B);
+
+ SHA_F1(E, A, B, C, D, t + 1);
+ SHA_F1(D, E, A, B, C, t + 2);
+ SHA_F1(C, D, E, A, B, t + 3);
+ SHA_F1(B, C, D, E, A, t + 4);
+
+#undef SHA_F1
+
+#define SHA_F2(A, B, C, D, E, t) \
+ E += ror27(A) + \
+ (W[t] = ror31(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16])) + \
+ (B^C^D) + 0x6ED9EBA1; \
+ B = ror2(B);
+
+ for (t = 20; t < 40; t += 5) {
+ SHA_F2(A, B, C, D, E, t + 0);
+ SHA_F2(E, A, B, C, D, t + 1);
+ SHA_F2(D, E, A, B, C, t + 2);
+ SHA_F2(C, D, E, A, B, t + 3);
+ SHA_F2(B, C, D, E, A, t + 4);
+ }
+
+#undef SHA_F2
+
+#define SHA_F3(A, B, C, D, E, t) \
+ E += ror27(A) + \
+ (W[t] = ror31(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16])) + \
+ ((B&C)|(D&(B|C))) + 0x8F1BBCDC; \
+ B = ror2(B);
+
+ for (; t < 60; t += 5) {
+ SHA_F3(A, B, C, D, E, t + 0);
+ SHA_F3(E, A, B, C, D, t + 1);
+ SHA_F3(D, E, A, B, C, t + 2);
+ SHA_F3(C, D, E, A, B, t + 3);
+ SHA_F3(B, C, D, E, A, t + 4);
+ }
+
+#undef SHA_F3
+
+#define SHA_F4(A, B, C, D, E, t) \
+ E += ror27(A) + \
+ (W[t] = ror31(W[t-3] ^ W[t-8] ^ W[t-14] ^ W[t-16])) + \
+ (B^C^D) + 0xCA62C1D6; \
+ B = ror2(B);
+
+ for (; t < 80; t += 5) {
+ SHA_F4(A, B, C, D, E, t + 0);
+ SHA_F4(E, A, B, C, D, t + 1);
+ SHA_F4(D, E, A, B, C, t + 2);
+ SHA_F4(C, D, E, A, B, t + 3);
+ SHA_F4(B, C, D, E, A, t + 4);
+ }
+
+#undef SHA_F4
+
+ ctx->state[0] += A;
+ ctx->state[1] += B;
+ ctx->state[2] += C;
+ ctx->state[3] += D;
+ ctx->state[4] += E;
+}
+
+void sha1_update(struct sha1_ctx *ctx, const uint8_t *data, uint32_t len)
+{
+ int i = ctx->count % sizeof(ctx->buf);
+ const uint8_t *p = (const uint8_t *)data;
+
+ ctx->count += len;
+
+ while (len > sizeof(ctx->buf) - i) {
+ memcpy(&ctx->buf.b[i], p, sizeof(ctx->buf) - i);
+ len -= sizeof(ctx->buf) - i;
+ p += sizeof(ctx->buf) - i;
+ sha1_transform(ctx);
+ i = 0;
+ }
+
+ while (len--) {
+ ctx->buf.b[i++] = *p++;
+ if (i == sizeof(ctx->buf)) {
+ sha1_transform(ctx);
+ i = 0;
+ }
+ }
+}
+
+
+uint8_t *sha1_final(struct sha1_ctx *ctx)
+{
+ uint32_t cnt = ctx->count * 8;
+ int i;
+
+ sha1_update(ctx, (uint8_t *)"\x80", 1);
+ while ((ctx->count % sizeof(ctx->buf)) != (sizeof(ctx->buf) - 8))
+ sha1_update(ctx, (uint8_t *)"\0", 1);
+
+ for (i = 0; i < 8; ++i) {
+ uint8_t tmp = cnt >> ((7 - i) * 8);
+ sha1_update(ctx, &tmp, 1);
+ }
+
+ for (i = 0; i < 5; i++)
+ ctx->buf.w[i] = __builtin_bswap32(ctx->state[i]);
+
+ return ctx->buf.b;
+}
+
+void sha1_init(struct sha1_ctx *ctx)
+{
+ ctx->state[0] = 0x67452301;
+ ctx->state[1] = 0xEFCDAB89;
+ ctx->state[2] = 0x98BADCFE;
+ ctx->state[3] = 0x10325476;
+ ctx->state[4] = 0xC3D2E1F0;
+ ctx->count = 0;
+}
diff --git ./src/security/tpm/sha1.h ./src/security/tpm/sha1.h
new file mode 100644
index 0000000..e7e28e6
--- /dev/null
+++ ./src/security/tpm/sha1.h
@@ -0,0 +1,31 @@
+/* Copyright (c) 2014 The Chromium OS Authors. All rights reserved.
