Merge branch 'ecc-devel-mpg' into development

library/CMakeLists.txt

@@ -16,6 +16,9 @@ set(src
      debug.c
      des.c
      dhm.c
+     ecp.c
+     ecdh.c
+     ecdsa.c
      entropy.c
      entropy_poll.c
      error.c

library/Makefile

@@ -39,7 +39,9 @@ OBJS=	aes.o		arc4.o		asn1parse.o		\
 		blowfish.o	camellia.o					\
 		certs.o		cipher.o	cipher_wrap.o	\
 		ctr_drbg.o	debug.o		des.o			\
-		dhm.o		entropy.o	entropy_poll.o	\
+		dhm.o		ecdh.o		ecdsa.o			\
+		ecp.o									\
+		entropy.o	entropy_poll.o				\
 		error.o		gcm.o		havege.o		\
 		md.o		md_wrap.o	md2.o			\
 		md4.o		md5.o		net.o			\

library/ecdh.c

@@ -0,0 +1,232 @@
+/*
+ *  Elliptic curve Diffie-Hellman
+ *
+ *  Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * References:
+ *
+ * SEC1 http://www.secg.org/index.php?action=secg,docs_secg
+ * RFC 4492
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_ECDH_C)
+
+#include "polarssl/ecdh.h"
+
+/*
+ * Generate public key: simple wrapper around ecp_gen_keypair
+ */
+int ecdh_gen_public( const ecp_group *grp, mpi *d, ecp_point *Q,
+                     int (*f_rng)(void *, unsigned char *, size_t),
+                     void *p_rng )
+{
+    return ecp_gen_keypair( grp, d, Q, f_rng, p_rng );
+}
+
+/*
+ * Compute shared secret (SEC1 3.3.1)
+ */
+int ecdh_compute_shared( const ecp_group *grp, mpi *z,
+                         const ecp_point *Q, const mpi *d )
+{
+    int ret;
+    ecp_point P;
+
+    ecp_point_init( &P );
+
+    /*
+     * Make sure Q is a valid pubkey before using it
+     */
+    MPI_CHK( ecp_check_pubkey( grp, Q ) );
+
+    MPI_CHK( ecp_mul( grp, &P, d, Q ) );
+
+    if( ecp_is_zero( &P ) )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    MPI_CHK( mpi_copy( z, &P.X ) );
+
+cleanup:
+    ecp_point_free( &P );
+
+    return( ret );
+}
+
+/*
+ * Initialize context
+ */
+void ecdh_init( ecdh_context *ctx )
+{
+    ecp_group_init( &ctx->grp );
+    mpi_init      ( &ctx->d   );
+    ecp_point_init( &ctx->Q   );
+    ecp_point_init( &ctx->Qp  );
+    mpi_init      ( &ctx->z   );
+    ctx->point_format = POLARSSL_ECP_PF_UNCOMPRESSED;
+}
+
+/*
+ * Free context
+ */
+void ecdh_free( ecdh_context *ctx )
+{
+    if( ctx == NULL )
+        return;
+
+    ecp_group_free( &ctx->grp );
+    mpi_free      ( &ctx->d   );
+    ecp_point_free( &ctx->Q   );
+    ecp_point_free( &ctx->Qp  );
+    mpi_free      ( &ctx->z   );
+}
+
+/*
+ * Setup and write the ServerKeyExhange parameters (RFC 4492)
+ *      struct {
+ *          ECParameters    curve_params;
+ *          ECPoint         public;
+ *      } ServerECDHParams;
+ */
+int ecdh_make_params( ecdh_context *ctx, size_t *olen,
+                      unsigned char *buf, size_t blen,
+                      int (*f_rng)(void *, unsigned char *, size_t),
+                      void *p_rng )
+{
+    int ret;
+    size_t grp_len, pt_len;
+
+    if( ctx == NULL || ctx->grp.pbits == 0 )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    if( ( ret = ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) )
+                != 0 )
+        return( ret );
+
+    if( ( ret = ecp_tls_write_group( &ctx->grp, &grp_len, buf, blen ) )
+                != 0 )
+        return( ret );
+
+    buf += grp_len;
+    blen -= grp_len;
+
+    if( ( ret = ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
+                                     &pt_len, buf, blen ) ) != 0 )
+        return( ret );
+
+    *olen = grp_len + pt_len;
+    return 0;
+}
+
+/*
+ * Read the ServerKeyExhange parameters (RFC 4492)
+ *      struct {
+ *          ECParameters    curve_params;
+ *          ECPoint         public;
+ *      } ServerECDHParams;
+ */
+int ecdh_read_params( ecdh_context *ctx,
+                      const unsigned char **buf, const unsigned char *end )
+{
+    int ret;
+
+    ecdh_init( ctx );
+
+    if( ( ret = ecp_tls_read_group( &ctx->grp, buf, end - *buf ) ) != 0 )
+        return( ret );
+
+    if( ( ret = ecp_tls_read_point( &ctx->grp, &ctx->Qp, buf, end - *buf ) )
+                != 0 )
+        return( ret );
+
+    return 0;
+}
+
+/*
+ * Setup and export the client public value
+ */
+int ecdh_make_public( ecdh_context *ctx, size_t *olen,
+                      unsigned char *buf, size_t blen,
+                      int (*f_rng)(void *, unsigned char *, size_t),
+                      void *p_rng )
+{
+    int ret;
+
+    if( ctx == NULL || ctx->grp.pbits == 0 )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    if( ( ret = ecdh_gen_public( &ctx->grp, &ctx->d, &ctx->Q, f_rng, p_rng ) )
+                != 0 )
+        return( ret );
+
+    return ecp_tls_write_point( &ctx->grp, &ctx->Q, ctx->point_format,
+                                olen, buf, blen );
+}
+
+/*
+ * Parse and import the client's public value
+ */
+int ecdh_read_public( ecdh_context *ctx,
+                      const unsigned char *buf, size_t blen )
+{
+    if( ctx == NULL )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    return ecp_tls_read_point( &ctx->grp, &ctx->Qp, &buf, blen );
+}
+
+/*
+ * Derive and export the shared secret
+ */
+int ecdh_calc_secret( ecdh_context *ctx, size_t *olen,
+                      unsigned char *buf, size_t blen )
+{
+    int ret;
+
+    if( ctx == NULL )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    if( ( ret = ecdh_compute_shared( &ctx->grp, &ctx->z, &ctx->Qp, &ctx->d ) )
+                != 0 )
+        return( ret );
+
+    *olen = mpi_size( &ctx->z );
+    return mpi_write_binary( &ctx->z, buf, blen );
+}
+
+
+#if defined(POLARSSL_SELF_TEST)
+
+/*
+ * Checkup routine
+ */
+int ecdh_self_test( int verbose )
+{
+    return( verbose++ );
+}
+
+#endif
+
+#endif /* defined(POLARSSL_ECDH_C) */

