tools, fit_check_sign: verify a signed fit image

add host tool "fit_check_sign" which verifies, if a fit image is
signed correct.
Signed-off-by: Heiko Schocher <hs@denx.de>
Cc: Simon Glass <sjg@chromium.org>

common/image-sig.c

@@ -19,9 +19,14 @@ DECLARE_GLOBAL_DATA_PTR;
 #define IMAGE_MAX_HASHED_NODES		100
 
 #ifdef USE_HOSTCC
-__attribute__((weak)) void *get_blob(void)
+void *host_blob;
+void image_set_host_blob(void *blob)
 {
-	return NULL;
+	host_blob = blob;
+}
+void *image_get_host_blob(void)
+{
+	return host_blob;
 }
 #endif
 
@@ -32,10 +37,9 @@ struct checksum_algo checksum_algos[] = {
 		RSA2048_BYTES,
 #if IMAGE_ENABLE_SIGN
 		EVP_sha1,
-#else
+#endif
 		sha1_calculate,
 		padding_sha1_rsa2048,
-#endif
 	},
 	{
 		"sha256",
@@ -43,10 +47,9 @@ struct checksum_algo checksum_algos[] = {
 		RSA2048_BYTES,
 #if IMAGE_ENABLE_SIGN
 		EVP_sha256,
-#else
+#endif
 		sha256_calculate,
 		padding_sha256_rsa2048,
-#endif
 	},
 	{
 		"sha256",
@@ -54,10 +57,9 @@ struct checksum_algo checksum_algos[] = {
 		RSA4096_BYTES,
 #if IMAGE_ENABLE_SIGN
 		EVP_sha256,
-#else
+#endif
 		sha256_calculate,
 		padding_sha256_rsa4096,
-#endif
 	}
 
 };

doc/uImage.FIT/signature.txt

@@ -357,6 +357,9 @@ Build FIT with signed configuration
 Test Verified Boot Run: unsigned config: OK
 Sign images
 Test Verified Boot Run: signed config: OK
+check signed config on the host
+OK
+Test Verified Boot Run: signed config: OK
 Test Verified Boot Run: signed config with bad hash: OK
 do sha256 test
 Build FIT with signed images
@@ -367,6 +370,9 @@ Build FIT with signed configuration
 Test Verified Boot Run: unsigned config: OK
 Sign images
 Test Verified Boot Run: signed config: OK
+check signed config on the host
+OK
+Test Verified Boot Run: signed config: OK
 Test Verified Boot Run: signed config with bad hash: OK
 
 Test passed

include/fdt_support.h

@@ -115,4 +115,9 @@ static inline int fdt_status_disabled_by_alias(void *fdt, const char* alias)
 }
 
 #endif /* ifdef CONFIG_OF_LIBFDT */
+
+#ifdef USE_HOSTCC
+int fdtdec_get_int(const void *blob, int node, const char *prop_name,
+		int default_val);
+#endif
 #endif /* ifndef __FDT_SUPPORT_H */

include/image.h

@@ -832,7 +832,7 @@ int calculate_hash(const void *data, int data_len, const char *algo,
 #if defined(CONFIG_FIT_SIGNATURE)
 # ifdef USE_HOSTCC
 #  define IMAGE_ENABLE_SIGN	1
-#  define IMAGE_ENABLE_VERIFY	0
+#  define IMAGE_ENABLE_VERIFY	1
 # include  <openssl/evp.h>
 #else
 #  define IMAGE_ENABLE_SIGN	0
@@ -844,7 +844,9 @@ int calculate_hash(const void *data, int data_len, const char *algo,
 #endif
 
