Store set lenghts in ccm context.
Signed-off-by: Mateusz Starzyk <mateusz.starzyk@mobica.com>
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index f9f8000..813959b 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -81,7 +81,10 @@
unsigned char MBEDTLS_PRIVATE(y)[16]; /*!< The Y working buffer */
unsigned char MBEDTLS_PRIVATE(ctr)[16]; /*!< The counter buffer */
unsigned char MBEDTLS_PRIVATE(q); /*!< The Q working value */
- size_t MBEDTLS_PRIVATE(plaintext_len); /*!< The counter buffer */
+ size_t MBEDTLS_PRIVATE(plaintext_len); /*!< Total plaintext length */
+ size_t MBEDTLS_PRIVATE(add_len); /*!< Total authentication data length */
+ size_t MBEDTLS_PRIVATE(tag_len); /*!< Total tag length */
+ size_t MBEDTLS_PRIVATE(processed); /*!< How many bytes of input data were processed (chunked input) */
int MBEDTLS_PRIVATE(mode); /*!< The operation to perform:
#MBEDTLS_CCM_ENCRYPT or
#MBEDTLS_CCM_DECRYPT or
diff --git a/library/ccm.c b/library/ccm.c
index 34531a4..36b1e91 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -172,10 +172,20 @@
/*
* First block B_0:
- * 0 .. 0 flags - set by: mbedtls_ccm_starts() and mbedtls_ccm_set_lenghts()
+ * 0 .. 0 flags
* 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts()
- * iv_len+1 .. 15 length - set by: mbedtls_ccm_calculate_first_block()
+ * iv_len+1 .. 15 length
+ *
+ * With flags as (bits):
+ * 7 0
+ * 6 add present?
+ * 5 .. 3 (t - 2) / 2
+ * 2 .. 0 q - 1
*/
+ ctx->b[0] |= ( ctx->add_len > 0 ) << 6;
+ ctx->b[0] |= ( ( ctx->tag_len - 2 ) / 2 ) << 3;
+ ctx->b[0] |= ctx->q - 1;
+
for( i = 0, len_left = ctx->plaintext_len; i < ctx->q; i++, len_left >>= 8 )
ctx->b[15-i] = (unsigned char)( len_left & 0xFF );
@@ -225,19 +235,8 @@
ctx->ctr[15] = 1;
/*
- * First block B_0:
- * 0 .. 0 flags - set by: mbedtls_ccm_starts() and mbedtls_ccm_set_lenghts()
- * 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts()
- * iv_len+1 .. 15 length - set by: mbedtls_ccm_calculate_first_block()
- *
- * With flags as (bits):
- * 7 0
- * 6 add present? - set by: mbedtls_ccm_set_lengths()
- * 5 .. 3 (t - 2) / 2 - set by: mbedtls_ccm_set_lengths()
- * 2 .. 0 q - 1 - set by: mbedtls_ccm_starts()
+ * See mbedtls_ccm_calculate_first_block() for B block layout description
*/
- ctx->b[0] |= ctx->q - 1;
-
memcpy( ctx->b + 1, iv, iv_len );
ctx->state |= CCM_STATE__STARTED;
@@ -267,22 +266,10 @@
mbedtls_ccm_clear_state(ctx);
}
- /*
- * First block B_0:
- * 0 .. 0 flags - set by: mbedtls_ccm_starts() and mbedtls_ccm_set_lenghts()
- * 1 .. iv_len nonce (aka iv) - set by: mbedtls_ccm_starts()
- * iv_len+1 .. 15 length - set by: mbedtls_ccm_calculate_first_block()
- *
- * With flags as (bits):
- * 7 0
- * 6 add present? - set by: mbedtls_ccm_set_lengths()
- * 5 .. 3 (t - 2) / 2 - set by: mbedtls_ccm_set_lengths()
- * 2 .. 0 q - 1 - set by: mbedtls_ccm_starts()
- */
- ctx->b[0] |= ( total_ad_len > 0 ) << 6;
- ctx->b[0] |= ( ( tag_len - 2 ) / 2 ) << 3;
-
ctx->plaintext_len = plaintext_len;
+ ctx->add_len = total_ad_len;
+ ctx->tag_len = tag_len;
+ ctx->processed = 0;
ctx->state |= CCM_STATE__LENGHTS_SET;
return mbedtls_ccm_calculate_first_block(ctx);