/*
 * Copyright (c) 2013, Google Inc.
 *
 * (C) Copyright 2008 Semihalf
 *
 * (C) Copyright 2000-2006
 * Wolfgang Denk, DENX Software Engineering, wd@denx.de.
 *
 * SPDX-License-Identifier:     GPL-2.0+
 */

#include "mkimage.h"
#include <bootm.h>
#include <image.h>
#include <version.h>

/**
 * fit_set_hash_value - set hash value in requested has node
 * @fit: pointer to the FIT format image header
 * @noffset: hash node offset
 * @value: hash value to be set
 * @value_len: hash value length
 *
 * fit_set_hash_value() attempts to set hash value in a node at offset
 * given and returns operation status to the caller.
 *
 * returns
 *     0, on success
 *     -1, on failure
 */
static int fit_set_hash_value(void *fit, int noffset, uint8_t *value,
                                int value_len)
{
        int ret;

        ret = fdt_setprop(fit, noffset, FIT_VALUE_PROP, value, value_len);
        if (ret) {
                printf("Can't set hash '%s' property for '%s' node(%s)\n",
                       FIT_VALUE_PROP, fit_get_name(fit, noffset, NULL),
                       fdt_strerror(ret));
                return ret == -FDT_ERR_NOSPACE ? -ENOSPC : -EIO;
        }

        return 0;
}

/**
 * fit_image_process_hash - Process a single subnode of the images/ node
 *
 * Check each subnode and process accordingly. For hash nodes we generate
 * a hash of the supplised data and store it in the node.
 *
 * @fit:        pointer to the FIT format image header
 * @image_name: name of image being processes (used to display errors)
 * @noffset:    subnode offset
 * @data:       data to process
 * @size:       size of data in bytes
 * @return 0 if ok, -1 on error
 */
static int fit_image_process_hash(void *fit, const char *image_name,
                int noffset, const void *data, size_t size)
{
        uint8_t value[FIT_MAX_HASH_LEN];
        const char *node_name;
        int value_len;
        char *algo;
        int ret;

        node_name = fit_get_name(fit, noffset, NULL);

        if (fit_image_hash_get_algo(fit, noffset, &algo)) {
                printf("Can't get hash algo property for '%s' hash node in '%s' image node\n",
                       node_name, image_name);
                return -ENOENT;
        }

        if (calculate_hash(data, size, algo, value, &value_len)) {
                printf("Unsupported hash algorithm (%s) for '%s' hash node in '%s' image node\n",
                       algo, node_name, image_name);
                return -EPROTONOSUPPORT;
        }

        ret = fit_set_hash_value(fit, noffset, value, value_len);
        if (ret) {
                printf("Can't set hash value for '%s' hash node in '%s' image node\n",
                       node_name, image_name);
                return ret;
        }

        return 0;
}

/**
 * fit_image_write_sig() - write the signature to a FIT
 *
 * This writes the signature and signer data to the FIT.
 *
 * @fit: pointer to the FIT format image header
 * @noffset: hash node offset
 * @value: signature value to be set
 * @value_len: signature value length
 * @comment: Text comment to write (NULL for none)
 *
 * returns
 *     0, on success
 *     -FDT_ERR_..., on failure
 */
static int fit_image_write_sig(void *fit, int noffset, uint8_t *value,
                int value_len, const char *comment, const char *region_prop,
                int region_proplen)
{
        int string_size;
        int ret;

        /*
         * Get the current string size, before we update the FIT and add
         * more
         */
        string_size = fdt_size_dt_strings(fit);

        ret = fdt_setprop(fit, noffset, FIT_VALUE_PROP, value, value_len);
        if (!ret) {
                ret = fdt_setprop_string(fit, noffset, "signer-name",
                                         "mkimage");
        }
        if (!ret) {
                ret = fdt_setprop_string(fit, noffset, "signer-version",
                                  PLAIN_VERSION);
        }
        if (comment && !ret)
                ret = fdt_setprop_string(fit, noffset, "comment", comment);
        if (!ret)
                ret = fit_set_timestamp(fit, noffset, time(NULL));
        if (region_prop && !ret) {
                uint32_t strdata[2];

                ret = fdt_setprop(fit, noffset, "hashed-nodes",
                                   region_prop, region_proplen);
                strdata[0] = 0;
                strdata[1] = cpu_to_fdt32(string_size);
                if (!ret) {
                        ret = fdt_setprop(fit, noffset, "hashed-strings",
                                          strdata, sizeof(strdata));
                }
        }

