RFC2047 MIME extensions encoding / decoding routines. More...

#include "config.h"
#include <assert.h>
#include <errno.h>
#include <iconv.h>
#include <regex.h>
#include <stdbool.h>
#include <string.h>
#include "mutt/mutt.h"
#include "address/lib.h"
#include "rfc2047.h"
#include "email_globals.h"
#include "envelope.h"
#include "mime.h"

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Macros
#define	ENCWORD_LEN_MAX 75

#define	ENCWORD_LEN_MIN 9 /* strlen ("=?.?.?.?=") */

#define	HSPACE(ch) (((ch) == '\0') \|\| ((ch) == ' ') \|\| ((ch) == '\t'))

#define	CONTINUATION_BYTE(ch) (((ch) &0xc0) == 0x80)

Typedefs
typedef size_t(*	encoder_t) (char str, const char buf, size_t buflen, const char *tocode)
	typedef encoder_t - Prototype for an encoding function More...

Functions
static size_t	b_encoder (char str, const char buf, size_t buflen, const char *tocode)
	Base64 Encode a string - Implements encoder_t. More...

static size_t	q_encoder (char str, const char buf, size_t buflen, const char *tocode)
	Quoted-printable Encode a string - Implements encoder_t. More...

static char *	parse_encoded_word (char str, enum ContentEncoding enc, char *charset, size_t charsetlen, char *text, size_t textlen)
	Parse a string and report RFC2047 elements. More...

static size_t	try_block (const char d, size_t dlen, const char fromcode, const char tocode, encoder_t encoder, size_t *wlen)
	Attempt to convert a block of text. More...

static size_t	encode_block (char str, char buf, size_t buflen, const char fromcode, const char tocode, encoder_t encoder)
	Encode a block of text using an encoder. More...

static size_t	choose_block (char d, size_t dlen, int col, const char fromcode, const char tocode, encoder_t encoder, size_t *wlen)
	Calculate how much data can be converted. More...

static void	finalize_chunk (struct Buffer res, struct Buffer buf, char *charset, size_t charsetlen)
	Perform charset conversion and filtering. More...

static char *	decode_word (const char *s, size_t len, enum ContentEncoding enc)
	Decode an RFC2047-encoded string. More...

static int	encode (const char d, size_t dlen, int col, const char fromcode, const char charsets, char e, size_t elen, const char *specials)
	RFC2047-encode a string. More...

void	rfc2047_encode (char *pd, const char specials, int col, const char *charsets)
	RFC-2047-encode a string. More...

void	rfc2047_decode (char **pd)
	Decode any RFC2047-encoded header fields. More...

void	rfc2047_encode_addrlist (struct AddressList al, const char tag)
	Encode any RFC2047 headers, where required, in an Address list. More...

void	rfc2047_decode_addrlist (struct AddressList *al)
	Decode any RFC2047 headers in an Address list. More...

void	rfc2047_decode_envelope (struct Envelope *env)
	Decode the fields of an Envelope. More...

void	rfc2047_encode_envelope (struct Envelope *env)
	Encode the fields of an Envelope. More...

Detailed Description

RFC2047 MIME extensions encoding / decoding routines.

Authors

Michael R. Elkins
Edmund Grimley Evans
Pietro Cerutti

Copyright: This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 2 of the License, or (at your option) any later version.

This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.

You should have received a copy of the GNU General Public License along with this program. If not, see http://www.gnu.org/licenses/.

Definition in file rfc2047.c.

Macro Definition Documentation

◆ ENCWORD_LEN_MAX

#define ENCWORD_LEN_MAX 75

Definition at line 45 of file rfc2047.c.

◆ ENCWORD_LEN_MIN

#define ENCWORD_LEN_MIN 9 /* strlen ("=?.?.?.?=") */

Definition at line 46 of file rfc2047.c.

◆ HSPACE

#define HSPACE ( ch ) (((ch) == '\0') || ((ch) == ' ') || ((ch) == '\t'))

Definition at line 48 of file rfc2047.c.

