}
-static int sae_get_rand(const u8 *order, size_t prime_len, u8 *val)
+static void buf_shift_right(u8 *buf, size_t len, size_t bits)
+{
+ size_t i;
+ for (i = len - 1; i > 0; i--)
+ buf[i] = (buf[i - 1] << (8 - bits)) | (buf[i] >> bits);
+ buf[0] >>= bits;
+}
+
+
+static int sae_get_rand(const u8 *order, size_t prime_len_bits, u8 *val)
{
int iter = 0;
+ size_t prime_len = (prime_len_bits + 7) / 8;
do {
- if (random_get_bytes(val, prime_len) < 0)
- return -1;
if (iter++ > 100)
return -1;
+ if (random_get_bytes(val, prime_len) < 0)
+ return -1;
+ if (prime_len_bits % 8)
+ buf_shift_right(val, prime_len, 8 - prime_len_bits % 8);
} while (os_memcmp(val, order, prime_len) >= 0 ||
val_zero_or_one(val, prime_len));
{
u8 mask[SAE_MAX_PRIME_LEN], order[SAE_MAX_PRIME_LEN];
struct crypto_bignum *bn;
+ size_t prime_len_bits = crypto_ec_prime_len_bits(sae->ec);
if (crypto_bignum_to_bin(crypto_ec_get_order(sae->ec),
order, sizeof(order), sae->prime_len) < 0)
return NULL;
- if (sae_get_rand(order, sae->prime_len, sae->sae_rand) < 0 ||
- sae_get_rand(order, sae->prime_len, mask) < 0)
+ if (sae_get_rand(order, prime_len_bits, sae->sae_rand) < 0 ||
+ sae_get_rand(order, prime_len_bits, mask) < 0)
return NULL;
wpa_hexdump_key(MSG_DEBUG, "SAE: rand",
sae->sae_rand, sae->prime_len);
u8 pwd_value[SAE_MAX_PRIME_LEN], prime[SAE_MAX_PRIME_LEN];
struct crypto_bignum *x;
int y_bit;
+ size_t bits;
if (crypto_bignum_to_bin(crypto_ec_get_prime(sae->ec),
prime, sizeof(prime), sae->prime_len) < 0)
wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-seed", pwd_seed, SHA256_MAC_LEN);
/* pwd-value = KDF-z(pwd-seed, "SAE Hunting and Pecking", p) */
- sha256_prf(pwd_seed, SHA256_MAC_LEN, "SAE Hunting and Pecking",
- prime, sae->prime_len, pwd_value, sae->prime_len);
+ bits = crypto_ec_prime_len_bits(sae->ec);
+ sha256_prf_bits(pwd_seed, SHA256_MAC_LEN, "SAE Hunting and Pecking",
+ prime, sae->prime_len, pwd_value, bits);
+ if (bits % 8)
+ buf_shift_right(pwd_value, sizeof(pwd_value), 8 - bits % 8);
wpa_hexdump_key(MSG_DEBUG, "SAE: pwd-value",
pwd_value, sae->prime_len);
int ret = -1;
mask = sae_get_rand_and_mask(sae);
- if (mask == NULL)
+ if (mask == NULL) {
+ wpa_printf(MSG_DEBUG, "SAE: Could not get rand/mask");
return -1;
+ }
x = crypto_bignum_init();
bn_rand = crypto_bignum_init_set(sae->sae_rand, sae->prime_len);
crypto_ec_point_invert(sae->ec, elem) < 0 ||
crypto_ec_point_to_bin(sae->ec, elem, sae->own_commit_element,
sae->own_commit_element + sae->prime_len) <
- 0)
+ 0) {
+ wpa_printf(MSG_DEBUG, "SAE: Could not compute commit-element");
goto fail;
+ }
wpa_hexdump(MSG_DEBUG, "SAE: commit-element x",
sae->own_commit_element, sae->prime_len);
/*
* Simultaneous authentication of equals
- * Copyright (c) 2012, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2012-2013, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
#define SAE_PMK_LEN 32
#define SAE_PMKID_LEN 16
#define SAE_KEYSEED_KEY_LEN 32
-#define SAE_MAX_PRIME_LEN 48
+#define SAE_MAX_PRIME_LEN 66
#define SAE_COMMIT_MAX_LEN (2 + 3 * SAE_MAX_PRIME_LEN)
#define SAE_CONFIRM_MAX_LEN (2 + SAE_MAX_PRIME_LEN)
size_t crypto_ec_prime_len(struct crypto_ec *e);
/**
+ * crypto_ec_prime_len_bits - Get length of the prime in bits
+ * @e: EC context from crypto_ec_init()
+ * Returns: Length of the prime defining the group in bits
+ */
+size_t crypto_ec_prime_len_bits(struct crypto_ec *e);
+
+/**
* crypto_ec_get_prime - Get prime defining an EC group
* @e: EC context from crypto_ec_init()
* Returns: Prime (bignum) defining the group
case 20:
nid = NID_secp384r1;
break;
+ case 21:
+ nid = NID_secp521r1;
+ break;
case 25:
nid = NID_X9_62_prime192v1;
break;
}
+size_t crypto_ec_prime_len_bits(struct crypto_ec *e)
+{
+ return BN_num_bits(e->prime);
+}
+
+
const struct crypto_bignum * crypto_ec_get_prime(struct crypto_ec *e)
{
return (const struct crypto_bignum *) e->prime;
/*
* SHA256-based PRF (IEEE 802.11r)
- * Copyright (c) 2003-2007, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2013, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
void sha256_prf(const u8 *key, size_t key_len, const char *label,
const u8 *data, size_t data_len, u8 *buf, size_t buf_len)
{
+ sha256_prf_bits(key, key_len, label, data, data_len, buf, buf_len * 8);
+}
+
+
+/**
+ * sha256_prf_bits - IEEE Std 802.11-2012, 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 sha256_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[SHA256_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[3] = length_le;
len[3] = sizeof(length_le);
- WPA_PUT_LE16(length_le, buf_len * 8);
+ WPA_PUT_LE16(length_le, buf_len_bits);
pos = 0;
while (pos < buf_len) {
plen = buf_len - pos;
} else {
hmac_sha256_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;
+ }
}
/*
* SHA256 hash implementation and interface functions
- * Copyright (c) 2003-2011, Jouni Malinen <j@w1.fi>
+ * Copyright (c) 2003-2013, Jouni Malinen <j@w1.fi>
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
size_t data_len, u8 *mac);
void sha256_prf(const u8 *key, size_t key_len, const char *label,
const u8 *data, size_t data_len, u8 *buf, size_t buf_len);
+void sha256_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);
void tls_prf_sha256(const u8 *secret, size_t secret_len,
const char *label, const u8 *seed, size_t seed_len,
u8 *out, size_t outlen);