kdf: add key derivation functions

generic sha code from git://w1.fi/hostap.git commit
5ea93947ca67ba83529798b806a15b247cdb2e93 which also happens
to be the source of our milenage code.

Related: SYS#5324
Change-Id: Ibf2e49edada944d91ceba62bd0d6b6ce69261fcd
diff --git a/src/gsm/kdf/sha256-internal.c b/src/gsm/kdf/sha256-internal.c
new file mode 100644
index 0000000..18cc8f8
--- /dev/null
+++ b/src/gsm/kdf/sha256-internal.c
@@ -0,0 +1,231 @@
+/*
+ * SHA-256 hash implementation and interface functions
+ * Copyright (c) 2003-2011, Jouni Malinen <j@w1.fi>
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License version 2 as
+ * published by the Free Software Foundation.
+ *
+ * Alternatively, this software may be distributed under the terms of BSD
+ * license.
+ *
+ * See README and COPYING for more details.
+ */
+
+
+#include "common.h"
+#include "sha256.h"
+#include "sha256_i.h"
+#include "crypto.h"
+
+
+/**
+ * sha256_vector - SHA256 hash for data vector
+ * @num_elem: Number of elements in the data vector
+ * @addr: Pointers to the data areas
+ * @len: Lengths of the data blocks
+ * @mac: Buffer for the hash
+ * Returns: 0 on success, -1 of failure
+ */
+int sha256_vector(size_t num_elem, const u8 *addr[], const size_t *len,
+		  u8 *mac)
+{
+	struct sha256_state ctx;
+	size_t i;
+
+	sha256_init(&ctx);
+	for (i = 0; i < num_elem; i++)
+		if (sha256_process(&ctx, addr[i], len[i]))
+			return -1;
+	if (sha256_done(&ctx, mac))
+		return -1;
+	return 0;
+}
+
+
+/* ===== start - public domain SHA256 implementation ===== */
+
+/* This is based on SHA256 implementation in LibTomCrypt that was released into
+ * public domain by Tom St Denis. */
+
+/* the K array */
+static const unsigned long K[64] = {
+	0x428a2f98UL, 0x71374491UL, 0xb5c0fbcfUL, 0xe9b5dba5UL, 0x3956c25bUL,
+	0x59f111f1UL, 0x923f82a4UL, 0xab1c5ed5UL, 0xd807aa98UL, 0x12835b01UL,
+	0x243185beUL, 0x550c7dc3UL, 0x72be5d74UL, 0x80deb1feUL, 0x9bdc06a7UL,
+	0xc19bf174UL, 0xe49b69c1UL, 0xefbe4786UL, 0x0fc19dc6UL, 0x240ca1ccUL,
+	0x2de92c6fUL, 0x4a7484aaUL, 0x5cb0a9dcUL, 0x76f988daUL, 0x983e5152UL,
+	0xa831c66dUL, 0xb00327c8UL, 0xbf597fc7UL, 0xc6e00bf3UL, 0xd5a79147UL,
+	0x06ca6351UL, 0x14292967UL, 0x27b70a85UL, 0x2e1b2138UL, 0x4d2c6dfcUL,
+	0x53380d13UL, 0x650a7354UL, 0x766a0abbUL, 0x81c2c92eUL, 0x92722c85UL,
+	0xa2bfe8a1UL, 0xa81a664bUL, 0xc24b8b70UL, 0xc76c51a3UL, 0xd192e819UL,
+	0xd6990624UL, 0xf40e3585UL, 0x106aa070UL, 0x19a4c116UL, 0x1e376c08UL,
+	0x2748774cUL, 0x34b0bcb5UL, 0x391c0cb3UL, 0x4ed8aa4aUL, 0x5b9cca4fUL,
+	0x682e6ff3UL, 0x748f82eeUL, 0x78a5636fUL, 0x84c87814UL, 0x8cc70208UL,
+	0x90befffaUL, 0xa4506cebUL, 0xbef9a3f7UL, 0xc67178f2UL
+};
+
+
+/* Various logical functions */
+#define RORc(x, y) \
+( ((((unsigned long) (x) & 0xFFFFFFFFUL) >> (unsigned long) ((y) & 31)) | \
+   ((unsigned long) (x) << (unsigned long) (32 - ((y) & 31)))) & 0xFFFFFFFFUL)
+#define Ch(x,y,z)       (z ^ (x & (y ^ z)))
+#define Maj(x,y,z)      (((x | y) & z) | (x & y)) 
+#define S(x, n)         RORc((x), (n))
+#define R(x, n)         (((x)&0xFFFFFFFFUL)>>(n))
+#define Sigma0(x)       (S(x, 2) ^ S(x, 13) ^ S(x, 22))
+#define Sigma1(x)       (S(x, 6) ^ S(x, 11) ^ S(x, 25))
+#define Gamma0(x)       (S(x, 7) ^ S(x, 18) ^ R(x, 3))
+#define Gamma1(x)       (S(x, 17) ^ S(x, 19) ^ R(x, 10))
+#ifndef MIN
+#define MIN(x, y) (((x) < (y)) ? (x) : (y))
+#endif
+
+/* compress 512-bits */
+static int sha256_compress(struct sha256_state *md, unsigned char *buf)
+{
