/*
- * Copyright (c) 2006-2007 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
+ * Copyright (c) 2006-2009 Bjorn Andersson <flex@kryo.se>, Erik Ekman <yarrick@kryo.se>
*
* Permission to use, copy, modify, and distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
#include "common.h"
#include "base64.h"
+#define BLKSIZE_RAW 3
+#define BLKSIZE_ENC 4
+
static const char cb64[] =
- "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-0123456789.";
+ "abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ-0123456789+";
static unsigned char rev64[128];
static int reverse_init = 0;
+static int base64_encode(char *, size_t *, const void *, size_t);
+static int base64_decode(void *, size_t *, const char *, size_t);
+static int base64_handles_dots();
+static int base64_blksize_raw();
+static int base64_blksize_enc();
+
#define REV64(x) rev64[(int) (x)]
-#define MODE (cb64[62])
-#define P62 (cb64[62])
-#define P63 (cb64[63])
static struct encoder base64_encoder =
{
- "BASE64",
+ "Base64",
base64_encode,
base64_decode,
base64_handles_dots,
- base64_handles_dots
+ base64_handles_dots,
+ base64_blksize_raw,
+ base64_blksize_enc
};
struct encoder
return &base64_encoder;
}
-int
+static int
base64_handles_dots()
{
return 0;
}
-static void
-findesc(int *count, unsigned char *esc, char c1, char c2, char c3, char c4)
+static int
+base64_blksize_raw()
{
- int min1 = 0;
- int min2 = 0;
-
- int num1 = 0xFF; /* a very big number */
- int num2 = 0xFE; /* a nearly as big number */
-
- int i;
-
- /* check if no more escapes needed */
- if (count[62] == 0 && count[63] == 0) {
- esc[0] = MODE;
- esc[1] = MODE;
- return;
- }
-
- for (i = 0; i < 62; i++) {
- if (i == c1 || i == c2 || i == c3 || i == c4) {
- continue;
- }
-
- if (count[i] < num1) {
- min2 = min1;
- num2 = num1;
- min1 = i;
- num1 = count[i];
- } else if (count[i] < num2) {
- min2 = i;
- num2 = count[i];
- }
- }
-
- esc[0] = cb64[min1];
- esc[1] = cb64[min2];
+ return BLKSIZE_RAW;
}
-
-static void
-escape_chars(char *buf, size_t buflen)
-{
- int counter[64];
- int escapes;
- int reset;
- int i;
- unsigned char temp[4096];
- unsigned char *r;
- unsigned char *w;
- unsigned char *e;
- unsigned char esc[2];
- memset(counter, 0, sizeof(counter));
- esc[0] = P62;
- esc[1] = P63;
-
- /* first, find the number of times each token is used */
- r = (unsigned char *) buf;
- w = temp;
- while (*r) {
- counter[REV64(*r)]++;
- *w++ = *r++;
- }
-
- /* check if work needed */
- if (counter[62] == 0 && counter[63] == 0)
- return;
-
- r = temp;
- w = (unsigned char *) buf;
- reset = 1;
- escapes = 0;
- /* check a block for esc chars */
- while (*r) {
- if (reset == 0 && escapes == 0 && (
- r[0] == esc[0] || r[1] == esc[0] ||r[2] == esc[0] ||r[2] == esc[0] ||
- r[0] == esc[1] || r[1] == esc[1] ||r[2] == esc[1] ||r[2] == esc[1])) {
- /* last set of escape chars were unused.
