Moved GCM to use cipher layer instead of AES directly
diff --git a/library/gcm.c b/library/gcm.c
index 99036a0..e041647 100644
--- a/library/gcm.c
+++ b/library/gcm.c
@@ -54,15 +54,17 @@
}
#endif
-static void gcm_gen_table( gcm_context *ctx )
+static int gcm_gen_table( gcm_context *ctx )
{
- int i, j;
+ int ret, i, j;
uint64_t hi, lo;
uint64_t vl, vh;
unsigned char h[16];
+ size_t olen = 0;
memset( h, 0, 16 );
- aes_crypt_ecb( &ctx->aes_ctx, AES_ENCRYPT, h, h );
+ if( ( ret = cipher_update( &ctx->cipher_ctx, h, 16, h, &olen ) ) != 0 )
+ return( ret );
ctx->HH[0] = 0;
ctx->HL[0] = 0;
@@ -99,18 +101,33 @@
HiL[j] = vl ^ ctx->HL[j];
}
}
+
+ return( 0 );
}
-int gcm_init( gcm_context *ctx, const unsigned char *key, unsigned int keysize )
+int gcm_init( gcm_context *ctx, cipher_id_t cipher, const unsigned char *key,
+ unsigned int keysize )
{
int ret;
+ const cipher_info_t *cipher_info;
memset( ctx, 0, sizeof(gcm_context) );
- if( ( ret = aes_setkey_enc( &ctx->aes_ctx, key, keysize ) ) != 0 )
+ cipher_info = cipher_info_from_values( cipher, keysize, POLARSSL_MODE_ECB );
+ if( cipher_info == NULL )
+ return( POLARSSL_ERR_GCM_BAD_INPUT );
+
+ if( ( ret = cipher_init_ctx( &ctx->cipher_ctx, cipher_info ) ) != 0 )
return( ret );
- gcm_gen_table( ctx );
+ if( ( ret = cipher_setkey( &ctx->cipher_ctx, key, keysize,
+ POLARSSL_ENCRYPT ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ if( ( ret = gcm_gen_table( ctx ) ) != 0 )
+ return( ret );
return( 0 );
}
@@ -176,10 +193,11 @@
const unsigned char *add,
size_t add_len )
{
+ int ret;
unsigned char work_buf[16];
size_t i;
const unsigned char *p;
- size_t use_len;
+ size_t use_len, olen = 0;
memset( ctx->y, 0x00, sizeof(ctx->y) );
memset( ctx->buf, 0x00, sizeof(ctx->buf) );
@@ -218,7 +236,11 @@
gcm_mult( ctx, ctx->y, ctx->y );
}
- aes_crypt_ecb( &ctx->aes_ctx, AES_ENCRYPT, ctx->y, ctx->base_ectr );
+ if( ( ret = cipher_update( &ctx->cipher_ctx, ctx->y, 16, ctx->base_ectr,
+ &olen ) ) != 0 )
+ {
+ return( ret );
+ }
ctx->add_len = add_len;
p = add;
@@ -243,11 +265,12 @@
const unsigned char *input,
unsigned char *output )
{
+ int ret;
unsigned char ectr[16];
size_t i;
const unsigned char *p;
unsigned char *out_p = output;
- size_t use_len;
+ size_t use_len, olen = 0;
if( output > input && (size_t) ( output - input ) < length )
return( POLARSSL_ERR_GCM_BAD_INPUT );
@@ -263,7 +286,11 @@
if( ++ctx->y[i - 1] != 0 )
break;
- aes_crypt_ecb( &ctx->aes_ctx, AES_ENCRYPT, ctx->y, ectr );
+ if( ( ret = cipher_update( &ctx->cipher_ctx, ctx->y, 16, ectr,
+ &olen ) ) != 0 )
+ {
+ return( ret );
+ }
for( i = 0; i < use_len; i++ )
{
@@ -613,6 +640,7 @@
unsigned char buf[64];
unsigned char tag_buf[16];
int i, j, ret;
+ cipher_id_t cipher = POLARSSL_CIPHER_ID_AES;
for( j = 0; j < 3; j++ )
{
@@ -623,7 +651,7 @@
if( verbose != 0 )
printf( " AES-GCM-%3d #%d (%s): ", key_len, i, "enc" );
- gcm_init( &ctx, key[key_index[i]], key_len );
+ gcm_init( &ctx, cipher, key[key_index[i]], key_len );
ret = gcm_crypt_and_tag( &ctx, GCM_ENCRYPT,
pt_len[i],
@@ -647,7 +675,7 @@
if( verbose != 0 )
printf( " AES-GCM-%3d #%d (%s): ", key_len, i, "dec" );
- gcm_init( &ctx, key[key_index[i]], key_len );
+ gcm_init( &ctx, cipher, key[key_index[i]], key_len );
ret = gcm_crypt_and_tag( &ctx, GCM_DECRYPT,
pt_len[i],
@@ -671,7 +699,7 @@
if( verbose != 0 )
printf( " AES-GCM-%3d #%d split (%s): ", key_len, i, "enc" );
- gcm_init( &ctx, key[key_index[i]], key_len );
+ gcm_init( &ctx, cipher, key[key_index[i]], key_len );
ret = gcm_starts( &ctx, GCM_ENCRYPT,
iv[iv_index[i]], iv_len[i],
@@ -734,7 +762,7 @@
if( verbose != 0 )
printf( " AES-GCM-%3d #%d split (%s): ", key_len, i, "dec" );
- gcm_init( &ctx, key[key_index[i]], key_len );
+ gcm_init( &ctx, cipher, key[key_index[i]], key_len );
ret = gcm_starts( &ctx, GCM_DECRYPT,
iv[iv_index[i]], iv_len[i],
