commit d35304338007519eed957ab63dcc1a6d386a5dcb
author Andrzej Kurek <Andrzej.Kurek@arm.com> Thu Dec 02 09:31:58 2021 +0100
committer Andrzej Kurek <Andrzej.Kurek@arm.com> Thu Dec 02 09:31:58 2021 +0100
tree 810183a4b964c8bf8997bc9d0c90d2714e74bd55
parent 5375fd9a3ff67333e0b0a8c187a7d151f4cfa12f

Return an error for IV lengths other than 12 with ChaCha20+Poly1305

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>

tests/suites/test_suite_cipher.function

diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index 73e548d..7d64fa7 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -758,7 +758,8 @@
     memset( decbuf, 0, sizeof( decbuf ) );
     memset( tag, 0, sizeof( tag ) );
 
-    if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
+    if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 ||
+        cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
         iv_len = 12;
     else
         iv_len = sizeof(iv);
@@ -887,6 +888,7 @@
 {
     unsigned char key[32];
     unsigned char iv[16];
+    size_t iv_len = sizeof(iv);
 
     mbedtls_cipher_context_t ctx_dec;
     const mbedtls_cipher_info_t *cipher_info;
@@ -907,6 +909,11 @@
     /* Initialise context */
     cipher_info = mbedtls_cipher_info_from_type( cipher );
     TEST_ASSERT( NULL != cipher_info);
+
+    if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 ||
+        cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
+        iv_len = 12;
+
     TEST_ASSERT( sizeof(key) * 8 >= cipher_info->key_bitlen );
 
     TEST_ASSERT( 0 == mbedtls_cipher_setup( &ctx_dec, cipher_info ) );
@@ -915,7 +922,7 @@
                                              key, cipher_info->key_bitlen,
                                              MBEDTLS_DECRYPT ) );
 
-    TEST_ASSERT( 0 == mbedtls_cipher_set_iv( &ctx_dec, iv, 16 ) );
+    TEST_ASSERT( 0 == mbedtls_cipher_set_iv( &ctx_dec, iv, iv_len ) );
 
     TEST_ASSERT( 0 == mbedtls_cipher_reset( &ctx_dec ) );
 
@@ -1003,7 +1010,8 @@
     (void) pad_mode;
 #endif /* MBEDTLS_CIPHER_MODE_WITH_PADDING */
 
-    if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
+    if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 ||
+        cipher_info->type == MBEDTLS_CIPHER_CHACHA20_POLY1305 )
         iv_len = 12;
     else
         iv_len = sizeof(iv);