commit 33ca6af8a3bd770cb454793b9f6fc52e5d43bb21
author Andrzej Kurek <Andrzej.Kurek@arm.com> Wed Dec 01 21:58:05 2021 +0100
committer Andrzej Kurek <Andrzej.Kurek@arm.com> Fri Jan 14 16:31:54 2022 +0100
tree 78c2db88b888b4ada5ffaa06aa963137bc4890fe
parent ce8a6173f754d7df0945cf867f480cba629aa545

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>

tests/suites/test_suite_cipher.function

diff --git a/tests/suites/test_suite_cipher.function b/tests/suites/test_suite_cipher.function
index fd2985b..c837a69 100644
--- a/tests/suites/test_suite_cipher.function
+++ b/tests/suites/test_suite_cipher.function
@@ -442,6 +442,8 @@
     if( NULL != strstr( cipher_info->name, "CCM*-NO-TAG") )
         iv_len = 13; /* For CCM, IV length is expected to be between 7 and 13 bytes.
                       * For CCM*-NO-TAG, IV length must be exactly 13 bytes long. */
+    else if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
+        iv_len = 12;
     else
         iv_len = sizeof(iv);
 
@@ -689,6 +691,8 @@
     if( NULL != strstr( cipher_info->name, "CCM*-NO-TAG") )
         iv_len = 13; /* For CCM, IV length is expected to be between 7 and 13 bytes.
                       * For CCM*-NO-TAG, IV length must be exactly 13 bytes long. */
+    else if( cipher_info->type == MBEDTLS_CIPHER_CHACHA20 )
+        iv_len = 12;
     else
         iv_len = sizeof(iv);
 
@@ -1130,3 +1134,40 @@
         TEST_ASSERT( dlen == (size_t) dlen_check );
 }
 /* END_CASE */
+
+/* BEGIN_CASE */
+void check_iv( int cipher_id, char * cipher_string,
+               int iv_len_val, int ret )
+{
+    size_t iv_len = iv_len_val;
+    unsigned char iv[16];
+
+    const mbedtls_cipher_info_t *cipher_info;
+    mbedtls_cipher_context_t ctx_dec;
+    mbedtls_cipher_context_t ctx_enc;
+
+    /*
+     * Prepare contexts
+     */
+    mbedtls_cipher_init( &ctx_dec );
+    mbedtls_cipher_init( &ctx_enc );
+
+    /* Check and get info structures */
+    cipher_info = mbedtls_cipher_info_from_type( cipher_id );
+    TEST_ASSERT( NULL != cipher_info );
+    TEST_ASSERT( mbedtls_cipher_info_from_string( cipher_string ) == cipher_info );
+    TEST_ASSERT( strcmp( mbedtls_cipher_info_get_name( cipher_info ),
+                         cipher_string ) == 0 );
+
+    /* Initialise enc and dec contexts */
+    TEST_ASSERT( 0 == mbedtls_cipher_setup( &ctx_dec, cipher_info ) );
+    TEST_ASSERT( 0 == mbedtls_cipher_setup( &ctx_enc, cipher_info ) );
+
+    TEST_ASSERT( ret == mbedtls_cipher_set_iv( &ctx_dec, iv, iv_len ) );
+    TEST_ASSERT( ret == mbedtls_cipher_set_iv( &ctx_enc, iv, iv_len ) );
+
+exit:
+    mbedtls_cipher_free( &ctx_dec );
+    mbedtls_cipher_free( &ctx_enc );
+}
+/* END_CASE */