Add ccm_init/free()
diff --git a/include/polarssl/ccm.h b/include/polarssl/ccm.h
index b794cd8..24405e4 100644
--- a/include/polarssl/ccm.h
+++ b/include/polarssl/ccm.h
@@ -36,6 +36,34 @@
extern "C" {
#endif
+/**
+ * \brief CCM context structure
+ */
+typedef struct {
+ cipher_context_t cipher_ctx; /*!< cipher context used */
+}
+ccm_context;
+
+/**
+ * \brief CCM initialization (encryption and decryption)
+ *
+ * \param ctx CCM context to be initialized
+ * \param cipher cipher to use (a 128-bit block cipher)
+ * \param key encryption key
+ * \param keysize key size in bits (must be acceptable by the cipher)
+ *
+ * \return 0 if successful, or a cipher specific error code
+ */
+int ccm_init( ccm_context *ctx, cipher_id_t cipher,
+ const unsigned char *key, unsigned int keysize );
+
+/**
+ * \brief Free a CCM context and underlying cipher sub-context
+ *
+ * \param ctx CCM context to free
+ */
+void ccm_free( ccm_context *ctx );
+
#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
/**
* \brief Checkup routine
diff --git a/library/ccm.c b/library/ccm.c
index b4ba3d5..453edfb 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -42,6 +42,45 @@
#include "polarssl/ccm.h"
+/*
+ * Initialize context
+ */
+int ccm_init( ccm_context *ctx, cipher_id_t cipher,
+ const unsigned char *key, unsigned int keysize )
+{
+ int ret;
+ const cipher_info_t *cipher_info;
+
+ memset( ctx, 0, sizeof( ccm_context ) );
+
+ cipher_info = cipher_info_from_values( cipher, keysize, POLARSSL_MODE_ECB );
+ if( cipher_info == NULL )
+ return( POLARSSL_ERR_CCM_BAD_INPUT );
+
+ if( cipher_info->block_size != 16 )
+ return( POLARSSL_ERR_CCM_BAD_INPUT );
+
+ if( ( ret = cipher_init_ctx( &ctx->cipher_ctx, cipher_info ) ) != 0 )
+ return( ret );
+
+ if( ( ret = cipher_setkey( &ctx->cipher_ctx, key, keysize,
+ POLARSSL_ENCRYPT ) ) != 0 )
+ {
+ return( ret );
+ }
+
+ return( 0 );
+}
+
+/*
+ * Free context
+ */
+void ccm_free( ccm_context *ctx )
+{
+ (void) cipher_free_ctx( &ctx->cipher_ctx );
+ memset( ctx, 0, sizeof( ccm_context ) );
+}
+
#if defined(POLARSSL_SELF_TEST) && defined(POLARSSL_AES_C)
diff --git a/tests/suites/test_suite_ccm.data b/tests/suites/test_suite_ccm.data
index 223e28a..61ae831 100644
--- a/tests/suites/test_suite_ccm.data
+++ b/tests/suites/test_suite_ccm.data
@@ -1,2 +1,18 @@
CCM self test
ccm_self_test:
+
+CCM init #1 AES-128: OK
+depends_on:POLARSSL_AES_C
+ccm_init:POLARSSL_CIPHER_ID_AES:128:0
+
+CCM init #2 CAMELLIA-256: OK
+depends_on:POLARSSL_CAMELLIA_C
+ccm_init:POLARSSL_CIPHER_ID_CAMELLIA:256:0
+
+CCM init #3 AES-224: bad key size
+depends_on:POLARSSL_AES_C
+ccm_init:POLARSSL_CIPHER_ID_AES:224:POLARSSL_ERR_CCM_BAD_INPUT
+
+CCM init #4 BLOWFISH-128: bad block size
+depends_on:POLARSSL_BLOWFISH_C
+ccm_init:POLARSSL_CIPHER_ID_BLOWFISH:128:POLARSSL_ERR_CCM_BAD_INPUT
diff --git a/tests/suites/test_suite_ccm.function b/tests/suites/test_suite_ccm.function
index 487d1c5..7137a60 100644
--- a/tests/suites/test_suite_ccm.function
+++ b/tests/suites/test_suite_ccm.function
@@ -13,3 +13,20 @@
TEST_ASSERT( ccm_self_test( 0 ) == 0 );
}
/* END_CASE */
+
+/* BEGIN_CASE */
+void ccm_init( int cipher_id, int key_size, int result )
+{
+ ccm_context ctx;
+ unsigned char key[32];
+ int ret;
+
+ memset( key, 0x2A, sizeof( key ) );
+ TEST_ASSERT( (unsigned) key_size <= 8 * sizeof( key ) );
+
+ ret = ccm_init( &ctx, cipher_id, key, key_size );
+ TEST_ASSERT( ret == result );
+
+ ccm_free( &ctx );
+}
+/* END_CASE */