Re: [PATCH v4 2/4] tools: mkimage: Add Allwinner TOC0 support

Andre Przywara
2021-10-20T23:50:03Z

On Tue, 19 Oct 2021 21:44:52 -0500
Samuel Holland <samuel@sholland.org> wrote:

> Most Allwinner sunxi SoCs have separate boot ROMs in non-secure and
> secure mode. The "non-secure" or "normal" boot ROM (NBROM) uses the
> existing sunxi_egon image type. The secure boot ROM (SBROM) uses a
> completely different image type, known as TOC0.
>
> A TOC0 image is composed of a header and two or more items. One item
> is the firmware binary. The others form a chain linking the firmware
> signature to the root-of-trust public key (ROTPK), which has its hash
> burned in the SoC's eFuses. Signatures are made using RSA-2048 + SHA256.
>
> The pseudo-ASN.1 structure is manually assembled; this is done to work
> around bugs/quirks in the boot ROM, which vary between SoCs. This TOC0
> implementation has been verified to work with the A50, A64, H5, H6,
> and H616 SBROMs, and it may work with other SoCs.
>
> Signed-off-by: Samuel Holland <samuel@sholland.org>

So without understanding anything from the crypto stuff (just knowing
that it's all slightly non-standard thanks to Allwinner), this looks
good to me. Tested on a Remix Mini PC (which ships with the secure fuse
burnt).
Thanks for the changes!

Acked-by: Andre Przywara <andre.przywara@arm.com>

Cheers,
Andre

> ---
>
> (no changes since v3)
>
> Changes in v3:
> - Removed TOOLS_LIBCRYPTO selection for sunxi, since most boards
> do not need it
> - Added __packed to all new "ABI" structs
> - Added entry to MAINTAINERS for sunxi tools
>
> Changes in v2:
> - Moved certificate and key item structures out of sunxi_image.h
> - Renamed "main" and "item" variables for clarity
> - Improved error messages, and added a hint about key generation
> - Added a comment explaining the purpose of the various key files
> - Mentioned testing this code on A50 in the commit message
>
> MAINTAINERS | 1 +
> common/image.c | 1 +
> include/image.h | 1 +
> include/sunxi_image.h | 37 ++
> tools/Makefile | 3 +-
> tools/sunxi_toc0.c | 907 ++++++++++++++++++++++++++++++++++++++++++
> 6 files changed, 949 insertions(+), 1 deletion(-)
> create mode 100644 tools/sunxi_toc0.c
>
> diff --git a/MAINTAINERS b/MAINTAINERS
> index 71f468c00a..0d62829f51 100644
> --- a/MAINTAINERS
> +++ b/MAINTAINERS
> @@ -475,6 +475,7 @@ F: board/sunxi/
> F: drivers/clk/sunxi/
> F: drivers/phy/allwinner/
> F: drivers/video/sunxi/
> +F: tools/sunxi*
>
> ARM TEGRA
> M: Tom Warren <twarren@nvidia.com>
> diff --git a/common/image.c b/common/image.c
> index 3fa60b5827..d15b47ebbe 100644
> --- a/common/image.c
> +++ b/common/image.c
> @@ -185,6 +185,7 @@ static const table_entry_t uimage_type[] = {
> { IH_TYPE_MTKIMAGE, "mtk_image", "MediaTek BootROM loadable Image" },
> { IH_TYPE_COPRO, "copro", "Coprocessor Image"},
> { IH_TYPE_SUNXI_EGON, "sunxi_egon", "Allwinner eGON Boot Image" },
> + { IH_TYPE_SUNXI_TOC0, "sunxi_toc0", "Allwinner TOC0 Boot Image" },
> { -1, "", "", },
> };
>
> diff --git a/include/image.h b/include/image.h
> index 34d13ada84..1547246ec8 100644
> --- a/include/image.h
> +++ b/include/image.h
> @@ -227,6 +227,7 @@ enum {
> IH_TYPE_IMX8IMAGE, /* Freescale IMX8Boot Image */
> IH_TYPE_COPRO, /* Coprocessor Image for remoteproc*/
> IH_TYPE_SUNXI_EGON, /* Allwinner eGON Boot Image */
> + IH_TYPE_SUNXI_TOC0, /* Allwinner TOC0 Boot Image */
>
> IH_TYPE_COUNT, /* Number of image types */
> };
> diff --git a/include/sunxi_image.h b/include/sunxi_image.h
> index 5b2055c0af..379ca9196e 100644
> --- a/include/sunxi_image.h
> +++ b/include/sunxi_image.h
> @@ -9,9 +9,13 @@
> *
> * Shared between mkimage and the SPL.
