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-rw-r--r--src/lib/base32.c324
1 files changed, 324 insertions, 0 deletions
diff --git a/src/lib/base32.c b/src/lib/base32.c
new file mode 100644
index 0000000..89ae978
--- /dev/null
+++ b/src/lib/base32.c
@@ -0,0 +1,324 @@
+/* Copyright (c) 2007-2018 Dovecot authors, see the included COPYING file */
+
+#include "lib.h"
+#include "base32.h"
+#include "buffer.h"
+
+static const char b32enc[] =
+ "ABCDEFGHIJKLMNOPQRSTUVWXYZ234567";
+
+static const char b32hexenc[] =
+ "0123456789ABCDEFGHIJKLMNOPQRSTUV";
+
+static const unsigned char b32dec[256] = {
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0-7 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 8-15 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16-23 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 24-31 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32-39 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 40-47 */
+ 0xff, 0xff, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, /* 48-55 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 56-63 */
+ 0xff, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, /* 64-71 */
+ 0x07, 0x08, 0x09, 0x0A, 0x0B, 0x0C, 0x0D, 0x0E, /* 72-79 */
+ 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, /* 80-87 */
+ 0x17, 0x18, 0x19, 0xff, 0xff, 0xff, 0xff, 0xff, /* 88-95 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 96-103 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 104-111 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 112-119 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 120-127 */
+
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 128-255 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+};
+
+static const unsigned char b32hexdec[256] = {
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 0-7 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 8-15 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 16-23 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 24-31 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 32-39 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 40-47 */
+ 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, /* 48-55 */
+ 0x08, 0x09, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 56-63 */
+ 0xff, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e, 0x0f, 0x10, /* 64-71 */
+ 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17, 0x18, /* 72-79 */
+ 0x19, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0xff, /* 80-87 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 88-95 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 96-103 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 104-111 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 112-119 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 120-127 */
+
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, /* 128-255 */
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+ 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
+};
+
+static void
+base32_encode_with_alphabet(const char *alph,
+ bool pad, const void *src, size_t src_size, buffer_t *dest)
+{
+ const unsigned char *src_c = src;
+ unsigned char tmp[8], endb;
+ size_t src_pos;
+
+ /* [5 3][2 5 1][4 4][1 5 2][3 5]
+ (5)(3 2)(5)(1 4)(4 1)(5)(2 3)(5)
+ */
+
+ /* encode main part */
+ for (src_pos = 0; src_pos + 4 < src_size; src_pos += 5) {
+ tmp[0] = alph[src_c[src_pos] >> 3];
+ tmp[1] = alph[((src_c[src_pos] & 0x07) << 2) |
+ ((src_c[src_pos+1] >> 6) & 0x03)];
+ tmp[2] = alph[((src_c[src_pos+1] >> 1) & 0x1f)];
+ tmp[3] = alph[((src_c[src_pos+1] & 0x01) << 4) |
+ (src_c[src_pos+2] >> 4)];
+ tmp[4] = alph[((src_c[src_pos+2] & 0x0f) << 1) |
+ (src_c[src_pos+3] >> 7)];
+ tmp[5] = alph[((src_c[src_pos+3] >> 2) & 0x1f)];
+ tmp[6] = alph[((src_c[src_pos+3] & 0x03) << 3) |
+ (src_c[src_pos+4] >> 5)];
+ tmp[7] = alph[src_c[src_pos+4] & 0x1f];
+ buffer_append(dest, tmp, 8);
+ }
+
+ /* encode last < 5 bytes if any */
+ if (src_pos < src_size) {
+ tmp[0] = alph[src_c[src_pos] >> 3];
+ switch (src_size - src_pos) {
+ case 1:
+ tmp[1] = alph[((src_c[src_pos] & 0x07) << 2)];
+ endb = 2;
+ break;
+ case 2:
+ tmp[1] = alph[((src_c[src_pos] & 0x07) << 2) |
+ ((src_c[src_pos+1] >> 6) & 0x03)];
+ tmp[2] = alph[((src_c[src_pos+1] >> 1) & 0x1f)];
