From f60c815dc745fed23125cab302bf9702fbeee09c Mon Sep 17 00:00:00 2001 From: Janos Follath Date: Fri, 27 Apr 2018 14:45:49 +0100 Subject: [PATCH] CCM*: Add public API Interface for CCM* (described in IEEE Std 802.15.4.). --- include/mbedtls/ccm.h | 194 +++++++++++++++++++++++++++++++++++++++++- 1 file changed, 193 insertions(+), 1 deletion(-) diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h index 5a34f3a0a..7d117d9a9 100644 --- a/include/mbedtls/ccm.h +++ b/include/mbedtls/ccm.h @@ -60,6 +60,55 @@ typedef struct { } mbedtls_ccm_context; +/** + * \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 @@ -97,7 +146,6 @@ 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 @@ -127,6 +175,82 @@ int mbedtls_ccm_encrypt_and_tag( mbedtls_ccm_context *ctx, size_t length, const unsigned char *input, unsigned char *output, 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 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. + * + * \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 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. + * + * \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. @@ -155,6 +279,74 @@ 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 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 ); + #ifdef __cplusplus } #endif