◆ CONTINUATION_BYTE

#define CONTINUATION_BYTE ( ch ) (((ch) &0xc0) == 0x80)

Definition at line 50 of file rfc2047.c.

Typedef Documentation

◆ encoder_t

typedef size_t(* encoder_t) (char *str, const char *buf, size_t buflen, const char *tocode)

typedef encoder_t - Prototype for an encoding function

Parameters

str	String to encode
buf	Buffer for result
buflen	Length of buffer
tocode	Character encoding

Return values

num	Bytes written to buffer

Definition at line 60 of file rfc2047.c.

Function Documentation

◆ b_encoder()

static size_t b_encoder	(	char *	str,
		const char *	buf,
		size_t	buflen,
		const char *	tocode
	)

static

Base64 Encode a string - Implements encoder_t.

Definition at line 65 of file rfc2047.c.

 {
   char *s0 = str;
 
   memcpy(str, "=?", 2);
   str += 2;
   memcpy(str, tocode, strlen(tocode));
   str += strlen(tocode);
   memcpy(str, "?B?", 3);
   str += 3;
 
   while (buflen)
   {
     char encoded[11];
     size_t ret;
     size_t in_len = MIN(3, buflen);
 
     ret = mutt_b64_encode(buf, in_len, encoded, sizeof(encoded));
     for (size_t i = 0; i < ret; i++)
       *str++ = encoded[i];
 
     buflen -= in_len;
     buf += in_len;
   }
 
   memcpy(str, "?=", 2);
   str += 2;
   return str - s0;
 }

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◆ q_encoder()

static size_t q_encoder	(	char *	str,
		const char *	buf,
		size_t	buflen,
		const char *	tocode
	)

static

Quoted-printable Encode a string - Implements encoder_t.

Definition at line 98 of file rfc2047.c.

 {
   static const char hex[] = "0123456789ABCDEF";
   char *s0 = str;
 
   memcpy(str, "=?", 2);
   str += 2;
   memcpy(str, tocode, strlen(tocode));
   str += strlen(tocode);
   memcpy(str, "?Q?", 3);
   str += 3;
   while (buflen--)
   {
     unsigned char c = *buf++;
     if (c == ' ')
       *str++ = '_';
     else if ((c >= 0x7f) || (c < 0x20) || (c == '_') || strchr(MimeSpecials, c))
     {
       *str++ = '=';
       *str++ = hex[(c & 0xf0) >> 4];
       *str++ = hex[c & 0x0f];
     }
     else
       *str++ = c;
   }
   memcpy(str, "?=", 2);
   str += 2;
   return str - s0;
 }

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◆ parse_encoded_word()

static char* parse_encoded_word	(	char *	str,
		enum ContentEncoding *	enc,
		char **	charset,
		size_t *	charsetlen,
		char **	text,
		size_t *	textlen
	)

static

Parse a string and report RFC2047 elements.

Parameters

[in]	str	String to parse
[out]	enc	Content encoding found in the first RFC2047 word
[out]	charset	Charset found in the first RFC2047 word
[out]	charsetlen	Length of the charset string found
[out]	text	Start of the first RFC2047 encoded text
[out]	textlen	Length of the encoded text found

Return values

ptr	Start of the RFC2047 encoded word
NULL	None was found

Definition at line 139 of file rfc2047.c.

 {
   regmatch_t match[4];
   size_t nmatch = 4;
   struct Regex *re = mutt_regex_compile("=\\?"
                                         "([^][()<>@,;:\\\"/?. =]+)" /* charset */
                                         "\\?"
                                         "([qQbB])" /* encoding */
                                         "\\?"
                                         "([^?]+)" /* encoded text - we accept whitespace
                                          as some mailers do that, see #1189. */
                                         "\\?=",
                                         REG_EXTENDED);
   assert(re && "Something is wrong with your RE engine.");
 
   char *res = NULL;
 
   if (mutt_regex_capture(re, str, nmatch, match))
   {
     /* Charset */
     *charset = str + match[1].rm_so;
     *charsetlen = match[1].rm_eo - match[1].rm_so;
 
