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rfc2047.h File Reference

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

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Functions

void rfc2047_decode (char **pd)
 Decode any RFC2047-encoded header fields.
 
void rfc2047_encode (char **pd, const char *specials, int col, const struct Slist *charsets)
 RFC-2047-encode a string.
 
void rfc2047_decode_addrlist (struct AddressList *al)
 Decode any RFC2047 headers in an Address list.
 
void rfc2047_encode_addrlist (struct AddressList *al, const char *tag)
 Encode any RFC2047 headers, where required, in an Address list.
 
void rfc2047_decode_envelope (struct Envelope *env)
 Decode the fields of an Envelope.
 
void rfc2047_encode_envelope (struct Envelope *env)
 Encode the fields of an Envelope.
 

Detailed Description

RFC2047 MIME extensions encoding / decoding routines.

Authors
  • Richard Russon
  • Pietro Cerutti

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.h.

Function Documentation

◆ rfc2047_decode()

void rfc2047_decode ( char ** pd)

Decode any RFC2047-encoded header fields.

Parameters
[in,out]pdString 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 665 of file rfc2047.c.

666{
667 if (!pd || !*pd)
668 return;
669
670 struct Buffer *buf = buf_pool_get(); // Output buffer
671 char *s = *pd; // Read pointer
672 char *beg = NULL; // Begin of encoded word
673 enum ContentEncoding enc = ENC_OTHER; // ENC_BASE64 or ENC_QUOTED_PRINTABLE
674 char *charset = NULL; // Which charset
675 size_t charsetlen; // Length of the charset
676 char *text = NULL; // Encoded text
677 size_t textlen = 0; // Length of encoded text
678
679 /* Keep some state in case the next decoded word is using the same charset
680 * and it happens to be split in the middle of a multibyte character.
681 * See https://github.com/neomutt/neomutt/issues/1015 */
682 struct Buffer *prev = buf_pool_get(); /* Previously decoded word */
683 char *prev_charset = NULL; /* Previously used charset */
684 size_t prev_charsetlen = 0; /* Length of the previously used charset */
685
686 const struct Slist *c_assumed_charset = cc_assumed_charset();
687 const char *c_charset = cc_charset();
688 while (*s)
689 {
690 beg = parse_encoded_word(s, &enc, &charset, &charsetlen, &text, &textlen);
691 if (beg != s)
692 {
693 /* Some non-encoded text was found */
694 size_t holelen = beg ? beg - s : mutt_str_len(s);
695
696 /* Ignore whitespace between encoded words */
697 if (beg && (mutt_str_lws_len(s, holelen) == holelen))
698 {
699 s = beg;
700 continue;
701 }
702
703 /* If we have some previously decoded text, add it now */
704 if (!buf_is_empty(prev))
705 {
706 finalize_chunk(buf, prev, prev_charset, prev_charsetlen);
707 }
708
709 /* Add non-encoded part */
710 if (slist_is_empty(c_assumed_charset))
711 {
712 buf_addstr_n(buf, s, holelen);
713 }
714 else
715 {
716 char *conv = mutt_strn_dup(s, holelen);
717 mutt_ch_convert_nonmime_string(c_assumed_charset, c_charset, &conv);
718 buf_addstr(buf, conv);
719 FREE(&conv);
720 }
721 s += holelen;
722 }
723 if (beg)
724 {
725 /* Some encoded text was found */
726 text[textlen] = '\0';
727 char *decoded = decode_word(text, textlen, enc);
728 if (!decoded)
729 {
730 goto done;
731 }
732 if (!buf_is_empty(prev) && ((prev_charsetlen != charsetlen) ||
733 !mutt_strn_equal(prev_charset, charset, charsetlen)))
734 {
735 /* Different charset, convert the previous chunk and add it to the
736 * final result */
737 finalize_chunk(buf, prev, prev_charset, prev_charsetlen);
738 }
739
740 buf_addstr(prev, decoded);
741 FREE(&decoded);
742 prev_charset = charset;
743 prev_charsetlen = charsetlen;
744 s = text + textlen + 2; /* Skip final ?= */
745 }
746 }
747
748 /* Save the last chunk */
749 if (!buf_is_empty(prev))
750 {
751 finalize_chunk(buf, prev, prev_charset, prev_charsetlen);
752 }
753
754 FREE(pd);
755 *pd = buf_strdup(buf);
756
757done:
758 buf_pool_release(&buf);
759 buf_pool_release(&prev);
760}
size_t buf_addstr_n(struct Buffer *buf, const char *s, size_t len)
Add a string to a Buffer, expanding it if necessary.
Definition buffer.c:96
bool buf_is_empty(const struct Buffer *buf)
Is the Buffer empty?
Definition buffer.c:291
size_t buf_addstr(struct Buffer *buf, const char *s)
Add a string to a Buffer.
Definition buffer.c:226
char * buf_strdup(const struct Buffer *buf)
Copy a Buffer's string.
Definition buffer.c:571
const char * cc_charset(void)
Get the cached value of $charset.
const struct Slist * cc_assumed_charset(void)
Get the cached value of $assumed_charset.
#define FREE(x)
Free memory and set the pointer to NULL.
Definition memory.h:68
ContentEncoding
Content-Transfer-Encoding.
Definition mime.h:47
@ ENC_OTHER
Encoding unknown.
Definition mime.h:48
int mutt_ch_convert_nonmime_string(const struct Slist *const assumed_charset, const char *charset, char **ps)
Try to convert a string using a list of character sets.
Definition charset.c:317
bool slist_is_empty(const struct Slist *list)
Is the slist empty?
Definition slist.c:140
char * mutt_strn_dup(const char *begin, size_t len)
Duplicate a sub-string.
Definition string.c:384
size_t mutt_str_lws_len(const char *s, size_t n)
Measure the linear-white-space at the beginning of a string.
Definition string.c:630
bool mutt_strn_equal(const char *a, const char *b, size_t num)
Check for equality of two strings (to a maximum), safely.
Definition string.c:429
size_t mutt_str_len(const char *a)
Calculate the length of a string, safely.
Definition string.c:500
struct Buffer * buf_pool_get(void)
Get a Buffer from the pool.
Definition pool.c:91
void buf_pool_release(struct Buffer **ptr)
Return a Buffer to the pool.
Definition pool.c:111
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.
Definition rfc2047.c:151
static char * decode_word(const char *s, size_t len, enum ContentEncoding enc)
Decode an RFC2047-encoded string.
Definition rfc2047.c:369
static void finalize_chunk(struct Buffer *res, struct Buffer *buf, char *charset, size_t charsetlen)
Perform charset conversion and filtering.
Definition rfc2047.c:345
String manipulation buffer.
Definition buffer.h:36
String list.
Definition slist.h:37
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◆ rfc2047_encode()

