Added code for calculating ip subnets.

1 files changed, 228 insertions, 0 deletions

diff --git a/src/md5.c b/src/md5.c
new file mode 100644
index 0000000..c909bb3
--- /dev/null
+++ b/src/md5.c
@@ -0,0 +1,228 @@
+/*
+ * This code implements the MD5 message-digest algorithm.
+ * The algorithm is due to Ron Rivest.  This code was
+ * written by Colin Plumb in 1993, no copyright is claimed.
+ * This code is in the public domain; do with it what you wish.
+ *
+ * Equivalent code is available from RSA Data Security, Inc.
+ * This code has been tested against that, and is equivalent,
+ * except that you don't need to include two pages of legalese
+ * with every copy.
+ *
+ * To compute the message digest of a chunk of bytes, declare an
+ * MD5Context structure, pass it to MD5Init, call MD5Update as
+ * needed on buffers full of bytes, and then call MD5Final, which
+ * will fill a supplied 16-byte array with the digest.
+ */
+
+#include <string.h>
+#include "md5.h"
+
+#ifdef BIG_ENDIAN
+void
+byteSwap(unsigned int *buf, unsigned words)
+{
+        unsigned char *p = (unsigned char *)buf;
+
+        do {
+                *buf++ = (unsigned int)((unsigned)p[3] << 8 | p[2]) << 16 |
+                        ((unsigned)p[1] << 8 | p[0]);
+                p += 4;
+        } while (--words);
+}
+#else
+#define byteSwap(buf,words)
+#endif
+
+/*
+ * Start MD5 accumulation.  Set bit count to 0 and buffer to mysterious
+ * initialization constants.
+ */
+void
+MD5Init(struct MD5Context *ctx)
+{
+        ctx->buf[0] = 0x67452301;
+        ctx->buf[1] = 0xefcdab89;
+        ctx->buf[2] = 0x98badcfe;
+        ctx->buf[3] = 0x10325476;
+
+        ctx->bytes[0] = 0;
+        ctx->bytes[1] = 0;
+}
+
+/*
+ * Update context to reflect the concatenation of another buffer full
+ * of bytes.
+ */
+void
+MD5Update(struct MD5Context *ctx, const unsigned char* buf, unsigned len)
+{
+        unsigned int t;
+
+        /* Update byte count */
+
+        t = ctx->bytes[0];
+        if ((ctx->bytes[0] = t + len) < t)
+                ctx->bytes[1]++;        /* Carry from low to high */
+
+        t = 64 - (t & 0x3f);    /* Space available in ctx->in (at least 1) */
+        if (t > len) {
+                memcpy((unsigned char *)ctx->in + 64 - t, buf, len);
+                return;
+        }
+        /* First chunk is an odd size */
+        memcpy((unsigned char *)ctx->in + 64 - t, buf, t);
+        byteSwap(ctx->in, 16);
+        MD5Transform(ctx->buf, ctx->in);
+        buf += t;
+        len -= t;
+
+        /* Process data in 64-byte chunks */
+        while (len >= 64) {
+                memcpy(ctx->in, buf, 64);
+                byteSwap(ctx->in, 16);
+                MD5Transform(ctx->buf, ctx->in);
+                buf += 64;
+                len -= 64;
+        }
+
+        /* Handle any remaining bytes of data. */
+        memcpy(ctx->in, buf, len);
+}
+
+/*
+ * Final wrapup - pad to 64-byte boundary with the bit pattern
