app-ethereum/src_features/setPlugin/cmd_setPlugin.c

#include "shared_context.h"
#include "apdu_constants.h"
#include "ui_flow.h"
#include "tokens.h"
#include "eth_plugin_interface.h"
#include "eth_plugin_internal.h"

// Supported internal plugins
#define ERC721_STR  "ERC721"
#define ERC1155_STR "ERC1155"

#define TYPE_SIZE               1
#define VERSION_SIZE            1
#define PLUGIN_NAME_LENGTH_SIZE 1
#define CHAIN_ID_SIZE           8
#define KEY_ID_SIZE             1
#define ALGORITHM_ID_SIZE       1
#define SIGNATURE_LENGTH_SIZE   1

#define HEADER_SIZE TYPE_SIZE + VERSION_SIZE + PLUGIN_NAME_LENGTH_SIZE

#define MIN_DER_SIG_SIZE 67
#define MAX_DER_SIG_SIZE 72

typedef enum Type {
    ETH_PLUGIN = 0x01,
} Type;

typedef enum Version {
    VERSION_1 = 0x01,
} Version;

typedef enum KeyId {
    TEST_KEY = 0x00,
    PERSO_V2_KEY_1 = 0x01,
    // Must ONLY be used with ERC721 and ERC1155 plugin
    AWS_PLUGIN_KEY_1 = 0x02,
} KeyId;

// Algorithm Id consists of a Key spec and an algorithm spec.
// Format is: KEYSPEC__ALGOSPEC
typedef enum AlgorithmID {
    ECC_SECG_P256K1__ECDSA_SHA_256 = 0x01,
} AlgorithmID;

#ifdef HAVE_NFT_TESTING_KEY
static const uint8_t LEDGER_TESTING_KEY[] = {
    0x04, 0xf5, 0x70, 0x0c, 0xa1, 0xe8, 0x74, 0x24, 0xc7, 0xc7, 0xd1, 0x19, 0xe7,
    0xe3, 0xc1, 0x89, 0xb1, 0x62, 0x50, 0x94, 0xdb, 0x6e, 0xa0, 0x40, 0x87, 0xc8,
    0x30, 0x00, 0x7d, 0x0b, 0x46, 0x9a, 0x53, 0x11, 0xee, 0x6a, 0x1a, 0xcd, 0x1d,
    0xa5, 0xaa, 0xb0, 0xf5, 0xc6, 0xdf, 0x13, 0x15, 0x8d, 0x28, 0xcc, 0x12, 0xd1,
    0xdd, 0xa6, 0xec, 0xe9, 0x46, 0xb8, 0x9d, 0x5c, 0x05, 0x49, 0x92, 0x59, 0xc4};
#endif
static const uint8_t LEDGER_PERSO_V2_PUBLIC_KEY[] = {};

// Only used for signing NFT plugins (ERC721 and ERC1155)
static const uint8_t LEDGER_NFT_SELECTOR_PUBLIC_KEY[] = {};

// Verification function used to verify the signature
typedef bool verificationAlgo(const cx_ecfp_public_key_t *,
                              int,
                              cx_md_t,
                              const unsigned char *,
                              unsigned int,
                              unsigned char *,
                              unsigned int);

// Returns the plugin type of a given plugin name.
// If the plugin name is not a specific known internal plugin, this function default return value is
// `EXERNAL`.
static pluginType_t getPluginType(char *pluginName, uint8_t pluginNameLength) {
    if (pluginNameLength == sizeof(ERC721_STR) - 1 &&
        strncmp(pluginName, ERC721_STR, pluginNameLength) == 0) {
        return ERC721;
    } else if (pluginNameLength == sizeof(ERC1155_STR) - 1 &&
               strncmp(pluginName, ERC1155_STR, pluginNameLength) == 0) {
        return ERC1155;
    } else {
        return EXTERNAL;
    }
}