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+/* SHA-1 functions */
+
+#ifndef _sha1_h_
+#define _sha1_h_
+
+#include <stdint.h>
+#include <commonlib/helpers.h>
+
+#define SHA1_DIGEST_SIZE 20
+#define SHA1_BLOCK_SIZE 64
+
+/* SHA-1 context */
+struct sha1_ctx {
+ uint32_t count;
+ uint32_t state[5];
+ union {
+ uint8_t b[SHA1_BLOCK_SIZE];
+ uint32_t w[DIV_ROUND_UP(SHA1_BLOCK_SIZE, sizeof(uint32_t))];
+ } buf;
+};
+
+void sha1_init(struct sha1_ctx *ctx);
+void sha1_update(struct sha1_ctx *ctx, const uint8_t *data, uint32_t len);
+uint8_t *sha1_final(struct sha1_ctx *ctx);
+
+#endif /* _sha1_h_ */
diff --git ./src/security/tpm/tss.h ./src/security/tpm/tss.h
index 8f3f1cb..5c569cb 100644
--- ./src/security/tpm/tss.h
+++ ./src/security/tpm/tss.h
@@ -147,6 +147,11 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
uint8_t *out_digest);
/**
+ * Perform a SHA1 hash on a region and extend a PCR with the hash.
+ */
+uint32_t tlcl_measure(int pcr_num, const void * start, size_t len);
+
+/**
* Get the entire set of permanent flags.
*/
uint32_t tlcl_get_permanent_flags(TPM_PERMANENT_FLAGS *pflags);
diff --git ./src/security/tpm/tss/tcg-1.2/tss.c ./src/security/tpm/tss/tcg-1.2/tss.c
index 161d29f..95e55b9 100644
--- ./src/security/tpm/tss/tcg-1.2/tss.c
+++ ./src/security/tpm/tss/tcg-1.2/tss.c
@@ -17,6 +17,7 @@
#include <arch/early_variables.h>
#include <assert.h>
#include <string.h>
+#include <security/tpm/sha1.h>
#include <security/tpm/tis.h>
#include <vb2_api.h>
#include <security/tpm/tss.h>
@@ -354,3 +355,23 @@ uint32_t tlcl_extend(int pcr_num, const uint8_t *in_digest,
kPcrDigestLength);
return result;
}
+
+
+uint32_t tlcl_measure(int pcr_num, const void * start, size_t len)
+{
+ VBDEBUG("TPM: pcr %d measure %p @ %zu: ", pcr_num, start, len);
+
+ struct sha1_ctx sha;
+ sha1_init(&sha);
+ sha1_update(&sha, start, len);
+
+ const uint8_t * hash = sha1_final(&sha);
+ for(unsigned i = 0 ; i < SHA1_DIGEST_SIZE ; i++)
+ VBDEBUG("%02x", hash[i]);
+ VBDEBUG("\n");
+
+ //hexdump(start, 128);
+
+ return tlcl_extend(pcr_num, hash, NULL);
+}
+