> */
> +
> #ifndef SUNXI_IMAGE_H
> #define SUNXI_IMAGE_H
>
> +#include <linux/compiler_attributes.h>
> +#include <linux/types.h>
> +
> #define BOOT0_MAGIC "eGON.BT0"
> #define BROM_STAMP_VALUE 0x5f0a6c39
> #define SPL_SIGNATURE "SPL" /* marks "sunxi" SPL header */
> @@ -79,4 +83,37 @@ struct boot_file_head {
> /* Compile time check to assure proper alignment of structure */
> typedef char boot_file_head_not_multiple_of_32[1 - 2*(sizeof(struct boot_file_head) % 32)];
>
> +struct __packed toc0_main_info {
> + uint8_t name[8];
> + __le32 magic;
> + __le32 checksum;
> + __le32 serial;
> + __le32 status;
> + __le32 num_items;
> + __le32 length;
> + uint8_t platform[4];
> + uint8_t reserved[8];
> + uint8_t end[4];
> +};
> +
> +#define TOC0_MAIN_INFO_NAME "TOC0.GLH"
> +#define TOC0_MAIN_INFO_MAGIC 0x89119800
> +#define TOC0_MAIN_INFO_END "MIE;"
> +
> +struct __packed toc0_item_info {
> + __le32 name;
> + __le32 offset;
> + __le32 length;
> + __le32 status;
> + __le32 type;
> + __le32 load_addr;
> + uint8_t reserved[4];
> + uint8_t end[4];
> +};
> +
> +#define TOC0_ITEM_INFO_NAME_CERT 0x00010101
> +#define TOC0_ITEM_INFO_NAME_FIRMWARE 0x00010202
> +#define TOC0_ITEM_INFO_NAME_KEY 0x00010303
> +#define TOC0_ITEM_INFO_END "IIE;"
> +
> #endif
> diff --git a/tools/Makefile b/tools/Makefile
> index a9b3d982d8..e2aeb097aa 100644
> --- a/tools/Makefile
> +++ b/tools/Makefile
> @@ -98,7 +98,8 @@ AES_OBJS-$(CONFIG_TOOLS_LIBCRYPTO) := $(addprefix lib/aes/, \
> LIBCRYPTO_OBJS-$(CONFIG_TOOLS_LIBCRYPTO) := \
> lib/fdt-libcrypto.o \
> kwbimage.o \
> - mxsimage.o
> + mxsimage.o \
> + sunxi_toc0.o
>
> ROCKCHIP_OBS = lib/rc4.o rkcommon.o rkimage.o rksd.o rkspi.o
>
> diff --git a/tools/sunxi_toc0.c b/tools/sunxi_toc0.c
> new file mode 100644
> index 0000000000..58a6e7a0a1
> --- /dev/null
> +++ b/tools/sunxi_toc0.c
> @@ -0,0 +1,907 @@
> +// SPDX-License-Identifier: GPL-2.0+
> +/*
> + * (C) Copyright 2018 Arm Ltd.
> + * (C) Copyright 2020-2021 Samuel Holland <samuel@sholland.org>
> + */
> +
> +#include <assert.h>
> +#include <stdint.h>
> +#include <stdio.h>
> +#include <stdlib.h>
> +#include <string.h>
> +
> +#include <openssl/asn1t.h>
> +#include <openssl/pem.h>
> +#include <openssl/rsa.h>
> +
> +#include <image.h>
> +#include <sunxi_image.h>
> +
> +#include "imagetool.h"
> +#include "mkimage.h"
> +
> +/*
> + * NAND requires 8K padding. For other devices, BROM requires only
> + * 512B padding, but let's use the larger padding to cover everything.
> + */
> +#define PAD_SIZE 8192
> +
> +#define pr_fmt(fmt) "mkimage (TOC0): %s: " fmt
> +#define pr_err(fmt, args...) fprintf(stderr, pr_fmt(fmt), "error", ##args)
> +#define pr_warn(fmt, args...) fprintf(stderr, pr_fmt(fmt), "warning", ##args)
> +#define pr_info(fmt, args...) fprintf(stderr, pr_fmt(fmt), "info", ##args)
> +
> +struct __packed toc0_key_item {
> + __le32 vendor_id;
> + __le32 key0_n_len;
> + __le32 key0_e_len;
> + __le32 key1_n_len;
> + __le32 key1_e_len;
> + __le32 sig_len;
> + uint8_t key0[512];
> + uint8_t key1[512];
> + uint8_t reserved[32];
> + uint8_t sig[256];
> +};
> +
> +/*
> + * This looks somewhat like an X.509 certificate, but it is not valid BER.
> + *
> + * Some differences:
> + * - Some X.509 certificate fields are missing or rearranged.
> + * - Some sequences have the wrong tag.
> + * - Zero-length sequences are accepted.
> + * - Large strings and integers must be an even number of bytes long.
> + * - Positive integers are not zero-extended to maintain their sign.
> + *
> + * See https://linux-sunxi.org/TOC0 for more information.