        return ret;
}

static int fit_image_setup_sig(struct image_sign_info *info,
                const char *keydir, void *fit, const char *image_name,
                int noffset, const char *require_keys, const char *engine_id)
{
        const char *node_name;
        char *algo_name;

        node_name = fit_get_name(fit, noffset, NULL);
        if (fit_image_hash_get_algo(fit, noffset, &algo_name)) {
                printf("Can't get algo property for '%s' signature node in '%s' image node\n",
                       node_name, image_name);
                return -1;
        }

        memset(info, '\0', sizeof(*info));
        info->keydir = keydir;
        info->keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);
        info->fit = 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->require_keys = require_keys;
        info->engine_id = engine_id;
        if (!info->checksum || !info->crypto) {
                printf("Unsupported signature algorithm (%s) for '%s' signature node in '%s' image node\n",
                       algo_name, node_name, image_name);
                return -1;
        }

        return 0;
}

/**
 * fit_image_process_sig- Process a single subnode of the images/ node
 *
 * Check each subnode and process accordingly. For signature nodes we
 * generate a signed hash of the supplised data and store it in the node.
 *
 * @keydir:     Directory containing keys to use for signing
 * @keydest:    Destination FDT blob to write public keys into
 * @fit:        pointer to the FIT format image header
 * @image_name: name of image being processes (used to display errors)
 * @noffset:    subnode offset
 * @data:       data to process
 * @size:       size of data in bytes
 * @comment:    Comment to add to signature nodes
 * @require_keys: Mark all keys as 'required'
 * @engine_id:  Engine to use for signing
 * @return 0 if ok, -1 on error
 */
static int fit_image_process_sig(const char *keydir, void *keydest,
                void *fit, const char *image_name,
                int noffset, const void *data, size_t size,
                const char *comment, int require_keys, const char *engine_id)
{
        struct image_sign_info info;
        struct image_region region;
        const char *node_name;
        uint8_t *value;
        uint value_len;
        int ret;

        if (fit_image_setup_sig(&info, keydir, fit, image_name, noffset,
                                require_keys ? "image" : NULL, engine_id))
                return -1;

        node_name = fit_get_name(fit, noffset, NULL);
        region.data = data;
        region.size = size;
        ret = info.crypto->sign(&info, &region, 1, &value, &value_len);
        if (ret) {
                printf("Failed to sign '%s' signature node in '%s' image node: %d\n",
                       node_name, image_name, ret);

                /* We allow keys to be missing */
                if (ret == -ENOENT)
                        return 0;
                return -1;
        }

        ret = fit_image_write_sig(fit, noffset, value, value_len, comment,
                        NULL, 0);
        if (ret) {
                if (ret == -FDT_ERR_NOSPACE)
                        return -ENOSPC;
                printf("Can't write signature for '%s' signature node in '%s' conf node: %s\n",
                       node_name, image_name, fdt_strerror(ret));
                return -1;
        }
        free(value);

        /* Get keyname again, as FDT has changed and invalidated our pointer */
        info.keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);

        if (keydest)
                ret = info.crypto->add_verify_data(&info, keydest);
        else
                return -1;

        /*
         * Write the public key into the supplied FDT file; this might fail
         * several times, since we try signing with successively increasing
         * size values
         */
        if (keydest && ret)
                return ret;

        return 0;
}

/**
 * fit_image_add_verification_data() - calculate/set verig. data for image node
 *
 * This adds hash and signature values for an component image node.
 *
 * All existing hash subnodes are checked, if algorithm property is set to
 * one of the supported hash algorithms, hash value is computed and
 * corresponding hash node property is set, for example:
 *
 * Input component image node structure:
 *
 * o image@1 (at image_noffset)
 *   | - data = [binary data]
 *   o hash@1
 *     |- algo = "sha1"
 *
 * Output component image node structure:
 *
 * o image@1 (at image_noffset)
 *   | - data = [binary data]
 *   o hash@1
 *     |- algo = "sha1"
 *     |- value = sha1(data)
 *
 * For signature details, please see doc/uImage.FIT/signature.txt
 *
 * @keydir      Directory containing *.key and *.crt files (or NULL)
 * @keydest     FDT Blob to write public keys into (NULL if none)
 * @fit:        Pointer to the FIT format image header
 * @image_noffset: Requested component image node
 * @comment:    Comment to add to signature nodes
 * @require_keys: Mark all keys as 'required'
 * @engine_id:  Engine to use for signing
 * @return: 0 on success, <0 on failure
 */
int fit_image_add_verification_data(const char *keydir, void *keydest,
                void *fit, int image_noffset, const char *comment,
                int require_keys, const char *engine_id)
{
        const char *image_name;
        const void *data;
        size_t size;
        int noffset;

