#include "common.h"

void ecdaa_rand(void *buffer, size_t buflen) {
    getrandom(buffer, buflen, 0);
}

char bin2hex(uint8_t byte) {
    uint8_t word = byte & 0x0f;
    char hex = 0;
    if (word >= 0 && word <= 9) hex = word + '0';
    else if (word >= 10 && word <= 15) hex = word - 10 + 'A';
    return hex;
}

uint8_t hex2bin(char hex) {
    uint8_t byte = 0;
    if (hex >= '0' && hex <= '9') byte = hex - '0';
    else if (hex >= 'a' && hex <= 'f') byte = hex - 'a' + 10;
    else if (hex >= 'A' && hex <= 'F') byte = hex - 'A' + 10;
    return byte;
}

void ecdaa_hextobin(const char *in_hex, uint8_t *out_bin, size_t outlen) {
    for (size_t i = 0, j = 0; i < outlen; i++, j+=2) {
        uint8_t val = hex2bin(in_hex[j]);
        val += hex2bin(in_hex[j+1]) * 16;
        out_bin[i] = (char) val;
    }
}

void ecdaa_bintohex(const uint8_t *in_bin, size_t inlen, char *out_hex) {
    for (size_t i = 0, j = 0; i < inlen; i++, j+=2) {
        out_hex[j] = bin2hex(in_bin[i]);
        out_hex[j+1] = bin2hex(in_bin[i] >> 4);
    }
}