Applied bit packing to BLISS public key

src/libstrongswan/plugins/bliss/bliss_param_set.c

@@ -123,6 +123,7 @@ static bliss_param_set_t bliss_param_sets[] = {
 		.oid = OID_BLISS_I,
 		.strength = 128,
 		.q = 12289,
+		.q_bits = 14,
 		.q2_inv = 6145,
 		.n = 512,
 		.n_bits = 9,
@@ -150,6 +151,7 @@ static bliss_param_set_t bliss_param_sets[] = {
 		.oid = OID_BLISS_III,
 		.strength = 160,
 		.q = 12289,
+		.q_bits = 14,
 		.q2_inv = 6145,
 		.n = 512,
 		.n_bits = 9,
@@ -177,6 +179,7 @@ static bliss_param_set_t bliss_param_sets[] = {
 		.oid = OID_BLISS_IV,
 		.strength = 192,
 		.q = 12289,
+		.q_bits = 14,
 		.q2_inv = 6145,
 		.n = 512,
 		.n_bits = 9,

src/libstrongswan/plugins/bliss/bliss_param_set.h

@@ -65,6 +65,11 @@ struct bliss_param_set_t {
 	 */
 	uint16_t q;
 
+	/**
+	 * Number of bits in q
+	 */
+	uint16_t q_bits;
+
 	/**
 	 * Inverse of (q + 2) mod 2q
 	 */

src/libstrongswan/plugins/bliss/bliss_private_key.c

@@ -430,7 +430,7 @@ METHOD(private_key_t, get_public_key, public_key_t*,
 	public_key_t *public;
 	chunk_t pubkey;
 
-	pubkey = bliss_public_key_info_encode(this->set->oid, this->A, this->set->n);
+	pubkey = bliss_public_key_info_encode(this->set->oid, this->A, this->set);
 	public = lib->creds->create(lib->creds, CRED_PUBLIC_KEY, KEY_BLISS,
 								BUILD_BLOB_ASN1_DER, pubkey, BUILD_END);
 	free(pubkey.ptr);
@@ -450,7 +450,7 @@ METHOD(private_key_t, get_encoding, bool,
 			chunk_t s1_chunk, s2_chunk, pubkey;
 			bool success = TRUE;
 
-			pubkey = bliss_public_key_encode(this->A, this->set->n);
+			pubkey = bliss_public_key_encode(this->A, this->set);
 
 			/* Build private key as two polynomials with 8 bit coefficients */
 			s1_chunk = chunk_create(this->s1, this->set->n);
@@ -458,7 +458,7 @@ METHOD(private_key_t, get_encoding, bool,
 
 			*encoding = asn1_wrap(ASN1_SEQUENCE, "mmss",
 							asn1_build_known_oid(this->set->oid),
-							pubkey,
+							asn1_bitstring("m", pubkey),
 							asn1_simple_object(ASN1_OCTET_STRING, s1_chunk),
 							asn1_simple_object(ASN1_OCTET_STRING, s2_chunk)
 						);
@@ -488,7 +488,7 @@ METHOD(private_key_t, get_fingerprint, bool,
 		return TRUE;
 	}
 	success = bliss_public_key_fingerprint(this->set->oid, this->A,
-										   this->set->n, type, fp);
+										   this->set, type, fp);
 	lib->encoding->cache(lib->encoding, type, this, *fp);
 
 	return success;
@@ -950,7 +950,7 @@ bliss_private_key_t *bliss_private_key_gen(key_type_t type, va_list args)
 static const asn1Object_t privkeyObjects[] = {
 	{ 0, "BLISSPrivateKey",		ASN1_SEQUENCE,     ASN1_NONE }, /*  0 */
 	{ 1,   "keyType",			ASN1_OID,          ASN1_BODY }, /*  1 */
-	{ 1,   "public",			ASN1_OCTET_STRING, ASN1_BODY }, /*  2 */
+	{ 1,   "public",			ASN1_BIT_STRING,   ASN1_BODY }, /*  2 */
 	{ 1,   "secret1",			ASN1_OCTET_STRING, ASN1_BODY }, /*  3 */
 	{ 1,   "secret2",			ASN1_OCTET_STRING, ASN1_BODY }, /*  4 */
 	{ 0, "exit",				ASN1_EOC,          ASN1_EXIT }
@@ -1012,11 +1012,10 @@ bliss_private_key_t *bliss_private_key_load(key_type_t type, va_list args)
 				}
 				break;
 			case PRIV_KEY_PUBLIC:
-				if (object.len != 2*this->set->n)
+				if (!bliss_public_key_from_asn1(object, this->set, &this->A))
 				{
 					goto end;
 				}
-				this->A = bliss_public_key_from_asn1(object, this->set->n);
 				break;
 			case PRIV_KEY_SECRET1:
 				if (object.len != this->set->n)

src/libstrongswan/plugins/bliss/bliss_public_key.c

@@ -14,8 +14,8 @@
  */
 
 #include "bliss_public_key.h"
-#include "bliss_param_set.h"
 #include "bliss_signature.h"
+#include "bliss_bitpacker.h"
 #include "bliss_fft.h"
 #include "bliss_utils.h"
 