        /* Get image data and data length */
        if (fit_image_get_data(fit, image_noffset, &data, &size)) {
                printf("Can't get image data/size\n");
                return -1;
        }

        image_name = fit_get_name(fit, image_noffset, NULL);

        /* Process all hash subnodes of the component image node */
        for (noffset = fdt_first_subnode(fit, image_noffset);
             noffset >= 0;
             noffset = fdt_next_subnode(fit, noffset)) {
                const char *node_name;
                int ret = 0;

                /*
                 * Check subnode name, must be equal to "hash" or "signature".
                 * Multiple hash nodes require unique unit node
                 * names, e.g. hash@1, hash@2, signature@1, etc.
                 */
                node_name = fit_get_name(fit, noffset, NULL);
                if (!strncmp(node_name, FIT_HASH_NODENAME,
                             strlen(FIT_HASH_NODENAME))) {
                        ret = fit_image_process_hash(fit, image_name, noffset,
                                                data, size);
                } else if (IMAGE_ENABLE_SIGN && keydir &&
                           !strncmp(node_name, FIT_SIG_NODENAME,
                                strlen(FIT_SIG_NODENAME))) {
                        ret = fit_image_process_sig(keydir, keydest,
                                fit, image_name, noffset, data, size,
                                comment, require_keys, engine_id);
                }
                if (ret)
                        return ret;
        }

        return 0;
}

struct strlist {
        int count;
        char **strings;
};

static void strlist_init(struct strlist *list)
{
        memset(list, '\0', sizeof(*list));
}

static void strlist_free(struct strlist *list)
{
        int i;

        for (i = 0; i < list->count; i++)
                free(list->strings[i]);
        free(list->strings);
}

static int strlist_add(struct strlist *list, const char *str)
{
        char *dup;

        dup = strdup(str);
        list->strings = realloc(list->strings,
                                (list->count + 1) * sizeof(char *));
        if (!list || !str)
                return -1;
        list->strings[list->count++] = dup;

        return 0;
}

static const char *fit_config_get_image_list(void *fit, int noffset,
                int *lenp, int *allow_missingp)
{
        static const char default_list[] = FIT_KERNEL_PROP "\0"
                        FIT_FDT_PROP;
        const char *prop;

        /* If there is an "image" property, use that */
        prop = fdt_getprop(fit, noffset, "sign-images", lenp);
        if (prop) {
                *allow_missingp = 0;
                return *lenp ? prop : NULL;
        }

        /* Default image list */
        *allow_missingp = 1;
        *lenp = sizeof(default_list);

        return default_list;
}

static int fit_config_get_hash_list(void *fit, int conf_noffset,
                                    int sig_offset, struct strlist *node_inc)
{
        int allow_missing;
        const char *prop, *iname, *end;
        const char *conf_name, *sig_name;
        char name[200], path[200];
        int image_count;
        int ret, len;

        conf_name = fit_get_name(fit, conf_noffset, NULL);
        sig_name = fit_get_name(fit, sig_offset, NULL);

        /*
         * Build a list of nodes we need to hash. We always need the root
         * node and the configuration.
         */
        strlist_init(node_inc);
        snprintf(name, sizeof(name), "%s/%s", FIT_CONFS_PATH, conf_name);
        if (strlist_add(node_inc, "/") ||
            strlist_add(node_inc, name))
                goto err_mem;

        /* Get a list of images that we intend to sign */
        prop = fit_config_get_image_list(fit, sig_offset, &len,
                                        &allow_missing);
        if (!prop)
                return 0;

        /* Locate the images */
        end = prop + len;
        image_count = 0;
        for (iname = prop; iname < end; iname += strlen(iname) + 1) {
                int noffset;
                int image_noffset;
                int hash_count;

                image_noffset = fit_conf_get_prop_node(fit, conf_noffset,
                                                       iname);
                if (image_noffset < 0) {
                        printf("Failed to find image '%s' in  configuration '%s/%s'\n",
                               iname, conf_name, sig_name);
                        if (allow_missing)
                                continue;

                        return -ENOENT;
                }

                ret = fdt_get_path(fit, image_noffset, path, sizeof(path));
                if (ret < 0)
                        goto err_path;
                if (strlist_add(node_inc, path))
                        goto err_mem;

                snprintf(name, sizeof(name), "%s/%s", FIT_CONFS_PATH,
                         conf_name);

                /* Add all this image's hashes */
                hash_count = 0;
                for (noffset = fdt_first_subnode(fit, image_noffset);
                     noffset >= 0;
                     noffset = fdt_next_subnode(fit, noffset)) {
                        const char *name = fit_get_name(fit, noffset, NULL);