> + */
> +struct __packed toc0_small_tag {
> + uint8_t tag;
> + uint8_t length;
> +};
> +
> +typedef struct toc0_small_tag toc0_small_int;
> +typedef struct toc0_small_tag toc0_small_oct;
> +typedef struct toc0_small_tag toc0_small_seq;
> +typedef struct toc0_small_tag toc0_small_exp;
> +
> +#define TOC0_SMALL_INT(len) { 0x02, (len) }
> +#define TOC0_SMALL_SEQ(len) { 0x30, (len) }
> +#define TOC0_SMALL_EXP(tag, len) { 0xa0 | (tag), len }
> +
> +struct __packed toc0_large_tag {
> + uint8_t tag;
> + uint8_t prefix;
> + uint8_t length_hi;
> + uint8_t length_lo;
> +};
> +
> +typedef struct toc0_large_tag toc0_large_int;
> +typedef struct toc0_large_tag toc0_large_bit;
> +typedef struct toc0_large_tag toc0_large_seq;
> +
> +#define TOC0_LARGE_INT(len) { 0x02, 0x82, (len) >> 8, (len) & 0xff }
> +#define TOC0_LARGE_BIT(len) { 0x03, 0x82, (len) >> 8, (len) & 0xff }
> +#define TOC0_LARGE_SEQ(len) { 0x30, 0x82, (len) >> 8, (len) & 0xff }
> +
> +struct __packed toc0_cert_item {
> + toc0_large_seq tag_totalSequence;
> + struct __packed toc0_totalSequence {
> + toc0_large_seq tag_mainSequence;
> + struct __packed toc0_mainSequence {
> + toc0_small_exp tag_explicit0;
> + struct __packed toc0_explicit0 {
> + toc0_small_int tag_version;
> + uint8_t version;
> + } explicit0;
> + toc0_small_int tag_serialNumber;
> + uint8_t serialNumber;
> + toc0_small_seq tag_signature;
> + toc0_small_seq tag_issuer;
> + toc0_small_seq tag_validity;
> + toc0_small_seq tag_subject;
> + toc0_large_seq tag_subjectPublicKeyInfo;
> + struct __packed toc0_subjectPublicKeyInfo {
> + toc0_small_seq tag_algorithm;
> + toc0_large_seq tag_publicKey;
> + struct __packed toc0_publicKey {
> + toc0_large_int tag_n;
> + uint8_t n[256];
> + toc0_small_int tag_e;
> + uint8_t e[3];
> + } publicKey;
> + } subjectPublicKeyInfo;
> + toc0_small_exp tag_explicit3;
> + struct __packed toc0_explicit3 {
> + toc0_small_seq tag_extension;
> + struct __packed toc0_extension {
> + toc0_small_int tag_digest;
> + uint8_t digest[32];
> + } extension;
> + } explicit3;
> + } mainSequence;
> + toc0_large_bit tag_sigSequence;
> + struct __packed toc0_sigSequence {
> + toc0_small_seq tag_algorithm;
> + toc0_large_bit tag_signature;
> + uint8_t signature[256];
> + } sigSequence;
> + } totalSequence;
> +};
> +
> +#define sizeof_field(TYPE, MEMBER) sizeof((((TYPE *)0)->MEMBER))
> +
> +static const struct toc0_cert_item cert_item_template = {
> + TOC0_LARGE_SEQ(sizeof(struct toc0_totalSequence)),
> + {
> + TOC0_LARGE_SEQ(sizeof(struct toc0_mainSequence)),
> + {
> + TOC0_SMALL_EXP(0, sizeof(struct toc0_explicit0)),
> + {
> + TOC0_SMALL_INT(sizeof_field(struct toc0_explicit0, version)),
> + 0,
> + },
> + TOC0_SMALL_INT(sizeof_field(struct toc0_mainSequence, serialNumber)),
> + 0,
> + TOC0_SMALL_SEQ(0),
> + TOC0_SMALL_SEQ(0),
> + TOC0_SMALL_SEQ(0),
> + TOC0_SMALL_SEQ(0),
> + TOC0_LARGE_SEQ(sizeof(struct toc0_subjectPublicKeyInfo)),
> + {
> + TOC0_SMALL_SEQ(0),
> + TOC0_LARGE_SEQ(sizeof(struct toc0_publicKey)),
> + {
> + TOC0_LARGE_INT(sizeof_field(struct toc0_publicKey, n)),
> + {},
> + TOC0_SMALL_INT(sizeof_field(struct toc0_publicKey, e)),
> + {},
> + },
> + },
> + TOC0_SMALL_EXP(3, sizeof(struct toc0_explicit3)),
> + {
> + TOC0_SMALL_SEQ(sizeof(struct toc0_extension)),
> + {
> + TOC0_SMALL_INT(sizeof_field(struct toc0_extension, digest)),
> + {},
> + },
> + },
> + },
> + TOC0_LARGE_BIT(sizeof(struct toc0_sigSequence)),
> + {
> + TOC0_SMALL_SEQ(0),
> + TOC0_LARGE_BIT(sizeof_field(struct toc0_sigSequence, signature)),
> + {},
> + },
> + },
> +};
> +
> +#define TOC0_DEFAULT_NUM_ITEMS 3
> +#define TOC0_DEFAULT_HEADER_LEN \
> + ALIGN( \
> + sizeof(struct toc0_main_info) + \
> + sizeof(struct toc0_item_info) * TOC0_DEFAULT_NUM_ITEMS + \
> + sizeof(struct toc0_cert_item) + \
> + sizeof(struct toc0_key_item), \
> + 32)
> +
> +static char *fw_key_file = "fw_key.pem";
> +static char *key_item_file = "key_item.bin";
> +static char *root_key_file = "root_key.pem";
> +
> +/*
> + * Create a key item in @buf, containing the public keys @root_key and @fw_key,
> + * and signed by the RSA key @root_key.
