diff ecc.c @ 765:5503e05ab3a4 ecc

- Rename buf_put_ecc_pubkey_string() to buf_put_ecc_raw_pubkey_string() - Reindent ecc.c properly
author Matt Johnston <matt@ucc.asn.au>
date Mon, 08 Apr 2013 23:56:31 +0800
parents f744321ac048
children d1575fdc29a6
line wrap: on
line diff
--- a/ecc.c	Mon Apr 08 23:12:35 2013 +0800
+++ b/ecc.c	Mon Apr 08 23:56:31 2013 +0800
@@ -31,16 +31,74 @@
 #endif
 
 static ecc_key * new_ecc_key(void) {
-   ecc_key *key = m_malloc(sizeof(*key));
-   key->pubkey.x = m_malloc(sizeof(mp_int));
-   key->pubkey.y = m_malloc(sizeof(mp_int));
-   key->pubkey.z = m_malloc(sizeof(mp_int));
-   key->k = m_malloc(sizeof(mp_int));
-   m_mp_init_multi(key->pubkey.x, key->pubkey.y, key->pubkey.z, key->k, NULL);
-   return key;
+	ecc_key *key = m_malloc(sizeof(*key));
+	key->pubkey.x = m_malloc(sizeof(mp_int));
+	key->pubkey.y = m_malloc(sizeof(mp_int));
+	key->pubkey.z = m_malloc(sizeof(mp_int));
+	key->k = m_malloc(sizeof(mp_int));
+	m_mp_init_multi(key->pubkey.x, key->pubkey.y, key->pubkey.z, key->k, NULL);
+	return key;
 }
 
-void buf_put_ecc_pubkey_string(buffer *buf, ecc_key *key) {
+// Copied from libtomcrypt ecc_import.c (version there is static), modified
+// for different mp_int pointer without LTC_SOURCE
+static int ecc_is_point(ecc_key *key)
+{
+	mp_int *prime, *b, *t1, *t2;
+	int err;
+
+	prime = m_malloc(sizeof(mp_int));
+	b = m_malloc(sizeof(mp_int));
+	t1 = m_malloc(sizeof(mp_int));
+	t2 = m_malloc(sizeof(mp_int));
+	
+	m_mp_init_multi(prime, b, t1, t2, NULL);
+	
+   /* load prime and b */
+	if ((err = mp_read_radix(prime, key->dp->prime, 16)) != CRYPT_OK)                          { goto error; }
+	if ((err = mp_read_radix(b, key->dp->B, 16)) != CRYPT_OK)                                  { goto error; }
+	
+   /* compute y^2 */
+	if ((err = mp_sqr(key->pubkey.y, t1)) != CRYPT_OK)                                         { goto error; }
+	
+   /* compute x^3 */
+	if ((err = mp_sqr(key->pubkey.x, t2)) != CRYPT_OK)                                         { goto error; }
+	if ((err = mp_mod(t2, prime, t2)) != CRYPT_OK)                                             { goto error; }
+	if ((err = mp_mul(key->pubkey.x, t2, t2)) != CRYPT_OK)                                     { goto error; }
+	
+   /* compute y^2 - x^3 */
+	if ((err = mp_sub(t1, t2, t1)) != CRYPT_OK)                                                { goto error; }
+	
+   /* compute y^2 - x^3 + 3x */
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
+	if ((err = mp_mod(t1, prime, t1)) != CRYPT_OK)                                             { goto error; }
+	while (mp_cmp_d(t1, 0) == LTC_MP_LT) {
+		if ((err = mp_add(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
+	}
+	while (mp_cmp(t1, prime) != LTC_MP_LT) {
+		if ((err = mp_sub(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
+	}
+	
+   /* compare to b */
+	if (mp_cmp(t1, b) != LTC_MP_EQ) {
+		err = CRYPT_INVALID_PACKET;
+	} else {
+		err = CRYPT_OK;
+	}
+	
+	error:
+	mp_clear_multi(prime, b, t1, t2, NULL);
+	m_free(prime);
+	m_free(b);
+	m_free(t1);
+	m_free(t2);
+	return err;
+}
+
+/* For the "ephemeral public key octet string" in ECDH (rfc5656 section 4) */
+void buf_put_ecc_raw_pubkey_string(buffer *buf, ecc_key *key) {
 	unsigned long len = key->dp->size*2 + 1;
 	buf_putint(buf, len);
 	int err = ecc_ansi_x963_export(key, buf_getwriteptr(buf, len), &len);
@@ -50,117 +108,61 @@
 	buf_incrwritepos(buf, len);
 }
 
