[hcoop/debian/exim4.git] / src / base64.c

/*************************************************
*     Exim - an Internet mail transport agent    *
*************************************************/

/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004, 2015 */
/* License: GPL */

/* Copyright (c) University of Cambridge 1995 - 2018 */
/* See the file NOTICE for conditions of use and distribution. */


#include "exim.h"
#ifdef WITH_CONTENT_SCAN	/* file-IO specific decode function */
# include "mime.h"

/* BASE64 decoder matrix */
static unsigned char mime_b64[256]={
/*   0 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/*  16 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/*  32 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,   62,  128,  128,  128,   63,
/*  48 */   52,   53,   54,   55,   56,   57,   58,   59,   60,   61,  128,  128,  128,  255,  128,  128,
/*  64 */  128,    0,    1,    2,    3,    4,    5,    6,    7,    8,    9,   10,   11,   12,   13,   14,
/*  80 */   15,   16,   17,   18,   19,   20,   21,   22,   23,   24,   25,  128,  128,  128,  128,  128,
/*  96 */  128,   26,   27,   28,   29,   30,   31,   32,   33,   34,   35,   36,   37,   38,   39,   40,
/* 112 */   41,   42,   43,   44,   45,   46,   47,   48,   49,   50,   51,  128,  128,  128,  128,  128,
/* 128 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 144 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 160 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 176 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 192 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 208 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 224 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,
/* 240 */  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128,  128
};

/* decode base64 MIME part */
ssize_t
mime_decode_base64(FILE * in, FILE * out, uschar * boundary)
{
uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
uschar *ipos, *opos;
ssize_t len, size = 0;
int bytestate = 0;

opos = obuf;

while (Ufgets(ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
  {
  if (boundary != NULL
     && Ustrncmp(ibuf, "--", 2) == 0
     && Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
     )
    break;

  for (ipos = ibuf ; *ipos != '\r' && *ipos != '\n' && *ipos != 0; ++ipos)
    if (*ipos == '=')			/* skip padding */
      ++bytestate;

    else if (mime_b64[*ipos] == 128)	/* skip bad characters */
      mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);

    /* simple state-machine */
    else switch((bytestate++) & 3)
      {
      case 0:
	*opos = mime_b64[*ipos] << 2; break;
      case 1:
	*opos++ |= mime_b64[*ipos] >> 4;
	*opos = mime_b64[*ipos] << 4; break;
      case 2:
	*opos++ |= mime_b64[*ipos] >> 2;
	*opos = mime_b64[*ipos] << 6; break;
      case 3:
	*opos++ |= mime_b64[*ipos]; break;
      }

  /* something to write? */
  len = opos - obuf;
  if (len > 0)
    {
    if (fwrite(obuf, 1, len, out) != len) return -1; /* error */
    size += len;
    /* copy incomplete last byte to start of obuf, where we continue */
    if ((bytestate & 3) != 0)
      *obuf = *opos;
    opos = obuf;
    }
  } /* while */

/* write out last byte if it was incomplete */
if (bytestate & 3)
  {
  if (fwrite(obuf, 1, 1, out) != 1) return -1;
  ++size;
  }

return size;
}

#endif	/*WITH_CONTENT_SCAN*/

/*************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************
 *************************************************/


/*************************************************
*          Decode byte-string in base 64         *
*************************************************/

/* This function decodes a string in base 64 format as defined in RFC 2045
(MIME) and required by the SMTP AUTH extension (RFC 2554). The decoding
algorithm is written out in a straightforward way. Turning it into some kind of
compact loop is messy and would probably run more slowly.

Arguments:
  code        points to the coded string, zero-terminated
  ptr         where to put the pointer to the result, which is in
              allocated store, and zero-terminated

Returns:      the number of bytes in the result,
              or -1 if the input was malformed

Whitespace in the input is ignored.
A zero is added on to the end to make it easy in cases where the result is to
be interpreted as text. This is not included in the count. */

static uschar dec64table[] = {
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /*  0-15 */
  255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 16-31 */
  255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63, /* 32-47 */
   52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,255,255,255, /* 48-63 */
  255,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14, /* 64-79 */
   15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255, /* 80-95 */
  255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 96-111 */
   41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255  /* 112-127*/
};

int
b64decode(const uschar *code, uschar **ptr)
{

int x, y;
uschar *result;

