php-src/ext/standard/base64.c
1999-09-24 19:35:25 +00:00

194 lines
5.3 KiB
C

/*
+----------------------------------------------------------------------+
| PHP version 4.0 |
+----------------------------------------------------------------------+
| Copyright (c) 1997, 1998, 1999 The PHP Group |
+----------------------------------------------------------------------+
| This source file is subject to version 2.0 of the PHP license, |
| that is bundled with this package in the file LICENSE, and is |
| available at through the world-wide-web at |
| http://www.php.net/license/2_0.txt. |
| If you did not receive a copy of the PHP license and are unable to |
| obtain it through the world-wide-web, please send a note to |
| license@php.net so we can mail you a copy immediately. |
+----------------------------------------------------------------------+
| Author: Jim Winstead (jimw@php.net) |
+----------------------------------------------------------------------+
*/
/* $Id$ */
#include <string.h>
#include "php.h"
#include "base64.h"
static char base64_table[] =
{ 'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
'0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/', '\0'
};
static char base64_pad = '=';
unsigned char *_php3_base64_encode(const unsigned char *string, int length, int *ret_length) {
const unsigned char *current = string;
int i = 0;
unsigned char *result = (unsigned char *)emalloc(((length + 3 - length % 3) * 4 / 3 + 1) * sizeof(char));
while (length > 2) { /* keep going until we have less than 24 bits */
result[i++] = base64_table[current[0] >> 2];
result[i++] = base64_table[((current[0] & 0x03) << 4) + (current[1] >> 4)];
result[i++] = base64_table[((current[1] & 0x0f) << 2) + (current[2] >> 6)];
result[i++] = base64_table[current[2] & 0x3f];
current += 3;
length -= 3; /* we just handle 3 octets of data */
}
/* now deal with the tail end of things */
if (length != 0) {
result[i++] = base64_table[current[0] >> 2];
if (length > 1) {
result[i++] = base64_table[((current[0] & 0x03) << 4) + (current[1] >> 4)];
result[i++] = base64_table[(current[1] & 0x0f) << 2];
result[i++] = base64_pad;
}
else {
result[i++] = base64_table[(current[0] & 0x03) << 4];
result[i++] = base64_pad;
result[i++] = base64_pad;
}
}
if(ret_length) {
*ret_length = i;
}
result[i] = '\0';
return result;
}
/* as above, but backwards. :) */
unsigned char *_php3_base64_decode(const unsigned char *string, int length, int *ret_length) {
const unsigned char *current = string;
int ch, i = 0, j = 0, k;
/* this sucks for threaded environments */
static short reverse_table[256];
static int table_built;
unsigned char *result;
if (++table_built == 1) {
char *chp;
for(ch = 0; ch < 256; ch++) {
chp = strchr(base64_table, ch);
if(chp) {
reverse_table[ch] = chp - base64_table;
} else {
reverse_table[ch] = -1;
}
}
}
result = (unsigned char *)emalloc((length / 4 * 3 + 1) * sizeof(char));
if (result == NULL) {
return NULL;
}
/* run through the whole string, converting as we go */
while ((ch = *current++) != '\0') {
if (ch == base64_pad) break;
ch = reverse_table[ch];
if (ch < 0) continue;
switch(i % 4) {
case 0:
result[j] = ch << 2;
break;
case 1:
result[j++] |= ch >> 4;
result[j] = (ch & 0x0f) << 4;
break;
case 2:
result[j++] |= ch >>2;
result[j] = (ch & 0x03) << 6;
break;
case 3:
result[j++] |= ch;
break;
}
i++;
}
k = j;
/* mop things up if we ended on a boundary */
if (ch == base64_pad) {
switch(i % 4) {
case 0:
case 1:
efree(result);
return NULL;
case 2:
k++;
case 3:
result[k++] = 0;
}
}
if(ret_length) {
*ret_length = j;
}
result[k] = '\0';
return result;
}
/* {{{ proto string base64_encode(string str)
Encodes string using MIME base64 algorithm */
PHP_FUNCTION(base64_encode) {
pval **string;
unsigned char *result;
int ret_length;
if (ARG_COUNT(ht)!=1 || getParametersEx(1,&string) == FAILURE) {
WRONG_PARAM_COUNT;
}
convert_to_string_ex(string);
result = _php3_base64_encode((*string)->value.str.val, (*string)->value.str.len, &ret_length);
if (result != NULL) {
return_value->value.str.val = result;
return_value->value.str.len = ret_length;
return_value->type = IS_STRING;
} else {
RETURN_FALSE;
}
}
/* }}} */
/* {{{ proto string base64_decode(string str)
Decodes string using MIME base64 algorithm */
PHP_FUNCTION(base64_decode) {
pval **string;
unsigned char *result;
int ret_length;
if (ARG_COUNT(ht)!=1 || getParametersEx(1,&string) == FAILURE) {
WRONG_PARAM_COUNT;
}
convert_to_string_ex(string);
result = _php3_base64_decode((*string)->value.str.val, (*string)->value.str.len, &ret_length);
if (result != NULL) {
return_value->value.str.val = result;
return_value->value.str.len = ret_length;
return_value->type = IS_STRING;
} else {
RETURN_FALSE;
}
}
/* }}} */
/*
* Local variables:
* tab-width: 4
* c-basic-offset: 4
* End:
*/