static void Base64decode()

in src/azure_base64.c [130:187]

• 48 lines of code
• 4 McCabe index (conditional complexity)

static void Base64decode(unsigned char *decodedString, const char *base64String)
{

    size_t numberOfEncodedChars;
    size_t indexOfFirstEncodedChar;
    size_t decodedIndex;

    //
    // We can only operate on individual bytes.  If we attempt to work
    // on anything larger we could get an alignment fault on some
    // architectures
    //

    numberOfEncodedChars = numberOfBase64Characters(base64String);
    indexOfFirstEncodedChar = 0;
    decodedIndex = 0;
    while (numberOfEncodedChars >= 4)
    {
        unsigned char c1;
        unsigned char c2;
        unsigned char c3;
        unsigned char c4;
        (void)base64toValue(base64String[indexOfFirstEncodedChar], &c1);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 1], &c2);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 2], &c3);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 3], &c4);
        decodedString[decodedIndex] = (c1 << 2) | (c2 >> 4);
        decodedIndex++;
        decodedString[decodedIndex] = ((c2 & 0x0f) << 4) | (c3 >> 2);
        decodedIndex++;
        decodedString[decodedIndex] = ((c3 & 0x03) << 6) | c4;
        decodedIndex++;
        numberOfEncodedChars -= 4;
        indexOfFirstEncodedChar += 4;

    }

    if (numberOfEncodedChars == 2)
    {
        unsigned char c1;
        unsigned char c2;
        (void)base64toValue(base64String[indexOfFirstEncodedChar], &c1);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 1], &c2);
        decodedString[decodedIndex] = (c1 << 2) | (c2 >> 4);
    }
    else if (numberOfEncodedChars == 3)
    {
        unsigned char c1;
        unsigned char c2;
        unsigned char c3;
        (void)base64toValue(base64String[indexOfFirstEncodedChar], &c1);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 1], &c2);
        (void)base64toValue(base64String[indexOfFirstEncodedChar + 2], &c3);
        decodedString[decodedIndex] = (c1 << 2) | (c2 >> 4);
        decodedIndex++;
        decodedString[decodedIndex] = ((c2 & 0x0f) << 4) | (c3 >> 2);
    }
}