                        if (strncmp(name, FIT_HASH_NODENAME,
                                    strlen(FIT_HASH_NODENAME)))
                                continue;
                        ret = fdt_get_path(fit, noffset, path, sizeof(path));
                        if (ret < 0)
                                goto err_path;
                        if (strlist_add(node_inc, path))
                                goto err_mem;
                        hash_count++;
                }

                if (!hash_count) {
                        printf("Failed to find any hash nodes in configuration '%s/%s' image '%s' - without these it is not possible to verify this image\n",
                               conf_name, sig_name, iname);
                        return -ENOMSG;
                }

                image_count++;
        }

        if (!image_count) {
                printf("Failed to find any images for configuration '%s/%s'\n",
                       conf_name, sig_name);
                return -ENOMSG;
        }

        return 0;

err_mem:
        printf("Out of memory processing configuration '%s/%s'\n", conf_name,
               sig_name);
        return -ENOMEM;

err_path:
        printf("Failed to get path for image '%s' in configuration '%s/%s': %s\n",
               iname, conf_name, sig_name, fdt_strerror(ret));
        return -ENOENT;
}

static int fit_config_get_data(void *fit, int conf_noffset, int noffset,
                struct image_region **regionp, int *region_countp,
                char **region_propp, int *region_proplen)
{
        char * const exc_prop[] = {"data"};
        struct strlist node_inc;
        struct image_region *region;
        struct fdt_region fdt_regions[100];
        const char *conf_name, *sig_name;
        char path[200];
        int count, i;
        char *region_prop;
        int ret, len;

        conf_name = fit_get_name(fit, conf_noffset, NULL);
        sig_name = fit_get_name(fit, conf_noffset, NULL);
        debug("%s: conf='%s', sig='%s'\n", __func__, conf_name, sig_name);

        /* Get a list of nodes we want to hash */
        ret = fit_config_get_hash_list(fit, conf_noffset, noffset, &node_inc);
        if (ret)
                return ret;

        /* Get a list of regions to hash */
        count = fdt_find_regions(fit, node_inc.strings, node_inc.count,
                        exc_prop, ARRAY_SIZE(exc_prop),
                        fdt_regions, ARRAY_SIZE(fdt_regions),
                        path, sizeof(path), 1);
        if (count < 0) {
                printf("Failed to hash configuration '%s/%s': %s\n", conf_name,
                       sig_name, fdt_strerror(ret));
                return -EIO;
        }
        if (count == 0) {
                printf("No data to hash for configuration '%s/%s': %s\n",
                       conf_name, sig_name, fdt_strerror(ret));
                return -EINVAL;
        }

        /* Build our list of data blocks */
        region = fit_region_make_list(fit, fdt_regions, count, NULL);
        if (!region) {
                printf("Out of memory hashing configuration '%s/%s'\n",
                       conf_name, sig_name);
                return -ENOMEM;
        }

        /* Create a list of all hashed properties */
        debug("Hash nodes:\n");
        for (i = len = 0; i < node_inc.count; i++) {
                debug("   %s\n", node_inc.strings[i]);
                len += strlen(node_inc.strings[i]) + 1;
        }
        region_prop = malloc(len);
        if (!region_prop) {
                printf("Out of memory setting up regions for configuration '%s/%s'\n",
                       conf_name, sig_name);
                return -ENOMEM;
        }
        for (i = len = 0; i < node_inc.count;
             len += strlen(node_inc.strings[i]) + 1, i++)
                strcpy(region_prop + len, node_inc.strings[i]);
        strlist_free(&node_inc);

        *region_countp = count;
        *regionp = region;
        *region_propp = region_prop;
        *region_proplen = len;

        return 0;
}

static int fit_config_process_sig(const char *keydir, void *keydest,
                void *fit, const char *conf_name, int conf_noffset,
                int noffset, const char *comment, int require_keys,
                const char *engine_id)
{
        struct image_sign_info info;
        const char *node_name;
        struct image_region *region;
        char *region_prop;
        int region_proplen;
        int region_count;
        uint8_t *value;
        uint value_len;
        int ret;

        node_name = fit_get_name(fit, noffset, NULL);
        if (fit_config_get_data(fit, conf_noffset, noffset, &region,
                                &region_count, &region_prop, &region_proplen))
                return -1;

        if (fit_image_setup_sig(&info, keydir, fit, conf_name, noffset,
                                require_keys ? "conf" : NULL, engine_id))
                return -1;

        ret = info.crypto->sign(&info, region, region_count, &value,
                                &value_len);
        free(region);
        if (ret) {
                printf("Failed to sign '%s' signature node in '%s' conf node\n",
                       node_name, conf_name);

