diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h
index 8585ce5e7..5d727e7cc 100644
--- a/include/mbedtls/ccm.h
+++ b/include/mbedtls/ccm.h
@@ -14,6 +14,18 @@
* Nonce - A unique value that is assigned to the payload and the
* associated data.
*
+ * Definition of CCM:
+ * http://csrc.nist.gov/publications/nistpubs/800-38C/SP800-38C_updated-July20_2007.pdf
+ * RFC 3610 "Counter with CBC-MAC (CCM)"
+ *
+ * Related:
+ * RFC 5116 "An Interface and Algorithms for Authenticated Encryption"
+ *
+ * Definition of CCM*:
+ * IEEE 802.15.4 - IEEE Standard for Local and metropolitan area networks
+ * Integer representation is fixed most-significant-octet-first order and
+ * the representation of octets is most-significant-bit-first order. This is
+ * consistent with RFC 3610.
*/
/*
* Copyright (C) 2006-2018, Arm Limited (or its affiliates), All Rights Reserved
@@ -102,7 +114,6 @@ void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
/**
* \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 RFC-3610:
* Counter with CBC-MAC (CCM), use
@@ -112,15 +123,17 @@ void mbedtls_ccm_free( mbedtls_ccm_context *ctx );
* \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 iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13. The length L of the message length field is
+ * 15 - \p iv_len.
* \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:
+ * \param tag The buffer holding the authentication field.
+ * \param tag_len The length of the authentication field to generate in Bytes:
* 4, 6, 8, 10, 12, 14 or 16.
*
* \return \c 0 on success.
@@ -133,21 +146,64 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
unsigned char *tag, size_t tag_len );
/**
- * \brief This function performs a CCM authenticated decryption of a
- * buffer.
+ * \brief This function encrypts a buffer using CCM*.
*
- * \param ctx The CCM context to use for decryption.
+ * \note The tag is written to a separate buffer. To concatenate
+ * the \p tag with the \p output, as done in RFC-3610:
+ * Counter with CBC-MAC (CCM), use
+ * \p tag = \p output + \p length, and make sure that the
+ * output buffer is at least \p length + \p tag_len wide.
+ *
+ * \note When using this function in a variable tag length context,
+ * the tag length has to be encoded into the \p iv passed to
+ * this function.
+ *
+ * \param ctx The CCM context to use for encryption.
* \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 iv Initialization vector (nonce).
+ * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13. The length L of the message length field is
+ * 15 - \p iv_len.
* \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.
+ * \param tag The buffer holding the authentication field.
+ * \param tag_len The length of the authentication field 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_star_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 performs a CCM authenticated decryption of a
+ * buffer.
+ *
+ * \param ctx The CCM context to use for decryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv Initialization vector (nonce).
+ * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13. The length L of the message length field is
+ * 15 - \p iv_len.
+ * \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 authentication field.
+ * \param tag_len The length of the authentication field in Bytes.
* 4, 6, 8, 10, 12, 14 or 16.
*
* \return \c 0 on success. This indicates that the message is authentic.
@@ -160,6 +216,43 @@ int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
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.
+ *
+ * \note When using this function in a variable tag length context,
+ * the tag length has to be decoded from \p iv and passed to
+ * this function as \p tag_len. (\p tag needs to be adjusted
+ * accordingly.)
+ *
+ * \param ctx The CCM context to use for decryption.
+ * \param length The length of the input data in Bytes.
+ * \param iv Initialization vector (nonce).
+ * \param iv_len The length of the nonce in Bytes: 7, 8, 9, 10, 11, 12,
+ * or 13. The length L of the message length field is
+ * 15 - \p iv_len.
+ * \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 authentication field.
+ * \param tag_len The length of the authentication field 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 #MBEDTLS_ERR_CCM_AUTH_FAILED if the tag does not match.
+ * \return A cipher-specific error code on calculation failure.
+ */
+int mbedtls_ccm_star_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 defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C)
/**
diff --git a/library/ccm.c b/library/ccm.c
index cf6520935..804eaf80f 100644
--- a/library/ccm.c
+++ b/library/ccm.c
@@ -152,8 +152,10 @@ static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
* Check length requirements: SP800-38C A.1
* Additional requirement: a < 2^16 - 2^8 to simplify the code.
* 'length' checked later (when writing it to the first block)
+ *
+ * Also, loosen the requirements to enable support for CCM* (IEEE 802.15.4).
