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3rdparty: Pull Everest x25519 key size into macro
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@yanesca
Christoph M. Wintersteiger authored and yanesca committed Aug 19, 2019
1 parent f21aba4 commit fb779f1
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Showing 2 changed files with 22 additions and 21 deletions.
5 changes: 3 additions & 2 deletions 3rdparty/everest/include/everest/x25519.h
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Original file line number Diff line number Diff line change
Expand Up @@ -27,6 +27,7 @@ extern "C" {
#endif

#define MBEDTLS_ECP_TLS_CURVE25519 0x1d
#define MBEDTLS_X25519_KEY_SIZE_BYTES 32

/**
* Defines the source of the imported EC key.
Expand All @@ -42,8 +43,8 @@ typedef enum
*/
typedef struct
{
unsigned char our_secret[32];
unsigned char peer_point[32];
unsigned char our_secret[MBEDTLS_X25519_KEY_SIZE_BYTES];
unsigned char peer_point[MBEDTLS_X25519_KEY_SIZE_BYTES];
} mbedtls_x25519_context;

/**
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38 changes: 19 additions & 19 deletions 3rdparty/everest/library/x25519.c
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Original file line number Diff line number Diff line change
Expand Up @@ -52,8 +52,8 @@ void mbedtls_x25519_free( mbedtls_x25519_context *ctx )
if( ctx == NULL )
return;

mbedtls_platform_zeroize( ctx->our_secret, 32 );
mbedtls_platform_zeroize( ctx->peer_point, 32 );
mbedtls_platform_zeroize( ctx->our_secret, MBEDTLS_X25519_KEY_SIZE_BYTES );
mbedtls_platform_zeroize( ctx->peer_point, MBEDTLS_X25519_KEY_SIZE_BYTES );
}

int mbedtls_x25519_make_params( mbedtls_x25519_context *ctx, size_t *olen,
Expand All @@ -63,9 +63,9 @@ int mbedtls_x25519_make_params( mbedtls_x25519_context *ctx, size_t *olen,
{
int ret = 0;

uint8_t base[32] = {0};
uint8_t base[MBEDTLS_X25519_KEY_SIZE_BYTES] = {0};

if( ( ret = f_rng( p_rng, ctx->our_secret, 32 ) ) != 0 )
if( ( ret = f_rng( p_rng, ctx->our_secret, MBEDTLS_X25519_KEY_SIZE_BYTES ) ) != 0 )
return ret;

*olen = 36;
Expand All @@ -75,13 +75,13 @@ int mbedtls_x25519_make_params( mbedtls_x25519_context *ctx, size_t *olen,
*buf++ = MBEDTLS_ECP_TLS_NAMED_CURVE;
*buf++ = MBEDTLS_ECP_TLS_CURVE25519 >> 8;
*buf++ = MBEDTLS_ECP_TLS_CURVE25519 & 0xFF;
*buf++ = 32;
*buf++ = MBEDTLS_X25519_KEY_SIZE_BYTES;

base[0] = 9;
Hacl_Curve25519_crypto_scalarmult( buf, ctx->our_secret, base );

base[0] = 0;
if( memcmp( buf, base, 32) == 0 )
if( memcmp( buf, base, MBEDTLS_X25519_KEY_SIZE_BYTES) == 0 )
return MBEDTLS_ERR_ECP_RANDOM_FAILED;

return( 0 );
Expand All @@ -93,11 +93,11 @@ int mbedtls_x25519_read_params( mbedtls_x25519_context *ctx,
if( end - *buf < 33 )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );

if( ( *(*buf)++ != 32 ) )
if( ( *(*buf)++ != MBEDTLS_X25519_KEY_SIZE_BYTES ) )
return( MBEDTLS_ERR_ECP_BAD_INPUT_DATA );

memcpy( ctx->peer_point, *buf, 32 );
*buf += 32;
memcpy( ctx->peer_point, *buf, MBEDTLS_X25519_KEY_SIZE_BYTES );
*buf += MBEDTLS_X25519_KEY_SIZE_BYTES;
return( 0 );
}