+ * 1 0* (64-bit count of bits processed, MSB-first)
+ */
+void
+MD5Final(unsigned char digest[16], struct MD5Context *ctx)
+{
+        int count = ctx->bytes[0] & 0x3f;       /* Number of bytes in ctx->in */
+        unsigned char *p = (unsigned char *)ctx->in + count;
+
+        /* Set the first char of padding to 0x80.  There is always room. */
+        *p++ = 0x80;
+
+        /* Bytes of padding needed to make 56 bytes (-8..55) */
+        count = 56 - 1 - count;
+
+        if (count < 0) {        /* Padding forces an extra block */
+                memset(p, 0, (unsigned int)count + 8);
+                byteSwap(ctx->in, 16);
+                MD5Transform(ctx->buf, ctx->in);
+                p = (unsigned char *)ctx->in;
+                count = 56;
+        }
+        memset(p, 0, (unsigned int)count);
+        byteSwap(ctx->in, 14);
+
+        /* Append length in bits and transform */
+        ctx->in[14] = ctx->bytes[0] << 3;
+        ctx->in[15] = ctx->bytes[1] << 3 | ctx->bytes[0] >> 29;
+        MD5Transform(ctx->buf, ctx->in);
+
+        byteSwap(ctx->buf, 4);
+        memcpy(digest, ctx->buf, 16);
+        memset(ctx, 0, sizeof(ctx));    /* In case it's sensitive */
+}
+
+/* The four core functions - F1 is optimized somewhat */
+
+/* #define F1(x, y, z) (x & y | ~x & z) */
+#define F1(x, y, z) (z ^ (x & (y ^ z)))
+#define F2(x, y, z) F1(z, x, y)
+#define F3(x, y, z) (x ^ y ^ z)
+#define F4(x, y, z) (y ^ (x | ~z))
+
+/* This is the central step in the MD5 algorithm. */
+#define MD5STEP(f,w,x,y,z,in,s) \
+         (w += f(x,y,z) + in, w = (w<<s | w>>(32-s)) + x)
+
+/*
+ * The core of the MD5 algorithm, this alters an existing MD5 hash to
+ * reflect the addition of 16 longwords of new data.  MD5Update blocks
+ * the data and converts bytes into longwords for this routine.
+ */
+void
+MD5Transform(unsigned int buf[4], unsigned int const in[16])
+{
+        register unsigned int a, b, c, d;
+
+        a = buf[0];
+        b = buf[1];
+        c = buf[2];
+        d = buf[3];
+
+        MD5STEP(F1, a, b, c, d, in[0] + 0xd76aa478, 7);
+        MD5STEP(F1, d, a, b, c, in[1] + 0xe8c7b756, 12);
+        MD5STEP(F1, c, d, a, b, in[2] + 0x242070db, 17);
+        MD5STEP(F1, b, c, d, a, in[3] + 0xc1bdceee, 22);
+        MD5STEP(F1, a, b, c, d, in[4] + 0xf57c0faf, 7);
+        MD5STEP(F1, d, a, b, c, in[5] + 0x4787c62a, 12);
+        MD5STEP(F1, c, d, a, b, in[6] + 0xa8304613, 17);
+        MD5STEP(F1, b, c, d, a, in[7] + 0xfd469501, 22);
+        MD5STEP(F1, a, b, c, d, in[8] + 0x698098d8, 7);
+        MD5STEP(F1, d, a, b, c, in[9] + 0x8b44f7af, 12);
+        MD5STEP(F1, c, d, a, b, in[10] + 0xffff5bb1, 17);
+        MD5STEP(F1, b, c, d, a, in[11] + 0x895cd7be, 22);
+        MD5STEP(F1, a, b, c, d, in[12] + 0x6b901122, 7);
+        MD5STEP(F1, d, a, b, c, in[13] + 0xfd987193, 12);
+        MD5STEP(F1, c, d, a, b, in[14] + 0xa679438e, 17);
