return done;
}
+
+/*
+ * returns length of decoded string in out, or -1 if out was too small
+ * according to out_size
+ */
+
+LWS_VISIBLE int
+lws_b64_decode_string(const char *in, char *out, int out_size)
+{
+ int len;
+ int i;
+ int done = 0;
+ unsigned char v;
+ unsigned char quad[4];
+
+ while (*in) {
+
+ len = 0;
+ for (i = 0; i < 4 && *in; i++) {
+
+ v = 0;
+ while (*in && !v) {
+
+ v = *in++;
+ v = (v < 43 || v > 122) ? 0 : decode[v - 43];
+ if (v)
+ v = (v == '$') ? 0 : v - 61;
+ if (*in) {
+ len++;
+ if (v)
+ quad[i] = v - 1;
+ } else
+ quad[i] = 0;
+ }
+ }
+ if (!len)
+ continue;
+
+ if (out_size < (done + len - 1))
+ /* out buffer is too small */
+ return -1;
+
+ if (len >= 2)
+ *out++ = quad[0] << 2 | quad[1] >> 4;
+ if (len >= 3)
+ *out++ = quad[1] << 4 | quad[2] >> 2;
+ if (len >= 4)
+ *out++ = ((quad[2] << 6) & 0xc0) | quad[3];
+
+ done += len - 1;
+ }
+
+ if (done + 1 >= out_size)
+ return -1;
+
+ *out++ = '\0';
+
+ return done;
+}
+
+int
+lws_b64_selftest(void)
+{
+ char buf[64];
+ int n;
+ int test;
+ static const char * const plaintext[] = {
+ "sanity check base 64"
+ };
+ static const char * const coded[] = {
+ "c2FuaXR5IGNoZWNrIGJhc2UgNjQ="
+ };
+
+ for (test = 0; test < sizeof plaintext / sizeof(plaintext[0]); test++) {
+
+ buf[sizeof(buf) - 1] = '\0';
+ n = lws_b64_encode_string(plaintext[test],
+ strlen(plaintext[test]), buf, sizeof buf);
+ if (n != strlen(coded[test]) || strcmp(buf, coded[test])) {
+ lwsl_err("Failed lws_b64 encode selftest "
+ "%d result '%s' %d\n", test, buf, n);
+ return -1;
+ }
+
+ buf[sizeof(buf) - 1] = '\0';
+ n = lws_b64_decode_string(coded[test], buf, sizeof buf);
+ if (n != strlen(plaintext[test]) ||
+ strcmp(buf, plaintext[test])) {
+ lwsl_err("Failed lws_b64 decode selftest "
+ "%d result '%s' %d\n", test, buf, n);
+ return -1;
+ }
+ }
+
+ return 0;
+}