Finish base64 decoding routine.

diff --git a/src/utils.c b/src/utils.c
index 6b44556..c58f8ca 100644 (file)
--- a/src/utils.c
+++ b/src/utils.c
@@ -34,12 +34,16 @@ static int charhex2bin(char c) {
 }
 
 static int charb64decode(char c) {
-       if(c > 'a')
+       if(c >= 'a')
                return c - 'a' + 26;
-       else if(c > 'A')
+       else if(c >= 'A')
                return c - 'A';
+       else if(c >= '0') 
+               return c - '0' + 52;
+       else if(c == '+')
+               return 62;
        else
-               return c - '0';
+               return 63;
 }
 
 void hex2bin(char *src, char *dst, int length) {
@@ -58,11 +62,11 @@ void bin2hex(char *src, char *dst, int length) {
 
 int b64decode(const char *src, char *dst, int length) {
        uint32_t triplet = 0;
-       unsigned char *udst;
+       unsigned char *udst = dst;
 
        for(int i = 0; i < length; i++) {
-               triplet |= charb64decode(src[i]) << (6 * (i % 4));
-               if((i % 4) == 3) {
+               triplet |= charb64decode(src[i]) << (6 * (i & 3));
+               if((i & 3) == 3) {
                        udst[0] = triplet & 0xff; triplet >>= 8;
                        udst[1] = triplet & 0xff; triplet >>= 8;
                        udst[2] = triplet;
@@ -70,11 +74,11 @@ int b64decode(const char *src, char *dst, int length) {
                        udst += 3;
                }
        }
-       if((length % 4) == 3) {
+       if((length & 3) == 3) {
                udst[0] = triplet & 0xff; triplet >>= 8;
                udst[1] = triplet & 0xff;
                return length / 4 * 3 + 2;
-       } else if((length % 4) == 2) {
+       } else if((length & 3) == 2) {
                udst[0] = triplet & 0xff;
                return length / 4 * 3 + 1;
        } else {