     /* Encoding: either Q or B */
     *enc = ((str[match[2].rm_so] == 'Q') || (str[match[2].rm_so] == 'q')) ?
                ENC_QUOTED_PRINTABLE :
                ENC_BASE64;
 
     *text = str + match[3].rm_so;
     *textlen = match[3].rm_eo - match[3].rm_so;
     res = str + match[0].rm_so;
   }
 
   mutt_regex_free(&re);
   return res;
 }

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◆ try_block()

static size_t try_block	(	const char *	d,
		size_t	dlen,
		const char *	fromcode,
		const char *	tocode,
		encoder_t *	encoder,
		size_t *	wlen
	)

static

Attempt to convert a block of text.

Parameters

d	String to convert
dlen	Length of string
fromcode	Original encoding
tocode	New encoding
encoder	Encoding function
wlen	Number of characters converted

Return values

0	Success, string converted
>0	Error, number of bytes that could be converted

If the data could be converted using encoder, then set *encoder and *wlen. Otherwise return an upper bound on the maximum length of the data which could be converted.

The data is converted from fromcode (which must be stateless) to tocode, unless fromcode is NULL, in which case the data is assumed to be already in tocode, which should be 8-bit and stateless.

Definition at line 196 of file rfc2047.c.

 {
   char buf[ENCWORD_LEN_MAX - ENCWORD_LEN_MIN + 1];
   const char *ib = NULL;
   char *ob = NULL;
   size_t ibl, obl;
   int count, len, len_b, len_q;
 
   if (fromcode)
   {
     iconv_t cd = mutt_ch_iconv_open(tocode, fromcode, 0);
     assert(cd != (iconv_t)(-1));
     ib = d;
     ibl = dlen;
     ob = buf;
     obl = sizeof(buf) - strlen(tocode);
     if ((iconv(cd, (ICONV_CONST char **) &ib, &ibl, &ob, &obl) == (size_t)(-1)) ||
         (iconv(cd, NULL, NULL, &ob, &obl) == (size_t)(-1)))
     {
       assert(errno == E2BIG);
       iconv_close(cd);
       assert(ib > d);
       return ((ib - d) == dlen) ? dlen : ib - d + 1;
     }
     iconv_close(cd);
   }
   else
   {
     if (dlen > (sizeof(buf) - strlen(tocode)))
       return sizeof(buf) - strlen(tocode) + 1;
     memcpy(buf, d, dlen);
     ob = buf + dlen;
   }
 
   count = 0;
   for (char *p = buf; p < ob; p++)
   {
     unsigned char c = *p;
     assert(strchr(MimeSpecials, '?'));
     if ((c >= 0x7f) || (c < 0x20) || (*p == '_') ||
         ((c != ' ') && strchr(MimeSpecials, *p)))
     {
       count++;
     }
   }
 
   len = ENCWORD_LEN_MIN - 2 + strlen(tocode);
   len_b = len + (((ob - buf) + 2) / 3) * 4;
   len_q = len + (ob - buf) + 2 * count;
 
   /* Apparently RFC1468 says to use B encoding for iso-2022-jp. */
   if (mutt_str_strcasecmp(tocode, "ISO-2022-JP") == 0)
     len_q = ENCWORD_LEN_MAX + 1;
 
   if ((len_b < len_q) && (len_b <= ENCWORD_LEN_MAX))
   {
     *encoder = b_encoder;
     *wlen = len_b;
     return 0;
   }
   else if (len_q <= ENCWORD_LEN_MAX)
   {
     *encoder = q_encoder;
     *wlen = len_q;
     return 0;
   }
   else
     return dlen;
 }

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◆ encode_block()

static size_t encode_block	(	char *	str,
		char *	buf,
		size_t	buflen,
		const char *	fromcode,
		const char *	tocode,
		encoder_t	encoder
	)

static

Encode a block of text using an encoder.

