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

[mech_eap.git] / libeap / src / crypto / aes-siv.c

diff --git a/libeap/src/crypto/aes-siv.c b/libeap/src/crypto/aes-siv.c
new file mode 100644 (file)
index 0000000..5ac82c2
--- /dev/null
+++ b/libeap/src/crypto/aes-siv.c
@@ -0,0 +1,188 @@
+/*
+ * AES SIV (RFC 5297)
+ * Copyright (c) 2013 Cozybit, Inc.
+ *
+ * This software may be distributed under the terms of the BSD license.
+ * See README for more details.
+ */
+
+#include "includes.h"
+
+#include "common.h"
+#include "aes.h"
+#include "aes_wrap.h"
+#include "aes_siv.h"
+
+
+static const u8 zero[AES_BLOCK_SIZE];
+
+
+static void dbl(u8 *pad)
+{
+       int i, carry;
+
+       carry = pad[0] & 0x80;
+       for (i = 0; i < AES_BLOCK_SIZE - 1; i++)
+               pad[i] = (pad[i] << 1) | (pad[i + 1] >> 7);
+       pad[AES_BLOCK_SIZE - 1] <<= 1;
+       if (carry)
+               pad[AES_BLOCK_SIZE - 1] ^= 0x87;
+}
+
+
+static void xor(u8 *a, const u8 *b)
+{
+       int i;
+
+       for (i = 0; i < AES_BLOCK_SIZE; i++)
+               *a++ ^= *b++;
+}
+
+
+static void xorend(u8 *a, int alen, const u8 *b, int blen)
+{
+       int i;
+
+       if (alen < blen)
+               return;
+
+       for (i = 0; i < blen; i++)
+               a[alen - blen + i] ^= b[i];
+}
+
+
+static void pad_block(u8 *pad, const u8 *addr, size_t len)
+{
+       os_memset(pad, 0, AES_BLOCK_SIZE);
+       os_memcpy(pad, addr, len);
+
+       if (len < AES_BLOCK_SIZE)
+               pad[len] = 0x80;
+}
+
+
+static int aes_s2v(const u8 *key, size_t num_elem, const u8 *addr[],
+                  size_t *len, u8 *mac)
+{
+       u8 tmp[AES_BLOCK_SIZE], tmp2[AES_BLOCK_SIZE];
+       u8 *buf = NULL;
+       int ret;
+       size_t i;
+
+       if (!num_elem) {
+               os_memcpy(tmp, zero, sizeof(zero));
+               tmp[AES_BLOCK_SIZE - 1] = 1;
+               return omac1_aes_128(key, tmp, sizeof(tmp), mac);
+       }
+
+       ret = omac1_aes_128(key, zero, sizeof(zero), tmp);
+       if (ret)
+               return ret;
+
+       for (i = 0; i < num_elem - 1; i++) {
+               ret = omac1_aes_128(key, addr[i], len[i], tmp2);
+               if (ret)
+                       return ret;
+
+               dbl(tmp);
+               xor(tmp, tmp2);
+       }
+       if (len[i] >= AES_BLOCK_SIZE) {
+               buf = os_malloc(len[i]);
+               if (!buf)
+                       return -ENOMEM;
+
+               os_memcpy(buf, addr[i], len[i]);
+               xorend(buf, len[i], tmp, AES_BLOCK_SIZE);
+               ret = omac1_aes_128(key, buf, len[i], mac);
+               bin_clear_free(buf, len[i]);
+               return ret;
+       }
+
+       dbl(tmp);
+       pad_block(tmp2, addr[i], len[i]);
+       xor(tmp, tmp2);
+
+       return omac1_aes_128(key, tmp, sizeof(tmp), mac);
+}
+
+
+int aes_siv_encrypt(const u8 *key, const u8 *pw,
+                   size_t pwlen, size_t num_elem,
+                   const u8 *addr[], const size_t *len, u8 *out)
+{
+       const u8 *_addr[6];
+       size_t _len[6];
+       const u8 *k1 = key, *k2 = key + 16;
+       u8 v[AES_BLOCK_SIZE];
+       size_t i;
+       u8 *iv, *crypt_pw;
+
+       if (num_elem > ARRAY_SIZE(_addr) - 1)
+               return -1;
+
+       for (i = 0; i < num_elem; i++) {
+               _addr[i] = addr[i];
+               _len[i] = len[i];
+       }
+       _addr[num_elem] = pw;
+       _len[num_elem] = pwlen;
+
+       if (aes_s2v(k1, num_elem + 1, _addr, _len, v))
+               return -1;
+
+       iv = out;
+       crypt_pw = out + AES_BLOCK_SIZE;
+
+       os_memcpy(iv, v, AES_BLOCK_SIZE);
+       os_memcpy(crypt_pw, pw, pwlen);
+
+       /* zero out 63rd and 31st bits of ctr (from right) */
+       v[8] &= 0x7f;
+       v[12] &= 0x7f;
+       return aes_128_ctr_encrypt(k2, v, crypt_pw, pwlen);
+}
+
+
+int aes_siv_decrypt(const u8 *key, const u8 *iv_crypt, size_t iv_c_len,
+                   size_t num_elem, const u8 *addr[], const size_t *len,
+                   u8 *out)
+{
+       const u8 *_addr[6];
+       size_t _len[6];
+       const u8 *k1 = key, *k2 = key + 16;
+       size_t crypt_len;
+       size_t i;
+       int ret;
+       u8 iv[AES_BLOCK_SIZE];
+       u8 check[AES_BLOCK_SIZE];
+
+       if (iv_c_len < AES_BLOCK_SIZE || num_elem > ARRAY_SIZE(_addr) - 1)
+               return -1;
+       crypt_len = iv_c_len - AES_BLOCK_SIZE;
+
+       for (i = 0; i < num_elem; i++) {
+               _addr[i] = addr[i];
+               _len[i] = len[i];
+       }
+       _addr[num_elem] = out;
+       _len[num_elem] = crypt_len;
+
+       os_memcpy(iv, iv_crypt, AES_BLOCK_SIZE);
+       os_memcpy(out, iv_crypt + AES_BLOCK_SIZE, crypt_len);
+
+       iv[8] &= 0x7f;
+       iv[12] &= 0x7f;
+
+       ret = aes_128_ctr_encrypt(k2, iv, out, crypt_len);
+       if (ret)
+               return ret;
+
+       ret = aes_s2v(k1, num_elem + 1, _addr, _len, check);
+       if (ret)
+               return ret;
+       if (os_memcmp(check, iv_crypt, AES_BLOCK_SIZE) == 0)
+               return 0;
+
+       return -1;
+}