Merge remote-tracking branch 'upstream-public/pr/1629' into evaluation
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index 8585ce5..1bc79d8 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -66,6 +66,55 @@
#endif /* MBEDTLS_CCM_ALT */
/**
+ * \brief The CCM* callback for encrypting with variable tag length.
+ * The function pointer is passed to the APIs called. This
+ * function calculates the nonce and returns it in a buffer.
+ *
+ * \warning This function must not return the same nonce more than once
+ * in the lifetime of the key!
+ *
+ * \note To prevent attacks taking advantage of the variable tag
+ * length CCM* encodes the tag length in the nonce. The method
+ * of encoding may vary. Standards might mandate encoding other
+ * information in the nonce (e.g. address and frame counter)
+ * too.
+ *
+ * \param app_ctx A pointer to structure containing the application context
+ * if it is necessary for calculating the initialisation vector
+ * (nonce).
+ * \param tag_len Length of the tag in bytes.
+ * \nonce Output variable, points to the buffer capable of holding the
+ * calculated nonce. Must be at least \p nonce_len bytes long.
+ * \nonce_len The length of the nonce in bytes.
+ *
+ * \return \c 0 on success.
+ * \return MBEDTLS_ERR_CCM_BAD_INPUT error code on failure.
+ */
+typedef int (*mbedtls_ccm_star_get_nonce_t)( void *app_ctx, size_t tag_len,
+ unsigned char *nonce,
+ size_t nonce_len );
+
+/**
+ * \brief The CCM* callback for decrypting with variable tag length.
+ * The function pointer is passed to the APIs called. This
+ * function calculates and returns the length of the tag in the
+ * output parameter.
+ *
+ * \param app_ctx A pointer to structure containing the application context
+ * if it is necessary for decoding the tag length or validating
+ * the initialisation vector (nonce).
+ * \param tag_len Output variable for holding the tag length in bytes.
+ * \nonce A buffer containing the nonce.
+ * \nonce_len The length of the nonce in bytes.
+ *
+ * \return \c 0 on success.
+ * \return MBEDTLS_ERR_CCM_BAD_INPUT error code on failure.
+ */
+typedef int (*mbedtls_ccm_star_get_tag_len_t)( void *app_ctx, size_t* tag_len,
+ const unsigned char *nonce,
+ size_t nonce_len );
+
+/**
* \brief This function initializes the specified CCM context,
* to make references valid, and prepare the context
* for mbedtls_ccm_setkey() or mbedtls_ccm_free().
@@ -102,7 +151,6 @@
/**
* \brief This function encrypts a buffer using CCM.
*
- *
* \note The tag is written to a separate buffer. To concatenate
* the \p tag with the \p output, as done in <em>RFC-3610:
* Counter with CBC-MAC (CCM)</em>, use
@@ -133,6 +181,82 @@
unsigned char *tag, size_t tag_len );
/**
+ * \brief This function encrypts a buffer using CCM* with fixed tag
+ * length.
+ *
+ * \note The tag is written to a separate buffer. To concatenate
+ * the \p tag with the \p output, as done in <em>RFC-3610:
+ * Counter with CBC-MAC (CCM)</em>, use
+ * \p tag = \p output + \p length, and make sure that the
+ * output buffer is at least \p length + \p tag_len wide.
+ *
+ * \param ctx The CCM context to use for encryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv Initialization vector (nonce).
+ * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
+ * \param add The additional data field.
+ * \param add_len The length of additional data in Bytes.
+ * Must be less than 2^16 - 2^8.
+ * \param input The buffer holding the input data.
+ * \param output The buffer holding the output data.
+ * Must be at least \p length Bytes wide.
+ * \param tag The buffer holding the tag.
+ * \param tag_len The length of the tag to generate in Bytes:
+ * 0, 4, 6, 8, 10, 12, 14 or 16.
+ *
+ * \warning Passing 0 as \p tag_len means that the message is no
+ * longer authenticated.
+ *
+ * \return \c 0 on success.
+ * \return A CCM or cipher-specific error code on failure.
+ */
+int mbedtls_ccm_sfix_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ unsigned char *tag, size_t tag_len );
+
+/**
+ * \brief This function encrypts a buffer using CCM* with variable
+ * tag length.
+ *
+ * \note The tag is written to a separate buffer. To concatenate
+ * the \p tag with the \p output, as done in <em>RFC-3610:
+ * Counter with CBC-MAC (CCM)</em>, use
+ * \p tag = \p output + \p length, and make sure that the
+ * output buffer is at least \p length + \p tag_len wide.
+ *
+ * \param ctx The CCM context to use for encryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13.
+ * \param add The additional data field.
+ * \param add_len The length of additional data in Bytes.
+ * Must be less than 2^16 - 2^8.
+ * \param input The buffer holding the input data.
+ * \param output The buffer holding the output data.
+ * Must be at least \p length Bytes wide.
+ * \param tag The buffer holding the tag.
+ * \param tag_len The length of the tag to generate in Bytes:
+ * 0, 4, 6, 8, 10, 12, 14 or 16.