Parameters

str	String to convert
buf	Buffer for result
buflen	Buffer length
fromcode	Original encoding
tocode	New encoding
encoder	Encoding function

Return values

num	Length of the encoded word

Encode the data (buf, buflen) into str using the encoder.

Definition at line 279 of file rfc2047.c.

 {
   if (!fromcode)
   {
     return (*encoder)(str, buf, buflen, tocode);
   }
 
   const iconv_t cd = mutt_ch_iconv_open(tocode, fromcode, 0);
   assert(cd != (iconv_t)(-1));
   const char *ib = buf;
   size_t ibl = buflen;
   char tmp[ENCWORD_LEN_MAX - ENCWORD_LEN_MIN + 1];
   char *ob = tmp;
   size_t obl = sizeof(tmp) - strlen(tocode);
   const size_t n1 = iconv(cd, (ICONV_CONST char **) &ib, &ibl, &ob, &obl);
   const size_t n2 = iconv(cd, NULL, NULL, &ob, &obl);
   assert(n1 != (size_t)(-1) && n2 != (size_t)(-1));
   iconv_close(cd);
   return (*encoder)(str, tmp, ob - tmp, tocode);
 }

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◆ choose_block()

static size_t choose_block	(	char *	d,
		size_t	dlen,
		int	col,
		const char *	fromcode,
		const char *	tocode,
		encoder_t *	encoder,
		size_t *	wlen
	)

static

Calculate how much data can be converted.

Parameters

d	String to convert
dlen	Length of string
col	Starting column to convert
fromcode	Original encoding
tocode	New encoding
encoder	Encoding function
wlen	Number of characters converted

Return values

num	Bytes that can be converted

Discover how much of the data (d, dlen) can be converted into a single encoded word. Return how much data can be converted, and set the length *wlen of the encoded word and *encoder. We start in column col, which limits the length of the word.

Definition at line 317 of file rfc2047.c.

 {
   const bool utf8 = fromcode && (mutt_str_strcasecmp(fromcode, "utf-8") == 0);
 
   size_t n = dlen;
   while (true)
   {
     assert(n > 0);
     const size_t nn = try_block(d, n, fromcode, tocode, encoder, wlen);
     if ((nn == 0) && (((col + *wlen) <= (ENCWORD_LEN_MAX + 1)) || (n <= 1)))
       break;
     n = ((nn != 0) ? nn : n) - 1;
     assert(n > 0);
     if (utf8)
       while ((n > 1) && CONTINUATION_BYTE(d[n]))
         n--;
   }
   return n;
 }

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◆ finalize_chunk()

static void finalize_chunk	(	struct Buffer *	res,
		struct Buffer *	buf,
		char *	charset,
		size_t	charsetlen
	)

static

Perform charset conversion and filtering.

Parameters

[out]	res	Buffer where the resulting string is appended
[in]	buf	Buffer with the input string
[in]	charset	Charset to use for the conversion
[in]	charsetlen	Length of the charset parameter

The buffer buf is reinitialized at the end of this function.

Definition at line 347 of file rfc2047.c.

 {
   if (!charset)
     return;
   char end = charset[charsetlen];
   charset[charsetlen] = '\0';
   mutt_ch_convert_string(&buf->data, charset, C_Charset, MUTT_ICONV_HOOK_FROM);
   charset[charsetlen] = end;
   mutt_mb_filter_unprintable(&buf->data);
   mutt_buffer_addstr(res, buf->data);
   FREE(&buf->data);
   mutt_buffer_init(buf);
 }

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◆ decode_word()

static char* decode_word	(	const char *	s,
		size_t	len,
		enum ContentEncoding	enc
	)

static

Decode an RFC2047-encoded string.

Parameters

s	String to decode
len	Length of the string
enc	Encoding type

Return values

ptr	Decoded string

Note: The caller must free the returned string

Definition at line 370 of file rfc2047.c.