Expand All @@ -108,11 +108,11 @@ int mbedtls_x25519_get_params( mbedtls_x25519_context *ctx, const mbedtls_ecp_ke

switch( side ) {
case MBEDTLS_X25519_ECDH_THEIRS:
mbedtls_ecp_point_write_binary( &key->grp, &key->Q, MBEDTLS_ECP_PF_COMPRESSED, &olen, ctx->peer_point, 32 );
mbedtls_ecp_point_write_binary( &key->grp, &key->Q, MBEDTLS_ECP_PF_COMPRESSED, &olen, ctx->peer_point, MBEDTLS_X25519_KEY_SIZE_BYTES );
/* untested; defensively throw an error for now. */
return(MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE);
case MBEDTLS_X25519_ECDH_OURS:
mbedtls_mpi_write_binary( &key->d, ctx->our_secret, 32 );
mbedtls_mpi_write_binary( &key->d, ctx->our_secret, MBEDTLS_X25519_KEY_SIZE_BYTES );
/* CMW: key->Q = key->d * base; do we need to set up ctx.peer_point here? */
/* untested; defensively throw an error for now. */
return( MBEDTLS_ERR_ECP_FEATURE_UNAVAILABLE );
Expand All @@ -130,16 +130,16 @@ int mbedtls_x25519_calc_secret( mbedtls_x25519_context *ctx, size_t *olen,
(( void )f_rng);
(( void )p_rng);

*olen = 32;
*olen = MBEDTLS_X25519_KEY_SIZE_BYTES;

if( blen < *olen )
return( MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL );

Hacl_Curve25519_crypto_scalarmult( buf, ctx->our_secret, ctx->peer_point);

/* Wipe the DH secret and don't let the peer chose a small subgroup point */
memset( ctx->our_secret, 0, 32 );
if( memcmp( buf, ctx->our_secret, 32) == 0 )
memset( ctx->our_secret, 0, MBEDTLS_X25519_KEY_SIZE_BYTES );
if( memcmp( buf, ctx->our_secret, MBEDTLS_X25519_KEY_SIZE_BYTES) == 0 )
return MBEDTLS_ERR_ECP_RANDOM_FAILED;

return( 0 );
Expand All @@ -150,7 +150,7 @@ int mbedtls_x25519_make_public( mbedtls_x25519_context *ctx, size_t *olen,
int( *f_rng )(void *, unsigned char *, size_t),
void *p_rng )
{
unsigned char base[32] = { 0 };
unsigned char base[MBEDTLS_X25519_KEY_SIZE_BYTES] = { 0 };

/* CMW: Is it okay that f_rng, p_rng are not used? */
(( void )f_rng);
Expand All @@ -162,13 +162,13 @@ int mbedtls_x25519_make_public( mbedtls_x25519_context *ctx, size_t *olen,
*olen = 33;
if( blen < *olen )
return(MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL);
*buf++ = 32;
*buf++ = MBEDTLS_X25519_KEY_SIZE_BYTES;

base[0] = 9;
Hacl_Curve25519_crypto_scalarmult( buf, ctx->our_secret, base );

base[0] = 0;
if( memcmp( buf, base, 32 ) == 0 )
if( memcmp( buf, base, MBEDTLS_X25519_KEY_SIZE_BYTES ) == 0 )
return MBEDTLS_ERR_ECP_RANDOM_FAILED;

return(0);
Expand All @@ -179,9 +179,9 @@ int mbedtls_x25519_read_public( mbedtls_x25519_context *ctx,
{
if( blen < 33 )
return(MBEDTLS_ERR_ECP_BUFFER_TOO_SMALL);
if( (*buf++ != 32) )
if( (*buf++ != MBEDTLS_X25519_KEY_SIZE_BYTES) )
return(MBEDTLS_ERR_ECP_BAD_INPUT_DATA);
memcpy( ctx->peer_point, buf, 32 );
memcpy( ctx->peer_point, buf, MBEDTLS_X25519_KEY_SIZE_BYTES );
return(0);
}

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