+ * \param get_iv A callback function returning the IV (nonce) with the
+ * tag length encoded in it.
+ * \param get_iv_ctx Context passed to the \p get_iv callback.
+ *
+ * \warning Passing 0 as \p tag_len means that the message is no
+ * longer authenticated.
+ *
+ * \return \c 0 on success.
+ * \return A CCM or cipher-specific error code on failure.
+ */
+int mbedtls_ccm_svar_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+ size_t iv_len, const unsigned char *add,
+ size_t add_len, const unsigned char *input,
+ unsigned char *output, unsigned char *tag,
+ size_t tag_len, mbedtls_ccm_star_get_nonce_t get_iv,
+ void *get_iv_ctx );
+
+/**
* \brief This function performs a CCM authenticated decryption of a
* buffer.
*
@@ -160,6 +284,74 @@
const unsigned char *input, unsigned char *output,
const unsigned char *tag, size_t tag_len );
+/**
+ * \brief This function performs a CCM* authenticated decryption of a
+ * buffer with fixed tag length.
+ *
+ * \param ctx The CCM context to use for decryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv Initialization vector.
+ * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12, or 13.
+ * \param add The additional data field.
+ * \param add_len The length of additional data in Bytes.
+ * Must be less than 2^16 - 2^8.
+ * \param input The buffer holding the input data.
+ * \param output The buffer holding the output data.
+ * Must be at least \p length Bytes wide.
+ * \param tag The buffer holding the tag.
+ * \param tag_len The length of the tag in Bytes.
+ * 0, 4, 6, 8, 10, 12, 14 or 16.
+ *
+ * \warning Passing 0 as \p tag_len means that the message is no
+ * longer authenticated.
+ *
+ * \return \c 0 on success. This indicates that the message is
+ * authentic.
+ * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
+ * \return A cipher-specific error code on calculation failure.
+ */
+int mbedtls_ccm_sfix_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ const unsigned char *tag, size_t tag_len );
+
+/**
+ * \brief This function performs a CCM* authenticated decryption
+ * of a buffer with variable tag length.
+ *
+ * \param ctx The CCM context to use for decryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv Initialization vector.
+ * \param iv_len The length of the IV in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13.
+ * \param add The additional data field.
+ * \param add_len The length of additional data in Bytes.
+ * Must be less than 2^16 - 2^8.
+ * \param input The buffer holding the input data. Unlike the \p input
+ * parameters of other Mbed TLS CCM functions, this buffer
+ * holds the concatenation of the encrypted data and the
+ * authentication tag.
+ * \param output The buffer holding the output data.
+ * Must be at least \p length Bytes wide.
+ * \param output_len The length of the decrypted data.
+ * \param get_tag_len A callback function returning the tag length.
+ * \param get_tlen_ctx Context passed to the \p get_tag_len callback.
+ *
+ *
+ * \return \c 0 on success. This indicates that the message is
+ * authentic.
+ * \return #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
+ * \return A cipher-specific error code on calculation failure.
+ */
+int mbedtls_ccm_svar_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ size_t* output_len,
+ mbedtls_ccm_star_get_tag_len_t get_tag_len,
+ void *get_tlen_ctx );
+
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/**
diff --git a/library/ccm.c b/library/ccm.c
index cf65209..72b82a0 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -154,7 +154,13 @@
* 'length' checked later (when writing it to the first block)
*/
if( tag_len < 4 || tag_len > 16 || tag_len % 2 != 0 )
- return( MBEDTLS_ERR_CCM_BAD_INPUT );
+ {
+ /*
+ * Loosen the requirements to enable support for CCM* (IEEE 802.15.4)
+ */
+ if( tag_len != 0 )
+ return( MBEDTLS_ERR_CCM_BAD_INPUT );
+ }
/* Also implies q is within bounds */
if( iv_len < 7 || iv_len > 13 )
@@ -302,7 +308,7 @@
/*
* Authenticated encryption
*/
-int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+int mbedtls_ccm_sfix_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *add, size_t add_len,
const unsigned char *input, unsigned char *output,
@@ -312,10 +318,41 @@
add, add_len, input, output, tag, tag_len ) );
}
+int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ unsigned char *tag, size_t tag_len )
+{