library/ecdsa.c

@@ -0,0 +1,190 @@
+/*
+ *  Elliptic curve DSA
+ *
+ *  Copyright (C) 2006-2013, Brainspark B.V.
+ *
+ *  This file is part of PolarSSL (http://www.polarssl.org)
+ *  Lead Maintainer: Paul Bakker <polarssl_maintainer at polarssl.org>
+ *
+ *  All rights reserved.
+ *
+ *  This program is free software; you can redistribute it and/or modify
+ *  it under the terms of the GNU General Public License as published by
+ *  the Free Software Foundation; either version 2 of the License, or
+ *  (at your option) any later version.
+ *
+ *  This program is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ *  GNU General Public License for more details.
+ *
+ *  You should have received a copy of the GNU General Public License along
+ *  with this program; if not, write to the Free Software Foundation, Inc.,
+ *  51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+ */
+
+/*
+ * References:
+ *
+ * SEC1 http://www.secg.org/index.php?action=secg,docs_secg
+ */
+
+#include "polarssl/config.h"
+
+#if defined(POLARSSL_ECDSA_C)
+
+#include "polarssl/ecdsa.h"
+
+/*
+ * Derive a suitable integer for group grp from a buffer of length len
+ * SEC1 4.1.3 step 5 aka SEC1 4.1.4 step 3
+ */
+static int derive_mpi( const ecp_group *grp, mpi *x,
+                       const unsigned char *buf, size_t blen )
+{
+    size_t n_size = (grp->nbits + 7) / 8;
+    return( mpi_read_binary( x, buf, blen > n_size ? n_size : blen ) );
+}
+
+/*
+ * Compute ECDSA signature of a hashed message (SEC1 4.1.3)
+ * Obviously, compared to SEC1 4.1.3, we skip step 4 (hash message)
+ */
+int ecdsa_sign( const ecp_group *grp, mpi *r, mpi *s,
+                const mpi *d, const unsigned char *buf, size_t blen,
+                int (*f_rng)(void *, unsigned char *, size_t), void *p_rng )
+{
+    int ret, key_tries, sign_tries;
+    ecp_point R;
+    mpi k, e;
+
+    ecp_point_init( &R );
+    mpi_init( &k );
+    mpi_init( &e );
+
+    sign_tries = 0;
+    do
+    {
+        /*
+         * Steps 1-3: generate a suitable ephemeral keypair
+         */
+        key_tries = 0;
+        do
+        {
+            MPI_CHK( ecp_gen_keypair( grp, &k, &R, f_rng, p_rng ) );
+            MPI_CHK( mpi_copy( r, &R.X ) );
+
+            if( key_tries++ > 10 )
+                return( POLARSSL_ERR_ECP_GENERIC );
+        }
+        while( mpi_cmp_int( r, 0 ) == 0 );
+
+        /*
+         * Step 5: derive MPI from hashed message
+         */
+        MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
+
+        /*
+         * Step 6: compute s = (e + r * d) / k mod n
+         */
+        MPI_CHK( mpi_mul_mpi( s, r, d ) );
+        MPI_CHK( mpi_add_mpi( &e, &e, s ) );
+        MPI_CHK( mpi_inv_mod( s, &k, &grp->N ) );
+        MPI_CHK( mpi_mul_mpi( s, s, &e ) );
+        MPI_CHK( mpi_mod_mpi( s, s, &grp->N ) );
+
+        if( sign_tries++ > 10 )
+            return( POLARSSL_ERR_ECP_GENERIC );
+    }
+    while( mpi_cmp_int( s, 0 ) == 0 );
+
+cleanup:
+    ecp_point_free( &R );
+    mpi_free( &k );