+ tmp[3] = alph[((src_c[src_pos+1] & 0x01) << 4)];
+ endb = 4;
+ break;
+ case 3:
+ tmp[1] = alph[((src_c[src_pos] & 0x07) << 2) |
+ ((src_c[src_pos+1] >> 6) & 0x03)];
+ tmp[2] = alph[((src_c[src_pos+1] >> 1) & 0x1f)];
+ tmp[3] = alph[((src_c[src_pos+1] & 0x01) << 4) |
+ (src_c[src_pos+2] >> 4)];
+ tmp[4] = alph[((src_c[src_pos+2] & 0x0f) << 1)];
+ endb = 5;
+ break;
+ case 4:
+ tmp[1] = alph[((src_c[src_pos] & 0x07) << 2) |
+ ((src_c[src_pos+1] >> 6) & 0x03)];
+ tmp[2] = alph[((src_c[src_pos+1] >> 1) & 0x1f)];
+ tmp[3] = alph[((src_c[src_pos+1] & 0x01) << 4) |
+ (src_c[src_pos+2] >> 4)];
+ tmp[4] = alph[((src_c[src_pos+2] & 0x0f) << 1) |
+ (src_c[src_pos+3] >> 7)];
+ tmp[5] = alph[((src_c[src_pos+3] >> 2) & 0x1f)];
+ tmp[6] = alph[((src_c[src_pos+3] & 0x03) << 3)];
+ endb = 7;
+ break;
+ default:
+ i_unreached();
+ }
+
+ /* add padding if required */
+ if (pad) {
+ memset(&tmp[endb], '=', sizeof(tmp)-endb);
+ buffer_append(dest, tmp, 8);
+ } else {
+ buffer_append(dest, tmp, endb);
+ }
+ }
+}
+
+void base32_encode(bool pad, const void *src, size_t src_size,
+ buffer_t *dest)
+{
+ base32_encode_with_alphabet(b32enc, pad, src, src_size, dest);
+}
+
+void base32hex_encode(bool pad, const void *src, size_t src_size,
+ buffer_t *dest)
+{
+ base32_encode_with_alphabet(b32hexenc, pad, src, src_size, dest);
+}
+
+#define IS_EMPTY(c) \
+ ((c) == '\n' || (c) == '\r' || (c) == ' ' || (c) == '\t')
+
+static int
+base32_decode_with_alphabet(const unsigned char *alph,
+ const void *src, size_t src_size, size_t *src_pos_r,
+ buffer_t *dest)
+{
+ const unsigned char *src_c = src;
+ size_t block_pos, src_pos;
+ unsigned char output[5], ipos, opos;
+ int ret = 1;
+
+ /* (5)(3 2)(5)(1 4)(4 1)(5)(2 3)(5)
+ [5 3][2 5 1][4 4][1 5 2][3 5]
+ */
+ ipos = opos = 0;
+ block_pos = 0;
+ for (src_pos = 0; src_pos < src_size; src_pos++) {
+ unsigned char input = alph[src_c[src_pos]];
+
+ if (input == 0xff) {
+ if (unlikely(!IS_EMPTY(src_c[src_pos])))
+ break;
+ continue;
+ }
+
+ ipos++;
+ switch (ipos) {
+ case 1:
+ output[0] = input << 3;
+ opos = 0;
+ break;
+ case 2:
+ output[0] |= input >> 2;
+ output[1] = (input & 0x03) << 6;
+ opos = 1;
+ break;
+ case 3:
+ output[1] |= input << 1;
+ opos = 1;
+ break;
+ case 4:
+ output[1] |= input >> 4;
+ output[2] = (input & 0x0f) << 4;
+ opos = 2;
+ break;
+ case 5:
+ output[2] |= input >> 1;
+ output[3] = (input & 0x01) << 7;
+ opos = 3;
+ break;
+ case 6:
+ output[3] |= input << 2;
+ opos = 3;
+ break;
+ case 7:
+ output[3] |= input >> 3;
+ output[4] = ((input & 0x07) << 5);
+ opos = 4;
+ break;
+ case 8:
+ output[4] |= input;
+ buffer_append(dest, output, 5);
+ ipos = 0;
+ opos = 0;
+ block_pos = src_pos;
+ break;
+ default:
+ i_unreached();
+ }
+ }
+
+ if (ipos > 0) {
+ for (; src_pos < src_size; src_pos++) {
+ if (src_c[src_pos] != '=') {
+ if (unlikely(!IS_EMPTY(src_c[src_pos]))) {
+ ret = -1;
+ break;
+ }
+ continue;
+ }
+ if (++ipos >= 8) {
+ buffer_append(dest, output, opos);
+ ipos = 0;
+ ret = 0;
+ src_pos++;
+ break;
+ }
+ }
+ }
+
+ if (src_pos_r != NULL) {
+ if (ipos == 0) {
+ for (; src_pos < src_size; src_pos++) {
+ if (!IS_EMPTY(src_c[src_pos]))
+ break;
+ }
+
+ *src_pos_r = src_pos;
+ } else {
+ *src_pos_r = block_pos;
+ }
+ }
+ return ret;
+}
+
+int base32_decode(const void *src, size_t src_size,
+ size_t *src_pos_r, buffer_t *dest)
+{
+ return base32_decode_with_alphabet
+ (b32dec, src, src_size, src_pos_r, dest);
+}
+int base32hex_decode(const void *src, size_t src_size,
+ size_t *src_pos_r, buffer_t *dest)
+{
+ return base32_decode_with_alphabet
+ (b32hexdec, src, src_size, src_pos_r, dest);
+}
+
+buffer_t *t_base32_decode_str(const char *str)
+{
+ buffer_t *buf;
+ size_t len = strlen(str);
+
+ buf = t_buffer_create(MAX_BASE32_DECODED_SIZE(len));
+ (void)base32_decode(str, len, NULL, buf);
+ return buf;
+}
+
+buffer_t *t_base32hex_decode_str(const char *str)
+{
+ buffer_t *buf;
+ size_t len = strlen(str);
+
+ buf = t_buffer_create(MAX_BASE32_DECODED_SIZE(len));
+ (void)base32hex_decode(str, len, NULL, buf);
+ return buf;
+}
+
+bool base32_is_valid_char(char c)
+{
+ return b32dec[(uint8_t)c] != 0xff;
+}
+
+bool base32hex_is_valid_char(char c)
+{
+ return b32hexdec[(uint8_t)c] != 0xff;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-12-24 13:18:08 +0000