cleanups for srp. Most mpi code has moved to gnutls_srp.c

1 files changed, 74 insertions, 131 deletions

diff --git a/lib/auth_srp.c b/lib/auth_srp.c
index 244477e00c..a4b6e40c17 100644
--- a/lib/auth_srp.c
+++ b/lib/auth_srp.c
@@ -24,14 +24,15 @@
 #include "auth_srp_passwd.h"
 #include "auth_srp.h"
 #include "gnutls_auth_int.h"
+#include "gnutls_srp.h"
 
-int gen_srp_server_kx( GNUTLS_KEY, opaque**);
-int gen_srp_server_kx2( GNUTLS_KEY, opaque**);
-int gen_srp_client_kx0( GNUTLS_KEY, opaque**);
+int gen_srp_server_kx(GNUTLS_KEY, opaque **);
+int gen_srp_server_kx2(GNUTLS_KEY, opaque **);
+int gen_srp_client_kx0(GNUTLS_KEY, opaque **);
 
-int proc_srp_server_kx( GNUTLS_KEY, opaque*, int);
-int proc_srp_server_kx2( GNUTLS_KEY, opaque*, int);
-int proc_srp_client_kx0( GNUTLS_KEY, opaque*, int);
+int proc_srp_server_kx(GNUTLS_KEY, opaque *, int);
+int proc_srp_server_kx2(GNUTLS_KEY, opaque *, int);
+int proc_srp_client_kx0(GNUTLS_KEY, opaque *, int);
 
 MOD_AUTH_STRUCT srp_auth_struct = {
 	"SRP",
@@ -60,34 +61,40 @@ MOD_AUTH_STRUCT srp_auth_struct = {
 #define S key->KEY
 
 /* Send the first key exchange message ( g, n, s) */
-int gen_srp_server_kx( GNUTLS_KEY key, opaque** data) {
+int gen_srp_server_kx(GNUTLS_KEY key, opaque ** data)
+{
 	size_t n_g, n_n;
 	uint16 _n_n, _n_g, _n_s;
-	size_t ret;	
+	size_t ret;
 	uint8 *data_n, *data_s;
 	uint8 *data_g;
-	GNUTLS_SRP_PWD_ENTRY * pwd_entry;
+	GNUTLS_SRP_PWD_ENTRY *pwd_entry;
+
+	if (key->username == NULL) {
+		return GNUTLS_E_INSUFICIENT_CRED;
+	}
 
 	pwd_entry = _gnutls_srp_pwd_read_entry( key, key->username);
 
-	if (pwd_entry==NULL) {
+	if (pwd_entry == NULL) {
 		return GNUTLS_E_PWD_ERROR;
 	}
 
 	gcry_mpi_print(GCRYMPI_FMT_USG, NULL, &n_g, pwd_entry->g);
 	gcry_mpi_print(GCRYMPI_FMT_USG, NULL, &n_n, pwd_entry->n);
 
+	/* copy from pwd_entry to local variables (actually in state) */
 	G = gcry_mpi_alloc_like(pwd_entry->g);
 	N = gcry_mpi_alloc_like(pwd_entry->n);
 	V = gcry_mpi_alloc_like(pwd_entry->v);
 
-	mpi_set( G, pwd_entry->g);
-	mpi_set( N, pwd_entry->n);
-	mpi_set( V, pwd_entry->v);
-	
+	mpi_set(G, pwd_entry->g);
+	mpi_set(N, pwd_entry->n);
+	mpi_set(V, pwd_entry->v);
+
 	(*data) = gnutls_malloc(n_n + n_g + pwd_entry->salt_size + 6);
 
-	/* copy G (generator) */
+	/* copy G (generator) to data */
 	data_g = (*data);
 	gcry_mpi_print(GCRYMPI_FMT_USG, &data_g[2], &n_g, G);
 	_n_g = n_g;
@@ -110,10 +117,10 @@ int gen_srp_server_kx( GNUTLS_KEY key, opaque** data) {
 #endif
 
