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crypto: Implement new crypto API functions for DH

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This implements crypto_dh_init() and crypto_dh_derive_secret() using
os_get_random() and crypto_mod_exp() for all crypto_*.c wrappers that
include crypto_mod_exp() implementation.

Signed-off-by: Jouni Malinen <j@w1.fi>
This commit is contained in:
Jouni Malinen 2017-12-24 17:25:39 +02:00
parent eac084cb38
commit 0e02f2a9fa
4 changed files with 144 additions and 0 deletions
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36
src/crypto/crypto_gnutls.c
View file

@ -154,6 +154,42 @@ void aes_decrypt_deinit(void *ctx)
}
int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey,
u8 *pubkey)
{
size_t pubkey_len, pad;
if (os_get_random(privkey, prime_len) < 0)
return -1;
if (os_memcmp(privkey, prime, prime_len) > 0) {
/* Make sure private value is smaller than prime */
privkey[0] = 0;
}
pubkey_len = prime_len;
if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len,
pubkey, &pubkey_len) < 0)
return -1;
if (pubkey_len < prime_len) {
pad = prime_len - pubkey_len;
os_memmove(pubkey + pad, pubkey, pubkey_len);
os_memset(pubkey, 0, pad);
}
return 0;
}
int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len,
const u8 *privkey, size_t privkey_len,
const u8 *pubkey, size_t pubkey_len,
u8 *secret, size_t *len)
{
return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len,
prime, prime_len, secret, len);
}
int crypto_mod_exp(const u8 *base, size_t base_len,
const u8 *power, size_t power_len,
const u8 *modulus, size_t modulus_len,

36
src/crypto/crypto_internal-modexp.c
View file

@ -13,6 +13,42 @@
#include "crypto.h"
int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey,
u8 *pubkey)
{
size_t pubkey_len, pad;
if (os_get_random(privkey, prime_len) < 0)
return -1;
if (os_memcmp(privkey, prime, prime_len) > 0) {
/* Make sure private value is smaller than prime */
privkey[0] = 0;
}
pubkey_len = prime_len;
if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len,
pubkey, &pubkey_len) < 0)
return -1;
if (pubkey_len < prime_len) {
pad = prime_len - pubkey_len;
os_memmove(pubkey + pad, pubkey, pubkey_len);
os_memset(pubkey, 0, pad);
}
return 0;
}
int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len,
const u8 *privkey, size_t privkey_len,
const u8 *pubkey, size_t pubkey_len,
u8 *secret, size_t *len)
{
return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len,
prime, prime_len, secret, len);
}
int crypto_mod_exp(const u8 *base, size_t base_len,
const u8 *power, size_t power_len,
const u8 *modulus, size_t modulus_len,

36
src/crypto/crypto_libtomcrypt.c
View file

@ -694,6 +694,42 @@ void crypto_global_deinit(void)
#ifdef CONFIG_MODEXP
int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey,
u8 *pubkey)
{
size_t pubkey_len, pad;
if (os_get_random(privkey, prime_len) < 0)
return -1;
if (os_memcmp(privkey, prime, prime_len) > 0) {
/* Make sure private value is smaller than prime */
privkey[0] = 0;
}
pubkey_len = prime_len;
if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len,
pubkey, &pubkey_len) < 0)
return -1;
if (pubkey_len < prime_len) {
pad = prime_len - pubkey_len;
os_memmove(pubkey + pad, pubkey, pubkey_len);
os_memset(pubkey, 0, pad);
}
return 0;
}
int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len,
const u8 *privkey, size_t privkey_len,
const u8 *pubkey, size_t pubkey_len,
u8 *secret, size_t *len)
{
return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len,
prime, prime_len, secret, len);
}
int crypto_mod_exp(const u8 *base, size_t base_len,
const u8 *power, size_t power_len,
const u8 *modulus, size_t modulus_len,

36
src/crypto/crypto_openssl.c
View file

@ -486,6 +486,42 @@ int aes_128_cbc_decrypt(const u8 *key, const u8 *iv, u8 *data, size_t data_len)
}
int crypto_dh_init(u8 generator, const u8 *prime, size_t prime_len, u8 *privkey,
u8 *pubkey)
{
size_t pubkey_len, pad;
if (os_get_random(privkey, prime_len) < 0)
return -1;
if (os_memcmp(privkey, prime, prime_len) > 0) {
/* Make sure private value is smaller than prime */
privkey[0] = 0;
}
pubkey_len = prime_len;
if (crypto_mod_exp(&generator, 1, privkey, prime_len, prime, prime_len,
pubkey, &pubkey_len) < 0)
return -1;
if (pubkey_len < prime_len) {
pad = prime_len - pubkey_len;
os_memmove(pubkey + pad, pubkey, pubkey_len);
os_memset(pubkey, 0, pad);
}
return 0;
}
int crypto_dh_derive_secret(u8 generator, const u8 *prime, size_t prime_len,
const u8 *privkey, size_t privkey_len,
const u8 *pubkey, size_t pubkey_len,
u8 *secret, size_t *len)
{
return crypto_mod_exp(pubkey, pubkey_len, privkey, privkey_len,
prime, prime_len, secret, len);
}
int crypto_mod_exp(const u8 *base, size_t base_len,
const u8 *power, size_t power_len,
const u8 *modulus, size_t modulus_len,