@@ -220,7 +220,7 @@ METHOD(public_key_t, get_encoding, bool,
 {
 	bool success = TRUE;
 
-	*encoding = bliss_public_key_info_encode(this->set->oid, this->A, this->set->n);
+	*encoding = bliss_public_key_info_encode(this->set->oid, this->A, this->set);
 
 	if (type != PUBKEY_SPKI_ASN1_DER)
 	{
@@ -244,7 +244,7 @@ METHOD(public_key_t, get_fingerprint, bool,
 		return TRUE;
 	}
 	success = bliss_public_key_fingerprint(this->set->oid, this->A,
-										   this->set->n, type, fp);
+										   this->set, type, fp);
 	lib->encoding->cache(lib->encoding, type, this, *fp);
 
 	return success;
@@ -361,21 +361,10 @@ bliss_public_key_t *bliss_public_key_load(key_type_t type, va_list args)
 				break;
 			}
 			case BLISS_SUBJECT_PUBLIC_KEY:
-				if (object.len > 0 && *object.ptr == 0x00)
+				if (!bliss_public_key_from_asn1(object, this->set, &this->A))
-				{
-					/* skip initial bit string octet defining 0 unused bits */
-					object = chunk_skip(object, 1);
-				}
-				if (!asn1_parse_simple_object(&object, ASN1_OCTET_STRING,
-						parser->get_level(parser)+1, "blissPublicKey"))
 				{
 					goto end;
 				}
-				if (object.len != 2*this->set->n)
-				{
-					goto end;
-				}
-				this->A = bliss_public_key_from_asn1(object, this->set->n);
 				break;
 		}
 	}
@@ -395,42 +384,51 @@ end:
 /**
  * See header.
  */
-uint32_t* bliss_public_key_from_asn1(chunk_t object, int n)
+bool bliss_public_key_from_asn1(chunk_t object, bliss_param_set_t *set,
+								uint32_t **pubkey)
 {
-	uint32_t *pubkey;
+	bliss_bitpacker_t *packer;
-	uint16_t coeff;
+	uint16_t coefficient;
-	u_char *pos;
 	int i;
 
-	pubkey = malloc(n * sizeof(uint32_t));
+	/* skip initial bit string octet defining unused bits */
-	pos = object.ptr;
+	object = chunk_skip(object, 1);
 
-	for (i = 0; i < n; i++)
+	if (8 * object.len < set->n * set->q_bits)
 	{
-		coeff = untoh16(pos);
+		return FALSE;
-		pubkey[i] = (uint32_t)coeff;
-		pos += 2;
 	}
+	*pubkey = malloc(set->n * sizeof(uint32_t));
 
-	return pubkey;
+	packer = bliss_bitpacker_create_from_data(object);
+
+	for (i = 0; i < set->n; i++)
+	{
+		packer->read_bits(packer, &coefficient, set->q_bits);
+		(*pubkey)[i] = (uint32_t)coefficient;
+	}
+	packer->destroy(packer);
+
+	return TRUE;
 }
 
 /**
  * See header.
  */
-chunk_t bliss_public_key_encode(uint32_t *pubkey, int n)
+chunk_t bliss_public_key_encode(uint32_t *pubkey, bliss_param_set_t *set)
 {
-	u_char *pos;
+	bliss_bitpacker_t *packer;
 	chunk_t encoding;
 	int i;
 
-	pos = asn1_build_object(&encoding, ASN1_OCTET_STRING, 2 * n);
+	packer = bliss_bitpacker_create(set->n * set->q_bits);
 
-	for (i = 0; i < n; i++)
+	for (i = 0; i < set->n; i++)
 	{
-		htoun16(pos, (uint16_t)pubkey[i]);
+		packer->write_bits(packer, pubkey[i], set->q_bits);
-		pos += 2;
 	}
+	encoding = packer->extract_buf(packer);
+	packer->destroy(packer);
 
 	return encoding;
 }
@@ -438,11 +436,12 @@ chunk_t bliss_public_key_encode(uint32_t *pubkey, int n)
 /**
  * See header.
  */
-chunk_t bliss_public_key_info_encode(int oid, uint32_t *pubkey, int n)
+chunk_t bliss_public_key_info_encode(int oid, uint32_t *pubkey,
+									 bliss_param_set_t *set)
 {
 	chunk_t encoding, pubkey_encoding;
 
