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-rw-r--r--mimehead.c367
1 files changed, 367 insertions, 0 deletions
diff --git a/mimehead.c b/mimehead.c
new file mode 100644
index 0000000..78997e0
--- /dev/null
+++ b/mimehead.c
@@ -0,0 +1,367 @@
+/* $Id: mimehead.c,v 1.10 2003/10/05 18:52:51 ukai Exp $ */
+/*
+ * MIME header support by Akinori ITO
+ */
+
+#include <sys/types.h>
+#include "fm.h"
+#include "myctype.h"
+#include "Str.h"
+
+#define MIME_ENCODED_LINE_LIMIT 80
+#define MIME_ENCODED_WORD_LENGTH_OFFSET 18
+#define MIME_ENCODED_WORD_LENGTH_ESTIMATION(x) \
+ (((x)+2)*4/3+MIME_ENCODED_WORD_LENGTH_OFFSET)
+#define MIME_DECODED_WORD_LENGTH_ESTIMATION(x) \
+ (((x)-MIME_ENCODED_WORD_LENGTH_OFFSET)/4*3)
+#define J_CHARSET "ISO-2022-JP"
+
+#define BAD_BASE64 255
+
+static
+ unsigned char
+c2e(char x)
+{
+ if ('A' <= x && x <= 'Z')
+ return (x) - 'A';
+ if ('a' <= x && x <= 'z')
+ return (x) - 'a' + 26;
+ if ('0' <= x && x <= '9')
+ return (x) - '0' + 52;
+ if (x == '+')
+ return 62;
+ if (x == '/')
+ return 63;
+ return BAD_BASE64;
+}
+
+static
+ int
+ha2d(char x, char y)
+{
+ int r = 0;
+
+ if ('0' <= x && x <= '9')
+ r = x - '0';
+ else if ('A' <= x && x <= 'F')
+ r = x - 'A' + 10;
+ else if ('a' <= x && x <= 'f')
+ r = x - 'a' + 10;
+
+ r <<= 4;
+
+ if ('0' <= y && y <= '9')
+ r += y - '0';
+ else if ('A' <= y && y <= 'F')
+ r += y - 'A' + 10;
+ else if ('a' <= y && y <= 'f')
+ r += y - 'a' + 10;
+
+ return r;
+
+}
+
+Str
+decodeB(char **ww)
+{
+ unsigned char c[4];
+ char *wp = *ww;
+ char d[3];
+ int i, n_pad;
+ Str ap = Strnew_size(strlen(wp));
+
+ n_pad = 0;
+ while (1) {
+ for (i = 0; i < 4; i++) {
+ c[i] = *(wp++);
+ if (*wp == '\0' || *wp == '?') {
+ i++;
+ for (; i < 4; i++) {
+ c[i] = '=';
+ }
+ break;
+ }
+ }
+ if (c[3] == '=') {
+ n_pad++;
+ c[3] = 'A';
+ if (c[2] == '=') {
+ n_pad++;
+ c[2] = 'A';
+ }
+ }
+ for (i = 0; i < 4; i++) {
+ c[i] = c2e(c[i]);
+ if (c[i] == BAD_BASE64) {
+ *ww = wp;
+ return ap;
+ }
+ }
+ d[0] = ((c[0] << 2) | (c[1] >> 4));
+ d[1] = ((c[1] << 4) | (c[2] >> 2));
+ d[2] = ((c[2] << 6) | c[3]);
+ for (i = 0; i < 3 - n_pad; i++) {
+ Strcat_char(ap, d[i]);
+ }
+ if (n_pad || *wp == '\0' || *wp == '?')
+ break;
+ }
+ *ww = wp;
+ return ap;
+}
+
+Str
+decodeU(char **ww)
+{
+ unsigned char c1, c2;
+ char *w = *ww;
+ int n, i;
+ Str a;
+
+ if (*w <= 0x20 || *w >= 0x60)
+ return Strnew_size(0);
+ n = *w - 0x20;
+ a = Strnew_size(n);
+ for (w++, i = 2; *w != '\0' && n; n--) {
+ c1 = (w[0] - 0x20) % 0x40;
+ c2 = (w[1] - 0x20) % 0x40;
+ Strcat_char(a, (c1 << i) | (c2 >> (6 - i)));
+ if (i == 6) {
+ w += 2;
+ i = 2;
+ }
+ else {
+ w++;
+ i += 2;
+ }
+ }
+ return a;
+}
+
+/* RFC2047 (4.2. The "Q" encoding) */
+Str
+decodeQ(char **ww)
+{
+ char *w = *ww;
+ Str a = Strnew_size(strlen(w));
+
+ for (; *w != '\0' && *w != '?'; w++) {
+ if (*w == '=') {
+ w++;
+ Strcat_char(a, ha2d(*w, *(w + 1)));
+ w++;
+ }
+ else if (*w == '_') {
+ Strcat_char(a, ' ');
+ }
+ else
+ Strcat_char(a, *w);
+ }
+ *ww = w;
+ return a;
+}
+
+/* RFC2045 (6.7. Quoted-Printable Content-Transfer-Encoding) */
+Str
+decodeQP(char **ww)
+{
+ char *w = *ww;
+ Str a = Strnew_size(strlen(w));
+
+ for (; *w != '\0'; w++) {
+ if (*w == '=') {
+ w++;
+ if (*w == '\n' || *w == '\r' || *w == ' ' || *w == '\t') {
+ while (*w != '\n' && *w != '\0')
+ w++;
+ if (*w == '\0')
+ break;
+ }
+ else {
+ if (*w == '\0' || *(w + 1) == '\0')
+ break;
+ Strcat_char(a, ha2d(*w, *(w + 1)));
+ w++;
+ }
+ }
+ else
+ Strcat_char(a, *w);
+ }
+ *ww = w;
+ return a;
+}
+
+#ifdef USE_M17N
+Str
+decodeWord(char **ow, wc_ces * charset)
+#else
+Str
+decodeWord0(char **ow)
+#endif
+{
+#ifdef USE_M17N
+ wc_ces c;
+#endif
+ char *p, *w = *ow;
+ char method;
+ Str a = Strnew();
+ Str tmp = Strnew();
+
+ if (*w != '=' || *(w + 1) != '?')
