/*
 * Copyright (c) 2013, Google Inc.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#ifdef USE_HOSTCC
#include "mkimage.h"
#include <time.h>
#else
#include <common.h>
#include <malloc.h>
DECLARE_GLOBAL_DATA_PTR;
#endif /* !USE_HOSTCC*/
#include <image.h>
#include <u-boot/rsa.h>
#include <u-boot/rsa-checksum.h>

#define IMAGE_MAX_HASHED_NODES          100

#ifdef USE_HOSTCC
void *host_blob;
void image_set_host_blob(void *blob)
{
        host_blob = blob;
}
void *image_get_host_blob(void)
{
        return host_blob;
}
#endif

struct checksum_algo checksum_algos[] = {
        {
                "sha1",
                SHA1_SUM_LEN,
                SHA1_DER_LEN,
                sha1_der_prefix,
#if IMAGE_ENABLE_SIGN
                EVP_sha1,
#endif
                hash_calculate,
        },
        {
                "sha256",
                SHA256_SUM_LEN,
                SHA256_DER_LEN,
                sha256_der_prefix,
#if IMAGE_ENABLE_SIGN
                EVP_sha256,
#endif
                hash_calculate,
        }

};

struct crypto_algo crypto_algos[] = {
        {
                "rsa2048",
                RSA2048_BYTES,
                rsa_sign,
                rsa_add_verify_data,
                rsa_verify,
        },
        {
                "rsa4096",
                RSA4096_BYTES,
                rsa_sign,
                rsa_add_verify_data,
                rsa_verify,
        }

};

struct checksum_algo *image_get_checksum_algo(const char *full_name)
{
        int i;
        const char *name;

        for (i = 0; i < ARRAY_SIZE(checksum_algos); i++) {
                name = checksum_algos[i].name;
                /* Make sure names match and next char is a comma */
                if (!strncmp(name, full_name, strlen(name)) &&
                    full_name[strlen(name)] == ',')
                        return &checksum_algos[i];
        }

        return NULL;
}

struct crypto_algo *image_get_crypto_algo(const char *full_name)
{
        int i;
        const char *name;

        /* Move name to after the comma */
        name = strchr(full_name, ',');
        if (!name)
                return NULL;
        name += 1;

        for (i = 0; i < ARRAY_SIZE(crypto_algos); i++) {
                if (!strcmp(crypto_algos[i].name, name))
                        return &crypto_algos[i];
        }

        return NULL;
}

/**
 * fit_region_make_list() - Make a list of image regions
 *
 * Given a list of fdt_regions, create a list of image_regions. This is a
 * simple conversion routine since the FDT and image code use different
 * structures.
 *
 * @fit: FIT image
 * @fdt_regions: Pointer to FDT regions
 * @count: Number of FDT regions
 * @region: Pointer to image regions, which must hold @count records. If
 * region is NULL, then (except for an SPL build) the array will be
 * allocated.
 * @return: Pointer to image regions
 */
struct image_region *fit_region_make_list(const void *fit,
                struct fdt_region *fdt_regions, int count,
                struct image_region *region)
{
        int i;

        debug("Hash regions:\n");
        debug("%10s %10s\n", "Offset", "Size");

        /*
         * Use malloc() except in SPL (to save code size). In SPL the caller
         * must allocate the array.
         */
#ifndef CONFIG_SPL_BUILD
        if (!region)
                region = calloc(sizeof(*region), count);
#endif
        if (!region)
                return NULL;
        for (i = 0; i < count; i++) {
                debug("%10x %10x\n", fdt_regions[i].offset,
                      fdt_regions[i].size);
                region[i].data = fit + fdt_regions[i].offset;
                region[i].size = fdt_regions[i].size;
        }

        return region;
}

static int fit_image_setup_verify(struct image_sign_info *info,
                const void *fit, int noffset, int required_keynode,
                char **err_msgp)
{
        char *algo_name;

        if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
                *err_msgp = "Can't get hash algo property";
                return -1;
        }
        memset(info, '\0', sizeof(*info));
        info->keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);
        info->fit = (void *)fit;
        info->node_offset = noffset;
        info->name = algo_name;
        info->checksum = image_get_checksum_algo(algo_name);
        info->crypto = image_get_crypto_algo(algo_name);
        info->fdt_blob = gd_fdt_blob();
        info->required_keynode = required_keynode;
        printf("%s:%s", algo_name, info->keyname);

        if (!info->checksum || !info->crypto) {
                *err_msgp = "Unknown signature algorithm";
                return -1;
        }

        return 0;
}

int fit_image_check_sig(const void *fit, int noffset, const void *data,
                size_t size, int required_keynode, char **err_msgp)
{
        struct image_sign_info info;
        struct image_region region;
        uint8_t *fit_value;
        int fit_value_len;

