/**
* Reads a chunk from the input stream. Returns the number of bytes
* recovered from the input stream, zero on end of file or -1 in case
* of BASE32 format error.
*/
STATIC int BASE32_ReadChunk(Base32Decode * decode, I8u chunk[4])
{
/* the index where the padding begins */
int end = ((decode->flags & FLAG_PAD) ? 0 : -1);
int n = 0;
while (n < DECODE_CHUNK_SIZE) {
int nextChar = FILE_Getc(decode->in);
if (nextChar < 0) {
break;
} else {
I8u k;
Char c = (Char)nextChar;
/* count this character */
decode->nread++;
if ((c & (~0x7f)) != 0) {
decode->flags |= FLAG_ERROR;
return -1;
}
/* ignore whitespaces */
if (IsSpace(c)) {
continue;
}
if (c == '=') {
if (end < 0) end = n;
decode->flags |= FLAG_PAD;
ASSERT(decode->decodeMap[(int)c] == 0);
k = 0;
} else {
if (decode->flags & FLAG_PAD) {
/* junk after the padding */
decode->flags |= FLAG_ERROR;
return -1;
}
/* run it through the decoding map */
k = decode->decodeMap[(int)c];
if (k == 0xff) {
decode->flags |= FLAG_ERROR;
return -1;
}
}
chunk[n++] = k;
}
}
if (n < DECODE_CHUNK_SIZE) {
int k = n;
while (k < DECODE_CHUNK_SIZE) chunk[k++] = 0;
}
if (end >= 0) {
return end;
} else {
return n;
}
}
/**
* The same thing as above but for 64-bit integers. Copy/pasted for
* efficiency reasons.
*/
Bool FILE_ReadMultiByte64(File * in, I64u * result)
{
I64u value = 0;
int i;
for (i=0; i<MAX_MULTI_INT_SIZE_64; i++) {
int c = FILE_Getc(in);
if (c < 0) {
return False;
} else {
value = (value << 7) | (c & 0x7f);
if (!(c & 0x80)) {
if (result) *result = value;
return True;
}
}
}
/* stream corrupted - too many continuation bytes */
return False;
}