+ goto convert_fail;
+ w += 2;
+ for (; *w != '?'; w++) {
+ if (*w == '\0')
+ goto convert_fail;
+ Strcat_char(tmp, *w);
+ }
+#ifdef USE_M17N
+ c = wc_guess_charset(tmp->ptr, 0);
+ if (!c)
+ goto convert_fail;
+#else
+ if (strcasecmp(tmp->ptr, "ISO-8859-1") != 0 && strcasecmp(tmp->ptr, "US_ASCII") != 0)
+ /* NOT ISO-8859-1 encoding ... don't convert */
+ goto convert_fail;
+#endif
+ w++;
+ method = *(w++);
+ if (*w != '?')
+ goto convert_fail;
+ w++;
+ p = w;
+ switch (TOUPPER(method)) {
+ case 'B':
+ a = decodeB(&w);
+ break;
+ case 'Q':
+ a = decodeQ(&w);
+ break;
+ default:
+ goto convert_fail;
+ }
+ if (p == w)
+ goto convert_fail;
+ if (*w == '?') {
+ w++;
+ if (*w == '=')
+ w++;
+ }
+ *ow = w;
+#ifdef USE_M17N
+ *charset = c;
+#endif
+ return a;
+
+ convert_fail:
+ return Strnew();
+}
+
+/*
+ * convert MIME encoded string to the original one
+ */
+#ifdef USE_M17N
+Str
+decodeMIME(Str orgstr, wc_ces * charset)
+#else
+Str
+decodeMIME0(Str orgstr)
+#endif
+{
+ char *org = orgstr->ptr, *endp = org + orgstr->length;
+ char *org0, *p;
+ Str cnv = NULL;
+
+#ifdef USE_M17N
+ *charset = 0;
+#endif
+ while (org < endp) {
+ if (*org == '=' && *(org + 1) == '?') {
+ if (cnv == NULL) {
+ cnv = Strnew_size(orgstr->length);
+ Strcat_charp_n(cnv, orgstr->ptr, org - orgstr->ptr);
+ }
+ nextEncodeWord:
+ p = org;
+ Strcat(cnv, decodeWord(&org, charset));
+ if (org == p) { /* Convert failure */
+ Strcat_charp(cnv, org);
+ return cnv;
+ }
+ org0 = org;
+ SPCRLoop:
+ switch (*org0) {
+ case ' ':
+ case '\t':
+ case '\n':
+ case '\r':
+ org0++;
+ goto SPCRLoop;
+ case '=':
+ if (org0[1] == '?') {
+ org = org0;
+ goto nextEncodeWord;
+ }
+ default:
+ break;
+ }
+ }
+ else {
+ if (cnv != NULL)
+ Strcat_char(cnv, *org);
+ org++;
+ }
+ }
+ if (cnv == NULL)
+ return orgstr;
+ return cnv;
+}
+
+/* encoding */
+
+static char Base64Table[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/=";
+
+Str
+encodeB(char *a)
+{
+ unsigned char d[3];
+ unsigned char c1, c2, c3, c4;
+ int i, n_pad;
+ Str w = Strnew();
+
+ while (1) {
+ if (*a == '\0')
+ break;
+ n_pad = 0;
+ d[1] = d[2] = 0;
+ for (i = 0; i < 3; i++) {
+ d[i] = a[i];
+ if (a[i] == '\0') {
+ n_pad = 3 - i;
+ break;
+ }
+ }
+ c1 = d[0] >> 2;
+ c2 = (((d[0] << 4) | (d[1] >> 4)) & 0x3f);
+ if (n_pad == 2) {
+ c3 = c4 = 64;
+ }
+ else if (n_pad == 1) {
+ c3 = ((d[1] << 2) & 0x3f);
+ c4 = 64;
+ }
+ else {
+ c3 = (((d[1] << 2) | (d[2] >> 6)) & 0x3f);
+ c4 = (d[2] & 0x3f);
+ }
+ Strcat_char(w, Base64Table[c1]);
+ Strcat_char(w, Base64Table[c2]);
+ Strcat_char(w, Base64Table[c3]);
+ Strcat_char(w, Base64Table[c4]);
+ if (n_pad)
+ break;
+ a += 3;
+ }
+ return w;
+}
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