*/
- if( tag_len < 4 || tag_len > 16 || tag_len % 2 != 0 )
+ if( tag_len == 2 || tag_len > 16 || tag_len % 2 != 0 )
return( MBEDTLS_ERR_CCM_BAD_INPUT );
/* Also implies q is within bounds */
@@ -302,7 +304,7 @@ static int ccm_auth_crypt( mbedtls_ccm_context *ctx, int mode, size_t length,
/*
* Authenticated encryption
*/
-int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
+int mbedtls_ccm_star_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 +314,23 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length,
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_star_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_star_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 +361,18 @@ int mbedtls_ccm_auth_decrypt( mbedtls_ccm_context *ctx, size_t length,
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_star_auth_decrypt( ctx, length, iv, iv_len, add,
+ add_len, input, output, tag, 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 90ba42d83..cad40d59c 100644
--- a/tests/suites/test_suite_ccm.data
+++ b/tests/suites/test_suite_ccm.data
@@ -41,6 +41,39 @@ ccm_lengths:5:10:65281:8:MBEDTLS_ERR_CCM_BAD_INPUT
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_star_lengths:5:10:5:8:0
+
+CCM* fixed tag lengths #2 all OK - tag length 0
+ccm_star_lengths:5:10:5:0:0
+
+CCM* encrypt and tag #1
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_encrypt_and_tag:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"":"ACDE480000000001":"00000005":2:"08D0842143010000000048DEAC020500000055CF000051525354":"223BC1EC841AB553":0
+
+CCM* encrypt and tag #2
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_encrypt_and_tag:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"61626364":"ACDE480000000001":"00000005":4:"69DC842143020000000048DEAC010000000048DEAC0405000000":"D43E022B":0
+
+CCM* encrypt and tag #3
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_encrypt_and_tag:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"CE":"ACDE480000000001":"00000005":6:"2BDC842143020000000048DEACFFFF010000000048DEAC060500000001":"D84FDE529061F9C6F1":0
+
+CCM* auth decrypt tag #1
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_auth_decrypt:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"223BC1EC841AB553":"ACDE480000000001":"00000005":2:"08D0842143010000000048DEAC020500000055CF000051525354":"":0
+
+CCM* auth decrypt tag #2
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_auth_decrypt:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"D43E022B":"ACDE480000000001":"00000005":4:"69DC842143020000000048DEAC010000000048DEAC0405000000":"61626364":0
+
+CCM* auth decrypt tag #3
+depends_on:MBEDTLS_AES_C
+mbedtls_ccm_star_auth_decrypt:MBEDTLS_CIPHER_ID_AES:"C0C1C2C3C4C5C6C7C8C9CACBCCCDCECF":"D84FDE529061F9C6F1":"ACDE480000000001":"00000005":6:"2BDC842143020000000048DEACFFFF010000000048DEAC060500000001":"CE":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 2f5c77c2c..58c856985 100644
--- a/tests/suites/test_suite_ccm.function
+++ b/tests/suites/test_suite_ccm.function
@@ -74,6 +74,47 @@ exit:
}
/* END_CASE */
+/* BEGIN_CASE depends_on:MBEDTLS_AES_C */
+void ccm_star_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_star_encrypt_and_tag( &ctx, msg_len, iv, iv_len,
+ add, add_len, msg, out, tag, tag_len ) == res );
+
+ decrypt_ret = mbedtls_ccm_star_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,
@@ -187,3 +228,140 @@ exit:
mbedtls_ccm_free( &ctx );
}
/* END_CASE */
+
+/* BEGIN_CASE */
+void mbedtls_ccm_star_encrypt_and_tag( int cipher_id,
+ char *key_hex, char *msg_hex,
+ char *source_address_hex, char *frame_counter_hex,
+ int sec_level, char *add_hex,
+ char *result_hex, int output_ret )
+{
+ unsigned char key[32];
+ unsigned char msg[50];
+ unsigned char iv[13];
+ unsigned char add[32];
+ unsigned char result[50];
