Preliminary WebSocket protocol support.

1 files changed, 121 insertions, 0 deletions

diff --git a/src/Base64.cc b/src/Base64.cc
new file mode 100644
index 0000000..3b638c6
--- /dev/null
+++ b/src/Base64.cc
@@ -0,0 +1,121 @@
+#include <functional>
+#include "Base64.h"
+
+static char cb64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
+static char lookup[] = {
+//  x0  x1  x2  x3  x4  x5  x6  x7  x8  x9  xA  xB  xC  xD  xE  xF
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 0x
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 1x
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,  // 2x
+    52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,  // 3x
+    -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,  // 4x
+    15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, -1,  // 5x
+    -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,  // 6x
+    41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,  // 7x
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 8x
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // 9x
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Ax
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Bx
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Cx
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Dx
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Ex
+    -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,  // Fx
+};
+
+const double Balau::Base64::ratio = 4 / 3;
+
+void Balau::Base64::encode_block(unsigned char in_tab[3], int len, char out[5]) {
+    out[0] = cb64[in_tab[0] >> 2];
+    out[1] = cb64[((in_tab[0] & 3) << 4) | ((in_tab[1] & 240) >> 4)];
+    out[2] = len > 1 ? cb64[((in_tab[1] & 15) << 2) | ((in_tab[2] & 192) >> 6)] : '=';
+    out[3] = len > 2 ? cb64[in_tab[2] & 63] : '=';
+    out[4] = 0;
+}
+
+Balau::String Balau::Base64::encode(const uint8_t * data, int stream_size) {
+    String encoded;
+    encoded.reserve(stream_size * ratio + 1);
+    unsigned char in_tab[3];
+    int len, i, s_pos;
+
+    s_pos = 0;
+
+    while (stream_size > 0) {
+        in_tab[0] = 0;
+        in_tab[1] = 0;
+        in_tab[2] = 0;
+
+        len = stream_size >= 3 ? 3 : stream_size;
+
+        for (i = 0; i < len; i++) {
+            in_tab[i] = data[s_pos + i];
+        }
+
+        char block[5];
+        encode_block(in_tab, len, block);
+
+        encoded += block;
+
+        s_pos += 3;
+        stream_size -= 3;
+    }
+
+    return encoded;
+}
+
+int Balau::Base64::stri(char x) {
+    return lookup[(unsigned char) x];
+}
+
+int Balau::Base64::decode_block(char s1, char s2, char s3, char s4, unsigned char * out_tab) {
+    int len, sb1, sb2, sb3, sb4;
+
+    len = s3 == '=' ? 1 : s4 == '=' ? 2 : 3;
+    s3 = (s3 == '=') || (s3 == 0) ? 'A' : s3;
+    s4 = (s4 == '=') || (s4 == 0) ? 'A' : s4;
+    
+    sb1 = stri(s1);
+    sb2 = stri(s2);
+    sb3 = stri(s3);
+    sb4 = stri(s4);
+    
+    out_tab[0] = (sb1 << 2) | (sb2 >> 4);
+    out_tab[1] = ((sb2 << 4) & 255) | (sb3 >> 2);
+    out_tab[2] = ((sb3 << 6) & 240) | sb4;
+    
+    return len;
+}
+
+int Balau::Base64::decode(const String & str_in, uint8_t * data_out) {
+    int s_len = str_in.strlen(), len = 0, i, t_len, idx;
+    char s1, s2, s3, s4;
+    unsigned char t_out[3];
+    unsigned char * out = (unsigned char *) malloc(s_len * 3 / 4 + 4);
+    unsigned char * p = out;
+    std::function<char()> readNext = [&]() {
+        char r = '=';
+
+        if (idx >= s_len)
+            return r;
+
+        do {
+            r = str_in[idx++];
+        } while (r == '\r' || r == '\n' || r == ' ' || r == '\t');
+
+        return r;
+    };
+    
+    for (idx = 0; idx < s_len;) {
+        s1 = readNext();
+        s2 = readNext();
+        s3 = readNext();
+        s4 = readNext();
+        t_len = decode_block(s1, s2, s3, s4, t_out);
+        
+        for (i = 0; i < t_len; i++) *(p++) = t_out[i];
+
+        len += t_len;
+    }
+
+    return len;
+}