+ if( tag_len == 0 )
+ return( MBEDTLS_ERR_CCM_BAD_INPUT );
+
+ return( mbedtls_ccm_sfix_encrypt_and_tag( ctx, length, iv, iv_len, add,
+ add_len, input, output, tag, tag_len ) );
+}
+
+#define CCM_MAX_IV_LEN 13
+
+int mbedtls_ccm_svar_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+ size_t iv_len, const unsigned char *add,
+ size_t add_len, const unsigned char *input,
+ unsigned char *output, unsigned char *tag,
+ size_t tag_len, mbedtls_ccm_star_get_nonce_t get_iv,
+ void *get_iv_ctx )
+{
+ unsigned char iv[CCM_MAX_IV_LEN];
+
+ if( get_iv( get_iv_ctx, tag_len, iv, iv_len ) != 0 )
+ return MBEDTLS_ERR_CCM_BAD_INPUT;
+
+ return( mbedtls_ccm_sfix_encrypt_and_tag( ctx, length, iv, iv_len, add,
+ add_len, input, output, tag, tag_len ) );
+}
+
/*
* Authenticated decryption
*/
-int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
+int mbedtls_ccm_sfix_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
const unsigned char *iv, size_t iv_len,
const unsigned char *add, size_t add_len,
const unsigned char *input, unsigned char *output,
@@ -346,6 +383,38 @@
return( 0 );
}
+int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ const unsigned char *tag, size_t tag_len )
+{
+ if( tag_len == 0 )
+ return( MBEDTLS_ERR_CCM_BAD_INPUT );
+
+ return( mbedtls_ccm_sfix_auth_decrypt( ctx, length, iv, iv_len, add,
+ add_len, input, output, tag, tag_len ) );
+}
+
+
+int mbedtls_ccm_svar_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
+ const unsigned char *iv, size_t iv_len,
+ const unsigned char *add, size_t add_len,
+ const unsigned char *input, unsigned char *output,
+ size_t* output_len,
+ mbedtls_ccm_star_get_tag_len_t get_tag_len,
+ void *get_tlen_ctx )
+{
+ size_t tag_len = 0;
+
+ if( get_tag_len( get_tlen_ctx, &tag_len, iv, iv_len ) != 0 )
+ return( MBEDTLS_ERR_CCM_BAD_INPUT );
+
+ *output_len = length - tag_len;
+
+ return( mbedtls_ccm_sfix_auth_decrypt( ctx, length, iv, iv_len, add,
+ add_len, input, output, input + length, tag_len ) );
+}
#endif /* !MBEDTLS_CCM_ALT */
#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
diff --git a/tests/suites/test_suite_ccm.data b/tests/suites/test_suite_ccm.data
index 90ba42d..a55ece1 100644
--- a/tests/suites/test_suite_ccm.data
+++ b/tests/suites/test_suite_ccm.data
@@ -41,6 +41,15 @@
CCM lengths #8 msg too long for this IV length (2^16, q = 2)
ccm_lengths:65536:13:5:8:MBEDTLS_ERR_CCM_BAD_INPUT
+CCM lengths #9 tag length 0
+ccm_lengths:5:10:5:0:MBEDTLS_ERR_CCM_BAD_INPUT
+
+CCM* fixed tag lengths #1 all OK
+ccm_sfix_lengths:5:10:5:8:0
+
+CCM* fixed tag lengths #2 all OK - tag length 0
+ccm_sfix_lengths:5:10:5:0:0
+
CCM encrypt and tag RFC 3610 #1
depends_on:MBEDTLS_AES_C
mbedtls_ccm_encrypt_and_tag:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"08090A0B0C0D0E0F101112131415161718191A1B1C1D1E":"00000003020100A0A1A2A3A4A5":"0001020304050607":"588C979A61C663D2F066D0C2C0F989806D5F6B61DAC38417E8D12CFDF926E0"
diff --git a/tests/suites/test_suite_ccm.function b/tests/suites/test_suite_ccm.function
index 2f5c77c..d64b697 100644
--- a/tests/suites/test_suite_ccm.function
+++ b/tests/suites/test_suite_ccm.function
@@ -74,6 +74,47 @@
}
/* END_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_AES_C */
+void ccm_sfix_lengths( int msg_len, int iv_len, int add_len, int tag_len,
+ int res )
+{
+ mbedtls_ccm_context ctx;
+ unsigned char key[16];
+ unsigned char msg[10];
+ unsigned char iv[14];
+ unsigned char add[10];
+ unsigned char out[10];
+ unsigned char tag[18];
+ int decrypt_ret;
+
+ mbedtls_ccm_init( &ctx );
+
+ memset( key, 0, sizeof( key ) );
+ memset( msg, 0, sizeof( msg ) );
+ memset( iv, 0, sizeof( iv ) );
+ memset( add, 0, sizeof( add ) );
+ memset( out, 0, sizeof( out ) );
+ memset( tag, 0, sizeof( tag ) );
+
+ TEST_ASSERT( mbedtls_ccm_setkey( &ctx, MBEDTLS_CIPHER_ID_AES,
+ key, 8 * sizeof( key ) ) == 0 );
+
+ TEST_ASSERT( mbedtls_ccm_sfix_encrypt_and_tag( &ctx, msg_len, iv, iv_len,
+ add, add_len, msg, out, tag, tag_len ) == res );
+
+ decrypt_ret = mbedtls_ccm_sfix_auth_decrypt( &ctx, msg_len, iv, iv_len, add,
+ add_len, msg, out, tag, tag_len );
+
+ if( res == 0 && tag_len != 0 )
+ TEST_ASSERT( decrypt_ret == MBEDTLS_ERR_CCM_AUTH_FAILED );
+ else
+ TEST_ASSERT( decrypt_ret == res );
+
+exit:
+ mbedtls_ccm_free( &ctx );
+}
+/* END_CASE */
+
/* BEGIN_CASE */
void mbedtls_ccm_encrypt_and_tag( int cipher_id,
char *key_hex, char *msg_hex,