 	/* copy the salt */
-	data_s = &data_n[2+n_n];
+	data_s = &data_n[2 + n_n];
 	_n_s = pwd_entry->salt_size;
-	memcpy( &data_s[2], pwd_entry->salt, _n_s);
-	
+	memcpy(&data_s[2], pwd_entry->salt, _n_s);
+
 #ifndef WORDS_BIGENDIAN
 	_n_s = byteswap16(_n_s);
 	memcpy(data_s, &_n_s, 2);
@@ -122,34 +129,22 @@ int gen_srp_server_kx( GNUTLS_KEY key, opaque** data) {
 #endif
 
 
-	ret = n_g+ n_n + pwd_entry->salt_size + 6;
+	ret = n_g + n_n + pwd_entry->salt_size + 6;
 	gnutls_free(pwd_entry);
-	
+
 	return ret;
 }
 
-/* send the second key exchange message ( B = (v + g^b) % N) */
-int gen_srp_server_kx2( GNUTLS_KEY key, opaque** data) {
-	size_t n_b, bits;
+/* send the second key exchange message  */
+int gen_srp_server_kx2(GNUTLS_KEY key, opaque ** data)
+{
+	size_t n_b;
 	uint16 _n_b;
-	MPI tmpB;
 	uint8 *data_b;
-	GNUTLS_MAC_HANDLE td;
-	opaque* hd;
-	MPI tmp1, tmp2;
-	uint32 u;
-	
-        bits = gcry_mpi_get_nbits( key->client_p);
-        _b = mpi_new(bits);	/* FIXME: allocate in secure memory */
-        gcry_mpi_randomize( _b, bits, GCRY_STRONG_RANDOM);
-
-        tmpB = mpi_new(bits);	/* FIXME: allocate in secure memory */
-        B = mpi_new(bits);	/* FIXME: allocate in secure memory */
-        mpi_powm( tmpB, G, _b, N);
-        mpi_addm( B, V, tmpB, N);
-        
-        mpi_release(tmpB);
-		
+
+	/* calculate:  B = (v + g^b) % N */
+	B = _gnutls_calc_srp_B( &_b, G, N, V);
+
 	gcry_mpi_print(GCRYMPI_FMT_USG, NULL, &n_b, B);
 
 	(*data) = gnutls_malloc(n_b + 2);
@@ -166,62 +161,45 @@ int gen_srp_server_kx2( GNUTLS_KEY key, opaque** data) {
 	memcpy(data_b, &_n_b, 2);
 #endif
 
-	/* hash B to get u */
-	td = gnutls_hash_init( GNUTLS_MAC_SHA);
-	gnutls_hash( td, &data_b[2], n_b);
-	hd = gnutls_hash_deinit(td);
-	memcpy( &u, hd, sizeof(u));
-	gnutls_free(hd);
-	
-	key->u = mpi_set_ui( NULL, u);
+	/* calculate u */
+	key->u = _gnutls_calc_srp_u(B);
 
-	/* CALC HERE */
 	/* S = (A * v^u) ^ b % N */
-	
-	S = gcry_mpi_alloc_like(N);
-	tmp1 = gcry_mpi_alloc_like(N);
-	tmp2 = gcry_mpi_alloc_like(N);
-
-	mpi_pow(tmp1, V, key->u);
-	mpi_mul(tmp2, A, tmp1);
-	mpi_release(tmp1);
+	S = _gnutls_calc_srp_S1( A, _b, key->u, V, N);
 
-	mpi_powm( S, tmp2, _b, N);
-	mpi_release(tmp2);
-	
 	mpi_release(A);
 	mpi_release(_b);
 	mpi_release(V);
 	mpi_release(key->u);
 	mpi_release(B);
+
 	return n_b + 2;
 }
 