+	u32 S[8], W[64], t0, t1;
+	u32 t;
+	int i;
+
+	/* copy state into S */
+	for (i = 0; i < 8; i++) {
+		S[i] = md->state[i];
+	}
+
+	/* copy the state into 512-bits into W[0..15] */
+	for (i = 0; i < 16; i++)
+		W[i] = WPA_GET_BE32(buf + (4 * i));
+
+	/* fill W[16..63] */
+	for (i = 16; i < 64; i++) {
+		W[i] = Gamma1(W[i - 2]) + W[i - 7] + Gamma0(W[i - 15]) +
+			W[i - 16];
+	}        
+
+	/* Compress */
+#define RND(a,b,c,d,e,f,g,h,i)                          \
+	t0 = h + Sigma1(e) + Ch(e, f, g) + K[i] + W[i];	\
+	t1 = Sigma0(a) + Maj(a, b, c);			\
+	d += t0;					\
+	h  = t0 + t1;
+
+	for (i = 0; i < 64; ++i) {
+		RND(S[0], S[1], S[2], S[3], S[4], S[5], S[6], S[7], i);
+		t = S[7]; S[7] = S[6]; S[6] = S[5]; S[5] = S[4]; 
+		S[4] = S[3]; S[3] = S[2]; S[2] = S[1]; S[1] = S[0]; S[0] = t;
+	}
+
+	/* feedback */
+	for (i = 0; i < 8; i++) {
+		md->state[i] = md->state[i] + S[i];
+	}
+	return 0;
+}
+
+
+/* Initialize the hash state */
+void sha256_init(struct sha256_state *md)
+{
+	md->curlen = 0;
+	md->length = 0;
+	md->state[0] = 0x6A09E667UL;
+	md->state[1] = 0xBB67AE85UL;
+	md->state[2] = 0x3C6EF372UL;
+	md->state[3] = 0xA54FF53AUL;
+	md->state[4] = 0x510E527FUL;
+	md->state[5] = 0x9B05688CUL;
+	md->state[6] = 0x1F83D9ABUL;
+	md->state[7] = 0x5BE0CD19UL;
+}
+
+/**
+   Process a block of memory though the hash
+   @param md     The hash state
+   @param in     The data to hash
+   @param inlen  The length of the data (octets)
+   @return CRYPT_OK if successful
+*/
+int sha256_process(struct sha256_state *md, const unsigned char *in,
+		   unsigned long inlen)
+{
+	unsigned long n;
+
+	if (md->curlen >= sizeof(md->buf))
+		return -1;
+
+	while (inlen > 0) {
+		if (md->curlen == 0 && inlen >= SHA256_BLOCK_SIZE) {
+			if (sha256_compress(md, (unsigned char *) in) < 0)
+				return -1;
+			md->length += SHA256_BLOCK_SIZE * 8;
+			in += SHA256_BLOCK_SIZE;
+			inlen -= SHA256_BLOCK_SIZE;
+		} else {
+			n = MIN(inlen, (SHA256_BLOCK_SIZE - md->curlen));
+			os_memcpy(md->buf + md->curlen, in, n);
+			md->curlen += n;
+			in += n;
+			inlen -= n;
+			if (md->curlen == SHA256_BLOCK_SIZE) {
+				if (sha256_compress(md, md->buf) < 0)
+					return -1;
+				md->length += 8 * SHA256_BLOCK_SIZE;
+				md->curlen = 0;
+			}
+		}
+	}
+
+	return 0;
+}
+
+
+/**
+   Terminate the hash to get the digest
+   @param md  The hash state
+   @param out [out] The destination of the hash (32 bytes)
+   @return CRYPT_OK if successful
+*/
+int sha256_done(struct sha256_state *md, unsigned char *out)
+{
+	int i;
+
+	if (md->curlen >= sizeof(md->buf))
+		return -1;
+
+	/* increase the length of the message */
+	md->length += md->curlen * 8;
+
+	/* append the '1' bit */
+	md->buf[md->curlen++] = (unsigned char) 0x80;
+
+	/* if the length is currently above 56 bytes we append zeros
+	 * then compress.  Then we can fall back to padding zeros and length
+	 * encoding like normal.
+	 */
+	if (md->curlen > 56) {
+		while (md->curlen < SHA256_BLOCK_SIZE) {
+			md->buf[md->curlen++] = (unsigned char) 0;
+		}
+		sha256_compress(md, md->buf);
+		md->curlen = 0;
+	}
+
+	/* pad up to 56 bytes of zeroes */
+	while (md->curlen < 56) {
+		md->buf[md->curlen++] = (unsigned char) 0;
+	}
+
+	/* store length */
+	WPA_PUT_BE64(md->buf + 56, md->length);
+	sha256_compress(md, md->buf);
+
+	/* copy output */
+	for (i = 0; i < 8; i++)
+		WPA_PUT_BE32(out + (4 * i), md->state[i]);
+
+	return 0;
+}
+
+/* ===== end - public domain SHA256 implementation ===== */