openssh/radix.c

/*
 *   radix.c
 *
 *   base-64 encoding pinched from lynx2-7-2, who pinched it from rpem.
 *   Originally written by Mark Riordan 12 August 1990 and 17 Feb 1991
 *   and placed in the public domain.
 *
 *   Dug Song <dugsong@UMICH.EDU>
 */

#include "includes.h"

#ifdef AFS
#include <krb.h>

char six2pr[64] = {
	'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
	'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
	'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
	'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
	'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

unsigned char pr2six[256];

int
uuencode(unsigned char *bufin, unsigned int nbytes, char *bufcoded)
{
	/* ENC is the basic 1 character encoding function to make a char printing */
#define ENC(c) six2pr[c]

	register char *outptr = bufcoded;
	unsigned int i;

	for (i = 0; i < nbytes; i += 3) {
		*(outptr++) = ENC(*bufin >> 2);						/* c1 */
		*(outptr++) = ENC(((*bufin << 4) & 060)   | ((bufin[1] >> 4) & 017));	/* c2 */
		*(outptr++) = ENC(((bufin[1] << 2) & 074) | ((bufin[2] >> 6) & 03));	/* c3 */
		*(outptr++) = ENC(bufin[2] & 077);					/* c4 */
		bufin += 3;
	}
	if (i == nbytes + 1) {
		outptr[-1] = '=';
	} else if (i == nbytes + 2) {
		outptr[-1] = '=';
		outptr[-2] = '=';
	}
	*outptr = '\0';
	return (outptr - bufcoded);
}

int
uudecode(const char *bufcoded, unsigned char *bufplain, int outbufsize)
{
	/* single character decode */
#define DEC(c) pr2six[(unsigned char)c]
#define MAXVAL 63

	static int first = 1;
	int nbytesdecoded, j;
	const char *bufin = bufcoded;
	register unsigned char *bufout = bufplain;
	register int nprbytes;

	/* If this is the first call, initialize the mapping table. */
	if (first) {
		first = 0;
		for (j = 0; j < 256; j++)
			pr2six[j] = MAXVAL + 1;
		for (j = 0; j < 64; j++)
			pr2six[(unsigned char) six2pr[j]] = (unsigned char) j;
	}
	/* Strip leading whitespace. */
	while (*bufcoded == ' ' || *bufcoded == '\t')
		bufcoded++;

	/*
	 * Figure out how many characters are in the input buffer. If this
	 * would decode into more bytes than would fit into the output
	 * buffer, adjust the number of input bytes downwards.
	 */
	bufin = bufcoded;
	while (DEC(*(bufin++)) <= MAXVAL);
	nprbytes = bufin - bufcoded - 1;
	nbytesdecoded = ((nprbytes + 3) / 4) * 3;
	if (nbytesdecoded > outbufsize)
		nprbytes = (outbufsize * 4) / 3;

	bufin = bufcoded;

	while (nprbytes > 0) {
		*(bufout++) = (unsigned char) (DEC(*bufin)   << 2 | DEC(bufin[1]) >> 4);
		*(bufout++) = (unsigned char) (DEC(bufin[1]) << 4 | DEC(bufin[2]) >> 2);
		*(bufout++) = (unsigned char) (DEC(bufin[2]) << 6 | DEC(bufin[3]));
		bufin += 4;
		nprbytes -= 4;
	}
	if (nprbytes & 03) {
		if (DEC(bufin[-2]) > MAXVAL)
			nbytesdecoded -= 2;
		else
			nbytesdecoded -= 1;
	}
	return (nbytesdecoded);
}

typedef unsigned char my_u_char;
typedef unsigned int my_u_int32_t;
typedef unsigned short my_u_short;

/* Nasty macros from BIND-4.9.2 */

#define GETSHORT(s, cp) { \
	register my_u_char *t_cp = (my_u_char*)(cp); \
	(s) = (((my_u_short)t_cp[0]) << 8) \
	    | (((my_u_short)t_cp[1])) \
	    ; \
	(cp) += 2; \
}

#define GETLONG(l, cp) { \
	register my_u_char *t_cp = (my_u_char*)(cp); \
	(l) = (((my_u_int32_t)t_cp[0]) << 24) \
	    | (((my_u_int32_t)t_cp[1]) << 16) \
	    | (((my_u_int32_t)t_cp[2]) << 8) \
	    | (((my_u_int32_t)t_cp[3])) \
	    ; \
	(cp) += 4; \
}