        *err_msgp = NULL;
        if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
                                   err_msgp))
                return -1;

        if (fit_image_hash_get_value(fit, noffset, &fit_value,
                                     &fit_value_len)) {
                *err_msgp = "Can't get hash value property";
                return -1;
        }

        region.data = data;
        region.size = size;

        if (info.crypto->verify(&info, &region, 1, fit_value, fit_value_len)) {
                *err_msgp = "Verification failed";
                return -1;
        }

        return 0;
}

static int fit_image_verify_sig(const void *fit, int image_noffset,
                const char *data, size_t size, const void *sig_blob,
                int sig_offset)
{
        int noffset;
        char *err_msg = "";
        int verified = 0;
        int ret;

        /* Process all hash subnodes of the component image node */
        fdt_for_each_subnode(noffset, fit, image_noffset) {
                const char *name = fit_get_name(fit, noffset, NULL);

                if (!strncmp(name, FIT_SIG_NODENAME,
                             strlen(FIT_SIG_NODENAME))) {
                        ret = fit_image_check_sig(fit, noffset, data,
                                                        size, -1, &err_msg);
                        if (ret) {
                                puts("- ");
                        } else {
                                puts("+ ");
                                verified = 1;
                                break;
                        }
                }
        }

        if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
                err_msg = "Corrupted or truncated tree";
                goto error;
        }

        return verified ? 0 : -EPERM;

error:
        printf(" error!\n%s for '%s' hash node in '%s' image node\n",
               err_msg, fit_get_name(fit, noffset, NULL),
               fit_get_name(fit, image_noffset, NULL));
        return -1;
}

int fit_image_verify_required_sigs(const void *fit, int image_noffset,
                const char *data, size_t size, const void *sig_blob,
                int *no_sigsp)
{
        int verify_count = 0;
        int noffset;
        int sig_node;

        /* Work out what we need to verify */
        *no_sigsp = 1;
        sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
        if (sig_node < 0) {
                debug("%s: No signature node found: %s\n", __func__,
                      fdt_strerror(sig_node));
                return 0;
        }

        fdt_for_each_subnode(noffset, sig_blob, sig_node) {
                const char *required;
                int ret;

                required = fdt_getprop(sig_blob, noffset, "required", NULL);
                if (!required || strcmp(required, "image"))
                        continue;
                ret = fit_image_verify_sig(fit, image_noffset, data, size,
                                        sig_blob, noffset);
                if (ret) {
                        printf("Failed to verify required signature '%s'\n",
                               fit_get_name(sig_blob, noffset, NULL));
                        return ret;
                }
                verify_count++;
        }

        if (verify_count)
                *no_sigsp = 0;

        return 0;
}

int fit_config_check_sig(const void *fit, int noffset, int required_keynode,
                         char **err_msgp)
{
        char * const exc_prop[] = {"data"};
        const char *prop, *end, *name;
        struct image_sign_info info;
        const uint32_t *strings;
        uint8_t *fit_value;
        int fit_value_len;
        int max_regions;
        int i, prop_len;
        char path[200];
        int count;

        debug("%s: fdt=%p, conf='%s', sig='%s'\n", __func__, gd_fdt_blob(),
              fit_get_name(fit, noffset, NULL),
              fit_get_name(gd_fdt_blob(), required_keynode, NULL));
        *err_msgp = NULL;
        if (fit_image_setup_verify(&info, fit, noffset, required_keynode,
                                   err_msgp))
                return -1;

        if (fit_image_hash_get_value(fit, noffset, &fit_value,
                                     &fit_value_len)) {
                *err_msgp = "Can't get hash value property";
                return -1;
        }

        /* Count the number of strings in the property */
        prop = fdt_getprop(fit, noffset, "hashed-nodes", &prop_len);
        end = prop ? prop + prop_len : prop;
        for (name = prop, count = 0; name < end; name++)
                if (!*name)
                        count++;
        if (!count) {
                *err_msgp = "Can't get hashed-nodes property";
                return -1;
        }

