app-ethereum/src_features/signMessageEIP712/ui_logic.c

#ifdef HAVE_EIP712_FULL_SUPPORT

#include <stdlib.h>
#include <stdbool.h>
#include "ui_logic.h"
#include "mem.h"
#include "mem_utils.h"
#include "os_io.h"
#include "ux_flow_engine.h"
#include "ui_flow_712.h"
#include "shared_context.h"
#include "ethUtils.h" // getEthDisplayableAddress
#include "utils.h" // uint256_to_decimal
#include "common_712.h"
#include "context.h" // eip712_context_deinit
#include "uint256.h" // tostring256 && tostring256_signed
#include "path.h" // path_get_root_type
#include "apdu_constants.h" // APDU response codes
#include "typed_data.h"
#include "commands_712.h"


static t_ui_context *ui_ctx = NULL;


/**
 * Checks on the UI context to determine if the next EIP 712 field should be shown
 *
 * @return whether the next field should be shown
 */
static bool ui_712_field_shown(void)
{
    bool ret = false;

    if (ui_ctx->filtering_mode == EIP712_FILTERING_BASIC)
    {
        if (N_storage.verbose_eip712 || (path_get_root_type() == ROOT_DOMAIN))
        {
            ret = true;
        }
    }
    else // EIP712_FILTERING_FULL
    {
        if (ui_ctx->field_flags & UI_712_FIELD_SHOWN)
        {
            ret = true;
        }
    }
    return ret;
}

/**
 * Set UI buffer
 *
 * @param[in] src source buffer
 * @param[in] src_length source buffer size
 * @param[in] dst destination buffer
 * @param[in] dst_length destination buffer length
 * @param[in] explicit_trunc if truncation should be explicitely shown
 */
static void ui_712_set_buf(const char *const src,
                           size_t src_length,
                           char *const dst,
                           size_t dst_length,
                           bool explicit_trunc)
{
    uint8_t cpy_length;

    if (src_length < dst_length)
    {
        cpy_length = src_length;
    }
    else
    {
        cpy_length = dst_length - 1;
    }
    memcpy(dst, src, cpy_length);
    dst[cpy_length] = '\0';
    if (explicit_trunc && (src_length > dst_length))
    {
        memcpy(dst + cpy_length - 3, "...", 3);
    }
}

/**
 * Skip the field if needed and reset its UI flags
 */
void    ui_712_finalize_field(void)
{
    if (!ui_712_field_shown())
    {
        ui_712_next_field();
    }
    ui_712_field_flags_reset();
}

/**
 * Set a new title for the EIP-712 generic UX_STEP
 *
 * @param[in] str the new title
 * @param[in] length its length
 */
void    ui_712_set_title(const char *const str, uint8_t length)
{
    ui_712_set_buf(str, length, strings.tmp.tmp2, sizeof(strings.tmp.tmp2), false);
}

/**
 * Set a new value for the EIP-712 generic UX_STEP
 *
 * @param[in] str the new value
 * @param[in] length its length
 */
void    ui_712_set_value(const char *const str, uint8_t length)
{
    ui_712_set_buf(str, length, strings.tmp.tmp, sizeof(strings.tmp.tmp), true);
}

/**
 * Redraw the dynamic UI step that shows EIP712 information
 */
void    ui_712_redraw_generic_step(void)
{
    if (!ui_ctx->shown) // Initialize if it is not already
    {
        ux_flow_init(0, ux_712_flow, NULL);
        ui_ctx->shown = true;
    }
    else
    {
        // not pretty, manually changes the internal state of the UX flow
        // so that we always land on the first screen of a paging step without any visible
        // screen glitching (quick screen switching)
        G_ux.flow_stack[G_ux.stack_count - 1].index = 0;
        // since the flow now thinks we are displaying the first step, do next
        ux_flow_next();
    }
}