 {
   const char *it = s;
   const char *end = s + len;
 
   if (enc == ENC_QUOTED_PRINTABLE)
   {
     struct Buffer buf = mutt_buffer_make(0);
     for (; it < end; it++)
     {
       if (*it == '_')
       {
         mutt_buffer_addch(&buf, ' ');
       }
       else if ((it[0] == '=') && (!(it[1] & ~127) && (hexval(it[1]) != -1)) &&
                (!(it[2] & ~127) && (hexval(it[2]) != -1)))
       {
         mutt_buffer_addch(&buf, (hexval(it[1]) << 4) | hexval(it[2]));
         it += 2;
       }
       else
       {
         mutt_buffer_addch(&buf, *it);
       }
     }
     mutt_buffer_addch(&buf, '\0');
     return buf.data;
   }
   else if (enc == ENC_BASE64)
   {
     const int olen = 3 * len / 4 + 1;
     char *out = mutt_mem_malloc(olen);
     int dlen = mutt_b64_decode(it, out, olen);
     if (dlen == -1)
     {
       FREE(&out);
       return NULL;
     }
     out[dlen] = '\0';
     return out;
   }
 
   assert(0); /* The enc parameter has an invalid value */
   return NULL;
 }

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◆ encode()

static int encode	(	const char *	d,
		size_t	dlen,
		int	col,
		const char *	fromcode,
		const char *	charsets,
		char **	e,
		size_t *	elen,
		const char *	specials
	)

static

RFC2047-encode a string.

Parameters

[in]	d	String to convert
[in]	dlen	Length of string
[in]	col	Starting column to convert
[in]	fromcode	Original encoding
[in]	charsets	List of allowable encodings (colon separated)
[out]	e	Encoded string
[out]	elen	Length of encoded string
[in]	specials	Special characters to be encoded

Return values

0 Success

Definition at line 428 of file rfc2047.c.

 {
   int rc = 0;
   char *buf = NULL;
   size_t bufpos, buflen;
   char *t0 = NULL, *t1 = NULL, *t = NULL;
   char *s0 = NULL, *s1 = NULL;
   size_t ulen, r, wlen = 0;
   encoder_t encoder = NULL;
   char *tocode1 = NULL;
   const char *tocode = NULL;
   const char *icode = "utf-8";
 
   /* Try to convert to UTF-8. */
   char *u = mutt_str_substr_dup(d, d + dlen);
   if (mutt_ch_convert_string(&u, fromcode, icode, 0) != 0)
   {
     rc = 1;
     icode = 0;
   }
   ulen = mutt_str_strlen(u);
 
   /* Find earliest and latest things we must encode. */
   s0 = 0;
   s1 = 0;
   t0 = 0;
   t1 = 0;
   for (t = u; t < (u + ulen); t++)
   {
     if ((*t & 0x80) || ((*t == '=') && (t[1] == '?') && ((t == u) || HSPACE(*(t - 1)))))
     {
       if (!t0)
         t0 = t;
       t1 = t;
     }
     else if (specials && *t && strchr(specials, *t))
     {
       if (!s0)
         s0 = t;
       s1 = t;
     }
   }
 
   /* If we have something to encode, include RFC822 specials */
   if (t0 && s0 && (s0 < t0))
     t0 = s0;
   if (t1 && s1 && (s1 > t1))
     t1 = s1;
 
   if (!t0)
   {
     /* No encoding is required. */
     *e = u;
     *elen = ulen;
     return rc;
   }
 
   /* Choose target charset. */
   tocode = fromcode;
   if (icode)
   {
     tocode1 = mutt_ch_choose(icode, charsets, u, ulen, 0, 0);
     if (tocode1)
       tocode = tocode1;
     else
     {
       rc = 2;
       icode = 0;
     }
   }
 
   /* Hack to avoid labelling 8-bit data as us-ascii. */
   if (!icode && mutt_ch_is_us_ascii(tocode))
     tocode = "unknown-8bit";
 
   /* Adjust t0 for maximum length of line. */
   t = u + (ENCWORD_LEN_MAX + 1) - col - ENCWORD_LEN_MIN;
   if (t < u)
     t = u;
   if (t < t0)
     t0 = t;
 
