summaryrefslogtreecommitdiffstats
path: root/src/lib-imap/imap-utf7.c
diff options
context:
space:
mode:
Diffstat (limited to 'src/lib-imap/imap-utf7.c')
-rw-r--r--src/lib-imap/imap-utf7.c380
1 files changed, 380 insertions, 0 deletions
diff --git a/src/lib-imap/imap-utf7.c b/src/lib-imap/imap-utf7.c
new file mode 100644
index 0000000..7ea53f5
--- /dev/null
+++ b/src/lib-imap/imap-utf7.c
@@ -0,0 +1,380 @@
+/* Copyright (c) 2008-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "str.h"
+#include "unichar.h"
+#include "imap-utf7.h"
+
+static const char imap_b64enc[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+,";
+
+#define XX 0xff
+static const unsigned char imap_b64dec[256] = {
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,62, 63,XX,XX,XX,
+ 52,53,54,55, 56,57,58,59, 60,61,XX,XX, XX,XX,XX,XX,
+ XX, 0, 1, 2, 3, 4, 5, 6, 7, 8, 9,10, 11,12,13,14,
+ 15,16,17,18, 19,20,21,22, 23,24,25,XX, XX,XX,XX,XX,
+ XX,26,27,28, 29,30,31,32, 33,34,35,36, 37,38,39,40,
+ 41,42,43,44, 45,46,47,48, 49,50,51,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX,
+ XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX, XX,XX,XX,XX
+};
+
+static void
+mbase64_encode(string_t *dest, const unsigned char *in, size_t len)
+{
+ str_append_c(dest, '&');
+ while (len >= 3) {
+ str_append_c(dest, imap_b64enc[in[0] >> 2]);
+ str_append_c(dest, imap_b64enc[((in[0] & 3) << 4) |
+ (in[1] >> 4)]);
+ str_append_c(dest, imap_b64enc[((in[1] & 0x0f) << 2) |
+ ((in[2] & 0xc0) >> 6)]);
+ str_append_c(dest, imap_b64enc[in[2] & 0x3f]);
+ in += 3;
+ len -= 3;
+ }
+ if (len > 0) {
+ str_append_c(dest, imap_b64enc[in[0] >> 2]);
+ if (len == 1)
+ str_append_c(dest, imap_b64enc[(in[0] & 0x03) << 4]);
+ else {
+ str_append_c(dest, imap_b64enc[((in[0] & 0x03) << 4) |
+ (in[1] >> 4)]);
+ str_append_c(dest, imap_b64enc[(in[1] & 0x0f) << 2]);
+ }
+ }
+ str_append_c(dest, '-');
+}
+
+static const char *
+imap_utf8_first_encode_char(const char *str, char escape_char)
+{
+ const char *p;
+
+ for (p = str; *p != '\0'; p++) {
+ if (*p == '&' || *p < 0x20 || *p >= 0x7f || *p == escape_char)
+ return p;
+ }
+ return NULL;
+}
+
+int imap_escaped_utf8_hex_to_char(const char *str, unsigned char *chr_r)
+{
+ unsigned int i = 0;
+ unsigned char c = 0;
+
+ /* NOTE: Only lowercase hex characters are allowed so the output is
+ reversible. */
+ for (;;) {
+ if (str[i] >= '0' && str[i] <= '9')
+ c += str[i] - '0';
+ else if (str[i] >= 'a' && str[i] <= 'f')
+ c += str[i] - 'a' + 10;
+ else
+ return -1;
+ if (++i == 2)
+ break;
+ c *= 0x10;
+ }
+ *chr_r = c;
+ return 0;
+}
+
+static int
+imap_utf8_to_utf7_int(const char *src, char escape_char, string_t *dest)
+{
+ const char *p;
+ unichar_t chr;
+ uint8_t *utf16, *u;
+ uint16_t u16;
+ unsigned char c;
+
+ p = imap_utf8_first_encode_char(src, escape_char);
+ if (p == NULL) {
+ /* no characters that need to be encoded */
+ str_append(dest, src);
+ return 0;
+ }
+
+ /* at least one encoded character */
+ str_append_data(dest, src, p-src);