-// Copied from libtomcrypt ecc_import.c (version there is static), modified
-// for different mp_int pointer without LTC_SOURCE
-static int ecc_is_point(ecc_key *key)
-{
-   mp_int *prime, *b, *t1, *t2;
-   int err;
+/* For the "ephemeral public key octet string" in ECDH (rfc5656 section 4) */
+ecc_key * buf_get_ecc_raw_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve) {
+	ecc_key *key = NULL;
+	int ret = DROPBEAR_FAILURE;
+	const unsigned int size = curve->dp->size;
+	buf_setpos(buf, 0);
+	unsigned int len = buf->len;
+	unsigned char first = buf_getbyte(buf);
+	if (first == 2 || first == 3) {
+		dropbear_log(LOG_WARNING, "Dropbear doesn't support ECC point compression");
+		return NULL;
+	}
+	if (first != 4 || len != 1+2*size) {
+		return NULL;
+	}
 
-   prime = m_malloc(sizeof(mp_int));
-   b = m_malloc(sizeof(mp_int));
-   t1 = m_malloc(sizeof(mp_int));
-   t2 = m_malloc(sizeof(mp_int));
-   
-   m_mp_init_multi(prime, b, t1, t2, NULL);
-   
-   /* load prime and b */
-   if ((err = mp_read_radix(prime, key->dp->prime, 16)) != CRYPT_OK)                          { goto error; }
-   if ((err = mp_read_radix(b, key->dp->B, 16)) != CRYPT_OK)                                  { goto error; }
-   
-   /* compute y^2 */
-   if ((err = mp_sqr(key->pubkey.y, t1)) != CRYPT_OK)                                         { goto error; }
-   
-   /* compute x^3 */
-   if ((err = mp_sqr(key->pubkey.x, t2)) != CRYPT_OK)                                         { goto error; }
-   if ((err = mp_mod(t2, prime, t2)) != CRYPT_OK)                                             { goto error; }
-   if ((err = mp_mul(key->pubkey.x, t2, t2)) != CRYPT_OK)                                     { goto error; }
-   
-   /* compute y^2 - x^3 */
-   if ((err = mp_sub(t1, t2, t1)) != CRYPT_OK)                                                { goto error; }
-   
-   /* compute y^2 - x^3 + 3x */
-   if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
-   if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
-   if ((err = mp_add(t1, key->pubkey.x, t1)) != CRYPT_OK)                                     { goto error; }
-   if ((err = mp_mod(t1, prime, t1)) != CRYPT_OK)                                             { goto error; }
-   while (mp_cmp_d(t1, 0) == LTC_MP_LT) {
-      if ((err = mp_add(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
-   }
-   while (mp_cmp(t1, prime) != LTC_MP_LT) {
-      if ((err = mp_sub(t1, prime, t1)) != CRYPT_OK)                                          { goto error; }
-   }
-   
-   /* compare to b */
-   if (mp_cmp(t1, b) != LTC_MP_EQ) {
-      err = CRYPT_INVALID_PACKET;
-   } else {
-      err = CRYPT_OK;
-   }
-   
-error:
-   mp_clear_multi(prime, b, t1, t2, NULL);
-   m_free(prime);
-   m_free(b);
-   m_free(t1);
-   m_free(t2);
-   return err;
-}
+	key = new_ecc_key();
+	key->dp = curve->dp;
+
+	if (mp_read_unsigned_bin(key->pubkey.x, buf_getptr(buf, size), size) != MP_OKAY) {
+		goto out;
+	}
+	buf_incrpos(buf, size);
 
-ecc_key * buf_get_ecc_pubkey(buffer *buf, const struct dropbear_ecc_curve *curve) {
-   ecc_key *key = NULL;
-   int ret = DROPBEAR_FAILURE;
-   const unsigned int size = curve->dp->size;
-   buf_setpos(buf, 0);
-   unsigned int len = buf->len;
-   unsigned char first = buf_getbyte(buf);
-   if (first == 2 || first == 3) {
-      dropbear_log(LOG_WARNING, "Dropbear doesn't support ECC point compression");
-      return NULL;
-   }
-   if (first != 4 || len != 1+2*size) {
-      return NULL;
-   }
+	if (mp_read_unsigned_bin(key->pubkey.y, buf_getptr(buf, size), size) != MP_OKAY) {
+		goto out;
+	}
+	buf_incrpos(buf, size);
 
-   key = new_ecc_key();
-   key->dp = curve->dp;
-
-   if (mp_read_unsigned_bin(key->pubkey.x, buf_getptr(buf, size), size) != MP_OKAY) {
-      goto out;
-   }
-   buf_incrpos(buf, size);
+	mp_set(key->pubkey.z, 1);
 
