denozord/strongswan-ext
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

refining changeset 4483 by introducing charon.dh_exponent_ansi_x9_42 key

Browse Source
This commit is contained in:
Andreas Steffen
2008-10-28 01:59:01 +00:00
parent 85ac2fa547
commit f5ab7f5f57
3 changed files with 62 additions and 27 deletions
Download Patch File Download Diff File Expand all files Collapse all files
src/libstrongswan/plugins/gmp/gmp_diffie_hellman.c
+35 -11
View File
@@ -303,6 +303,11 @@ struct modulus_entry_t {
*/ */
size_t modulus_len; size_t modulus_len;
/*
* Optimum length of exponent in bytes.
*/
size_t opt_exponent_len;
/* /*
* Generator value. * Generator value.
*/ */
@@ -310,17 +315,17 @@ struct modulus_entry_t {
}; };
/** /**
* All supported modulus values. * All supported modulus values - optimum exponent size according to RFC 3526.
*/ */
static modulus_entry_t modulus_entries[] = { static modulus_entry_t modulus_entries[] = {
{MODP_768_BIT, group1_modulus, sizeof(group1_modulus), 2}, {MODP_768_BIT, group1_modulus, sizeof(group1_modulus), 32, 2},
{MODP_1024_BIT, group2_modulus, sizeof(group2_modulus), 2}, {MODP_1024_BIT, group2_modulus, sizeof(group2_modulus), 32, 2},
{MODP_1536_BIT, group5_modulus, sizeof(group5_modulus), 2}, {MODP_1536_BIT, group5_modulus, sizeof(group5_modulus), 32, 2},
{MODP_2048_BIT, group14_modulus, sizeof(group14_modulus), 2}, {MODP_2048_BIT, group14_modulus, sizeof(group14_modulus), 48, 2},
{MODP_3072_BIT, group15_modulus, sizeof(group15_modulus), 2}, {MODP_3072_BIT, group15_modulus, sizeof(group15_modulus), 48, 2},
{MODP_4096_BIT, group16_modulus, sizeof(group16_modulus), 2}, {MODP_4096_BIT, group16_modulus, sizeof(group16_modulus), 64, 2},
{MODP_6144_BIT, group17_modulus, sizeof(group17_modulus), 2}, {MODP_6144_BIT, group17_modulus, sizeof(group17_modulus), 64, 2},
{MODP_8192_BIT, group18_modulus, sizeof(group18_modulus), 2}, {MODP_8192_BIT, group18_modulus, sizeof(group18_modulus), 64, 2},
}; };
typedef struct private_gmp_diffie_hellman_t private_gmp_diffie_hellman_t; typedef struct private_gmp_diffie_hellman_t private_gmp_diffie_hellman_t;
@@ -374,6 +379,11 @@ struct private_gmp_diffie_hellman_t {
*/ */
size_t p_len; size_t p_len;
/**
* Optimal exponent length.
*/
size_t opt_exponent_len;
/** /**
* True if shared secret is computed and stored in my_public_value. * True if shared secret is computed and stored in my_public_value.
*/ */
@@ -504,6 +514,7 @@ static status_t set_modulus(private_gmp_diffie_hellman_t *this)
chunk.len = modulus_entries[i].modulus_len; chunk.len = modulus_entries[i].modulus_len;
mpz_import(this->p, chunk.len, 1, 1, 1, 0, chunk.ptr); mpz_import(this->p, chunk.len, 1, 1, 1, 0, chunk.ptr);
this->p_len = chunk.len; this->p_len = chunk.len;
this->opt_exponent_len = modulus_entries[i].opt_exponent_len;
mpz_set_ui(this->g, modulus_entries[i].generator); mpz_set_ui(this->g, modulus_entries[i].generator);
status = SUCCESS; status = SUCCESS;
break; break;
@@ -534,6 +545,8 @@ gmp_diffie_hellman_t *gmp_diffie_hellman_create(diffie_hellman_group_t group)
private_gmp_diffie_hellman_t *this = malloc_thing(private_gmp_diffie_hellman_t); private_gmp_diffie_hellman_t *this = malloc_thing(private_gmp_diffie_hellman_t);
rng_t *rng; rng_t *rng;
chunk_t random; chunk_t random;
bool ansi_x9_42;
size_t exponent_len;
/* public functions */ /* public functions */
this->public.dh.get_shared_secret = (status_t (*)(diffie_hellman_t *, chunk_t *)) get_shared_secret; this->public.dh.get_shared_secret = (status_t (*)(diffie_hellman_t *, chunk_t *)) get_shared_secret;
@@ -567,11 +580,22 @@ gmp_diffie_hellman_t *gmp_diffie_hellman_create(diffie_hellman_group_t group)
destroy(this); destroy(this);
return NULL; return NULL;
} }
rng->allocate_bytes(rng, DH_EXPONENT_ENTROPY_SIZE / BITS_PER_BYTE, &random);
ansi_x9_42 = lib->settings->get_int(lib->settings,
"charon.dh_exponent_ansi_x9_42", TRUE);
exponent_len = (ansi_x9_42) ? this->p_len : this->opt_exponent_len;
rng->allocate_bytes(rng, exponent_len, &random);
rng->destroy(rng); rng->destroy(rng);
if (ansi_x9_42)
{
/* achieve bitsof(p)-1 by setting MSB to 0 */
*random.ptr &= 0x7F;
}
mpz_import(this->xa, random.len, 1, 1, 1, 0, random.ptr); mpz_import(this->xa, random.len, 1, 1, 1, 0, random.ptr);
chunk_free(&random); chunk_free(&random);
DBG2("size of DH secret exponent: %u bits", mpz_sizeinbase(this->xa, 2));
mpz_powm(this->ya, this->g, this->xa, this->p); mpz_powm(this->ya, this->g, this->xa, this->p);
return &this->public; return &this->public;
src/libstrongswan/plugins/openssl/openssl_diffie_hellman.c
+27 -11
View File
@@ -37,6 +37,11 @@ struct modulus_entry_t {
*/ */
BIGNUM *(*get_prime)(BIGNUM *bn); BIGNUM *(*get_prime)(BIGNUM *bn);
/*
* Optimum length of exponent in bits.
