CALCUL DE CLEF RIB

long atoln(int n, const char* s) {
	long v=0;
	char* p = s;
	while(n-->0)
		v = v*10 + *(p++)-'0';
	return v;
}

unsigned int computeRIBkey(char* s, char* key) {
	int i;
	char r[21];

	if (!s || !key)
		return 0;

	for (i=0; i<21; i++)
		if(s[i]>='0' && s[i]<='9')
			r[i] = s[i];
		else if(s[i]>='a' && s[i]<='z')
			r[i] = '1' + (s[i]-'a')%9;
		else if(s[i]>='A' && s[i]<='Z')
			r[i] = '1' + (s[i]-'A')%9;
		else
			return 0;

	i = 97-((89*atoln(5, r) + 15*atoln(5, r+5) + 3*atoln(11, r+10))%97);
	if (i<10)
		key[0] = '0';
	else
		key[0] = '0'+i/10;
	key[1] = '0'+i%10;
	key[2] = 0;
	return 1;
}