-	pubkey_encoding = bliss_public_key_encode(pubkey, n);
+	pubkey_encoding = bliss_public_key_encode(pubkey, set);
 
 	encoding = asn1_wrap(ASN1_SEQUENCE, "mm",
 					asn1_wrap(ASN1_SEQUENCE, "mm",
@@ -456,7 +455,8 @@ chunk_t bliss_public_key_info_encode(int oid, uint32_t *pubkey, int n)
 /**
  * See header.
  */
-bool bliss_public_key_fingerprint(int oid, uint32_t *pubkey, int n,
+bool bliss_public_key_fingerprint(int oid, uint32_t *pubkey,
+								  bliss_param_set_t *set,
 								  cred_encoding_type_t type, chunk_t *fp)
 {
 	hasher_t *hasher;
@@ -465,10 +465,10 @@ bool bliss_public_key_fingerprint(int oid, uint32_t *pubkey, int n,
 	switch (type)
 	{
 		case KEYID_PUBKEY_SHA1:
-			key = bliss_public_key_encode(pubkey, n);
+			key = bliss_public_key_encode(pubkey, set);
 			break;
 		case KEYID_PUBKEY_INFO_SHA1:
-			key = bliss_public_key_info_encode(oid, pubkey, n);
+			key = bliss_public_key_info_encode(oid, pubkey, set);
 			break;
 		default:
 			return FALSE;

src/libstrongswan/plugins/bliss/bliss_public_key.h

@@ -21,6 +21,8 @@
 #ifndef BLISS_PUBLIC_KEY_H_
 #define BLISS_PUBLIC_KEY_H_
 
+#include "bliss_param_set.h"
+
 #include <credentials/builder.h>
 #include <credentials/cred_encoding.h>
 #include <credentials/keys/public_key.h>
@@ -52,44 +54,48 @@ bliss_public_key_t *bliss_public_key_load(key_type_t type, va_list args);
 /* The following functions are shared with the bliss_private_key class */
 
 /**
- * Parse an ASN.1 OCTET STRING into an array of public key coefficients
+ * Parse an ASN.1 BIT STRING into an array of public key coefficients
  *
- * @param object	ASN.1 encoded subjectPublicKey
+ * @param data		packed subjectPublicKey
- * @param n			number of public key coefficients
+ * @param set		BLISS parameter set for public key vector
- * @result			coefficients of public key vector
+ * @param pubkey	coefficients of public key vector
+ * @return			TRUE if parsing successful
  */
-uint32_t* bliss_public_key_from_asn1(chunk_t object, int n);
+bool bliss_public_key_from_asn1(chunk_t object, bliss_param_set_t *set,
+								uint32_t **pubkey);
 
 /**
  * Encode a raw BLISS subjectPublicKey in ASN.1 DER format
  *
  * @param			coefficients of public key vector
- * @param n			number of public key coefficients
+ * @param set		BLISS parameter set for the public key vector
  * @result			ASN.1 encoded subjectPublicKey
  */
-chunk_t bliss_public_key_encode(uint32_t *pubkey, int n);
+chunk_t bliss_public_key_encode(uint32_t *pubkey, bliss_param_set_t *set);
 
 /**
  * Encode a BLISS subjectPublicKeyInfo record in ASN.1 DER format
  *
  * @param oid		BLISS public key type OID
  * @param pubkey	coefficients of public key vector
- * @param n			number of public key coefficients
+ * @param n			BLISS parameter set for the public key vector
  * @result			ASN.1 encoded subjectPublicKeyInfo record
  */
-chunk_t bliss_public_key_info_encode(int oid, uint32_t *pubkey, int n);
+chunk_t bliss_public_key_info_encode(int oid, uint32_t *pubkey,
+									 bliss_param_set_t *set);
 
 /**
  * Generate a BLISS public key fingerprint
  *
  * @param oid		BLISS public key type OID
  * @param pubkey	coefficients of public key vector
- * @param n			number of public key coefficients
+ * @param n			BLISS parameter set for the public key vector
  * @param type		type of fingerprint to be generated
  * @param fp		generated fingerprint (must be freed by caller)
  * @result			TRUE if generation was successful
  */
-bool bliss_public_key_fingerprint(int oid, uint32_t *pubkey, int n,
+bool bliss_public_key_fingerprint(int oid, uint32_t *pubkey,
+								  bliss_param_set_t *set,
 								  cred_encoding_type_t type, chunk_t *fp);
 
 #endif /** BLISS_PUBLIC_KEY_H_ @}*/