> + */
> +static int toc0_create_key_item(uint8_t *buf, uint32_t *len,
> + RSA *root_key, RSA *fw_key)
> +{
> + struct toc0_key_item *key_item = (void *)buf;
> + uint8_t digest[SHA256_DIGEST_LENGTH];
> + int ret = EXIT_FAILURE;
> + unsigned int sig_len;
> + int n_len, e_len;
> +
> + /* Store key 0. */
> + n_len = BN_bn2bin(RSA_get0_n(root_key), key_item->key0);
> + e_len = BN_bn2bin(RSA_get0_e(root_key), key_item->key0 + n_len);
> + if (n_len + e_len > sizeof(key_item->key0)) {
> + pr_err("Root key is too big for key item\n");
> + goto err;
> + }
> + key_item->key0_n_len = cpu_to_le32(n_len);
> + key_item->key0_e_len = cpu_to_le32(e_len);
> +
> + /* Store key 1. */
> + n_len = BN_bn2bin(RSA_get0_n(fw_key), key_item->key1);
> + e_len = BN_bn2bin(RSA_get0_e(fw_key), key_item->key1 + n_len);
> + if (n_len + e_len > sizeof(key_item->key1)) {
> + pr_err("Firmware key is too big for key item\n");
> + goto err;
> + }
> + key_item->key1_n_len = cpu_to_le32(n_len);
> + key_item->key1_e_len = cpu_to_le32(e_len);
> +
> + /* Sign the key item. */
> + key_item->sig_len = cpu_to_le32(RSA_size(root_key));
> + SHA256(buf, key_item->sig - buf, digest);
> + if (!RSA_sign(NID_sha256, digest, sizeof(digest),
> + key_item->sig, &sig_len, root_key)) {
> + pr_err("Failed to sign key item\n");
> + goto err;
> + }
> + if (sig_len != sizeof(key_item->sig)) {
> + pr_err("Bad key item signature length\n");
> + goto err;
> + }
> +
> + *len = sizeof(*key_item);
> + ret = EXIT_SUCCESS;
> +
> +err:
> + return ret;
> +}
> +
> +/*
> + * Verify the key item in @buf, containing two public keys @key0 and @key1,
> + * and signed by the RSA key @key0. If @root_key is provided, only signatures
> + * by that key will be accepted. @key1 is returned in @key.
> + */
> +static int toc0_verify_key_item(const uint8_t *buf, uint32_t len,
> + RSA *root_key, RSA **fw_key)
> +{
> + struct toc0_key_item *key_item = (void *)buf;
> + uint8_t digest[SHA256_DIGEST_LENGTH];
> + int ret = EXIT_FAILURE;
> + int n_len, e_len;
> + RSA *key0 = NULL;
> + RSA *key1 = NULL;
> + BIGNUM *n, *e;
> +
> + if (len < sizeof(*key_item))
> + goto err;
> +
> + /* Load key 0. */
> + n_len = le32_to_cpu(key_item->key0_n_len);
> + e_len = le32_to_cpu(key_item->key0_e_len);
> + if (n_len + e_len > sizeof(key_item->key0)) {
> + pr_err("Bad root key size in key item\n");
> + goto err;
> + }
> + n = BN_bin2bn(key_item->key0, n_len, NULL);
> + e = BN_bin2bn(key_item->key0 + n_len, e_len, NULL);
> + key0 = RSA_new();
> + if (!key0)
> + goto err;
> + if (!RSA_set0_key(key0, n, e, NULL))
> + goto err;
> +
> + /* If a root key was provided, compare it to key 0. */
> + if (root_key && (BN_cmp(n, RSA_get0_n(root_key)) ||
> + BN_cmp(e, RSA_get0_e(root_key)))) {
> + pr_err("Wrong root key in key item\n");
> + goto err;
> + }
> +
> + /* Verify the key item signature. */
> + SHA256(buf, key_item->sig - buf, digest);
> + if (!RSA_verify(NID_sha256, digest, sizeof(digest),
> + key_item->sig, le32_to_cpu(key_item->sig_len), key0)) {
> + pr_err("Bad key item signature\n");
> + goto err;
> + }
> +
> + if (fw_key) {
> + /* Load key 1. */
> + n_len = le32_to_cpu(key_item->key1_n_len);
> + e_len = le32_to_cpu(key_item->key1_e_len);
> + if (n_len + e_len > sizeof(key_item->key1)) {
> + pr_err("Bad firmware key size in key item\n");
> + goto err;
> + }
> + n = BN_bin2bn(key_item->key1, n_len, NULL);
> + e = BN_bin2bn(key_item->key1 + n_len, e_len, NULL);
> + key1 = RSA_new();
> + if (!key1)
> + goto err;
> + if (!RSA_set0_key(key1, n, e, NULL))
> + goto err;
> +
> + if (*fw_key) {
> + /* If a FW key was provided, compare it to key 1. */
> + if (BN_cmp(n, RSA_get0_n(*fw_key)) ||
> + BN_cmp(e, RSA_get0_e(*fw_key))) {
> + pr_err("Wrong firmware key in key item\n");
> + goto err;
> + }
> + } else {
> + /* Otherwise, send key1 back to the caller. */
> + *fw_key = key1;
> + key1 = NULL;
> + }
> + }
> +
> + ret = EXIT_SUCCESS;
> +
> +err:
> + RSA_free(key0);
> + RSA_free(key1);
> +
> + return ret;
> +}
> +
> +/*
> + * Create a certificate in @buf, describing the firmware with SHA256 digest
> + * @digest, and signed by the RSA key @fw_key.
> + */
> +static int toc0_create_cert_item(uint8_t *buf, uint32_t *len, RSA *fw_key,
> + uint8_t digest[static SHA256_DIGEST_LENGTH])
> +{
> + struct toc0_cert_item *cert_item = (void *)buf;
> + uint8_t cert_digest[SHA256_DIGEST_LENGTH];
> + struct toc0_totalSequence *totalSequence;
> + struct toc0_sigSequence *sigSequence;
> + struct toc0_extension *extension;
> + struct toc0_publicKey *publicKey;
> + int ret = EXIT_FAILURE;
> + unsigned int sig_len;
> +
> + memcpy(cert_item, &cert_item_template, sizeof(*cert_item));
> + *len = sizeof(*cert_item);
> +
> + /*
> + * Fill in the public key.
