Incorrect decode with wrapped text

[ceztko]

I noticed the library fails with base64 encoded wrapped text (typically column text). Wrapped text can be obtained for example by using this online tool and clicking "Split lines into 76 character wide chunks", I fixed it by improving DecodeLength function and skipping newlines also in Decode. I changed the code a bit to adapt to my tastes but it should give the idea of what is needed to fix it:

size_t DecodedLength(const char *str, size_t len)
{
    size_t numEq = 0;
    size_t size = 0;

    for (size_t i = 0; i < len; i++) {
        char ch = str[i];
        if (ch == '\n' || ch == '\r')
            continue;

        if (ch == '=')
            numEq++;

        size++;
    }

    return ((6 * size) / 8) - numEq;
}

bool Decode(const char *str, size_t len, std::string &out)
{
    int i = 0, j = 0;
    size_t dec_len = 0;
    unsigned char a3[3];
    unsigned char a4[4];

    out.resize(DecodedLength(str, len));

    while (len--) {
        char ch = *str;
        if (ch == '=') {
            break;
        }

        if (ch == '\n' || ch == '\r') {
            str++;
            continue;
        }

        a4[i++] = *(str++);
        if (i == 4) {
            for (i = 0; i < 4; i++) {
                a4[i] = b64_lookup(a4[i]);
            }

            a4_to_a3(a3, a4);

            for (i = 0; i < 3; i++) {
                out[dec_len++] = a3[i];
            }

            i = 0;
        }
    }

    if (i) {
        for (j = i; j < 4; j++) {
            a4[j] = '\0';
        }

        for (j = 0; j < 4; j++) {
            a4[j] = b64_lookup(a4[j]);
        }

        a4_to_a3(a3, a4);

        for (j = 0; j < i - 1; j++) {
            out[dec_len++] = a3[j];
        }
    }

    return (dec_len == out.size());
}

[ceztko]

The DecodedLength function had a mistake (inverse iteration with unsigned index, I don't know why but works on Windows and don't give any warning). Fixed.