 #ifdef USE_HOSTCC
-# define gd_fdt_blob()		NULL
+void *image_get_host_blob(void);
+void image_set_host_blob(void *host_blob);
+# define gd_fdt_blob()		image_get_host_blob()
 #else
 # define gd_fdt_blob()		(gd->fdt_blob)
 #endif
@@ -881,14 +883,11 @@ struct checksum_algo {
 	const int checksum_len;
 	const int pad_len;
 #if IMAGE_ENABLE_SIGN
-	const EVP_MD *(*calculate)(void);
-#else
-#if IMAGE_ENABLE_VERIFY
+	const EVP_MD *(*calculate_sign)(void);
+#endif
 	void (*calculate)(const struct image_region region[],
 			  int region_count, uint8_t *checksum);
 	const uint8_t *rsa_padding;
-#endif
-#endif
 };
 
 struct image_sig_algo {
@@ -1009,7 +1008,11 @@ struct image_region *fit_region_make_list(const void *fit,
 
 static inline int fit_image_check_target_arch(const void *fdt, int node)
 {
+#ifndef USE_HOSTCC
 	return fit_image_check_arch(fdt, node, IH_ARCH_DEFAULT);
+#else
+	return 0;
+#endif
 }
 
 #ifdef CONFIG_FIT_VERBOSE

lib/fdtdec.c

@@ -3,6 +3,7 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#ifndef USE_HOSTCC
 #include <common.h>
 #include <serial.h>
 #include <libfdt.h>
@@ -643,3 +644,22 @@ int fdtdec_read_fmap_entry(const void *blob, int node, const char *name,
 
 	return 0;
 }
+#else
+#include "libfdt.h"
+#include "fdt_support.h"
+
+int fdtdec_get_int(const void *blob, int node, const char *prop_name,
+		int default_val)
+{
+	const int *cell;
+	int len;
+
+	cell = fdt_getprop_w((void *)blob, node, prop_name, &len);
+	if (cell && len >= sizeof(int)) {
+		int val = fdt32_to_cpu(cell[0]);
+
+		return val;
+	}
+	return default_val;
+}
+#endif

lib/rsa/rsa-checksum.c

@@ -4,14 +4,18 @@
  * SPDX-License-Identifier:    GPL-2.0+
  */
 
+#ifndef USE_HOSTCC
 #include <common.h>
 #include <fdtdec.h>
-#include <rsa.h>
-#include <sha1.h>
-#include <sha256.h>
 #include <asm/byteorder.h>
 #include <asm/errno.h>
 #include <asm/unaligned.h>
+#else
+#include "fdt_host.h"
+#endif
+#include <rsa.h>
+#include <sha1.h>
+#include <sha256.h>
 
 /* PKCS 1.5 paddings as described in the RSA PKCS#1 v2.1 standard. */
 

lib/rsa/rsa-sign.c

@@ -193,7 +193,7 @@ static int rsa_sign_with_key(RSA *rsa, struct checksum_algo *checksum_algo,
 		goto err_create;
 	}
 	EVP_MD_CTX_init(context);
-	if (!EVP_SignInit(context, checksum_algo->calculate())) {
+	if (!EVP_SignInit(context, checksum_algo->calculate_sign())) {
 		ret = rsa_err("Signer setup failed");
 		goto err_sign;
 	}

lib/rsa/rsa-verify.c

@@ -4,17 +4,28 @@
  * SPDX-License-Identifier:	GPL-2.0+
  */
 
+#ifndef USE_HOSTCC
 #include <common.h>
 #include <fdtdec.h>
-#include <rsa.h>
-#include <sha1.h>
-#include <sha256.h>
+#include <asm/types.h>
 #include <asm/byteorder.h>
 #include <asm/errno.h>
+#include <asm/types.h>
 #include <asm/unaligned.h>
+#else
+#include "fdt_host.h"
+#include "mkimage.h"
+#include <fdt_support.h>
+#endif
+#include <rsa.h>
+#include <sha1.h>
+#include <sha256.h>
 
 #define UINT64_MULT32(v, multby)  (((uint64_t)(v)) * ((uint32_t)(multby)))
 