   /* Adjust t0 until we can encode a character after a space. */
   for (; t0 > u; t0--)
   {
     if (!HSPACE(*(t0 - 1)))
       continue;
     t = t0 + 1;
     if (icode)
       while ((t < (u + ulen)) && CONTINUATION_BYTE(*t))
         t++;
     if ((try_block(t0, t - t0, icode, tocode, &encoder, &wlen) == 0) &&
         ((col + (t0 - u) + wlen) <= (ENCWORD_LEN_MAX + 1)))
     {
       break;
     }
   }
 
   /* Adjust t1 until we can encode a character before a space. */
   for (; t1 < (u + ulen); t1++)
   {
     if (!HSPACE(*t1))
       continue;
     t = t1 - 1;
     if (icode)
       while (CONTINUATION_BYTE(*t))
         t--;
     if ((try_block(t, t1 - t, icode, tocode, &encoder, &wlen) == 0) &&
         ((1 + wlen + (u + ulen - t1)) <= (ENCWORD_LEN_MAX + 1)))
     {
       break;
     }
   }
 
   /* We shall encode the region [t0,t1). */
 
   /* Initialise the output buffer with the us-ascii prefix. */
   buflen = 2 * ulen;
   buf = mutt_mem_malloc(buflen);
   bufpos = t0 - u;
   memcpy(buf, u, t0 - u);
 
   col += t0 - u;
 
   t = t0;
   while (true)
   {
     /* Find how much we can encode. */
     size_t n = choose_block(t, t1 - t, col, icode, tocode, &encoder, &wlen);
     if (n == (t1 - t))
     {
       /* See if we can fit the us-ascii suffix, too. */
       if ((col + wlen + (u + ulen - t1)) <= (ENCWORD_LEN_MAX + 1))
         break;
       n = t1 - t - 1;
       if (icode)
         while (CONTINUATION_BYTE(t[n]))
           n--;
       if (n == 0)
       {
         /* This should only happen in the really stupid case where the
          * only word that needs encoding is one character long, but
          * there is too much us-ascii stuff after it to use a single
          * encoded word. We add the next word to the encoded region
          * and try again. */
         assert(t1 < (u + ulen));
         for (t1++; (t1 < (u + ulen)) && !HSPACE(*t1); t1++)
           ;
         continue;
       }
       n = choose_block(t, n, col, icode, tocode, &encoder, &wlen);
     }
 
     /* Add to output buffer. */
     const char *line_break = "\n\t";
     const int lb_len = 2; /* strlen(line_break) */
 
     if ((bufpos + wlen + lb_len) > buflen)
     {
       buflen = bufpos + wlen + lb_len;
       mutt_mem_realloc(&buf, buflen);
     }
     r = encode_block(buf + bufpos, t, n, icode, tocode, encoder);
     assert(r == wlen);
     bufpos += wlen;
     memcpy(buf + bufpos, line_break, lb_len);
     bufpos += lb_len;
 
     col = 1;
 
     t += n;
   }
 
   /* Add last encoded word and us-ascii suffix to buffer. */
   buflen = bufpos + wlen + (u + ulen - t1);
   mutt_mem_realloc(&buf, buflen + 1);
   r = encode_block(buf + bufpos, t, t1 - t, icode, tocode, encoder);
   assert(r == wlen);
   bufpos += wlen;
   memcpy(buf + bufpos, t1, u + ulen - t1);
 
   FREE(&tocode1);
   FREE(&u);
 
   buf[buflen] = '\0';
 
   *e = buf;
   *elen = buflen + 1;
   return rc;
 }

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◆ rfc2047_encode()

void rfc2047_encode	(	char **	pd,
		const char *	specials,
		int	col,
		const char *	charsets
	)

RFC-2047-encode a string.