        /* Add a sanity check here since we are using the stack */
        if (count > IMAGE_MAX_HASHED_NODES) {
                *err_msgp = "Number of hashed nodes exceeds maximum";
                return -1;
        }

        /* Create a list of node names from those strings */
        char *node_inc[count];

        debug("Hash nodes (%d):\n", count);
        for (name = prop, i = 0; name < end; name += strlen(name) + 1, i++) {
                debug("   '%s'\n", name);
                node_inc[i] = (char *)name;
        }

        /*
         * Each node can generate one region for each sub-node. Allow for
         * 7 sub-nodes (hash@1, signature@1, etc.) and some extra.
         */
        max_regions = 20 + count * 7;
        struct fdt_region fdt_regions[max_regions];

        /* Get a list of regions to hash */
        count = fdt_find_regions(fit, node_inc, count,
                        exc_prop, ARRAY_SIZE(exc_prop),
                        fdt_regions, max_regions - 1,
                        path, sizeof(path), 0);
        if (count < 0) {
                *err_msgp = "Failed to hash configuration";
                return -1;
        }
        if (count == 0) {
                *err_msgp = "No data to hash";
                return -1;
        }
        if (count >= max_regions - 1) {
                *err_msgp = "Too many hash regions";
                return -1;
        }

        /* Add the strings */
        strings = fdt_getprop(fit, noffset, "hashed-strings", NULL);
        if (strings) {
                fdt_regions[count].offset = fdt_off_dt_strings(fit) +
                                fdt32_to_cpu(strings[0]);
                fdt_regions[count].size = fdt32_to_cpu(strings[1]);
                count++;
        }

        /* Allocate the region list on the stack */
        struct image_region region[count];

        fit_region_make_list(fit, fdt_regions, count, region);
        if (info.crypto->verify(&info, region, count, fit_value,
                                fit_value_len)) {
                *err_msgp = "Verification failed";
                return -1;
        }

        return 0;
}

static int fit_config_verify_sig(const void *fit, int conf_noffset,
                const void *sig_blob, int sig_offset)
{
        int noffset;
        char *err_msg = "";
        int verified = 0;
        int ret;

        /* Process all hash subnodes of the component conf node */
        fdt_for_each_subnode(noffset, fit, conf_noffset) {
                const char *name = fit_get_name(fit, noffset, NULL);

                if (!strncmp(name, FIT_SIG_NODENAME,
                             strlen(FIT_SIG_NODENAME))) {
                        ret = fit_config_check_sig(fit, noffset, sig_offset,
                                                   &err_msg);
                        if (ret) {
                                puts("- ");
                        } else {
                                puts("+ ");
                                verified = 1;
                                break;
                        }
                }
        }

        if (noffset == -FDT_ERR_TRUNCATED || noffset == -FDT_ERR_BADSTRUCTURE) {
                err_msg = "Corrupted or truncated tree";
                goto error;
        }

        return verified ? 0 : -EPERM;

error:
        printf(" error!\n%s for '%s' hash node in '%s' config node\n",
               err_msg, fit_get_name(fit, noffset, NULL),
               fit_get_name(fit, conf_noffset, NULL));
        return -1;
}

int fit_config_verify_required_sigs(const void *fit, int conf_noffset,
                const void *sig_blob)
{
        int noffset;
        int sig_node;

        /* Work out what we need to verify */
        sig_node = fdt_subnode_offset(sig_blob, 0, FIT_SIG_NODENAME);
        if (sig_node < 0) {
                debug("%s: No signature node found: %s\n", __func__,
                      fdt_strerror(sig_node));
                return 0;
        }

        fdt_for_each_subnode(noffset, sig_blob, sig_node) {
                const char *required;
                int ret;

                required = fdt_getprop(sig_blob, noffset, "required", NULL);
                if (!required || strcmp(required, "conf"))
                        continue;
                ret = fit_config_verify_sig(fit, conf_noffset, sig_blob,
                                            noffset);
                if (ret) {
                        printf("Failed to verify required signature '%s'\n",
                               fit_get_name(sig_blob, noffset, NULL));
                        return ret;
                }
        }

        return 0;
}

int fit_config_verify(const void *fit, int conf_noffset)
{
        return fit_config_verify_required_sigs(fit, conf_noffset,
                                               gd_fdt_blob());
}