+#define get_unaligned_be32(a) fdt32_to_cpu(*(uint32_t *)a)
+#define put_unaligned_be32(a, b) (*(uint32_t *)(b) = cpu_to_fdt32(a))
+
 /**
  * subtract_modulus() - subtract modulus from the given value
  *
@@ -150,7 +161,6 @@ static int pow_mod(const struct rsa_public_key *key, uint32_t *inout)
 	/* Convert to bigendian byte array */
 	for (i = key->len - 1, ptr = inout; (int)i >= 0; i--, ptr++)
 		put_unaligned_be32(result[i], ptr);
-
 	return 0;
 }
 

test/vboot/vboot_test.sh

@@ -47,6 +47,7 @@ O=$(readlink -f ${O})
 dtc="-I dts -O dtb -p 2000"
 uboot="${O}/u-boot"
 mkimage="${O}/tools/mkimage"
+fit_check_sign="${O}/tools/fit_check_sign"
 keys="${dir}/dev-keys"
 echo ${mkimage} -D "${dtc}"
 
@@ -99,6 +100,25 @@ function do_test {
 
 	run_uboot "signed config" "dev+"
 
+	echo check signed config on the host
+	if ! ${fit_check_sign} -f test.fit -k sandbox-u-boot.dtb >${tmp}; then
+		echo
+		echo "Verified boot key check on host failed, output follows:"
+		cat ${tmp}
+		false
+	else
+		if ! grep -q "dev+" ${tmp}; then
+			echo
+			echo "Verified boot key check failed, output follows:"
+			cat ${tmp}
+			false
+		else
+			echo "OK"
+		fi
+	fi
+
+	run_uboot "signed config" "dev+"
+
 	# Increment the first byte of the signature, which should cause failure
 	sig=$(fdtget -t bx test.fit /configurations/conf@1/signature@1 value)
 	newbyte=$(printf %x $((0x${sig:0:2} + 1)))

tools/.gitignore

 /bmp_logo
 /envcrc
+/fit_check_sign
 /fit_info
 /gen_eth_addr
 /img2srec

tools/Makefile

@@ -61,13 +61,13 @@ mkenvimage$(SFX)-objs := crc32.o mkenvimage.o os_support.o
 
 hostprogs-y += dumpimage$(SFX) mkimage$(SFX)
 ifdef CONFIG_FIT_SIGNATURE
-hostprogs-y += fit_info$(SFX)
+hostprogs-y += fit_info$(SFX) fit_check_sign$(SFX)
 endif
 
 FIT_SIG_OBJS-$(CONFIG_FIT_SIGNATURE) := image-sig.o
 # Flattened device tree objects
 LIBFDT_OBJS := fdt.o fdt_ro.o fdt_rw.o fdt_strerror.o fdt_wip.o
-RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := rsa-sign.o
+RSA_OBJS-$(CONFIG_FIT_SIGNATURE) := rsa-sign.o rsa-verify.o rsa-checksum.o
 
 # common objs for dumpimage and mkimage
 dumpimage-mkimage-objs := aisimage.o \
@@ -97,6 +97,7 @@ dumpimage-mkimage-objs := aisimage.o \
 dumpimage$(SFX)-objs := $(dumpimage-mkimage-objs) dumpimage.o
 mkimage$(SFX)-objs   := $(dumpimage-mkimage-objs) mkimage.o
 fit_info$(SFX)-objs   := $(dumpimage-mkimage-objs) fit_info.o
+fit_check_sign$(SFX)-objs   := $(dumpimage-mkimage-objs) fit_check_sign.o
 
 # TODO(sjg@chromium.org): Is this correct on Mac OS?
 
@@ -105,6 +106,7 @@ ifneq ($(CONFIG_MX23)$(CONFIG_MX28),)
 HOSTLOADLIBES_dumpimage$(SFX) := -lssl -lcrypto
 HOSTLOADLIBES_mkimage$(SFX) := -lssl -lcrypto
 HOSTLOADLIBES_fit_info$(SFX) := -lssl -lcrypto
+HOSTLOADLIBES_fit_check_sign$(SFX) := -lssl -lcrypto
 # Add CONFIG_MXS into host CFLAGS, so we can check whether or not register
 # the mxsimage support within tools/mxsimage.c .
 HOSTCFLAGS_mxsimage.o += -DCONFIG_MXS
@@ -114,6 +116,7 @@ ifdef CONFIG_FIT_SIGNATURE
 HOSTLOADLIBES_dumpimage$(SFX) := -lssl -lcrypto
 HOSTLOADLIBES_mkimage$(SFX) := -lssl -lcrypto
 HOSTLOADLIBES_fit_info$(SFX) := -lssl -lcrypto
+HOSTLOADLIBES_fit_check_sign$(SFX) := -lssl -lcrypto
 