+ utf16 = t_malloc0(MALLOC_MULTIPLY(strlen(p), 2));
+ while (*p != '\0') {
+ if (*p == escape_char &&
+ imap_escaped_utf8_hex_to_char(p+1, &c) == 0) {
+ str_append_c(dest, c);
+ p += 3;
+ continue;
+ }
+ if (*p == '&') {
+ str_append(dest, "&-");
+ p++;
+ continue;
+ }
+ if (*p >= 0x20 && *p < 0x7f) {
+ str_append_c(dest, *p);
+ p++;
+ continue;
+ }
+
+ u = utf16;
+ while (*p != '\0' && (*p < 0x20 || *p >= 0x7f)) {
+ if (uni_utf8_get_char(p, &chr) <= 0)
+ return -1;
+ /* @UNSAFE */
+ if (chr < UTF16_SURROGATE_BASE) {
+ *u++ = chr >> 8;
+ *u++ = chr & 0xff;
+ } else {
+ u16 = UTF16_SURROGATE_HIGH(chr);
+ *u++ = u16 >> 8;
+ *u++ = u16 & 0xff;
+ u16 = UTF16_SURROGATE_LOW(chr);
+ *u++ = u16 >> 8;
+ *u++ = u16 & 0xff;
+ }
+ p += uni_utf8_char_bytes((unsigned char)*p);
+ }
+ mbase64_encode(dest, utf16, u-utf16);
+ }
+ return 0;
+}
+
+int imap_utf8_to_utf7(const char *src, string_t *dest)
+{
+ return imap_utf8_to_utf7_int(src, '\0', dest);
+}
+
+int imap_escaped_utf8_to_utf7(const char *src, char escape_char, string_t *dest)
+{
+ i_assert(escape_char != '&');
+
+ return imap_utf8_to_utf7_int(src, escape_char, dest);
+}
+
+int t_imap_utf8_to_utf7(const char *src, const char **dest_r)
+{
+ string_t *str;
+ int ret;
+
+ if (imap_utf8_first_encode_char(src, '\0') == NULL) {
+ *dest_r = src;
+ return 0;
+ }
+
+ str = t_str_new(64);
+ ret = imap_utf8_to_utf7(src, str);
+ *dest_r = str_c(str);
+ return ret;
+}
+
+static int utf16buf_to_utf8(string_t *dest, const unsigned char output[4],
+ unsigned int *_pos, unsigned int len)
+{
+ unsigned int pos = *_pos;
+ uint16_t high, low;
+ unichar_t chr;
+
+ if (len % 2 != 0)
+ return -1;
+
+ high = (output[pos % 4] << 8) | output[(pos+1) % 4];
+ if (high < UTF16_SURROGATE_HIGH_FIRST ||
+ high > UTF16_SURROGATE_HIGH_MAX) {
+ /* single byte */
+ size_t oldlen = str_len(dest);
+
+ if (high == 0) {
+ /* Encoded NUL isn't going to work in Dovecot code,
+ even though it's technically valid. Return failure
+ so the callers don't even get a chance to handle the
+ NUL in the string inconsistently. */
+ return -1;
+ }
+ uni_ucs4_to_utf8_c(high, dest);
+ if (str_len(dest) - oldlen == 1) {
+ unsigned char last = str_data(dest)[oldlen];
+ if (last >= 0x20 && last < 0x7f)
+ return -1;
+ }
+ *_pos = (pos + 2) % 4;
+ return 0;
+ }
+
+ if (high > UTF16_SURROGATE_HIGH_LAST)
+ return -1;
+ if (len != 4) {
+ /* missing the second character */
+ return -1;
+ }
+
+ low = (output[(pos+2)%4] << 8) | output[(pos+3) % 4];
+ if (low < UTF16_SURROGATE_LOW_FIRST || low > UTF16_SURROGATE_LOW_LAST)
+ return -1;
+
+ chr = UTF16_SURROGATE_BASE +
+ (((high & UTF16_SURROGATE_MASK) << UTF16_SURROGATE_SHIFT) |
+ (low & UTF16_SURROGATE_MASK));
+ uni_ucs4_to_utf8_c(chr, dest);
+ return 0;
+}
+
+static int mbase64_decode_to_utf8(string_t *dest, const char **_src)
+{
+ const char *src = *_src;
+ unsigned char input[4], output[4];
+ unsigned int outstart = 0, outpos = 0;
+
+ while (*src != '-') {
+ input[0] = imap_b64dec[(uint8_t)src[0]];
+ if (input[0] == 0xff)
+ return -1;
