use reverse lookup array, submitted by bfranklin@dct.com, #1755

diff --git a/ext/standard/base64.c b/ext/standard/base64.c
index 70675d14e352ef5db937b48387901655eb945ff5..32c63a36c4c82f221f95dfbd62d181c5e642e717 100644 (file)
--- a/ext/standard/base64.c
+++ b/ext/standard/base64.c
@@ -71,6 +71,19 @@ unsigned char *_php3_base64_encode(const unsigned char *string, int length, int
 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;
+
+       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;
+       }
 
        unsigned char *result = (unsigned char *)emalloc((length / 4 * 3 + 1) * sizeof(char));
        if (result == NULL) {
@@ -80,9 +93,8 @@ unsigned char *_php3_base64_decode(const unsigned char *string, int length, int
        /* run through the whole string, converting as we go */
        while ((ch = *current++) != '\0') {
                if (ch == base64_pad) break;
-               ch = (int)strchr(base64_table, ch);
-               if (ch == 0) continue;
-               ch -= (int)base64_table;
+               ch = reverse_table[ch];
+               if (ch < 0) continue;
 
                switch(i % 4) {
                case 0: