ethereum-erc20-tx-data.c

#include <stdlib.h>
#include <stdio.h>

#define DATA_TYPE_ADDRESS 1

#define DATA_TYPE_UINT256 2

int is_match(char *a, char *b)
{
    return !(a[0] ^ b[0] | a[1] ^ b[1] | a[2] ^ b[2] | a[3] ^ b[3]);
}

/*
Result:

Method name: Transfer
Number of parameters: 2
To address: 0x97fb750807bf06a1553b6436763d29767a1f73d9
Value: 0x1f0dd440
*/
int main()
{

    char sig[] = {0xa9, 0x05, 0x9c, 0xbb, 0x8, 'T', 'r', 'a', 'n', 's', 'f', 'e', 'r', 0x2, DATA_TYPE_ADDRESS, DATA_TYPE_UINT256};
    char tx[] = {0xa9, 0x05, 0x9c, 0xbb,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x97, 0xfb, 0x75, 0x08, 0x07, 0xbf, 0x06, 0xa1, 0x55, 0x3b, 0x64, 0x36, 0x76, 0x3d, 0x29, 0x76, 0x7a, 0x1f, 0x73, 0xd9,
                 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x1f, 0x0d, 0xd4, 0x40};
    int tx_seek = 4;
    int sig_seek = 4;

    if (is_match(sig, tx))
    {
        int sig_seek_end = sig_seek + sig[sig_seek];
        int tx_seek_end = tx_seek;
        sig_seek += 1;
        sig_seek_end += 1;
        printf("Method name: ");
        for (; sig_seek < sig_seek_end; sig_seek++)
        {
            printf("%c", sig[sig_seek]);
        }
        printf("\nNumber of parameters: %d\n", sig[sig_seek]);
        sig_seek_end = sig_seek + sig[sig_seek];
        sig_seek += 1;
        for (; sig_seek <= sig_seek_end; sig_seek++)
        {
            if (sig[sig_seek] == DATA_TYPE_ADDRESS)
            {
                tx_seek += 12;
                tx_seek_end = tx_seek + 20;
                printf("To address: 0x");
                for (; tx_seek < tx_seek_end; tx_seek++)
                {
                    printf("%.2x", tx[tx_seek]);
                }
                printf("\n");
            }

            if (sig[sig_seek] == DATA_TYPE_UINT256)
            {
                tx_seek_end += 32;
                printf("Value: 0x");
                for (; tx_seek < tx_seek_end; tx_seek++)
                {
                    if (tx[tx_seek] > 0)
                    {
                        printf("%.2x", tx[tx_seek]);
                    }
                }
                printf("\n");
            }
        }
    }

    return EXIT_SUCCESS;
}