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

RFC-2047-encode a string.

Parameters
[in,out]pdString to be encoded, and resulting encoded string
[in]specialsSpecial characters to be encoded
[in]colStarting index in string
[in]charsetsList of charsets to choose from

Definition at line 632 of file rfc2047.c.

633{
634 if (!pd || !*pd)
635 return;
636
637 const char *const c_charset = cc_charset();
638 if (!c_charset)
639 return;
640
641 struct Slist *fallback = NULL;
642 if (!charsets)
643 {
644 fallback = slist_parse("utf-8", D_SLIST_SEP_COLON);
645 charsets = fallback;
646 }
647
648 char *e = NULL;
649 size_t elen = 0;
650 encode(*pd, strlen(*pd), col, c_charset, charsets, &e, &elen, specials);
651
652 slist_free(&fallback);
653 FREE(pd);
654 *pd = e;
655}
struct Slist * slist_parse(const char *str, uint32_t flags)
Parse a list of strings into a list.
Definition slist.c:177
void slist_free(struct Slist **ptr)
Free an Slist object.
Definition slist.c:124
static int encode(const char *d, size_t dlen, int col, const char *fromcode, const struct Slist *charsets, char **e, size_t *elen, const char *specials)
RFC2047-encode a string.
Definition rfc2047.c:430
#define D_SLIST_SEP_COLON
Slist items are colon-separated.
Definition types.h:112
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◆ rfc2047_decode_addrlist()

void rfc2047_decode_addrlist ( struct AddressList * al)

Decode any RFC2047 headers in an Address list.

Parameters
alAddressList
Note
rfc2047_decode() may realloc the data pointer it's given, so work on a copy to avoid breaking the Buffer

Definition at line 805 of file rfc2047.c.

806{
807 if (!al)
808 return;
809
810 const bool assumed = !slist_is_empty(cc_assumed_charset());
811 struct Address *a = NULL;
812 char *data = NULL;
813 TAILQ_FOREACH(a, al, entries)
814 {
815 if (a->personal && ((buf_find_string(a->personal, "=?")) || assumed))
816 {
817 data = buf_strdup(a->personal);
818 rfc2047_decode(&data);
819 buf_strcpy(a->personal, data);
820 FREE(&data);
821 }
822 else if (a->group && a->mailbox && buf_find_string(a->mailbox, "=?"))
823 {
824 data = buf_strdup(a->mailbox);
825 rfc2047_decode(&data);
826 buf_strcpy(a->mailbox, data);
827 FREE(&data);
828 }
829 }
830}
const char * buf_find_string(const struct Buffer *buf, const char *s)
Return a pointer to a substring found in the buffer.
Definition buffer.c:638
size_t buf_strcpy(struct Buffer *buf, const char *s)
Copy a string into a Buffer.
Definition buffer.c:395
#define TAILQ_FOREACH(var, head, field)
Definition queue.h:782
void rfc2047_decode(char **pd)
Decode any RFC2047-encoded header fields.
Definition rfc2047.c:665
An email address.
Definition address.h:35
struct Buffer * personal
Real name of address.
Definition address.h:36
bool group
Group mailbox?
Definition address.h:38
struct Buffer * mailbox
Mailbox and host address.
Definition address.h:37
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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
alAddressList
tagHeader tag (used for wrapping calculation)
Note
rfc2047_encode() may realloc the data pointer it's given, so work on a copy to avoid breaking the Buffer

Definition at line 770 of file rfc2047.c.