 
 /* return A = g^a % N */
-int gen_srp_client_kx0( GNUTLS_KEY key, opaque** data) {
-	size_t n_a, bits;
+int gen_srp_client_kx0(GNUTLS_KEY key, opaque ** data)
+{
+	size_t n_a;
 	uint16 _n_a;
 	uint8 *data_a;
 	char *username;
 	char *password;
-	SRP_CLIENT_CREDENTIALS* cred = _gnutls_get_kx_cred( key, GNUTLS_KX_SRP);
+	SRP_CLIENT_CREDENTIALS *cred =
+	    _gnutls_get_kx_cred(key, GNUTLS_KX_SRP);
+
+	if (cred == NULL)
+		return GNUTLS_E_INSUFICIENT_CRED;
 
-	if (cred==NULL) return  GNUTLS_E_INSUFICIENT_CRED;
-	
 	username = cred->username;
 	password = cred->password;
 
-	if (username==NULL || password == NULL) 
-		 return  GNUTLS_E_INSUFICIENT_CRED;
-        
-        bits = gcry_mpi_get_nbits( N);
-        _a = mpi_new(bits);	/* FIXME: allocate in secure memory */
-        gcry_mpi_randomize(_a, bits, GCRY_STRONG_RANDOM);
+	if (username == NULL || password == NULL)
+		return GNUTLS_E_INSUFICIENT_CRED;
+
+	/* calc A = g^a % N */
+	A = _gnutls_calc_srp_A( &_a, G, N);
 
-        A = mpi_new(bits);	/* FIXME: allocate in secure memory */
-        mpi_powm( A, G, _a, N);
-        
 	gcry_mpi_print(GCRYMPI_FMT_USG, NULL, &n_a, A);
 
 	(*data) = gnutls_malloc(n_a + 2);
@@ -241,26 +219,28 @@ int gen_srp_client_kx0( GNUTLS_KEY key, opaque** data) {
 }
 
 /* receive the first key exchange message ( g, n, s) */
-int proc_srp_server_kx( GNUTLS_KEY key, opaque* data, int data_size) {
+int proc_srp_server_kx(GNUTLS_KEY key, opaque * data, int data_size)
+{
 	uint16 n_s, n_g, n_n;
 	size_t _n_s, _n_g, _n_n;
 	uint8 *data_n;
 	uint8 *data_g;
 	uint8 *data_s;
 	int i;
-	GNUTLS_MAC_HANDLE td;
-	opaque* hd;
+	opaque *hd;
 	char *username;
 	char *password;
-	SRP_CLIENT_CREDENTIALS* cred = _gnutls_get_kx_cred( key, GNUTLS_KX_SRP);
+	SRP_CLIENT_CREDENTIALS *cred =
+	    _gnutls_get_kx_cred(key, GNUTLS_KX_SRP);
+
+	if (cred == NULL)
+		return GNUTLS_E_INSUFICIENT_CRED;
 
-	if (cred==NULL) return GNUTLS_E_INSUFICIENT_CRED;
-	
 	username = cred->username;
 	password = cred->password;
 
-	if (username==NULL || password == NULL) 
-		 return GNUTLS_E_INSUFICIENT_CRED;
+	if (username == NULL || password == NULL)
+		return GNUTLS_E_INSUFICIENT_CRED;
 
 	i = 0;
 	memcpy(&n_g, &data[i], 2);
@@ -302,47 +282,33 @@ int proc_srp_server_kx( GNUTLS_KEY key, opaque* data, int data_size) {
 	_n_g = n_g;
 	_n_n = n_n;
 
-	if (gcry_mpi_scan(&N,
-			      GCRYMPI_FMT_USG, data_n, &_n_n) != 0) {
+	if (gcry_mpi_scan(&N, GCRYMPI_FMT_USG, data_n, &_n_n) != 0) {
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
 
-	if (gcry_mpi_scan(&G,
-			      GCRYMPI_FMT_USG, data_g, &_n_g) != 0) {
+	if (gcry_mpi_scan(&G, GCRYMPI_FMT_USG, data_g, &_n_g) != 0) {
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
 