+        MD5STEP(F1, b, c, d, a, in[15] + 0x49b40821, 22);
+
+        MD5STEP(F2, a, b, c, d, in[1] + 0xf61e2562, 5);
+        MD5STEP(F2, d, a, b, c, in[6] + 0xc040b340, 9);
+        MD5STEP(F2, c, d, a, b, in[11] + 0x265e5a51, 14);
+        MD5STEP(F2, b, c, d, a, in[0] + 0xe9b6c7aa, 20);
+        MD5STEP(F2, a, b, c, d, in[5] + 0xd62f105d, 5);
+        MD5STEP(F2, d, a, b, c, in[10] + 0x02441453, 9);
+        MD5STEP(F2, c, d, a, b, in[15] + 0xd8a1e681, 14);
+        MD5STEP(F2, b, c, d, a, in[4] + 0xe7d3fbc8, 20);
+        MD5STEP(F2, a, b, c, d, in[9] + 0x21e1cde6, 5);
+        MD5STEP(F2, d, a, b, c, in[14] + 0xc33707d6, 9);
+        MD5STEP(F2, c, d, a, b, in[3] + 0xf4d50d87, 14);
+        MD5STEP(F2, b, c, d, a, in[8] + 0x455a14ed, 20);
+        MD5STEP(F2, a, b, c, d, in[13] + 0xa9e3e905, 5);
+        MD5STEP(F2, d, a, b, c, in[2] + 0xfcefa3f8, 9);
+        MD5STEP(F2, c, d, a, b, in[7] + 0x676f02d9, 14);
+        MD5STEP(F2, b, c, d, a, in[12] + 0x8d2a4c8a, 20);
+
+        MD5STEP(F3, a, b, c, d, in[5] + 0xfffa3942, 4);
+        MD5STEP(F3, d, a, b, c, in[8] + 0x8771f681, 11);
+        MD5STEP(F3, c, d, a, b, in[11] + 0x6d9d6122, 16);
+        MD5STEP(F3, b, c, d, a, in[14] + 0xfde5380c, 23);
+        MD5STEP(F3, a, b, c, d, in[1] + 0xa4beea44, 4);
+        MD5STEP(F3, d, a, b, c, in[4] + 0x4bdecfa9, 11);
+        MD5STEP(F3, c, d, a, b, in[7] + 0xf6bb4b60, 16);
+        MD5STEP(F3, b, c, d, a, in[10] + 0xbebfbc70, 23);
+        MD5STEP(F3, a, b, c, d, in[13] + 0x289b7ec6, 4);
+        MD5STEP(F3, d, a, b, c, in[0] + 0xeaa127fa, 11);
+        MD5STEP(F3, c, d, a, b, in[3] + 0xd4ef3085, 16);
+        MD5STEP(F3, b, c, d, a, in[6] + 0x04881d05, 23);
+        MD5STEP(F3, a, b, c, d, in[9] + 0xd9d4d039, 4);
+        MD5STEP(F3, d, a, b, c, in[12] + 0xe6db99e5, 11);
+        MD5STEP(F3, c, d, a, b, in[15] + 0x1fa27cf8, 16);
+        MD5STEP(F3, b, c, d, a, in[2] + 0xc4ac5665, 23);
+
+        MD5STEP(F4, a, b, c, d, in[0] + 0xf4292244, 6);
+        MD5STEP(F4, d, a, b, c, in[7] + 0x432aff97, 10);
+        MD5STEP(F4, c, d, a, b, in[14] + 0xab9423a7, 15);
+        MD5STEP(F4, b, c, d, a, in[5] + 0xfc93a039, 21);
+        MD5STEP(F4, a, b, c, d, in[12] + 0x655b59c3, 6);
+        MD5STEP(F4, d, a, b, c, in[3] + 0x8f0ccc92, 10);
+        MD5STEP(F4, c, d, a, b, in[10] + 0xffeff47d, 15);
+        MD5STEP(F4, b, c, d, a, in[1] + 0x85845dd1, 21);
+        MD5STEP(F4, a, b, c, d, in[8] + 0x6fa87e4f, 6);
+        MD5STEP(F4, d, a, b, c, in[15] + 0xfe2ce6e0, 10);
+        MD5STEP(F4, c, d, a, b, in[6] + 0xa3014314, 15);
+        MD5STEP(F4, b, c, d, a, in[13] + 0x4e0811a1, 21);
+        MD5STEP(F4, a, b, c, d, in[4] + 0xf7537e82, 6);
+        MD5STEP(F4, d, a, b, c, in[11] + 0xbd3af235, 10);
+        MD5STEP(F4, c, d, a, b, in[2] + 0x2ad7d2bb, 15);
+        MD5STEP(F4, b, c, d, a, in[9] + 0xeb86d391, 21);
+
+        buf[0] += a;
+        buf[1] += b;
+        buf[2] += c;
+        buf[3] += d;
+}