blob: 76693647a095f8bf6cb404ef0ff69f06e8910b44 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0+
/*
* (C) Copyright 2018 Arm Ltd.
* (C) Copyright 2020-2021 Samuel Holland <samuel@sholland.org>
*/
#define OPENSSL_API_COMPAT 0x10101000L
#include <assert.h>
#include <stdint.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <openssl/asn1t.h>
#include <openssl/bn.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)
#if defined(LIBRESSL_VERSION_NUMBER) && LIBRESSL_VERSION_NUMBER < 0x3050000fL
#define RSA_get0_n(key) (key)->n
#define RSA_get0_e(key) (key)->e
#define RSA_get0_d(key) (key)->d
#endif
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 (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, struct image_tool_params *params)
{
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
);