> + *
> + * Only 2048-bit RSA keys are supported. Since this uses a fixed-size
> + * structure, it may fail for non-standard exponents.
> + */
> + totalSequence = &cert_item->totalSequence;
> + publicKey = &totalSequence->mainSequence.subjectPublicKeyInfo.publicKey;
> + if (BN_bn2binpad(RSA_get0_n(fw_key), publicKey->n, sizeof(publicKey->n)) < 0 ||
> + BN_bn2binpad(RSA_get0_e(fw_key), publicKey->e, sizeof(publicKey->e)) < 0) {
> + pr_err("Firmware key is too big for certificate\n");
> + goto err;
> + }
> +
> + /* Fill in the firmware digest. */
> + extension = &totalSequence->mainSequence.explicit3.extension;
> + memcpy(&extension->digest, digest, SHA256_DIGEST_LENGTH);
> +
> + /*
> + * Sign the certificate.
> + *
> + * In older SBROM versions (and by default in newer versions),
> + * the last 4 bytes of the certificate are not signed.
> + *
> + * (The buffer passed to SHA256 starts at tag_mainSequence, but
> + * the buffer size does not include the length of that tag.)
> + */
> + SHA256((uint8_t *)totalSequence, sizeof(struct toc0_mainSequence), cert_digest);
> + sigSequence = &totalSequence->sigSequence;
> + if (!RSA_sign(NID_sha256, cert_digest, SHA256_DIGEST_LENGTH,
> + sigSequence->signature, &sig_len, fw_key)) {
> + pr_err("Failed to sign certificate\n");
> + goto err;
> + }
> + if (sig_len != sizeof(sigSequence->signature)) {
> + pr_err("Bad certificate signature length\n");
> + goto err;
> + }
> +
> + ret = EXIT_SUCCESS;
> +
> +err:
> + return ret;
> +}
> +
> +/*
> + * Verify the certificate in @buf, describing the firmware with SHA256 digest
> + * @digest, and signed by the RSA key contained within. If @fw_key is provided,
> + * only that key will be accepted.
> + *
> + * This function is only expected to work with images created by mkimage.
> + */
> +static int toc0_verify_cert_item(const uint8_t *buf, uint32_t len, RSA *fw_key,
> + uint8_t digest[static SHA256_DIGEST_LENGTH])
> +{
> + const struct toc0_cert_item *cert_item = (const void *)buf;
> + uint8_t cert_digest[SHA256_DIGEST_LENGTH];
> + const struct toc0_totalSequence *totalSequence;
> + const struct toc0_sigSequence *sigSequence;
> + const struct toc0_extension *extension;
> + const struct toc0_publicKey *publicKey;
> + int ret = EXIT_FAILURE;
> + RSA *key = NULL;
> + BIGNUM *n, *e;
> +
> + /* Extract the public key from the certificate. */
> + totalSequence = &cert_item->totalSequence;
> + publicKey = &totalSequence->mainSequence.subjectPublicKeyInfo.publicKey;
> + n = BN_bin2bn(publicKey->n, sizeof(publicKey->n), NULL);
> + e = BN_bin2bn(publicKey->e, sizeof(publicKey->e), NULL);
> + key = RSA_new();
> + if (!key)
> + goto err;
> + if (!RSA_set0_key(key, n, e, NULL))
> + goto err;
> +
> + /* If a key was provided, compare it to the embedded key. */
> + if (fw_key && (BN_cmp(RSA_get0_n(key), RSA_get0_n(fw_key)) ||
> + BN_cmp(RSA_get0_e(key), RSA_get0_e(fw_key)))) {
> + pr_err("Wrong firmware key in certificate\n");
> + goto err;
> + }
> +
> + /* If a digest was provided, compare it to the embedded digest. */
> + extension = &totalSequence->mainSequence.explicit3.extension;
> + if (digest && memcmp(&extension->digest, digest, SHA256_DIGEST_LENGTH)) {
> + pr_err("Wrong firmware digest in certificate\n");
> + goto err;
> + }
> +
> + /* Verify the certificate's signature. See the comment above. */
> + SHA256((uint8_t *)totalSequence, sizeof(struct toc0_mainSequence), cert_digest);
> + sigSequence = &totalSequence->sigSequence;
> + if (!RSA_verify(NID_sha256, cert_digest, SHA256_DIGEST_LENGTH,
> + sigSequence->signature,
> + sizeof(sigSequence->signature), key)) {
> + pr_err("Bad certificate signature\n");
> + goto err;
> + }
> +
> + ret = EXIT_SUCCESS;
> +
> +err:
> + RSA_free(key);
> +
> + return ret;
> +}
> +
> +/*
> + * Always create a TOC0 containing 3 items. The extra item will be ignored on
> + * SoCs which do not support it.