/**
 * Called on the intermediate dummy screen between the dynamic step
 * && the approve/reject screen
 */
void    ui_712_next_field(void)
{
    if (ui_ctx == NULL)
    {
        apdu_response_code = APDU_RESPONSE_CONDITION_NOT_SATISFIED;
        return;
    }
    if  (ui_ctx->structs_to_review > 0)
    {
        ui_712_review_struct(path_get_nth_field_to_last(ui_ctx->structs_to_review));
        ui_ctx->structs_to_review -= 1;
    }
    else
    {
        if (!ui_ctx->end_reached)
        {
            handle_eip712_return_code(true);
        }
        else
        {
            if (ui_ctx->pos == UI_712_POS_REVIEW)
            {
                ux_flow_next();
                ui_ctx->pos = UI_712_POS_END;
            }
            else
            {
                ux_flow_prev();
                ui_ctx->pos = UI_712_POS_REVIEW;
            }
        }
    }
}

/**
 * Used to notify of a new struct to review
 *
 * @param[in] struct_ptr pointer to the structure to be shown
 */
void    ui_712_review_struct(const void *const struct_ptr)
{
    const char *struct_name;
    uint8_t struct_name_length;
    const char *const title = "Review struct";

    if (ui_ctx == NULL)
    {
        return;
    }

    ui_712_set_title(title, strlen(title));
    if ((struct_name = get_struct_name(struct_ptr, &struct_name_length)) != NULL)
    {
        ui_712_set_value(struct_name, struct_name_length);
    }
    ui_712_redraw_generic_step();
}

/**
 * Show the hash of the message on the generic UI step
 */
void    ui_712_message_hash(void)
{
    const char *const title = "Message hash";

    ui_712_set_title(title, strlen(title));
    snprintf(strings.tmp.tmp,
             sizeof(strings.tmp.tmp),
             "0x%.*H",
             KECCAK256_HASH_BYTESIZE,
             tmpCtx.messageSigningContext712.messageHash);
    ui_712_redraw_generic_step();
}

/**
 * Format a given data as a string
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 */
static void ui_712_format_str(const uint8_t *const data, uint8_t length)
{
    if (ui_712_field_shown())
    {
        ui_712_set_value((char*)data, length);
    }
}

/**
 * Format a given data as a string representation of an address
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 * @return if the formatting was successful
 */
static bool ui_712_format_addr(const uint8_t *const data, uint8_t length)
{
    if (length != ADDRESS_LENGTH)
    {
        apdu_response_code = APDU_RESPONSE_INVALID_DATA;
        return false;
    }
    if (ui_712_field_shown())
    {
        getEthDisplayableAddress((uint8_t*)data,
                                 strings.tmp.tmp,
                                 sizeof(strings.tmp.tmp),
                                 &global_sha3,
                                 chainConfig->chainId);
    }
    return true;
}

/**
 * Format given data as a string representation of a boolean
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 * @return if the formatting was successful
 */
static bool ui_712_format_bool(const uint8_t *const data, uint8_t length)
{
    const char *const true_str = "true";
    const char *const false_str = "false";
    const char *str;

    if (length != 1)
    {
        apdu_response_code = APDU_RESPONSE_INVALID_DATA;
        return false;
    }
    str = *data ? true_str : false_str;
    if (ui_712_field_shown())
    {
        ui_712_set_value(str, strlen(str));
    }
    return true;
}

/**
 * Format given data as a string representation of bytes
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 */
static void ui_712_format_bytes(const uint8_t *const data, uint8_t length)
{
    if (ui_712_field_shown())
    {
        snprintf(strings.tmp.tmp,
                sizeof(strings.tmp.tmp),
                "0x%.*H",
                length,
                data);
        // +2 for the "0x"
        // x2 for each byte value is represented by 2 ASCII characters
        if ((2 + (length * 2)) > (sizeof(strings.tmp.tmp) - 1))
        {
            strings.tmp.tmp[sizeof(strings.tmp.tmp) - 1 - 3] = '\0';
            strcat(strings.tmp.tmp, "...");
        }
    }
}