                /* We allow keys to be missing */
                if (ret == -ENOENT)
                        return 0;
                return -1;
        }

        ret = fit_image_write_sig(fit, noffset, value, value_len, comment,
                                region_prop, region_proplen);
        if (ret) {
                if (ret == -FDT_ERR_NOSPACE)
                        return -ENOSPC;
                printf("Can't write signature for '%s' signature node in '%s' conf node: %s\n",
                       node_name, conf_name, fdt_strerror(ret));
                return -1;
        }
        free(value);
        free(region_prop);

        /* Get keyname again, as FDT has changed and invalidated our pointer */
        info.keyname = fdt_getprop(fit, noffset, "key-name-hint", NULL);

        /* Write the public key into the supplied FDT file */
        if (keydest) {
                ret = info.crypto->add_verify_data(&info, keydest);
                if (ret == -ENOSPC)
                        return -ENOSPC;
                if (ret) {
                        printf("Failed to add verification data for '%s' signature node in '%s' image node\n",
                               node_name, conf_name);
                }
                return ret;
        }

        return 0;
}

static int fit_config_add_verification_data(const char *keydir, void *keydest,
                void *fit, int conf_noffset, const char *comment,
                int require_keys, const char *engine_id)
{
        const char *conf_name;
        int noffset;

        conf_name = fit_get_name(fit, conf_noffset, NULL);

        /* Process all hash subnodes of the configuration node */
        for (noffset = fdt_first_subnode(fit, conf_noffset);
             noffset >= 0;
             noffset = fdt_next_subnode(fit, noffset)) {
                const char *node_name;
                int ret = 0;

                node_name = fit_get_name(fit, noffset, NULL);
                if (!strncmp(node_name, FIT_SIG_NODENAME,
                             strlen(FIT_SIG_NODENAME))) {
                        ret = fit_config_process_sig(keydir, keydest,
                                fit, conf_name, conf_noffset, noffset, comment,
                                require_keys, engine_id);
                }
                if (ret)
                        return ret;
        }

        return 0;
}

int fit_add_verification_data(const char *keydir, void *keydest, void *fit,
                              const char *comment, int require_keys,
                              const char *engine_id)
{
        int images_noffset, confs_noffset;
        int noffset;
        int ret;

        /* Find images parent node offset */
        images_noffset = fdt_path_offset(fit, FIT_IMAGES_PATH);
        if (images_noffset < 0) {
                printf("Can't find images parent node '%s' (%s)\n",
                       FIT_IMAGES_PATH, fdt_strerror(images_noffset));
                return images_noffset;
        }

        /* Process its subnodes, print out component images details */
        for (noffset = fdt_first_subnode(fit, images_noffset);
             noffset >= 0;
             noffset = fdt_next_subnode(fit, noffset)) {
                /*
                 * Direct child node of the images parent node,
                 * i.e. component image node.
                 */
                ret = fit_image_add_verification_data(keydir, keydest,
                                fit, noffset, comment, require_keys, engine_id);
                if (ret)
                        return ret;
        }

        /* If there are no keys, we can't sign configurations */
        if (!IMAGE_ENABLE_SIGN || !keydir)
                return 0;

        /* Find configurations parent node offset */
        confs_noffset = fdt_path_offset(fit, FIT_CONFS_PATH);
        if (confs_noffset < 0) {
                printf("Can't find images parent node '%s' (%s)\n",
                       FIT_CONFS_PATH, fdt_strerror(confs_noffset));
                return -ENOENT;
        }

        /* Process its subnodes, print out component images details */
        for (noffset = fdt_first_subnode(fit, confs_noffset);
             noffset >= 0;
             noffset = fdt_next_subnode(fit, noffset)) {
                ret = fit_config_add_verification_data(keydir, keydest,
                                                       fit, noffset, comment,
                                                       require_keys,
                                                       engine_id);
                if (ret)
                        return ret;
        }

        return 0;
}

#ifdef CONFIG_FIT_SIGNATURE
int fit_check_sign(const void *fit, const void *key)
{
        int cfg_noffset;
        int ret;

        cfg_noffset = fit_conf_get_node(fit, NULL);
        if (!cfg_noffset)
                return -1;

        printf("Verifying Hash Integrity ... ");
        ret = fit_config_verify(fit, cfg_noffset);
        if (ret)
                return ret;
        ret = bootm_host_load_images(fit, cfg_noffset);

        return ret;
}
#endif