void handleSetPlugin(uint8_t p1,
                     uint8_t p2,
                     uint8_t *workBuffer,
                     uint16_t dataLength,
                     unsigned int *flags,
                     unsigned int *tx) {
    UNUSED(p1);
    UNUSED(p2);
    UNUSED(flags);
    PRINTF("Handling set Plugin\n");
    uint8_t hash[INT256_LENGTH] = {0};
    cx_ecfp_public_key_t pluginKey = {0};
    tokenContext_t *tokenContext = &dataContext.tokenContext;

    uint8_t offset = 0;

    if (dataLength <= HEADER_SIZE) {
        PRINTF("Data too small for headers: expected at least %d, got %d\n",
               HEADER_SIZE,
               dataLength);
        THROW(0x6A80);
    }

    enum Type type = workBuffer[offset];
    PRINTF("Type: %d\n", type);
    switch (type) {
        case ETH_PLUGIN:
            break;
        default:
            PRINTF("Unsupported type %d\n", type);
            THROW(0x6a80);
            break;
    }
    offset += TYPE_SIZE;

    uint8_t version = workBuffer[offset];
    PRINTF("version: %d\n", version);
    switch (version) {
        case VERSION_1:
            break;
        default:
            PRINTF("Unsupported version %d\n", version);
            THROW(0x6a80);
            break;
    }
    offset += VERSION_SIZE;

    uint8_t pluginNameLength = workBuffer[offset];
    offset += PLUGIN_NAME_LENGTH_SIZE;

    // Size of the payload (everything except the signature)
    uint8_t payloadSize = HEADER_SIZE + pluginNameLength + ADDRESS_LENGTH + SELECTOR_SIZE +
                          CHAIN_ID_SIZE + KEY_ID_SIZE + ALGORITHM_ID_SIZE;
    if (dataLength < payloadSize) {
        PRINTF("Data too small for payload: expected at least %d, got %d\n",
               payloadSize,
               dataLength);
        THROW(0x6A80);
    }

    // `+ 1` because we want to add a null terminating character.
    if (pluginNameLength + 1 > sizeof(tokenContext->pluginName)) {
        PRINTF("plugin name too big: expected max %d, got %d\n",
               sizeof(dataContext.tokenContext.pluginName),
               pluginNameLength + 1);
        THROW(0x6A80);
    }

    // Safe because we've checked the size before.
    memcpy(tokenContext->pluginName, workBuffer + offset, pluginNameLength);
    tokenContext->pluginName[pluginNameLength] = '\0';

    PRINTF("Length: %d\n", pluginNameLength);
    PRINTF("plugin name: %s\n", tokenContext->pluginName);
    offset += pluginNameLength;

    memcpy(tokenContext->contractAddress, workBuffer + offset, ADDRESS_LENGTH);
    PRINTF("Address: %.*H\n", ADDRESS_LENGTH, workBuffer + offset);
    offset += ADDRESS_LENGTH;

    memcpy(tokenContext->methodSelector, workBuffer + offset, SELECTOR_SIZE);
    PRINTF("Selector: %.*H\n", SELECTOR_SIZE, tokenContext->methodSelector);
    offset += SELECTOR_SIZE;

    // TODO: store chainID and assert that tx is using the same chainid.
    // uint64_t chainid = u64_from_BE(workBuffer + offset, CHAIN_ID_SIZE);
    // PRINTF("ChainID: %.*H\n", sizeof(chainid), &chainid);
    offset += CHAIN_ID_SIZE;

    enum KeyId keyId = workBuffer[offset];
    uint8_t const *rawKey;
    uint8_t rawKeyLen;

    PRINTF("KeyID: %d\n", keyId);
    switch (keyId) {
#ifdef HAVE_NFT_TESTING_KEY
        case TEST_KEY:
            rawKey = LEDGER_TESTING_KEY;
            rawKeyLen = sizeof(LEDGER_TESTING_KEY);
            break;
#endif
        case PERSO_V2_KEY_1:
            rawKey = LEDGER_PERSO_V2_PUBLIC_KEY;
            rawKeyLen = sizeof(LEDGER_PERSO_V2_PUBLIC_KEY);
            break;
        case AWS_PLUGIN_KEY_1:
            rawKey = LEDGER_NFT_SELECTOR_PUBLIC_KEY;
            rawKeyLen = sizeof(LEDGER_NFT_SELECTOR_PUBLIC_KEY);
            break;
        default:
            PRINTF("KeyID %d not supported\n", keyId);
            THROW(0x6A80);
            break;
    }