#define PUTSHORT(s, cp) { \
	register my_u_short t_s = (my_u_short)(s); \
	register my_u_char *t_cp = (my_u_char*)(cp); \
	*t_cp++ = t_s >> 8; \
	*t_cp   = t_s; \
	(cp) += 2; \
}

#define PUTLONG(l, cp) { \
	register my_u_int32_t t_l = (my_u_int32_t)(l); \
	register my_u_char *t_cp = (my_u_char*)(cp); \
	*t_cp++ = t_l >> 24; \
	*t_cp++ = t_l >> 16; \
	*t_cp++ = t_l >> 8; \
	*t_cp   = t_l; \
	(cp) += 4; \
}

#define GETSTRING(s, p, p_l) {			\
    register char* p_targ = (p) + p_l;		\
    register char* s_c = (s);			\
    register char* p_c = (p);			\
    while (*p_c && (p_c < p_targ)) {		\
	*s_c++ = *p_c++;			\
    }						\
    if (p_c == p_targ) {			\
	return 1;				\
    }						\
    *s_c = *p_c++;				\
    (p_l) = (p_l) - (p_c - (p));		\
    (p) = p_c;					\
}


int
creds_to_radix(CREDENTIALS *creds, unsigned char *buf)
{
	char *p, *s;
	int len;
	char temp[2048];

	p = temp;
	*p++ = 1;		/* version */
	s = creds->service;
	while (*s)
		*p++ = *s++;
	*p++ = *s;
	s = creds->instance;
	while (*s)
		*p++ = *s++;
	*p++ = *s;
	s = creds->realm;
	while (*s)
		*p++ = *s++;
	*p++ = *s;

	s = creds->pname;
	while (*s)
		*p++ = *s++;
	*p++ = *s;
	s = creds->pinst;
	while (*s)
		*p++ = *s++;
	*p++ = *s;
	/* Null string to repeat the realm. */
	*p++ = '\0';

	PUTLONG(creds->issue_date, p);
	{
		unsigned int endTime;
		endTime = (unsigned int) krb_life_to_time(creds->issue_date,
							  creds->lifetime);
		PUTLONG(endTime, p);
	}

	memcpy(p, &creds->session, sizeof(creds->session));
	p += sizeof(creds->session);

	PUTSHORT(creds->kvno, p);
	PUTLONG(creds->ticket_st.length, p);

	memcpy(p, creds->ticket_st.dat, creds->ticket_st.length);
	p += creds->ticket_st.length;
	len = p - temp;

	return (uuencode((unsigned char *)temp, len, (char *)buf));
}

int
radix_to_creds(const char *buf, CREDENTIALS *creds)
{

	char *p;
	int len, tl;
	char version;
	char temp[2048];

	if (!(len = uudecode(buf, (unsigned char *)temp, sizeof(temp))))
		return 0;

	p = temp;

	/* check version and length! */
	if (len < 1)
		return 0;
	version = *p;
	p++;
	len--;

	GETSTRING(creds->service, p, len);
	GETSTRING(creds->instance, p, len);
	GETSTRING(creds->realm, p, len);

	GETSTRING(creds->pname, p, len);
	GETSTRING(creds->pinst, p, len);
	/* Ignore possibly different realm. */
	while (*p && len)
		p++, len--;
	if (len == 0)
		return 0;
	p++, len--;

	/* Enough space for remaining fixed-length parts? */
	if (len < (4 + 4 + sizeof(creds->session) + 2 + 4))
		return 0;

	GETLONG(creds->issue_date, p);
	len -= 4;
	{
		unsigned int endTime;
		GETLONG(endTime, p);
		len -= 4;
		creds->lifetime = krb_time_to_life(creds->issue_date, endTime);
	}

	memcpy(&creds->session, p, sizeof(creds->session));
	p += sizeof(creds->session);
	len -= sizeof(creds->session);

	GETSHORT(creds->kvno, p);
	len -= 2;
	GETLONG(creds->ticket_st.length, p);
	len -= 4;

	tl = creds->ticket_st.length;
	if (tl < 0 || tl > len || tl > sizeof(creds->ticket_st.dat))
		return 0;

	memcpy(creds->ticket_st.dat, p, tl);
	p += tl;
	len -= tl;

	return 1;
}
#endif /* AFS */