*/
long opt_exponent_len;
/* /*
* Generator value. * Generator value.
*/ */
@@ -44,17 +49,17 @@ struct modulus_entry_t {
}; };
/** /**
* All supported modulus values. * All supported modulus values - optimum exponent size according to RFC 3526.
*/ */
static modulus_entry_t modulus_entries[] = { static modulus_entry_t modulus_entries[] = {
{MODP_768_BIT, get_rfc2409_prime_768, 2}, {MODP_768_BIT, get_rfc2409_prime_768, 256, 2},
{MODP_1024_BIT, get_rfc2409_prime_1024, 2}, {MODP_1024_BIT, get_rfc2409_prime_1024, 256, 2},
{MODP_1536_BIT, get_rfc3526_prime_1536, 2}, {MODP_1536_BIT, get_rfc3526_prime_1536, 256, 2},
{MODP_2048_BIT, get_rfc3526_prime_2048, 2}, {MODP_2048_BIT, get_rfc3526_prime_2048, 384, 2},
{MODP_3072_BIT, get_rfc3526_prime_3072, 2}, {MODP_3072_BIT, get_rfc3526_prime_3072, 384, 2},
{MODP_4096_BIT, get_rfc3526_prime_4096, 2}, {MODP_4096_BIT, get_rfc3526_prime_4096, 512, 2},
{MODP_6144_BIT, get_rfc3526_prime_6144, 2}, {MODP_6144_BIT, get_rfc3526_prime_6144, 512, 2},
{MODP_8192_BIT, get_rfc3526_prime_8192, 2}, {MODP_8192_BIT, get_rfc3526_prime_8192, 512, 2},
}; };
typedef struct private_openssl_diffie_hellman_t private_openssl_diffie_hellman_t; typedef struct private_openssl_diffie_hellman_t private_openssl_diffie_hellman_t;
@@ -83,6 +88,11 @@ struct private_openssl_diffie_hellman_t {
*/ */
BIGNUM *pub_key; BIGNUM *pub_key;
/*
* Optimum length of exponent in bits.
*/
long opt_exponent_len;
/** /**
* Shared secret * Shared secret
*/ */
@@ -180,6 +190,7 @@ static status_t set_modulus(private_openssl_diffie_hellman_t *this)
this->dh->p = modulus_entries[i].get_prime(NULL); this->dh->p = modulus_entries[i].get_prime(NULL);
this->dh->g = BN_new(); this->dh->g = BN_new();
BN_set_word(this->dh->g, modulus_entries[i].generator); BN_set_word(this->dh->g, modulus_entries[i].generator);
this->opt_exponent_len = modulus_entries[i].opt_exponent_len;
return SUCCESS; return SUCCESS;
} }
} }
@@ -202,6 +213,7 @@ static void destroy(private_openssl_diffie_hellman_t *this)
*/ */
openssl_diffie_hellman_t *openssl_diffie_hellman_create(diffie_hellman_group_t group) openssl_diffie_hellman_t *openssl_diffie_hellman_create(diffie_hellman_group_t group)
{ {
bool ansi_x9_42;
private_openssl_diffie_hellman_t *this = malloc_thing(private_openssl_diffie_hellman_t); private_openssl_diffie_hellman_t *this = malloc_thing(private_openssl_diffie_hellman_t);
this->public.dh.get_shared_secret = (status_t (*)(diffie_hellman_t *, chunk_t *)) get_shared_secret; this->public.dh.get_shared_secret = (status_t (*)(diffie_hellman_t *, chunk_t *)) get_shared_secret;
@@ -217,8 +229,7 @@ openssl_diffie_hellman_t *openssl_diffie_hellman_create(diffie_hellman_group_t g
free(this); free(this);
return NULL; return NULL;
} }
this->dh->length = DH_EXPONENT_ENTROPY_SIZE;
this->group = group; this->group = group;
this->computed = FALSE; this->computed = FALSE;
@@ -232,12 +243,17 @@ openssl_diffie_hellman_t *openssl_diffie_hellman_create(diffie_hellman_group_t g
return NULL; return NULL;
} }
ansi_x9_42 = lib->settings->get_bool(lib->settings,
"charon.dh_exponent_ansi_x9_42", TRUE);
this->dh->length = (ansi_x9_42) ? 0 : this->opt_exponent_len;
/* generate my public and private values */ /* generate my public and private values */
if (!DH_generate_key(this->dh)) if (!DH_generate_key(this->dh))
{ {
destroy(this); destroy(this);
return NULL; return NULL;
} }
DBG2("size of DH secret exponent: %d bits", BN_num_bits(this->dh->priv_key));
return &this->public; return &this->public;
} }
src/libstrongswan/utils.h
-5
View File
@@ -40,11 +40,6 @@
*/ */
#define BUF_LEN 512 #define BUF_LEN 512
/**
* Entropy in bits of secret Diffie-Hellman exponents
*/
#define DH_EXPONENT_ENTROPY_SIZE 512
/** /**
* Macro compares two strings for equality * Macro compares two strings for equality
*/ */