Parameters

[in,out]	pd	String to be encoded, and resulting encoded string
[in]	specials	Special characters to be encoded
[in]	col	Starting index in string
[in]	charsets	List of charsets to choose from

Definition at line 627 of file rfc2047.c.

 {
   if (!C_Charset || !pd || !*pd)
     return;
 
   if (!charsets)
     charsets = "utf-8";
 
   char *e = NULL;
   size_t elen = 0;
   encode(*pd, strlen(*pd), col, C_Charset, charsets, &e, &elen, specials);
 
   FREE(pd);
   *pd = e;
 }

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◆ rfc2047_decode()

void rfc2047_decode ( char ** pd )

Decode any RFC2047-encoded header fields.

Parameters

[in,out] pd String to be decoded, and resulting decoded string

Try to decode anything that looks like a valid RFC2047 encoded header field, ignoring RFC822 parsing rules. If decoding fails, for example due to an invalid base64 string, the original input is left untouched.

Definition at line 651 of file rfc2047.c.

 {
   if (!pd || !*pd)
     return;
 
   struct Buffer buf = mutt_buffer_make(0); /* Output buffer            */
   char *s = *pd;            /* Read pointer                           */
   char *beg = NULL;         /* Begin of encoded word                  */
   enum ContentEncoding enc; /* ENC_BASE64 or ENC_QUOTED_PRINTABLE     */
   char *charset = NULL;     /* Which charset                          */
   size_t charsetlen;        /* Length of the charset                  */
   char *text = NULL;        /* Encoded text                           */
   size_t textlen;           /* Length of encoded text                 */
 
   /* Keep some state in case the next decoded word is using the same charset
    * and it happens to be split in the middle of a multibyte character.
    * See https://github.com/neomutt/neomutt/issues/1015 */
   struct Buffer prev = mutt_buffer_make(0); /* Previously decoded word  */
   char *prev_charset = NULL;  /* Previously used charset                */
   size_t prev_charsetlen = 0; /* Length of the previously used charset  */
 
   while (*s)
   {
     beg = parse_encoded_word(s, &enc, &charset, &charsetlen, &text, &textlen);
     if (beg != s)
     {
       /* Some non-encoded text was found */
       size_t holelen = beg ? beg - s : mutt_str_strlen(s);
 
       /* Ignore whitespace between encoded words */
       if (beg && (mutt_str_lws_len(s, holelen) == holelen))
       {
         s = beg;
         continue;
       }
 
       /* If we have some previously decoded text, add it now */
       if (!mutt_buffer_is_empty(&prev))
       {
         finalize_chunk(&buf, &prev, prev_charset, prev_charsetlen);
       }
 
       /* Add non-encoded part */
       {
         if (C_AssumedCharset)
         {
           char *conv = mutt_str_substr_dup(s, s + holelen);
           mutt_ch_convert_nonmime_string(&conv);
           mutt_buffer_addstr(&buf, conv);
           FREE(&conv);
         }
         else
         {
           mutt_buffer_addstr_n(&buf, s, holelen);
         }
       }
       s += holelen;
     }
     if (beg)
     {
       /* Some encoded text was found */
       text[textlen] = '\0';
       char *decoded = decode_word(text, textlen, enc);
       if (!decoded)
       {
         return;
       }
       if (prev.data && ((prev_charsetlen != charsetlen) ||
                         (mutt_str_strncmp(prev_charset, charset, charsetlen) != 0)))
       {
         /* Different charset, convert the previous chunk and add it to the
          * final result */
         finalize_chunk(&buf, &prev, prev_charset, prev_charsetlen);
       }
 
       mutt_buffer_addstr(&prev, decoded);
       FREE(&decoded);
       prev_charset = charset;
       prev_charsetlen = charsetlen;
       s = text + textlen + 2; /* Skip final ?= */
     }
   }
 
   /* Save the last chunk */
   if (prev.data)
   {
     finalize_chunk(&buf, &prev, prev_charset, prev_charsetlen);
   }
 
   mutt_buffer_addch(&buf, '\0');
   FREE(pd);
   *pd = buf.data;
 }

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◆ rfc2047_encode_addrlist()

void rfc2047_encode_addrlist	(	struct AddressList *	al,
		const char *	tag
	)

Encode any RFC2047 headers, where required, in an Address list.