-   if (mp_read_unsigned_bin(key->pubkey.y, buf_getptr(buf, size), size) != MP_OKAY) {
-      goto out;
-   }
-   buf_incrpos(buf, size);
-
-   mp_set(key->pubkey.z, 1);
-
-   if (ecc_is_point(key) != CRYPT_OK) {
-      goto out;
-   }
+	if (ecc_is_point(key) != CRYPT_OK) {
+		goto out;
+	}
 
    // SEC1 3.2.3.1 Check that Q != 0
-   if (mp_cmp_d(key->pubkey.x, 0) == LTC_MP_EQ) {
-      goto out;
-   }
-   if (mp_cmp_d(key->pubkey.y, 0) == LTC_MP_EQ) {
-      goto out;
-   }
+	if (mp_cmp_d(key->pubkey.x, 0) == LTC_MP_EQ) {
+		goto out;
+	}
+	if (mp_cmp_d(key->pubkey.y, 0) == LTC_MP_EQ) {
+		goto out;
+	}
 
-   ret = DROPBEAR_SUCCESS;
+	ret = DROPBEAR_SUCCESS;
 
-out:
-   if (ret == DROPBEAR_FAILURE) {
-      if (key) {
-         ecc_free(key);
-         m_free(key);
-         key = NULL;
-      }
-   }
+	out:
+	if (ret == DROPBEAR_FAILURE) {
+		if (key) {
+			ecc_free(key);
+			m_free(key);
+			key = NULL;
+		}
+	}
 
-   return key;
+	return key;
 
 }
 
@@ -168,56 +170,56 @@
 // a mp_int instead.
 mp_int * dropbear_ecc_shared_secret(ecc_key *public_key, ecc_key *private_key)
 {
-   ecc_point *result = NULL;
-   mp_int *prime = NULL, *shared_secret = NULL;
-   int err = DROPBEAR_FAILURE;
+	ecc_point *result = NULL;
+	mp_int *prime = NULL, *shared_secret = NULL;
+	int err = DROPBEAR_FAILURE;
 
    /* type valid? */
-   if (private_key->type != PK_PRIVATE) {
-   	goto done;
-   }
+	if (private_key->type != PK_PRIVATE) {
+		goto done;
+	}
 
-   if (private_key->dp != public_key->dp) {
-   	goto done;
-   }
+	if (private_key->dp != public_key->dp) {
+		goto done;
+	}
 
    /* make new point */
-   result = ltc_ecc_new_point();
-   if (result == NULL) {
-      goto done;
-   }
+	result = ltc_ecc_new_point();
+	if (result == NULL) {
+		goto done;
+	}
 
-   prime = m_malloc(sizeof(*prime));
-   m_mp_init(prime);
+	prime = m_malloc(sizeof(*prime));
+	m_mp_init(prime);
 
-   if (mp_read_radix(prime, (char *)private_key->dp->prime, 16) != CRYPT_OK) { 
-	   	goto done; 
-   }
-   if (ltc_mp.ecc_ptmul(private_key->k, &public_key->pubkey, result, prime, 1) != CRYPT_OK) { 
-	   	goto done; 
-   }
+	if (mp_read_radix(prime, (char *)private_key->dp->prime, 16) != CRYPT_OK) { 
+		goto done; 
+	}
+	if (ltc_mp.ecc_ptmul(private_key->k, &public_key->pubkey, result, prime, 1) != CRYPT_OK) { 
+		goto done; 
+	}
 
-   err = DROPBEAR_SUCCESS;
-done:
+	err = DROPBEAR_SUCCESS;
+	done:
 	if (err == DROPBEAR_SUCCESS) {
 		shared_secret = m_malloc(sizeof(*shared_secret));
-      m_mp_init(shared_secret);
-      mp_copy(result->x, shared_secret);
+		m_mp_init(shared_secret);
+		mp_copy(result->x, shared_secret);
 	}
 
 	if (prime) {
-	   mp_clear(prime);
-	   m_free(prime);
+		mp_clear(prime);
+		m_free(prime);
 	}
-   if (result)
-   {
-      ltc_ecc_del_point(result);
-   }
+	if (result)
+	{
+		ltc_ecc_del_point(result);
+	}
 
-   if (err == DROPBEAR_FAILURE) {
-   	 dropbear_exit("ECC error");
-   }
-   return shared_secret;
+	if (err == DROPBEAR_FAILURE) {
+		dropbear_exit("ECC error");
+	}
+	return shared_secret;
 }
 
 #endif