Return an error for IV lengths other than 12 with ChaCha20
The implementation was silently overwriting the IV length to 12
even though the caller passed a different value.
Change the behavior to signal that a different length is not supported.
Signed-off-by: Andrzej Kurek <andrzej.kurek@arm.com>
diff --git a/library/cipher.c b/library/cipher.c
index 03e84c6..39c105c 100644
--- a/library/cipher.c
+++ b/library/cipher.c
@@ -386,6 +386,12 @@
#if defined(MBEDTLS_CHACHA20_C)
if ( ctx->cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
{
+ /* Even though the actual_iv_size is overwritten with a correct value
+ * of 12 from the cipher info, return an error to indicate that
+ * the input iv_len is wrong. */
+ if( iv_len != 12 )
+ return( MBEDTLS_ERR_CIPHER_BAD_INPUT_DATA );
+
if ( 0 != mbedtls_chacha20_starts( (mbedtls_chacha20_context*)ctx->cipher_ctx,
iv,
0U ) ) /* Initial counter value */