Parameters

al	AddressList
tag	Header tag (used for wrapping calculation)

Definition at line 750 of file rfc2047.c.

 {
   if (!al)
     return;
 
   int col = tag ? strlen(tag) + 2 : 32;
   struct Address *a = NULL;
   TAILQ_FOREACH(a, al, entries)
   {
     if (a->personal)
       rfc2047_encode(&a->personal, AddressSpecials, col, C_SendCharset);
     else if (a->group && a->mailbox)
       rfc2047_encode(&a->mailbox, AddressSpecials, col, C_SendCharset);
   }
 }

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◆ rfc2047_decode_addrlist()

void rfc2047_decode_addrlist ( struct AddressList * al )

Decode any RFC2047 headers in an Address list.

Parameters

al	AddressList

Definition at line 770 of file rfc2047.c.

 {
   if (!al)
     return;
 
   struct Address *a = NULL;
   TAILQ_FOREACH(a, al, entries)
   {
     if (a->personal && ((strstr(a->personal, "=?")) || C_AssumedCharset))
     {
       rfc2047_decode(&a->personal);
     }
     else if (a->group && a->mailbox && strstr(a->mailbox, "=?"))
       rfc2047_decode(&a->mailbox);
   }
 }

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◆ rfc2047_decode_envelope()

void rfc2047_decode_envelope ( struct Envelope * env )

Decode the fields of an Envelope.

Parameters

env Envelope

Definition at line 791 of file rfc2047.c.

 {
   if (!env)
     return;
   rfc2047_decode_addrlist(&env->from);
   rfc2047_decode_addrlist(&env->to);
   rfc2047_decode_addrlist(&env->cc);
   rfc2047_decode_addrlist(&env->bcc);
   rfc2047_decode_addrlist(&env->reply_to);
   rfc2047_decode_addrlist(&env->mail_followup_to);
   rfc2047_decode_addrlist(&env->return_path);
   rfc2047_decode_addrlist(&env->sender);
   rfc2047_decode(&env->x_label);
   rfc2047_decode(&env->subject);
 }

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◆ rfc2047_encode_envelope()

void rfc2047_encode_envelope ( struct Envelope * env )

Encode the fields of an Envelope.

Parameters

env Envelope

Definition at line 811 of file rfc2047.c.

 {
   if (!env)
     return;
   rfc2047_encode_addrlist(&env->from, "From");
   rfc2047_encode_addrlist(&env->to, "To");
   rfc2047_encode_addrlist(&env->cc, "Cc");
   rfc2047_encode_addrlist(&env->bcc, "Bcc");
   rfc2047_encode_addrlist(&env->reply_to, "Reply-To");
   rfc2047_encode_addrlist(&env->mail_followup_to, "Mail-Followup-To");
   rfc2047_encode_addrlist(&env->sender, "Sender");
   rfc2047_encode(&env->x_label, NULL, sizeof("X-Label:"), C_SendCharset);
   rfc2047_encode(&env->subject, NULL, sizeof("Subject:"), C_SendCharset);
 }

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Macros

Typedefs

Functions

Detailed Description

Macro Definition Documentation

◆ ENCWORD_LEN_MAX

◆ ENCWORD_LEN_MIN

◆ HSPACE

◆ CONTINUATION_BYTE

Typedef Documentation

◆ encoder_t

Function Documentation

◆ b_encoder()

◆ q_encoder()

◆ parse_encoded_word()

◆ try_block()

◆ encode_block()

◆ choose_block()

◆ finalize_chunk()

◆ decode_word()

◆ encode()

◆ rfc2047_encode()

◆ rfc2047_decode()

◆ rfc2047_encode_addrlist()

◆ rfc2047_decode_addrlist()

◆ rfc2047_decode_envelope()

◆ rfc2047_encode_envelope()