Add more tests for the entropy module

include/polarssl/entropy.h

@@ -183,7 +183,7 @@ int entropy_gather( entropy_context *ctx );
  *
  * \param data      Entropy context
  * \param output    Buffer to fill
- * \param len       Length of buffer
+ * \param len       Number of bytes desired, must be at most ENTROPY_BLOCK_SIZE
  *
  * \return          0 if successful, or POLARSSL_ERR_ENTROPY_SOURCE_FAILED
  */

tests/suites/test_suite_entropy.data

@@ -4,5 +4,38 @@ entropy_seed_file:"data_files/entropy_seed":0
 Entropy write/update seed file
 entropy_seed_file:"no_such_dir/file":POLARSSL_ERR_ENTROPY_FILE_IO_ERROR
 
+Entropy too many sources
+entropy_too_many_sources:
+
+Entropy output length #1
+entropy_func_len:0:0
+
+Entropy output length #2
+entropy_func_len:1:0
+
+Entropy output length #3
+entropy_func_len:2:0
+
+Entropy output length #4
+entropy_func_len:31:0
+
+Entropy output length #5
+entropy_func_len:65:POLARSSL_ERR_ENTROPY_SOURCE_FAILED
+
+Entropy failing source
+entropy_source_fail:"data_files/entropy_seed"
+
+Entropy threshold #1
+entropy_threshold:16:2:8
+
+Entropy threshold #2
+entropy_threshold:32:1:32
+
+Entropy thershold #3
+entropy_threshold:16:0:POLARSSL_ERR_ENTROPY_SOURCE_FAILED
+
+Entropy thershold #4
+entropy_threshold:1024:1:POLARSSL_ERR_ENTROPY_SOURCE_FAILED
+
 Entropy self test
 entropy_selftest:

tests/suites/test_suite_entropy.function

@@ -1,5 +1,38 @@
 /* BEGIN_HEADER */
 #include <polarssl/entropy.h>
+
+/*
+ * Number of calls made to entropy_dummy_source()
+ */
+static size_t entropy_dummy_calls;
+
+/*
+ * Dummy entropy source
+ *
+ * If data is NULL, write exactly the requested length.
+ * Otherwise, write the length indicated by data or error if negative
+ */
+static int entropy_dummy_source( void *data, unsigned char *output,
+                                 size_t len, size_t *olen )
+{
+    entropy_dummy_calls++;
+
+    if( data == NULL )
+        *olen = len;
+    else
+    {
+        int *d = (int *) data;
+
+        if( *d < 0 )
+            return( POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
+        else
+            *olen = *d;
+    }
+
+    memset( output, 0x2a, *olen );
+
+    return( 0 );
+}
 /* END_HEADER */
 
 /* BEGIN_DEPENDENCIES
@@ -21,6 +54,115 @@ void entropy_seed_file( char *path, int ret )
 }
 /* END_CASE */
 
+/* BEGIN_CASE */
+void entropy_too_many_sources( )
+{
+    entropy_context ctx;
+    size_t i;
+
+    entropy_init( &ctx );
+
+    /*
+     * It's hard to tell precisely when the error will occur,
+     * since we don't know how many sources were automatically added.
+     */
+    for( i = 0; i < ENTROPY_MAX_SOURCES; i++ )
+        (void) entropy_add_source( &ctx, entropy_dummy_source, NULL, 16 );
+
+    TEST_ASSERT( entropy_add_source( &ctx, entropy_dummy_source, NULL, 16 )
+                 == POLARSSL_ERR_ENTROPY_MAX_SOURCES );
+
+    entropy_free( &ctx );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void entropy_func_len( int len, int ret )
+{
+    entropy_context ctx;
+    unsigned char buf[ENTROPY_BLOCK_SIZE + 10] = { 0 };
+    unsigned char acc[ENTROPY_BLOCK_SIZE + 10] = { 0 };
+    size_t i, j;
+
+    entropy_init( &ctx );
+
+    /*
+     * See comments in entropy_self_test()
+     */
+    for( i = 0; i < 8; i++ )
+    {
+        TEST_ASSERT( entropy_func( &ctx, buf, len ) == ret );
+        for( j = 0; j < sizeof( buf ); j++ )
+            acc[j] |= buf[j];
+    }
+
+    if( ret == 0 )
+        for( j = 0; j < (size_t) len; j++ )
+            TEST_ASSERT( acc[j] != 0 );
+
+    for( j = len; j < sizeof( buf ); j++ )
+        TEST_ASSERT( acc[j] == 0 );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void entropy_source_fail( char *path )
+{
+    entropy_context ctx;
+    int fail = -1;
+    unsigned char buf[16];
+
+    entropy_init( &ctx );
+
+    TEST_ASSERT( entropy_add_source( &ctx, entropy_dummy_source, &fail, 16 )
+                 == 0 );
+
+    TEST_ASSERT( entropy_func( &ctx, buf, sizeof( buf ) )
+                 == POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
+    TEST_ASSERT( entropy_gather( &ctx )
+                 == POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
+#if defined(POLARSSL_FS_IO)
+    TEST_ASSERT( entropy_write_seed_file( &ctx, path )
+                 == POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
+    TEST_ASSERT( entropy_update_seed_file( &ctx, path )
+                 == POLARSSL_ERR_ENTROPY_SOURCE_FAILED );
+#else
+    ((void) path);
+#endif
+
+    entropy_free( &ctx );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void entropy_threshold( int threshold, int chunk_size, int result )
+{
+    entropy_context ctx;
+    unsigned char buf[ENTROPY_BLOCK_SIZE] = { 0 };
+    int ret;
+
+    entropy_init( &ctx );
+
+    TEST_ASSERT( entropy_add_source( &ctx, entropy_dummy_source,
+                                     &chunk_size, threshold ) == 0 );
+
+    entropy_dummy_calls = 0;
+    ret = entropy_func( &ctx, buf, sizeof( buf ) );
+
+    if( result >= 0 )
+    {
+        TEST_ASSERT( ret == 0 );
+        TEST_ASSERT( entropy_dummy_calls == (size_t) result );
+    }
+    else
+    {
+        TEST_ASSERT( ret == result );
+    }
+
+    entropy_free( &ctx );
+}
+/* END_CASE */
+
 /* BEGIN_CASE depends_on:POLARSSL_SELF_TEST */
 void entropy_selftest( )
 {