{
  int l = Ustrlen(code);
  *ptr = result = store_get(1 + l/4 * 3 + l%4);
}

/* Each cycle of the loop handles a quantum of 4 input bytes. For the last
quantum this may decode to 1, 2, or 3 output bytes. */

while ((x = *code++) != 0)
  {
  if (isspace(x)) continue;
  /* debug_printf("b64d: '%c'\n", x); */

  if (x > 127 || (x = dec64table[x]) == 255) return -1;

  while (isspace(y = *code++)) ;
  /* debug_printf("b64d: '%c'\n", y); */
  if (y > 127 || (y = dec64table[y]) == 255)
    return -1;

  *result++ = (x << 2) | (y >> 4);
  /* debug_printf("b64d:      -> %02x\n", result[-1]); */

  while (isspace(x = *code++)) ;
  /* debug_printf("b64d: '%c'\n", x); */
  if (x == '=')		/* endmarker, but there should be another */
    {
    while (isspace(x = *code++)) ;
    /* debug_printf("b64d: '%c'\n", x); */
    if (x != '=') return -1;
    while (isspace(y = *code++)) ;
    if (y != 0) return -1;
    /* debug_printf("b64d: DONE\n"); */
    break;
    }
  else
    {
    if (x > 127 || (x = dec64table[x]) == 255) return -1;
    *result++ = (y << 4) | (x >> 2);
    /* debug_printf("b64d:      -> %02x\n", result[-1]); */

    while (isspace(y = *code++)) ;
    /* debug_printf("b64d: '%c'\n", y); */
    if (y == '=')
      {
      while (isspace(y = *code++)) ;
      if (y != 0) return -1;
      /* debug_printf("b64d: DONE\n"); */
      break;
      }
    else
      {
      if (y > 127 || (y = dec64table[y]) == 255) return -1;
      *result++ = (x << 6) | y;
      /* debug_printf("b64d:      -> %02x\n", result[-1]); */
      }
    }
  }

*result = 0;
return result - *ptr;
}


/*************************************************
*          Encode byte-string in base 64         *
*************************************************/

/* This function encodes a string of bytes, containing any values whatsoever,
in base 64 as defined in RFC 2045 (MIME) and required by the SMTP AUTH
extension (RFC 2554). The encoding algorithm is written out in a
straightforward way. Turning it into some kind of compact loop is messy and
would probably run more slowly.

Arguments:
  clear       points to the clear text bytes
  len         the number of bytes to encode

Returns:      a pointer to the zero-terminated base 64 string, which
              is in working store
*/

static uschar *enc64table =
  US"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";

uschar *
b64encode(uschar *clear, int len)
{
uschar *code = store_get(4*((len+2)/3) + 1);
uschar *p = code;

while (len-- >0)
  {
  int x, y;

  x = *clear++;
  *p++ = enc64table[(x >> 2) & 63];

  if (len-- <= 0)
    {
    *p++ = enc64table[(x << 4) & 63];
    *p++ = '=';
    *p++ = '=';
    break;
    }

  y = *clear++;
  *p++ = enc64table[((x << 4) | ((y >> 4) & 15)) & 63];

  if (len-- <= 0)
    {
    *p++ = enc64table[(y << 2) & 63];
    *p++ = '=';
    break;
    }

  x = *clear++;
  *p++ = enc64table[((y << 2) | ((x >> 6) & 3)) & 63];

  *p++ = enc64table[x & 63];
  }

*p = 0;

