Commit 92a64fd5 authored by filatov's avatar filatov
Browse files

fix BN serialization padding (thanks Michal Kazmierowski)

parent e5925bfe

tools/itscertgen/generator/ecc_openssl.c

+21 −13
Original line number Diff line number Diff line
@@ -19,6 +19,8 @@ 
#include <openssl/ecdsa.h>

#include <string.h>



#define FIELD_SIZE 32



#define ARRAYSIZE(A) (sizeof(A)/sizeof(A[0]))



static char * _bin2hex(char * hex, int hlen, const char * bin, int blen);
@@ -172,6 +174,7 @@ int ecc_api_key_public(void* key, char * px, char * py) 
	BIGNUM x, y;

	int bcount = -1;



	if( key && px && py ) {

		ecgroup = EC_KEY_get0_group(eckey);

		ecpoint = EC_KEY_get0_public_key(eckey);
@@ -179,16 +182,17 @@ int ecc_api_key_public(void* key, char * px, char * py) 
		BN_init(&x); BN_init(&y);

		if (EC_POINT_get_affine_coordinates_GFp(ecgroup, ecpoint, &x, &y, NULL)){

			bcount = BN_num_bytes(&x);

		if (px){

			for(; bcount < FIELD_SIZE; bcount++)

				*(px++) = 0; // add padding with zeros

			BN_bn2bin(&x, (unsigned char*)px);

		}

	

			bcount = BN_num_bytes(&y);

		if (py){

			for(; bcount < FIELD_SIZE; bcount++)

				*(py++) = 0; // add padding with zeros

			BN_bn2bin(&y, (unsigned char*)py);

		}

	}

		BN_clear_free(&x); BN_clear_free(&y);

	}

	return bcount;

}
@@ -446,12 +450,16 @@ int ecc_sign(void * key, const char * data, int length, char ** psig, int max 
			ecdsa = ECDSA_do_sign(hash, 32, eckey);

			EC_KEY_free(eckey);

			if (ecdsa){

				int bcount;

				int i, bcount;

				*(sig++) = 0; // ECC_POINT type (x_coordinate_only)

				bcount = BN_num_bytes(ecdsa->r);

				for(i=bcount; i < FIELD_SIZE; i++)

					*(sig++) = 0; // add padding with zeros

				BN_bn2bin(ecdsa->r, sig);

				sig += bcount;

				bcount = BN_num_bytes(ecdsa->s);

				for(i=bcount; i < FIELD_SIZE; i++)

					*(sig++) = 0; // add padding with zeros

				BN_bn2bin(ecdsa->s, sig);

				sig += bcount;

				ECDSA_SIG_free(ecdsa);