+ input[1] = imap_b64dec[(uint8_t)src[1]];
+ if (input[1] == 0xff)
+ return -1;
+
+ output[outpos % 4] = (input[0] << 2) | (input[1] >> 4);
+ if (++outpos % 4 == outstart) {
+ if (utf16buf_to_utf8(dest, output, &outstart, 4) < 0)
+ return -1;
+ }
+
+ input[2] = imap_b64dec[(uint8_t)src[2]];
+ if (input[2] == 0xff) {
+ if (src[2] != '-')
+ return -1;
+
+ src += 2;
+ break;
+ }
+
+ output[outpos % 4] = ((input[1] << 4) & 0xff) | (input[2] >> 2);
+ if (++outpos % 4 == outstart) {
+ if (utf16buf_to_utf8(dest, output, &outstart, 4) < 0)
+ return -1;
+ }
+
+ input[3] = imap_b64dec[(uint8_t)src[3]];
+ if (input[3] == 0xff) {
+ if (src[3] != '-')
+ return -1;
+
+ src += 3;
+ break;
+ }
+
+ output[outpos % 4] = ((input[2] << 6) & 0xc0) | input[3];
+ if (++outpos % 4 == outstart) {
+ if (utf16buf_to_utf8(dest, output, &outstart, 4) < 0)
+ return -1;
+ }
+
+ src += 4;
+ }
+ if (outstart != outpos % 4) {
+ if (utf16buf_to_utf8(dest, output, &outstart,
+ (4 + outpos - outstart) % 4) < 0)
+ return -1;
+ }
+
+ /* Found the ending '-'. Make sure it's not followed by unnecessary
+ shift. Note that '&' is always escaped as "&-" so it's not an
+ unnecessary shift. */
+ if (src[1] == '&' && src[2] != '-')
+ return -1;
+
+ *_src = src + 1;
+ return 0;
+}
+
+static int
+imap_utf7_to_utf8_int(const char *src, const char *escape_chars, string_t *dest)
+{
+ const char *p;
+
+ for (p = src; *p != '\0'; p++) {
+ if (*p < 0x20 || *p >= 0x7f) {
+ if (escape_chars[0] == '\0')
+ return -1;
+ break;
+ }
+ if (*p == '&' || strchr(escape_chars, *p) != NULL)
+ break;
+ }
+ if (*p == '\0') {
+ /* no IMAP-UTF-7 encoded characters */
+ str_append(dest, src);
+ return 0;
+ }
+
+ /* at least one encoded character */
+ str_append_data(dest, src, p-src);
+ while (*p != '\0') {
+ if (strchr(escape_chars, *p) != NULL ||
+ *p < 0x20 || *p >= 0x7f) {
+ str_printfa(dest, "%c%02x", escape_chars[0],
+ (unsigned char)*p);
+ p++;
+ } else if (*p == '&') {
+ if (*++p == '-') {
+ str_append_c(dest, '&');
+ p++;
+ } else {
+ size_t orig_size = str_len(dest);
+ if (mbase64_decode_to_utf8(dest, &p) < 0) {
+ if (escape_chars[0] == '\0')
+ return -1;
+ str_truncate(dest, orig_size);
+ str_printfa(dest, "%c26", escape_chars[0]);
+ }
+ }
+ } else {
+ str_append_c(dest, *p++);
+ }
+ }
+ return 0;
+}
+
+int imap_utf7_to_utf8(const char *src, string_t *dest)
+{
+ return imap_utf7_to_utf8_int(src, "", dest);
+}
+
+void imap_utf7_to_utf8_escaped(const char *src, const char *escape_chars,
+ string_t *dest)
+{
+ i_assert(escape_chars[0] != '&');
+
+ if (imap_utf7_to_utf8_int(src, escape_chars, dest) < 0)
+ i_unreached();
+}
+
+bool imap_utf7_is_valid(const char *src)
+{
+ const char *p;
+ int ret;
+
+ for (p = src; *p != '\0'; p++) {
+ if (*p < 0x20 || *p >= 0x7f)
+ return FALSE;
+ if (*p == '&') {
+ /* slow scan */
+ T_BEGIN {
+ string_t *tmp = t_str_new(128);
+ ret = imap_utf7_to_utf8(p, tmp);
+ } T_END;
+ if (ret < 0)
+ return FALSE;
+ }
+ }
+ return TRUE;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-10 01:46:34 +0000