- * if we reset last escape switch then maybe we dont have to switch now */
-
- /* change the latest escape switch to 999 (RESET) */
- e[1] = MODE;
- e[2] = MODE;
-
- /* store default esc chars */
- esc[0] = P62;
- esc[1] = P63;
-
- reset = 1;
- }
- /* these two if blocks can not be combined because a block can contain both
- * char 9 and/or . and the current escape chars. */
- if (r[0] == esc[0] || r[1] == esc[0] ||r[2] == esc[0] ||r[2] == esc[0] ||
- r[0] == esc[1] || r[1] == esc[1] ||r[2] == esc[1] ||r[2] == esc[1]) {
- /* switch escape chars */
- escapes = 0;
- reset = 0;
-
- /* find 2 suitable escape chars */
- findesc(counter, esc, REV64(r[0]), REV64(r[1]), REV64(r[2]), REV64(r[3]));
-
- /* store escape switch position */
- e = w;
-
- /* write new escape chars */
- *w++ = MODE;
- *w++ = esc[0];
- *w++ = esc[1];
- }
-
- /* update counter on remaining chars */
- for (i = 0; i < 4; i++) {
- if (r[i])
- counter[REV64(r[i])]--;
- }
-
- /* do the escaping */
- for (i = 0; i < 4; i++) {
- if (r[i] == P62) {
- r[i] = esc[0];
- escapes++;
- } else if (r[i] == P63) {
- r[i] = esc[1];
- escapes++;
- }
- }
-
- /* copy back to buf */
- *w++ = *r++;
- *w++ = *r++;
- *w++ = *r++;
- *w++ = *r++;
- }
+static int
+base64_blksize_enc()
+{
+ return BLKSIZE_ENC;
}
-int
+static int
base64_encode(char *buf, size_t *buflen, const void *data, size_t size)
{
size_t newsize;
}
/* how many chars can we encode within the buf */
- maxsize = 3 * (*buflen / 4 - 1) - 1;
+ maxsize = BLKSIZE_RAW * (*buflen / BLKSIZE_ENC - 1) - 1;
/* how big will the encoded data be */
- newsize = 4 * (size / 3 + 1) + 1;
+ newsize = BLKSIZE_ENC * (size / BLKSIZE_RAW + 1) + 1;
/* if the buffer is too small, eat some of the data */
if (*buflen < newsize) {
size = maxsize;
p = s = (unsigned char *) buf;
q = (unsigned char *)data;
- for(i=0;i<size;i+=3) {
+ for(i=0;i<size;i+=BLKSIZE_RAW) {
p[0] = cb64[((q[0] & 0xfc) >> 2)];
p[1] = cb64[(((q[0] & 0x03) << 4) | ((q[1] & 0xf0) >> 4))];
p[2] = (i+1 < size) ? cb64[((q[1] & 0x0f) << 2 ) | ((q[2] & 0xc0) >> 6)] : '\0';
p[3] = (i+2 < size) ? cb64[(q[2] & 0x3f)] : '\0';
- q += 3;
- p += 4;
+ q += BLKSIZE_RAW;
+ p += BLKSIZE_ENC;
}
*p = 0;
- escape_chars(buf, *buflen);
-
/* store number of bytes from data that was used */
*buflen = size;
return 3;
}
-int
+static int
base64_decode(void *buf, size_t *buflen, const char *str, size_t slen)
{
unsigned char *q;
size_t maxsize;
const char *p;
unsigned char c;
- unsigned char block[4];
- unsigned char prot62;
- unsigned char prot63;
+ unsigned char block[BLKSIZE_ENC];
int len;
int i;
}
/* chars needed to decode slen */
- newsize = 3 * (slen / 4 + 1) + 1;
+ newsize = BLKSIZE_RAW * (slen / BLKSIZE_ENC + 1) + 1;
/* encoded chars that fit in buf */
- maxsize = 4 * (*buflen / 3 + 1) + 1;
+ maxsize = BLKSIZE_ENC * (*buflen / BLKSIZE_RAW + 1) + 1;
/* if the buffer is too small, eat some of the data */
if (*buflen < newsize) {
slen = maxsize;
}
- prot62 = P62;
- prot63 = P63;
q = buf;
- for (p = str; *p; p += 4) {
- /* handle escape instructions */
- if (*p == MODE) {
- p++;
- if (p[0] == MODE && p[1] == MODE) {
- /* reset escape chars */
- prot62 = P62;
- prot63 = P63;
-
- p += 2;
- } else {
- prot62 = *p++;
- prot63 = *p++;
- }
- }
+ for (p = str; *p; p += BLKSIZE_ENC) {
/* since the str is const, we unescape in another buf */
- for (i = 0; i < 4; i++) {
+ for (i = 0; i < BLKSIZE_ENC; i++) {
block[i] = p[i];
- if (prot62 == block[i]) {
- block[i] = P62;
- } else if (prot63 == block[i]) {
- block[i] = P63;
- }
}
len = decode_token(block, (unsigned char *) q, slen);
q += len;
- slen -= 4;
+ slen -= BLKSIZE_ENC;
- if (len < 3)
+ if (len < BLKSIZE_RAW)
break;
}
*q = '\0';
ToastFreeware / debian / iodine.git / blobdiff