/**
 * Format given data as a string representation of an integer
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 * @return if the formatting was successful
 */
static bool ui_712_format_int(const uint8_t *const data,
                              uint8_t length,
                              const void *const field_ptr)
{
    uint256_t value256;
    uint128_t value128;
    int32_t value32;
    int16_t value16;

    switch (get_struct_field_typesize(field_ptr) * 8)
    {
        case 256:
            convertUint256BE(data, length, &value256);
            if (ui_712_field_shown())
            {
                tostring256_signed(&value256, 10, strings.tmp.tmp, sizeof(strings.tmp.tmp));
            }
            break;
        case 128:
            convertUint128BE(data, length, &value128);
            if (ui_712_field_shown())
            {
                tostring128_signed(&value128, 10, strings.tmp.tmp, sizeof(strings.tmp.tmp));
            }
            break;
        case 64:
            convertUint64BEto128(data, length, &value128);
            if (ui_712_field_shown())
            {
                tostring128_signed(&value128, 10, strings.tmp.tmp, sizeof(strings.tmp.tmp));
            }
            break;
        case 32:
            value32 = 0;
            for (int i = 0; i < length; ++i)
            {
                ((uint8_t*)&value32)[length - 1 - i] = data[i];
            }
            if (ui_712_field_shown())
            {
                snprintf(strings.tmp.tmp,
                         sizeof(strings.tmp.tmp),
                         "%d",
                         value32);
            }
            break;
        case 16:
            value16 = 0;
            for (int i = 0; i < length; ++i)
            {
                ((uint8_t*)&value16)[length - 1 - i] = data[i];
            }
            if (ui_712_field_shown())
            {
                snprintf(strings.tmp.tmp,
                         sizeof(strings.tmp.tmp),
                         "%d",
                         value16); // expanded to 32 bits
            }
            break;
        case 8:
            if (ui_712_field_shown())
            {
                snprintf(strings.tmp.tmp,
                         sizeof(strings.tmp.tmp),
                         "%d",
                         ((int8_t*)data)[0]); // expanded to 32 bits
            }
            break;
        default:
            PRINTF("Unhandled field typesize\n");
            apdu_response_code = APDU_RESPONSE_INVALID_DATA;
            return false;
    }
    return true;
}

/**
 * Format given data as a string representation of an unsigned integer
 *
 * @param[in] data the data that needs formatting
 * @param[in] length its length
 */
static void ui_712_format_uint(const uint8_t *const data, uint8_t length)
{
    uint256_t value256;

    convertUint256BE(data, length, &value256);
    if (ui_712_field_shown())
    {
        tostring256(&value256, 10, strings.tmp.tmp, sizeof(strings.tmp.tmp));
    }
}

/**
 * Used to notify of a new field to review in the current struct (key + value)
 *
 * @param[in] field_ptr pointer to the new struct field
 * @param[in] data pointer to the field's raw value
 * @param[in] length field's raw value byte-length
 */
bool    ui_712_new_field(const void *const field_ptr, const uint8_t *const data, uint8_t length)
{
    const char *key;
    uint8_t key_len;

    if (ui_ctx == NULL)
    {
        apdu_response_code = APDU_RESPONSE_CONDITION_NOT_SATISFIED;
        return false;
    }

    // Key
    if ((key = get_struct_field_keyname(field_ptr, &key_len)) == NULL)
    {
        apdu_response_code = APDU_RESPONSE_CONDITION_NOT_SATISFIED;
        return false;
    }

    if (ui_712_field_shown() && !(ui_ctx->field_flags & UI_712_FIELD_NAME_PROVIDED))
    {
        ui_712_set_title(key, key_len);
    }

    // Value
    switch (struct_field_type(field_ptr))
    {
        case TYPE_SOL_STRING:
            ui_712_format_str(data, length);
            break;
        case TYPE_SOL_ADDRESS:
            if (ui_712_format_addr(data, length) == false)
            {
                return false;
            }
            break;
        case TYPE_SOL_BOOL:
            if (ui_712_format_bool(data, length) == false)
            {
                return false;
            }
            break;
        case TYPE_SOL_BYTES_FIX:
        case TYPE_SOL_BYTES_DYN:
            ui_712_format_bytes(data, length);
            break;
        case TYPE_SOL_INT:
            if (ui_712_format_int(data, length, field_ptr) == false)
            {
                return false;
            }
            break;
        case TYPE_SOL_UINT:
            ui_712_format_uint(data, length);
            break;
        default:
            PRINTF("Unhandled type\n");
            return false;
    }