return code;
}


/* End of base64.c */
/* vi: sw ai sw=2
*/
Commit	Line	Data
2ea97746 CE	1	/*************************************************
	2	* Exim - an Internet mail transport agent *
	3	*************************************************/
	4
	5	/* Copyright (c) Tom Kistner <tom@duncanthrax.net> 2004, 2015 */
	6	/* License: GPL */
	7
	8	/* Copyright (c) University of Cambridge 1995 - 2018 */
	9	/* See the file NOTICE for conditions of use and distribution. */
	10
	11
	12	#include "exim.h"
	13	#ifdef WITH_CONTENT_SCAN /* file-IO specific decode function */
	14	# include "mime.h"
	15
	16	/* BASE64 decoder matrix */
	17	static unsigned char mime_b64[256]={
	18	/* 0 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	19	/* 16 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	20	/* 32 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 62, 128, 128, 128, 63,
	21	/* 48 */ 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 128, 128, 128, 255, 128, 128,
	22	/* 64 */ 128, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14,
	23	/* 80 */ 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 128, 128, 128, 128, 128,
	24	/* 96 */ 128, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
	25	/* 112 */ 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 128, 128, 128, 128, 128,
	26	/* 128 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	27	/* 144 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	28	/* 160 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	29	/* 176 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	30	/* 192 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	31	/* 208 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	32	/* 224 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128,
	33	/* 240 */ 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128, 128
	34	};
	35
	36	/* decode base64 MIME part */
	37	ssize_t
	38	mime_decode_base64(FILE * in, FILE * out, uschar * boundary)
	39	{
	40	uschar ibuf[MIME_MAX_LINE_LENGTH], obuf[MIME_MAX_LINE_LENGTH];
	41	uschar ipos, opos;
	42	ssize_t len, size = 0;
	43	int bytestate = 0;
	44
	45	opos = obuf;
	46
	47	while (Ufgets(ibuf, MIME_MAX_LINE_LENGTH, in) != NULL)
	48	{
	49	if (boundary != NULL
	50	&& Ustrncmp(ibuf, "--", 2) == 0
	51	&& Ustrncmp((ibuf+2), boundary, Ustrlen(boundary)) == 0
	52	)
	53	break;
	54
	55	for (ipos = ibuf ; ipos != '\r' && ipos != '\n' && *ipos != 0; ++ipos)
	56	if (ipos == '=') / skip padding */
	57	++bytestate;
	58
	59	else if (mime_b64[ipos] == 128) / skip bad characters */
	60	mime_set_anomaly(MIME_ANOMALY_BROKEN_BASE64);
	61
	62	/* simple state-machine */
	63	else switch((bytestate++) & 3)
	64	{
65	case 0:
66	opos = mime_b64[ipos] << 2; break;
67	case 1:
68	opos++ \|= mime_b64[ipos] >> 4;
69	opos = mime_b64[ipos] << 4; break;
70	case 2:
71	opos++ \|= mime_b64[ipos] >> 2;
72	opos = mime_b64[ipos] << 6; break;
73	case 3:
74	opos++ \|= mime_b64[ipos]; break;
75	}
76
77	/* something to write? */
78	len = opos - obuf;
79	if (len > 0)
80	{
81	if (fwrite(obuf, 1, len, out) != len) return -1; /* error */
82	size += len;
83	/* copy incomplete last byte to start of obuf, where we continue */
84	if ((bytestate & 3) != 0)
85	obuf = opos;
86	opos = obuf;
87	}
88	} /* while */
89
90	/* write out last byte if it was incomplete */
91	if (bytestate & 3)
92	{
93	if (fwrite(obuf, 1, 1, out) != 1) return -1;
94	++size;
95	}
96
97	return size;
98	}
99
100	#endif /WITH_CONTENT_SCAN/
101
102	/*************************************************
103	*************************************************
104	*************************************************
105	*************************************************
106	*************************************************
107	*************************************************
108	*************************************************
109	*************************************************
110	*************************************************
111	*************************************************
112	*************************************************
113	*************************************************
114	*************************************************
115	*************************************************
116	*************************************************
117	*************************************************/
118
119
120	/*************************************************
121	* Decode byte-string in base 64 *
122	*************************************************/
123
124	/* This function decodes a string in base 64 format as defined in RFC 2045
125	(MIME) and required by the SMTP AUTH extension (RFC 2554). The decoding