 	/* generate x = SHA(s | SHA(U | ":" | p))
 	 */
-	td = gnutls_hash_init( GNUTLS_MAC_SHA);
-	gnutls_hash( td, username, strlen(username));
-	gnutls_hash( td, ":", 1);
-	gnutls_hash( td, password, strlen(password));
-	hd = gnutls_hash_deinit(td);
-
-	td = gnutls_hash_init( GNUTLS_MAC_SHA);
-	gnutls_hash( td, data_s, n_s);
-	gnutls_hash( td, hd, 20);
-	gnutls_free(hd);
-	
-	hd = gnutls_hash_deinit(td);
-	
+	hd = _gnutls_calc_srp_sha( username, password, data_s, n_s);
 	_n_g = 20;
-	if (gcry_mpi_scan(&key->x,
-			      GCRYMPI_FMT_USG, hd, &_n_g) != 0) {
+	if (gcry_mpi_scan(&key->x, GCRYMPI_FMT_USG, hd, &_n_g) != 0) {
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
 
 	gnutls_free(hd);
 	
-
 	return 0;
 }
 
-int proc_srp_client_kx0( GNUTLS_KEY key, opaque* data, int data_size) {
+/* just read A and put it to state */
+int proc_srp_client_kx0(GNUTLS_KEY key, opaque * data, int data_size)
+{
 	uint16 n_A;
 	size_t _n_A;
 
@@ -351,8 +317,7 @@ int proc_srp_client_kx0( GNUTLS_KEY key, opaque* data, int data_size) {
 	n_A = byteswap16(n_A);
 #endif
 	_n_A = n_A;
-	if (gcry_mpi_scan(&A,
-		      GCRYMPI_FMT_USG, &data[2], &_n_A)) {
+	if (gcry_mpi_scan(&A, GCRYMPI_FMT_USG, &data[2], &_n_A)) {
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
@@ -361,45 +326,24 @@ int proc_srp_client_kx0( GNUTLS_KEY key, opaque* data, int data_size) {
 }
 
 
-int proc_srp_server_kx2( GNUTLS_KEY key, opaque* data, int data_size) {
+int proc_srp_server_kx2(GNUTLS_KEY key, opaque * data, int data_size)
+{
 	uint16 n_B;
 	size_t _n_B;
-	MPI tmp1, tmp2, tmp3, tmp4;
 
 	memcpy(&n_B, &data[0], 2);
 #ifndef WORDS_BIGENDIAN
 	n_B = byteswap16(n_B);
 #endif
 	_n_B = n_B;
-	if (gcry_mpi_scan(&B,
-		      GCRYMPI_FMT_USG, &data[2], &_n_B)) {
+	if (gcry_mpi_scan(&B, GCRYMPI_FMT_USG, &data[2], &_n_B)) {
 		gnutls_assert();
 		return GNUTLS_E_MPI_SCAN_FAILED;
 	}
 
-	/* CALC HERE */
 	/* S = (B - g^x) ^ (a + u * x) % N */
+	S = _gnutls_calc_srp_S2( B, G, key->x, _a, key->u, N);
 
-	S = gcry_mpi_alloc_like(N);
-	tmp1 = gcry_mpi_alloc_like(N);
-	tmp2 = gcry_mpi_alloc_like(N);
-
-	mpi_pow(tmp1, G, V);
-	mpi_sub(tmp2, B, tmp1);
-	mpi_release(tmp1);
-
-
-	tmp3 = gcry_mpi_alloc_like(N);
-	tmp4 = gcry_mpi_alloc_like(N);
-	
-	mpi_add( tmp3, key->u, V);
-	mpi_add( tmp4, _a, tmp3);
-	mpi_release(tmp3);
-	
-	mpi_powm( S, tmp2, tmp4, N);
-	mpi_release(tmp2);
-	mpi_release(tmp4);
-	
 	mpi_release(A);
 	mpi_release(_b);
 	mpi_release(V);
@@ -407,4 +351,3 @@ int proc_srp_server_kx2( GNUTLS_KEY key, opaque* data, int data_size) {
 	mpi_release(B);
 	return 0;
 }
-