> + */
> +static int toc0_create(uint8_t *buf, uint32_t len, RSA *root_key, RSA *fw_key,
> + uint8_t *key_item, uint32_t key_item_len,
> + uint8_t *fw_item, uint32_t fw_item_len, uint32_t fw_addr)
> +{
> + struct toc0_main_info *main_info = (void *)buf;
> + struct toc0_item_info *item_info = (void *)(main_info + 1);
> + uint8_t digest[SHA256_DIGEST_LENGTH];
> + uint32_t *buf32 = (void *)buf;
> + RSA *orig_fw_key = fw_key;
> + int ret = EXIT_FAILURE;
> + uint32_t checksum = 0;
> + uint32_t item_offset;
> + uint32_t item_length;
> + int i;
> +
> + /* Hash the firmware for inclusion in the certificate. */
> + SHA256(fw_item, fw_item_len, digest);
> +
> + /* Create the main TOC0 header, containing three items. */
> + memcpy(main_info->name, TOC0_MAIN_INFO_NAME, sizeof(main_info->name));
> + main_info->magic = cpu_to_le32(TOC0_MAIN_INFO_MAGIC);
> + main_info->checksum = cpu_to_le32(BROM_STAMP_VALUE);
> + main_info->num_items = cpu_to_le32(TOC0_DEFAULT_NUM_ITEMS);
> + memcpy(main_info->end, TOC0_MAIN_INFO_END, sizeof(main_info->end));
> +
> + /* The first item links the ROTPK to the signing key. */
> + item_offset = sizeof(*main_info) +
> + sizeof(*item_info) * TOC0_DEFAULT_NUM_ITEMS;
> + /* Using an existing key item avoids needing the root private key. */
> + if (key_item) {
> + item_length = sizeof(*key_item);
> + if (toc0_verify_key_item(key_item, item_length,
> + root_key, &fw_key))
> + goto err;
> + memcpy(buf + item_offset, key_item, item_length);
> + } else if (toc0_create_key_item(buf + item_offset, &item_length,
> + root_key, fw_key)) {
> + goto err;
> + }
> +
> + item_info->name = cpu_to_le32(TOC0_ITEM_INFO_NAME_KEY);
> + item_info->offset = cpu_to_le32(item_offset);
> + item_info->length = cpu_to_le32(item_length);
> + memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
> +
> + /* The second item contains a certificate signed by the firmware key. */
> + item_offset = item_offset + item_length;
> + if (toc0_create_cert_item(buf + item_offset, &item_length,
> + fw_key, digest))
> + goto err;
> +
> + item_info++;
> + item_info->name = cpu_to_le32(TOC0_ITEM_INFO_NAME_CERT);
> + item_info->offset = cpu_to_le32(item_offset);
> + item_info->length = cpu_to_le32(item_length);
> + memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
> +
> + /* The third item contains the actual boot code. */
> + item_offset = ALIGN(item_offset + item_length, 32);
> + item_length = fw_item_len;
> + if (buf + item_offset != fw_item)
> + memmove(buf + item_offset, fw_item, item_length);
> +
> + item_info++;
> + item_info->name = cpu_to_le32(TOC0_ITEM_INFO_NAME_FIRMWARE);
> + item_info->offset = cpu_to_le32(item_offset);
> + item_info->length = cpu_to_le32(item_length);
> + item_info->load_addr = cpu_to_le32(fw_addr);
> + memcpy(item_info->end, TOC0_ITEM_INFO_END, sizeof(item_info->end));
> +
> + /* Pad to the required block size with 0xff to be flash-friendly. */
> + item_offset = item_offset + item_length;
> + item_length = ALIGN(item_offset, PAD_SIZE) - item_offset;
> + memset(buf + item_offset, 0xff, item_length);
> +
> + /* Fill in the total padded file length. */
> + item_offset = item_offset + item_length;
> + main_info->length = cpu_to_le32(item_offset);
> +
> + /* Verify enough space was provided when creating the image. */
> + assert(len >= item_offset);
> +
> + /* Calculate the checksum. Yes, it's that simple. */
> + for (i = 0; i < item_offset / 4; ++i)
> + checksum += le32_to_cpu(buf32[i]);
> + main_info->checksum = cpu_to_le32(checksum);
> +
> + ret = EXIT_SUCCESS;
> +
> +err:
> + if (fw_key != orig_fw_key)
> + RSA_free(fw_key);
> +
> + return ret;
> +}
> +
> +static const struct toc0_item_info *
> +toc0_find_item(const struct toc0_main_info *main_info, uint32_t name,
> + uint32_t *offset, uint32_t *length)
> +{
> + const struct toc0_item_info *item_info = (void *)(main_info + 1);
> + uint32_t item_offset, item_length;
> + uint32_t num_items, main_length;
> + int i;
> +
> + num_items = le32_to_cpu(main_info->num_items);
> + main_length = le32_to_cpu(main_info->length);
> +
> + for (i = 0; i < num_items; ++i, ++item_info) {
> + if (le32_to_cpu(item_info->name) != name)
> + continue;
> +
> + item_offset = le32_to_cpu(item_info->offset);
> + item_length = le32_to_cpu(item_info->length);
> +
> + if (item_offset > main_length ||
> + item_length > main_length - item_offset)
> + continue;
> +
> + *offset = item_offset;
> + *length = item_length;
> +
> + return item_info;
> + }
> +
> + return NULL;
> +}
> +
> +static int toc0_verify(const uint8_t *buf, uint32_t len, RSA *root_key)
> +{
> + const struct toc0_main_info *main_info = (void *)buf;
> + const struct toc0_item_info *item_info;
> + uint8_t digest[SHA256_DIGEST_LENGTH];
> + uint32_t main_length = le32_to_cpu(main_info->length);