+ unsigned char source_address[8];
+ unsigned char frame_counter[4];
+ mbedtls_ccm_context ctx;
+ size_t i, key_len, msg_len, iv_len, add_len, result_len, source_address_len, frame_counter_len, tag_len;
+ int ret;
+
+ mbedtls_ccm_init( &ctx );
+
+ memset( key, 0x00, sizeof( key ) );
+ memset( msg, 0x00, sizeof( msg ) );
+ memset( iv, 0x00, sizeof( iv ) );
+ memset( add, 0x00, sizeof( add ) );
+ memset( result, 0x00, sizeof( result ) );
+ memset( source_address, 0x00, sizeof( source_address ) );
+ memset( frame_counter, 0x00, sizeof( frame_counter ) );
+
+ key_len = unhexify( key, key_hex );
+ msg_len = unhexify( msg, msg_hex );
+ add_len = unhexify( add, add_hex );
+ result_len = unhexify( result, result_hex );
+ source_address_len = unhexify( source_address, source_address_hex );
+ frame_counter_len = unhexify( frame_counter, frame_counter_hex );
+
+ if( sec_level % 4 == 0)
+ tag_len = 0;
+ else
+ tag_len = 1 << ( sec_level % 4 + 1);
+
+ for( i = 0; i < source_address_len; i++ )
+ iv[i] = source_address[i];
+
+ for( i = 0; i < frame_counter_len; i++ )
+ iv[source_address_len + i] = frame_counter[i];
+
+ iv[source_address_len + frame_counter_len] = sec_level;
+ iv_len = sizeof( iv );
+
+ TEST_ASSERT( mbedtls_ccm_setkey( &ctx, cipher_id, key, key_len * 8 ) == 0 );
+
+ ret = mbedtls_ccm_star_encrypt_and_tag( &ctx, msg_len, iv, iv_len,
+ add, add_len, msg, msg, msg + msg_len, tag_len );
+
+ TEST_ASSERT( ret == output_ret );
+
+ TEST_ASSERT( memcmp( msg, result, result_len ) == 0 );
+
+ /* Check we didn't write past the end */
+ TEST_ASSERT( msg[result_len] == 0 && msg[result_len + 1] == 0 );
+
+exit:
+ mbedtls_ccm_free( &ctx );
+}
+/* END_CASE */
+
+/* BEGIN_CASE */
+void mbedtls_ccm_star_auth_decrypt( int cipher_id,
+ char *key_hex, char *msg_hex,
+ char *source_address_hex, char *frame_counter_hex,
+ int sec_level, char *add_hex,
+ char *result_hex, int output_ret )
+{
+ unsigned char key[32];
+ unsigned char msg[50];
+ unsigned char iv[13];
+ unsigned char add[32];
+ unsigned char tag[16];
+ unsigned char result[50];
+ unsigned char source_address[8];
+ unsigned char frame_counter[4];
+ mbedtls_ccm_context ctx;
+ size_t i, key_len, msg_len, iv_len, add_len, tag_len, result_len, source_address_len, frame_counter_len;
+ int ret;
+
+ mbedtls_ccm_init( &ctx );
+
+ memset( key, 0x00, sizeof( key ) );
+ memset( msg, 0x00, sizeof( msg ) );
+ memset( iv, 0x00, sizeof( iv ) );
+ memset( add, 0x00, sizeof( add ) );
+ memset( result, 0x00, sizeof( result ) );
+ memset( source_address, 0x00, sizeof( source_address ) );
+ memset( frame_counter, 0x00, sizeof( frame_counter ) );
+ memset( tag, 0x00, sizeof( tag ) );
+
+ key_len = unhexify( key, key_hex );
+ msg_len = unhexify( msg, msg_hex );
+ add_len = unhexify( add, add_hex );
+ result_len = unhexify( result, result_hex );
+ source_address_len = unhexify( source_address, source_address_hex );
+ frame_counter_len = unhexify( frame_counter, frame_counter_hex );
+
+ if( sec_level % 4 == 0)
+ tag_len = 0;
+ else
+ tag_len = 1 << ( sec_level % 4 + 1);
+
+ for( i = 0; i < source_address_len; i++ )
+ iv[i] = source_address[i];
+
+ for( i = 0; i < frame_counter_len; i++ )
+ iv[source_address_len + i] = frame_counter[i];
+
+ iv[source_address_len + frame_counter_len] = sec_level;
+ iv_len = sizeof( iv );
+
+ msg_len -= tag_len;
+ memcpy( tag, msg + msg_len, tag_len );
+
+ TEST_ASSERT( mbedtls_ccm_setkey( &ctx, cipher_id, key, key_len * 8 ) == 0 );
+
+ ret = mbedtls_ccm_star_auth_decrypt( &ctx, msg_len, iv, iv_len,
+ add, add_len, msg, msg, msg + msg_len, tag_len );
+
+ TEST_ASSERT( ret == output_ret );
+
+ TEST_ASSERT( memcmp( msg, result, result_len ) == 0 );
+
+ /* Check we didn't write past the end (where the original tag is) */
+ TEST_ASSERT( memcmp( msg + msg_len, tag, tag_len ) == 0 );
+
+exit:
+ mbedtls_ccm_free( &ctx );
+}
+/* END_CASE */