+    mpi_free( &e );
+
+    return( ret );
+}
+
+/*
+ * Verify ECDSA signature of hashed message (SEC1 4.1.4)
+ * Obviously, compared to SEC1 4.1.3, we skip step 2 (hash message)
+ */
+int ecdsa_verify( const ecp_group *grp,
+                  const unsigned char *buf, size_t blen,
+                  const ecp_point *Q, const mpi *r, const mpi *s)
+{
+    int ret;
+    mpi e, s_inv, u1, u2;
+    ecp_point R, P;
+
+    ecp_point_init( &R ); ecp_point_init( &P );
+    mpi_init( &e ); mpi_init( &s_inv ); mpi_init( &u1 ); mpi_init( &u2 );
+
+    /*
+     * Step 1: make sure r and s are in range 1..n-1
+     */
+    if( mpi_cmp_int( r, 1 ) < 0 || mpi_cmp_mpi( r, &grp->N ) >= 0 ||
+        mpi_cmp_int( s, 1 ) < 0 || mpi_cmp_mpi( s, &grp->N ) >= 0 )
+    {
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+    }
+
+    /*
+     * Additional precaution: make sure Q is valid
+     */
+    MPI_CHK( ecp_check_pubkey( grp, Q ) );
+
+    /*
+     * Step 3: derive MPI from hashed message
+     */
+    MPI_CHK( derive_mpi( grp, &e, buf, blen ) );
+
+    /*
+     * Step 4: u1 = e / s mod n, u2 = r / s mod n
+     */
+    MPI_CHK( mpi_inv_mod( &s_inv, s, &grp->N ) );
+
+    MPI_CHK( mpi_mul_mpi( &u1, &e, &s_inv ) );
+    MPI_CHK( mpi_mod_mpi( &u1, &u1, &grp->N ) );
+
+    MPI_CHK( mpi_mul_mpi( &u2, r, &s_inv ) );
+    MPI_CHK( mpi_mod_mpi( &u2, &u2, &grp->N ) );
+
+    /*
+     * Step 5: R = u1 G + u2 Q
+     */
+    MPI_CHK( ecp_mul( grp, &R, &u1, &grp->G ) );
+    MPI_CHK( ecp_mul( grp, &P, &u2, Q ) );
+    MPI_CHK( ecp_add( grp, &R, &R, &P ) );
+
+    if( ecp_is_zero( &R ) )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+    /*
+     * Step 6: check that xR == r
+     */
+    if( mpi_cmp_mpi( &R.X, r ) != 0 )
+        return( POLARSSL_ERR_ECP_BAD_INPUT_DATA );
+
+cleanup:
+    ecp_point_free( &R ); ecp_point_free( &P );
+    mpi_free( &e ); mpi_free( &s_inv ); mpi_free( &u1 ); mpi_free( &u2 );
+
+    return( ret );
+}
+
+
+#if defined(POLARSSL_SELF_TEST)
+
+/*
+ * Checkup routine
+ */
+int ecdsa_self_test( int verbose )
+{
+    return( verbose++ );
+}
+
+#endif
+
+#endif /* defined(POLARSSL_ECDSA_C) */

library/error.c

@@ -63,6 +63,10 @@
 #include "polarssl/dhm.h"
 #endif
 
+#if defined(POLARSSL_ECP_C)
+#include "polarssl/ecp.h"
+#endif
+
 #if defined(POLARSSL_ENTROPY_C)
 #include "polarssl/entropy.h"
 #endif
@@ -182,6 +186,13 @@ void error_strerror( int ret, char *buf, size_t buflen )
             snprintf( buf, buflen, "DHM - Calculation of the DHM secret failed" );
 #endif /* POLARSSL_DHM_C */
 
+#if defined(POLARSSL_ECP_C)
+        if( use_ret == -(POLARSSL_ERR_ECP_BAD_INPUT_DATA) )
+            snprintf( buf, buflen, "ECP - Bad input parameters to function" );
+        if( use_ret == -(POLARSSL_ERR_ECP_GENERIC) )
+            snprintf( buf, buflen, "ECP -  Generic ECP error" );
+#endif /* POLARSSL_ECP_C */
+
 #if defined(POLARSSL_MD_C)
         if( use_ret == -(POLARSSL_ERR_MD_FEATURE_UNAVAILABLE) )
             snprintf( buf, buflen, "MD - The selected feature is not available" );