Merged the hostap_2.6 updates, and the Leap of Faith work, from the hostap_update...

[mech_eap.git] / libeap / src / crypto / sha384-prf.c

diff --git a/libeap/src/crypto/sha384-prf.c b/libeap/src/crypto/sha384-prf.c
new file mode 100644 (file)
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--- /dev/null
+++ b/libeap/src/crypto/sha384-prf.c
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+/*
+ * SHA384-based KDF (IEEE 802.11ac)
+ * Copyright (c) 2003-2015, Jouni Malinen <j@w1.fi>
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "sha384.h"
+#include "crypto.h"
+
+
+/**
+ * sha384_prf - SHA384-based Key derivation function (IEEE 802.11ac, 11.6.1.7.2)
+ * @key: Key for KDF
+ * @key_len: Length of the key in bytes
+ * @label: A unique label for each purpose of the PRF
+ * @data: Extra data to bind into the key
+ * @data_len: Length of the data
+ * @buf: Buffer for the generated pseudo-random key
+ * @buf_len: Number of bytes of key to generate
+ *
+ * This function is used to derive new, cryptographically separate keys from a
+ * given key.
+ */
+void sha384_prf(const u8 *key, size_t key_len, const char *label,
+               const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
+{
+       sha384_prf_bits(key, key_len, label, data, data_len, buf, buf_len * 8);
+}
+
+
+/**
+ * sha384_prf_bits - IEEE Std 802.11ac-2013, 11.6.1.7.2 Key derivation function
+ * @key: Key for KDF
+ * @key_len: Length of the key in bytes
+ * @label: A unique label for each purpose of the PRF
+ * @data: Extra data to bind into the key
+ * @data_len: Length of the data
+ * @buf: Buffer for the generated pseudo-random key
+ * @buf_len: Number of bits of key to generate
+ *
+ * This function is used to derive new, cryptographically separate keys from a
+ * given key. If the requested buf_len is not divisible by eight, the least
+ * significant 1-7 bits of the last octet in the output are not part of the
+ * requested output.
+ */
+void sha384_prf_bits(const u8 *key, size_t key_len, const char *label,
+                    const u8 *data, size_t data_len, u8 *buf,
+                    size_t buf_len_bits)
+{
+       u16 counter = 1;
+       size_t pos, plen;
+       u8 hash[SHA384_MAC_LEN];
+       const u8 *addr[4];
+       size_t len[4];
+       u8 counter_le[2], length_le[2];
+       size_t buf_len = (buf_len_bits + 7) / 8;
+
+       addr[0] = counter_le;
+       len[0] = 2;
+       addr[1] = (u8 *) label;
+       len[1] = os_strlen(label);
+       addr[2] = data;
+       len[2] = data_len;
+       addr[3] = length_le;
+       len[3] = sizeof(length_le);
+
+       WPA_PUT_LE16(length_le, buf_len_bits);
+       pos = 0;
+       while (pos < buf_len) {
+               plen = buf_len - pos;
+               WPA_PUT_LE16(counter_le, counter);
+               if (plen >= SHA384_MAC_LEN) {
+                       hmac_sha384_vector(key, key_len, 4, addr, len,
+                                          &buf[pos]);
+                       pos += SHA384_MAC_LEN;
+               } else {
+                       hmac_sha384_vector(key, key_len, 4, addr, len, hash);
+                       os_memcpy(&buf[pos], hash, plen);
+                       pos += plen;
+                       break;
+               }
+               counter++;
+       }
+
+       /*
+        * Mask out unused bits in the last octet if it does not use all the
+        * bits.
+        */
+       if (buf_len_bits % 8) {
+               u8 mask = 0xff << (8 - buf_len_bits % 8);
+               buf[pos - 1] &= mask;
+       }
+
+       os_memset(hash, 0, sizeof(hash));
+}