771{
772 if (!al)
773 return;
774
775 int col = tag ? strlen(tag) + 2 : 32;
776 struct Address *a = NULL;
777 char *data = NULL;
778 const struct Slist *const c_send_charset = cs_subset_slist(NeoMutt->sub, "send_charset");
779 TAILQ_FOREACH(a, al, entries)
780 {
781 if (a->personal)
782 {
783 data = buf_strdup(a->personal);
784 rfc2047_encode(&data, AddressSpecials, col, c_send_charset);
785 buf_strcpy(a->personal, data);
786 FREE(&data);
787 }
788 else if (a->group && a->mailbox)
789 {
790 data = buf_strdup(a->mailbox);
791 rfc2047_encode(&data, AddressSpecials, col, c_send_charset);
792 buf_strcpy(a->mailbox, data);
793 FREE(&data);
794 }
795 }
796}
const char AddressSpecials[]
Characters with special meaning for email addresses.
Definition address.c:45
const struct Slist * cs_subset_slist(const struct ConfigSubset *sub, const char *name)
Get a string-list config item by name.
Definition helpers.c:242
void rfc2047_encode(char **pd, const char *specials, int col, const struct Slist *charsets)
RFC-2047-encode a string.
Definition rfc2047.c:632
Container for Accounts, Notifications.
Definition neomutt.h:41
struct ConfigSubset * sub
Inherited config items.
Definition neomutt.h:49
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◆ rfc2047_decode_envelope()

void rfc2047_decode_envelope ( struct Envelope * env)

Decode the fields of an Envelope.

Parameters
envEnvelope

Definition at line 836 of file rfc2047.c.

837{
838 if (!env)
839 return;
848 rfc2047_decode(&env->x_label);
849
850 char *subj = env->subject;
851 *(char **) &env->subject = NULL;
852 rfc2047_decode(&subj);
853 mutt_env_set_subject(env, subj);
854 FREE(&subj);
855}
void mutt_env_set_subject(struct Envelope *env, const char *subj)
Set both subject and real_subj to subj.
Definition envelope.c:68
void rfc2047_decode_addrlist(struct AddressList *al)
Decode any RFC2047 headers in an Address list.
Definition rfc2047.c:805
struct AddressList return_path
Return path for the Email.
Definition envelope.h:58
char *const subject
Email's subject.
Definition envelope.h:70
struct AddressList to
Email's 'To' list.
Definition envelope.h:60
struct AddressList reply_to
Email's 'reply-to'.
Definition envelope.h:64
struct AddressList mail_followup_to
Email's 'mail-followup-to'.
Definition envelope.h:65
struct AddressList cc
Email's 'Cc' list.
Definition envelope.h:61
struct AddressList sender
Email's sender.
Definition envelope.h:63
struct AddressList bcc
Email's 'Bcc' list.
Definition envelope.h:62
char * x_label
X-Label.
Definition envelope.h:76
struct AddressList from
Email's 'From' list.
Definition envelope.h:59
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◆ rfc2047_encode_envelope()

void rfc2047_encode_envelope ( struct Envelope * env)

Encode the fields of an Envelope.

Parameters
envEnvelope

Definition at line 861 of file rfc2047.c.

862{
863 if (!env)
864 return;
865 rfc2047_encode_addrlist(&env->from, "From");
866 rfc2047_encode_addrlist(&env->to, "To");
867 rfc2047_encode_addrlist(&env->cc, "Cc");
868 rfc2047_encode_addrlist(&env->bcc, "Bcc");
869 rfc2047_encode_addrlist(&env->reply_to, "Reply-To");
870 rfc2047_encode_addrlist(&env->mail_followup_to, "Mail-Followup-To");
871 rfc2047_encode_addrlist(&env->sender, "Sender");
872 const struct Slist *const c_send_charset = cs_subset_slist(NeoMutt->sub, "send_charset");
873 rfc2047_encode(&env->x_label, NULL, sizeof("X-Label:"), c_send_charset);
874
875 char *subj = env->subject;
876 *(char **) &env->subject = NULL;
877 rfc2047_encode(&subj, NULL, sizeof("Subject:"), c_send_charset);
878 mutt_env_set_subject(env, subj);
879 FREE(&subj);
880}
void rfc2047_encode_addrlist(struct AddressList *al, const char *tag)
Encode any RFC2047 headers, where required, in an Address list.
Definition rfc2047.c:770
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