    // Check if this field is supposed to be displayed
    if (ui_712_field_shown())
    {
        ui_712_redraw_generic_step();
    }
    return true;
}

/**
 * Used to signal that we are done with reviewing the structs and we can now have
 * the option to approve or reject the signature
 */
void    ui_712_end_sign(void)
{
    if (ui_ctx == NULL)
    {
        apdu_response_code = APDU_RESPONSE_CONDITION_NOT_SATISFIED;
        return;
    }
    ui_ctx->end_reached = true;

    if (N_storage.verbose_eip712 || (ui_ctx->filtering_mode == EIP712_FILTERING_FULL))
    {
        ui_712_next_field();
    }
}

/**
 * Initializes the UI context structure in memory
 */
bool    ui_712_init(void)
{
    if ((ui_ctx = MEM_ALLOC_AND_ALIGN_TYPE(*ui_ctx)))
    {
        ui_ctx->shown = false;
        ui_ctx->end_reached = false;
        ui_ctx->pos = UI_712_POS_REVIEW;
        ui_ctx->filtering_mode = EIP712_FILTERING_BASIC;
    }
    else
    {
        apdu_response_code = APDU_RESPONSE_INSUFFICIENT_MEMORY;
    }
    return ui_ctx != NULL;
}

/**
 * Deinit function that simply unsets the struct pointer to NULL
 */
void    ui_712_deinit(void)
{
    ui_ctx = NULL;
}

/**
 * Approve button handling, calls the common handler function then
 * deinitializes the EIP712 context altogether.
 * @param[in] e unused here, just needed to match the UI function signature
 * @return unused here, just needed to match the UI function signature
 */
unsigned int ui_712_approve(const bagl_element_t *e)
{
    ui_712_approve_cb(e);
    eip712_context_deinit();
    return 0;
}

/**
 * Reject button handling, calls the common handler function then
 * deinitializes the EIP712 context altogether.

 * @param[in] e unused here, just needed to match the UI function signature
 * @return unused here, just needed to match the UI function signature
 */
unsigned int ui_712_reject(const bagl_element_t *e)
{
    ui_712_reject_cb(e);
    eip712_context_deinit();
    return 0;
}

/**
 * Set a structure field's UI flags
 *
 * @param[in] show if this field should be shown on the device
 * @param[in] name_provided if a substitution name has been provided
 */
void    ui_712_flag_field(bool show, bool name_provided)
{
    if (show)
    {
        ui_ctx->field_flags |= UI_712_FIELD_SHOWN;
    }
    if (name_provided)
    {
        ui_ctx->field_flags |= UI_712_FIELD_NAME_PROVIDED;
    }
}

/**
 * Set the UI filtering mode
 *
 * @param[in] the new filtering mode
 */
void    ui_712_set_filtering_mode(e_eip712_filtering_mode mode)
{
    ui_ctx->filtering_mode = mode;
}

/**
 * Get the UI filtering mode
 *
 * @return current filtering mode
 */
e_eip712_filtering_mode ui_712_get_filtering_mode(void)
{
    return ui_ctx->filtering_mode;
}

/**
 * Reset all the UI struct field flags
 */
void    ui_712_field_flags_reset(void)
{
    ui_ctx->field_flags = 0;
}

/**
 * Add a struct to the UI review queue
 *
 * Makes it so the user will have to go through a "Review struct" screen
 */
void    ui_712_queue_struct_to_review(void)
{
    if (N_storage.verbose_eip712)
    {
        ui_ctx->structs_to_review += 1;
    }
}

#endif // HAVE_EIP712_FULL_SUPPORT