> + uint32_t checksum = BROM_STAMP_VALUE;
> + uint32_t *buf32 = (void *)buf;
> + uint32_t length, offset;
> + int ret = EXIT_FAILURE;
> + RSA *fw_key = NULL;
> + int i;
> +
> + if (len < main_length)
> + goto err;
> +
> + /* Verify the main header. */
> + if (memcmp(main_info->name, TOC0_MAIN_INFO_NAME, sizeof(main_info->name)))
> + goto err;
> + if (le32_to_cpu(main_info->magic) != TOC0_MAIN_INFO_MAGIC)
> + goto err;
> + /* Verify the checksum without modifying the buffer. */
> + for (i = 0; i < main_length / 4; ++i)
> + checksum += le32_to_cpu(buf32[i]);
> + if (checksum != 2 * le32_to_cpu(main_info->checksum))
> + goto err;
> + /* The length must be at least 512 byte aligned. */
> + if (main_length % 512)
> + goto err;
> + if (memcmp(main_info->end, TOC0_MAIN_INFO_END, sizeof(main_info->end)))
> + goto err;
> +
> + /* Verify the key item if present (it is optional). */
> + item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_KEY,
> + &offset, &length);
> + if (!item_info)
> + fw_key = root_key;
> + else if (toc0_verify_key_item(buf + offset, length, root_key, &fw_key))
> + goto err;
> +
> + /* Hash the firmware to compare with the certificate. */
> + item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_FIRMWARE,
> + &offset, &length);
> + if (!item_info) {
> + pr_err("Missing firmware item\n");
> + goto err;
> + }
> + SHA256(buf + offset, length, digest);
> +
> + /* Verify the certificate item. */
> + item_info = toc0_find_item(main_info, TOC0_ITEM_INFO_NAME_CERT,
> + &offset, &length);
> + if (!item_info) {
> + pr_err("Missing certificate item\n");
> + goto err;
> + }
> + if (toc0_verify_cert_item(buf + offset, length, fw_key, digest))
> + goto err;
> +
> + ret = EXIT_SUCCESS;
> +
> +err:
> + if (fw_key != root_key)
> + RSA_free(fw_key);
> +
> + return ret;
> +}
> +
> +static int toc0_check_params(struct image_tool_params *params)
> +{
> + if (!params->dflag)
> + return -EINVAL;
> +
> + /*
> + * If a key directory was provided, look for key files there.
> + * Otherwise, look for them in the current directory. The key files are
> + * the "quoted" terms in the description below.
> + *
> + * A summary of the chain of trust on most SoCs:
> + * 1) eFuse contains a SHA256 digest of the public "root key".
> + * 2) Private "root key" signs the certificate item (generated here).
> + * 3) Certificate item contains a SHA256 digest of the firmware item.
> + *
> + * A summary of the chain of trust on the H6 (by default; a bit in the
> + * BROM_CONFIG eFuse makes it work like above):
> + * 1) eFuse contains a SHA256 digest of the public "root key".
> + * 2) Private "root key" signs the "key item" (generated here).
> + * 3) "Key item" contains the public "root key" and public "fw key".
> + * 4) Private "fw key" signs the certificate item (generated here).
> + * 5) Certificate item contains a SHA256 digest of the firmware item.
> + *
> + * This means there are three valid ways to generate a TOC0:
> + * 1) Provide the private "root key" only. This works everywhere.
> + * For H6, the "root key" will also be used as the "fw key".
> + * 2) FOR H6 ONLY: Provide the private "root key" and a separate
> + * private "fw key".
> + * 3) FOR H6 ONLY: Provide the private "fw key" and a pre-existing
> + * "key item" containing the corresponding public "fw key".
> + * In this case, the private "root key" can be kept offline. The
> + * "key item" can be extracted from a TOC0 image generated using
> + * method #2 above.
> + *
> + * Note that until the ROTPK_HASH eFuse is programmed, any "root key"
> + * will be accepted by the BROM.
> + */
> + if (params->keydir) {
> + if (asprintf(&fw_key_file, "%s/%s", params->keydir, fw_key_file) < 0)
> + return -ENOMEM;
> + if (asprintf(&key_item_file, "%s/%s", params->keydir, key_item_file) < 0)
> + return -ENOMEM;
> + if (asprintf(&root_key_file, "%s/%s", params->keydir, root_key_file) < 0)
> + return -ENOMEM;
> + }
> +
> + return 0;
> +}
> +
> +static int toc0_verify_header(unsigned char *buf, int image_size,
> + struct image_tool_params *params)
> +{
> + int ret = EXIT_FAILURE;
> + RSA *root_key = NULL;
> + FILE *fp;
> +
> + /* A root public key is optional. */
> + fp = fopen(root_key_file, "rb");
> + if (fp) {
> + pr_info("Verifying image with existing root key\n");
> + root_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
> + if (!root_key)
> + root_key = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL);
> + fclose(fp);
> + if (!root_key) {
> + pr_err("Failed to read public key from '%s'\n",
> + root_key_file);
> + goto err;
> + }
> + }
> +
> + ret = toc0_verify(buf, image_size, root_key);
> +
> +err:
> + RSA_free(root_key);
> +
> + return ret;
> +}
> +
> +static const char *toc0_item_name(uint32_t name)
> +{