    PRINTF("RawKey: %.*H\n", rawKeyLen, rawKey);
    offset += KEY_ID_SIZE;

    uint8_t algorithmId = workBuffer[offset];
    PRINTF("Algorithm: %d\n", algorithmId);
    cx_curve_t curve;
    verificationAlgo *verificationFn;
    cx_md_t hashId;

    switch (algorithmId) {
        case ECC_SECG_P256K1__ECDSA_SHA_256:
            curve = CX_CURVE_256K1;
            verificationFn = (verificationAlgo*)cx_ecdsa_verify;
            hashId = CX_SHA256;
            break;
        default:
            PRINTF("Incorrect algorithmId %d\n", algorithmId);
            THROW(0x6a80);
            break;
    }
    offset += ALGORITHM_ID_SIZE;
    PRINTF("hashing: %.*H\n", payloadSize, workBuffer);
    cx_hash_sha256(workBuffer, payloadSize, hash, sizeof(hash));

    if (dataLength < payloadSize + SIGNATURE_LENGTH_SIZE) {
        PRINTF("Data too short to hold signature length\n");
        THROW(0x6a80);
    }

    uint8_t signatureLen = workBuffer[offset];
    PRINTF("Sigature len: %d\n", signatureLen);
    if (signatureLen < MIN_DER_SIG_SIZE || signatureLen > MAX_DER_SIG_SIZE) {
        PRINTF("SignatureLen too big or too small. Must be between %d and %d, got %d\n",
               MIN_DER_SIG_SIZE,
               MAX_DER_SIG_SIZE,
               signatureLen);
        THROW(0x6a80);
    }
    offset += SIGNATURE_LENGTH_SIZE;

    if (dataLength < payloadSize + SIGNATURE_LENGTH_SIZE + signatureLen) {
        PRINTF("Signature could not fit in data\n");
        THROW(0x6a80);
    }

    cx_ecfp_init_public_key(curve, rawKey, rawKeyLen, &pluginKey);
    if (!verificationFn(&pluginKey,
                        CX_LAST,
                        hashId,
                        hash,
                        sizeof(hash),
                        workBuffer + offset,
                        signatureLen)) {
#ifndef HAVE_BYPASS_SIGNATURES
        PRINTF("Invalid NFT signature\n");
        THROW(0x6A80);
#endif
    }

    pluginType = getPluginType(tokenContext->pluginName, pluginNameLength);
    if (keyId == AWS_PLUGIN_KEY_1) {
        if (pluginType != ERC721 && pluginType != ERC1155) {
            PRINTF("AWS key must only be used to set NFT internal plugins\n");
            THROW(0x6A80);
        }
    }

    switch (pluginType) {
        case EXTERNAL: {
            PRINTF("Check external plugin %s\n", tokenContext->pluginName);

            // Check if the plugin is present on the device
            uint32_t params[2];
            params[0] = (uint32_t) tokenContext->pluginName;
            params[1] = ETH_PLUGIN_CHECK_PRESENCE;
            BEGIN_TRY {
                TRY {
                    os_lib_call(params);
                }
                CATCH_OTHER(e) {
                    PRINTF("%s external plugin is not present\n", tokenContext->pluginName);
                    memset(tokenContext->pluginName, 0, sizeof(tokenContext->pluginName));
                    THROW(0x6984);
                }
                FINALLY {
                }
            }
            END_TRY;
            break;
        }
        default:
            break;
    }

    G_io_apdu_buffer[(*tx)++] = 0x90;
    G_io_apdu_buffer[(*tx)++] = 0x00;
}