 # This affects include/image.h, but including the board config file
 # is tricky, so manually define this options here.

tools/fdt_host.h

@@ -11,4 +11,6 @@
 #include "../include/libfdt.h"
 #include "../include/fdt_support.h"
 
+int fit_check_sign(const void *working_fdt, const void *key);
+
 #endif /* __FDT_HOST_H__ */

tools/fdtdec.c

+#include "../lib/fdtdec.c"

tools/fit_check_sign.c

+/*
+ * (C) Copyright 2014
+ * DENX Software Engineering
+ * Heiko Schocher <hs@denx.de>
+ *
+ * Based on:
+ * (C) Copyright 2008 Semihalf
+ *
+ * (C) Copyright 2000-2004
+ * DENX Software Engineering
+ * Wolfgang Denk, wd@denx.de
+ *
+ * Updated-by: Prafulla Wadaskar <prafulla@marvell.com>
+ *		FIT image specific code abstracted from mkimage.c
+ *		some functions added to address abstraction
+ *
+ * All rights reserved.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#include "mkimage.h"
+#include "fit_common.h"
+#include <image.h>
+#include <u-boot/crc.h>
+
+void usage(char *cmdname)
+{
+	fprintf(stderr, "Usage: %s -f fit file -k key file\n"
+			 "          -f ==> set fit file which should be checked'\n"
+			 "          -k ==> set key file which contains the key'\n",
+		cmdname);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, char **argv)
+{
+	int ffd = -1;
+	int kfd = -1;
+	struct stat fsbuf;
+	struct stat ksbuf;
+	void *fit_blob;
+	char *fdtfile = NULL;
+	char *keyfile = NULL;
+	char cmdname[50];
+	int ret;
+	void *key_blob;
+	int c;
+
+	strcpy(cmdname, *argv);
+	while ((c = getopt(argc, argv, "f:k:")) != -1)
+		switch (c) {
+		case 'f':
+			fdtfile = optarg;
+			break;
+		case 'k':
+			keyfile = optarg;
+			break;
+		default:
+			usage(cmdname);
+			break;
+	}
+
+	ffd = mmap_fdt(cmdname, fdtfile, &fit_blob, &fsbuf, 0);
+	if (ffd < 0)
+		return EXIT_FAILURE;
+	kfd = mmap_fdt(cmdname, keyfile, &key_blob, &ksbuf, 0);
+	if (ffd < 0)
+		return EXIT_FAILURE;
+
+	image_set_host_blob(key_blob);
+	ret = fit_check_sign(fit_blob, key_blob);
+
+	if (ret)
+		ret = EXIT_SUCCESS;
+	else
+		ret = EXIT_FAILURE;
+
+	(void) munmap((void *)fit_blob, fsbuf.st_size);
+	(void) munmap((void *)key_blob, ksbuf.st_size);
+
+	close(ffd);
+	close(kfd);
+	exit(ret);
+}

tools/image-host.c

@@ -695,3 +695,18 @@ int fit_add_verification_data(const char *keydir, void *keydest, void *fit,
 
 	return 0;
 }
+
+#ifdef CONFIG_FIT_SIGNATURE
+int fit_check_sign(const void *working_fdt, const void *key)
+{
+	int cfg_noffset;
+	int ret;
+
+	cfg_noffset = fit_conf_get_node(working_fdt, NULL);
+	if (!cfg_noffset)
+		return -1;
+
+	ret = fit_config_verify(working_fdt, cfg_noffset);
+	return ret;
+}
+#endif

tools/rsa-checksum.c

+#include "../lib/rsa/rsa-checksum.c"

tools/rsa-verify.c

+#include "../lib/rsa/rsa-verify.c"