126	algorithm is written out in a straightforward way. Turning it into some kind of
127	compact loop is messy and would probably run more slowly.
128
129	Arguments:
130	code points to the coded string, zero-terminated
131	ptr where to put the pointer to the result, which is in
132	allocated store, and zero-terminated
133
134	Returns: the number of bytes in the result,
135	or -1 if the input was malformed
136
137	Whitespace in the input is ignored.
138	A zero is added on to the end to make it easy in cases where the result is to
139	be interpreted as text. This is not included in the count. */
140
141	static uschar dec64table[] = {
142	255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 0-15 */
143	255,255,255,255,255,255,255,255,255,255,255,255,255,255,255,255, /* 16-31 */
144	255,255,255,255,255,255,255,255,255,255,255, 62,255,255,255, 63, /* 32-47 */
145	52, 53, 54, 55, 56, 57, 58, 59, 60, 61,255,255,255,255,255,255, /* 48-63 */
146	255, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, /* 64-79 */
147	15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,255,255,255,255,255, /* 80-95 */
148	255, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, /* 96-111 */
149	41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51,255,255,255,255,255 /* 112-127*/
150	};
151
152	int
153	b64decode(const uschar code, uschar *ptr)
154	{
155
156	int x, y;
157	uschar *result;
158
159	{
160	int l = Ustrlen(code);
161	ptr = result = store_get(1 + l/4 3 + l%4);
162	}
163
164	/* Each cycle of the loop handles a quantum of 4 input bytes. For the last
165	quantum this may decode to 1, 2, or 3 output bytes. */
166
167	while ((x = *code++) != 0)
168	{
169	if (isspace(x)) continue;
170	/* debug_printf("b64d: '%c'\n", x); */
171
172	if (x > 127 \|\| (x = dec64table[x]) == 255) return -1;
173
174	while (isspace(y = *code++)) ;
175	/* debug_printf("b64d: '%c'\n", y); */
176	if (y > 127 \|\| (y = dec64table[y]) == 255)
177	return -1;
178
179	*result++ = (x << 2) \| (y >> 4);
180	/* debug_printf("b64d: -> %02x\n", result[-1]); */
181
182	while (isspace(x = *code++)) ;
183	/* debug_printf("b64d: '%c'\n", x); */
184	if (x == '=') /* endmarker, but there should be another */
185	{
186	while (isspace(x = *code++)) ;
187	/* debug_printf("b64d: '%c'\n", x); */
188	if (x != '=') return -1;
189	while (isspace(y = *code++)) ;
190	if (y != 0) return -1;
191	/* debug_printf("b64d: DONE\n"); */
192	break;
193	}
194	else
195	{
196	if (x > 127 \|\| (x = dec64table[x]) == 255) return -1;
197	*result++ = (y << 4) \| (x >> 2);
198	/* debug_printf("b64d: -> %02x\n", result[-1]); */
199
200	while (isspace(y = *code++)) ;
201	/* debug_printf("b64d: '%c'\n", y); */
202	if (y == '=')
203	{
204	while (isspace(y = *code++)) ;
205	if (y != 0) return -1;
206	/* debug_printf("b64d: DONE\n"); */
207	break;
208	}
209	else
210	{
211	if (y > 127 \|\| (y = dec64table[y]) == 255) return -1;
212	*result++ = (x << 6) \| y;
213	/* debug_printf("b64d: -> %02x\n", result[-1]); */
214	}
215	}
216	}
217
218	*result = 0;
219	return result - *ptr;
220	}
221
222
223	/*************************************************
224	* Encode byte-string in base 64 *
225	*************************************************/
226
227	/* This function encodes a string of bytes, containing any values whatsoever,
228	in base 64 as defined in RFC 2045 (MIME) and required by the SMTP AUTH
229	extension (RFC 2554). The encoding algorithm is written out in a
230	straightforward way. Turning it into some kind of compact loop is messy and
231	would probably run more slowly.
232
233	Arguments:
234	clear points to the clear text bytes
235	len the number of bytes to encode
236
237	Returns: a pointer to the zero-terminated base 64 string, which
238	is in working store
239	*/
240
241	static uschar *enc64table =
242	US"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
243
244	uschar *
245	b64encode(uschar *clear, int len)
246	{
247	uschar code = store_get(4((len+2)/3) + 1);
248	uschar *p = code;
249
250	while (len-- >0)
251	{
252	int x, y;
253
254	x = *clear++;
255	*p++ = enc64table[(x >> 2) & 63];
256
257	if (len-- <= 0)
258	{
259	*p++ = enc64table[(x << 4) & 63];
260	*p++ = '=';
261	*p++ = '=';
262	break;
263	}
264
265	y = *clear++;
266	*p++ = enc64table[((x << 4) \| ((y >> 4) & 15)) & 63];
267
268	if (len-- <= 0)
269	{
270	*p++ = enc64table[(y << 2) & 63];
271	*p++ = '=';
272	break;
273	}
274
275	x = *clear++;
276	*p++ = enc64table[((y << 2) \| ((x >> 6) & 3)) & 63];
277
278	*p++ = enc64table[x & 63];
279	}
280
281	*p = 0;
282
283	return code;
284	}
285
286
287	/* End of base64.c */
288	/* vi: sw ai sw=2
289	*/