> + if (name == TOC0_ITEM_INFO_NAME_CERT)
> + return "Certificate";
> + if (name == TOC0_ITEM_INFO_NAME_FIRMWARE)
> + return "Firmware";
> + if (name == TOC0_ITEM_INFO_NAME_KEY)
> + return "Key";
> + return "(unknown)";
> +}
> +
> +static void toc0_print_header(const void *buf)
> +{
> + const struct toc0_main_info *main_info = buf;
> + const struct toc0_item_info *item_info = (void *)(main_info + 1);
> + uint32_t head_length, main_length, num_items;
> + uint32_t item_offset, item_length, item_name;
> + int load_addr = -1;
> + int i;
> +
> + num_items = le32_to_cpu(main_info->num_items);
> + head_length = sizeof(*main_info) + num_items * sizeof(*item_info);
> + main_length = le32_to_cpu(main_info->length);
> +
> + printf("Allwinner TOC0 Image\n"
> + "Size: %d bytes\n"
> + "Contents: %d items\n"
> + " 00000000:%08x Headers\n",
> + main_length, num_items, head_length);
> +
> + for (i = 0; i < num_items; ++i, ++item_info) {
> + item_offset = le32_to_cpu(item_info->offset);
> + item_length = le32_to_cpu(item_info->length);
> + item_name = le32_to_cpu(item_info->name);
> +
> + if (item_name == TOC0_ITEM_INFO_NAME_FIRMWARE)
> + load_addr = le32_to_cpu(item_info->load_addr);
> +
> + printf(" %08x:%08x %s\n",
> + item_offset, item_length,
> + toc0_item_name(item_name));
> + }
> +
> + if (num_items && item_offset + item_length < main_length) {
> + item_offset = item_offset + item_length;
> + item_length = main_length - item_offset;
> +
> + printf(" %08x:%08x Padding\n",
> + item_offset, item_length);
> + }
> +
> + if (load_addr != -1)
> + printf("Load address: 0x%08x\n", load_addr);
> +}
> +
> +static void toc0_set_header(void *buf, struct stat *sbuf, int ifd,
> + struct image_tool_params *params)
> +{
> + uint32_t key_item_len = 0;
> + uint8_t *key_item = NULL;
> + int ret = EXIT_FAILURE;
> + RSA *root_key = NULL;
> + RSA *fw_key = NULL;
> + FILE *fp;
> +
> + /* Either a key item or the root private key is required. */
> + fp = fopen(key_item_file, "rb");
> + if (fp) {
> + pr_info("Creating image using existing key item\n");
> + key_item_len = sizeof(struct toc0_key_item);
> + key_item = OPENSSL_malloc(key_item_len);
> + if (!key_item || fread(key_item, key_item_len, 1, fp) != 1) {
> + pr_err("Failed to read key item from '%s'\n",
> + root_key_file);
> + goto err;
> + }
> + fclose(fp);
> + fp = NULL;
> + }
> +
> + fp = fopen(root_key_file, "rb");
> + if (fp) {
> + root_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
> + if (!root_key)
> + root_key = PEM_read_RSAPublicKey(fp, NULL, NULL, NULL);
> + fclose(fp);
> + fp = NULL;
> + }
> +
> + /* When using an existing key item, the root key is optional. */
> + if (!key_item && (!root_key || !RSA_get0_d(root_key))) {
> + pr_err("Failed to read private key from '%s'\n",
> + root_key_file);
> + pr_info("Try 'openssl genrsa -out root_key.pem'\n");
> + goto err;
> + }
> +
> + /* The certificate/firmware private key is always required. */
> + fp = fopen(fw_key_file, "rb");
> + if (fp) {
> + fw_key = PEM_read_RSAPrivateKey(fp, NULL, NULL, NULL);
> + fclose(fp);
> + fp = NULL;
> + }
> + if (!fw_key) {
> + /* If the root key is a private key, it can be used instead. */
> + if (root_key && RSA_get0_d(root_key)) {
> + pr_info("Using root key as firmware key\n");
> + fw_key = root_key;
> + } else {
> + pr_err("Failed to read private key from '%s'\n",
> + fw_key_file);
> + goto err;
> + }
> + }
> +
> + /* Warn about potential compatibility issues. */
> + if (key_item || fw_key != root_key)
> + pr_warn("Only H6 supports separate root and firmware keys\n");
> +
> + ret = toc0_create(buf, params->file_size, root_key, fw_key,
> + key_item, key_item_len,
> + buf + TOC0_DEFAULT_HEADER_LEN,
> + params->orig_file_size, params->addr);
> +
> +err:
> + OPENSSL_free(key_item);
> + OPENSSL_free(root_key);
> + if (fw_key != root_key)
> + OPENSSL_free(fw_key);
> + if (fp)
> + fclose(fp);
> +
> + if (ret != EXIT_SUCCESS)
> + exit(ret);
> +}
> +
> +static int toc0_check_image_type(uint8_t type)
> +{
> + return type == IH_TYPE_SUNXI_TOC0 ? 0 : 1;
> +}
> +
> +static int toc0_vrec_header(struct image_tool_params *params,
> + struct image_type_params *tparams)
> +{
> + tparams->hdr = calloc(tparams->header_size, 1);
> +
> + /* Save off the unpadded data size for SHA256 calculation. */
> + params->orig_file_size = params->file_size - TOC0_DEFAULT_HEADER_LEN;
> +
> + /* Return padding to 8K blocks. */
> + return ALIGN(params->file_size, PAD_SIZE) - params->file_size;
> +}
> +
> +U_BOOT_IMAGE_TYPE(
> + sunxi_toc0,
> + "Allwinner TOC0 Boot Image support",
> + TOC0_DEFAULT_HEADER_LEN,
> + NULL,
> + toc0_check_params,
> + toc0_verify_header,
> + toc0_print_header,
> + toc0_set_header,
> + NULL,
> + toc0_check_image_type,
> + NULL,
> + toc0_vrec_header
> +);