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Diffstat (limited to 'include/mbedtls/ccm.h')
| -rw-r--r-- | include/mbedtls/ccm.h | 518 |
1 files changed, 518 insertions, 0 deletions
diff --git a/include/mbedtls/ccm.h b/include/mbedtls/ccm.h new file mode 100644 index 0000000..a98111b --- /dev/null +++ b/include/mbedtls/ccm.h @@ -0,0 +1,518 @@ +/** + * \file ccm.h + * + * \brief This file provides an API for the CCM authenticated encryption + * mode for block ciphers. + * + * CCM combines Counter mode encryption with CBC-MAC authentication + * for 128-bit block ciphers. + * + * Input to CCM includes the following elements: + * <ul><li>Payload - data that is both authenticated and encrypted.</li> + * <li>Associated data (Adata) - data that is authenticated but not + * encrypted, For example, a header.</li> + * <li>Nonce - A unique value that is assigned to the payload and the + * associated data.</li></ul> + * + * 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 The Mbed TLS Contributors + * SPDX-License-Identifier: Apache-2.0 OR GPL-2.0-or-later + */ + +#ifndef MBEDTLS_CCM_H +#define MBEDTLS_CCM_H +#include "mbedtls/private_access.h" + +#include "mbedtls/build_info.h" + +#include "mbedtls/cipher.h" + +#define MBEDTLS_CCM_DECRYPT 0 +#define MBEDTLS_CCM_ENCRYPT 1 +#define MBEDTLS_CCM_STAR_DECRYPT 2 +#define MBEDTLS_CCM_STAR_ENCRYPT 3 + +/** Bad input parameters to the function. */ +#define MBEDTLS_ERR_CCM_BAD_INPUT -0x000D +/** Authenticated decryption failed. */ +#define MBEDTLS_ERR_CCM_AUTH_FAILED -0x000F + +#ifdef __cplusplus +extern "C" { +#endif + +#if !defined(MBEDTLS_CCM_ALT) +// Regular implementation +// + +/** + * \brief The CCM context-type definition. The CCM context is passed + * to the APIs called. + */ +typedef struct mbedtls_ccm_context { + unsigned char MBEDTLS_PRIVATE(y)[16]; /*!< The Y working buffer */ + unsigned char MBEDTLS_PRIVATE(ctr)[16]; /*!< The counter buffer */ + size_t MBEDTLS_PRIVATE(plaintext_len); /*!< Total plaintext length */ + size_t MBEDTLS_PRIVATE(add_len); /*!< Total authentication data length */ + size_t MBEDTLS_PRIVATE(tag_len); /*!< Total tag length */ + size_t MBEDTLS_PRIVATE(processed); /*!< Track how many bytes of input data + were processed (chunked input). + Used independently for both auth data + and plaintext/ciphertext. + This variable is set to zero after + auth data input is finished. */ + unsigned int MBEDTLS_PRIVATE(q); /*!< The Q working value */ + unsigned int MBEDTLS_PRIVATE(mode); /*!< The operation to perform: + #MBEDTLS_CCM_ENCRYPT or + #MBEDTLS_CCM_DECRYPT or + #MBEDTLS_CCM_STAR_ENCRYPT or + #MBEDTLS_CCM_STAR_DECRYPT. */ + mbedtls_cipher_context_t MBEDTLS_PRIVATE(cipher_ctx); /*!< The cipher context used. */ + int MBEDTLS_PRIVATE(state); /*!< Working value holding context's + state. Used for chunked data input */ +} +mbedtls_ccm_context; + +#else /* MBEDTLS_CCM_ALT */ +#include "ccm_alt.h" +#endif /* MBEDTLS_CCM_ALT */ + +/** + * \brief This function initializes the specified CCM context, + * to make references valid, and prepare the context + * for mbedtls_ccm_setkey() or mbedtls_ccm_free(). + * + * \param ctx The CCM context to initialize. This must not be \c NULL. + */ +void mbedtls_ccm_init(mbedtls_ccm_context *ctx); + +/** + * \brief This function initializes the CCM context set in the + * \p ctx parameter and sets the encryption key. + * + * \param ctx The CCM context to initialize. This must be an initialized + * context. + * \param cipher The 128-bit block cipher to use. + * \param key The encryption key. This must not be \c NULL. + * \param keybits The key size in bits. This must be acceptable by the cipher. + * + * \return \c 0 on success. + * \return A CCM or cipher-specific error code on failure. + */ +int mbedtls_ccm_setkey(mbedtls_ccm_context *ctx, + mbedtls_cipher_id_t cipher, + const unsigned char *key, + unsigned int keybits); + +/** + * \brief This function releases and clears the specified CCM context + * and underlying cipher sub-context. + * + * \param ctx The CCM context to clear. If this is \c NULL, the function + * has no effect. Otherwise, this must be initialized. + */ +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 <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. This must be + * initialized and bound to a key. + * \param length The length of the input data in Bytes. + * \param iv The initialization vector (nonce). This must be a readable + * buffer of at least \p iv_len Bytes. + * \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 ad The additional data field. If \p ad_len is greater than + * zero, \p ad must be a readable buffer of at least that + * length. + * \param ad_len The length of additional data in Bytes. + * This must be less than `2^16 - 2^8`. + * \param input The buffer holding the input data. If \p length is greater + * than zero, \p input must be a readable buffer of at least + * that length. + * \param output The buffer holding the output data. If \p length is greater + * than zero, \p output must be a writable buffer of at least + * that length. + * \param tag The buffer holding the authentication field. This must be a + * writable buffer of at least \p tag_len Bytes. + * \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. + * \return A CCM or cipher-specific error code on failure. + */ +int mbedtls_ccm_encrypt_and_tag(mbedtls_ccm_context *ctx, size_t length, + const unsigned char *iv, size_t iv_len, + const unsigned char *ad, size_t ad_len, + const unsigned char *input, unsigned char *output, + unsigned char *tag, size_t tag_len); + +/** + * \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 + * \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. This must be + * initialized and bound to a key. + * \param length The length of the input data in Bytes. + * For tag length = 0, input length is ignored. + * \param iv The initialization vector (nonce). This must be a readable + * buffer of at least \p iv_len Bytes. + * \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 ad The additional data field. This must be a readable buffer of + * at least \p ad_len Bytes. + * \param ad_len The length of additional data in Bytes. + * This must be less than 2^16 - 2^8. + * \param input The buffer holding the input data. If \p length is greater + * than zero, \p input must be a readable buffer of at least + * that length. + * \param output The buffer holding the output data. If \p length is greater + * than zero, \p output must be a writable buffer of at least + * that length. + * \param tag The buffer holding the authentication field. This must be a + * writable buffer of at least \p tag_len Bytes. + * \param tag_len The length of the authentication field to generate in Bytes: + * 0, 4, 6, 8, 10, 12, 14 or 16. + * + * \warning Passing \c 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 *ad, size_t ad_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. This must be + * initialized and bound to a key. + * \param length The length of the input data in Bytes. + * \param iv The initialization vector (nonce). This must be a readable + * buffer of at least \p iv_len Bytes. + * \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 ad The additional data field. This must be a readable buffer + * of at least that \p ad_len Bytes.. + * \param ad_len The length of additional data in Bytes. + * This must be less than 2^16 - 2^8. + * \param input The buffer holding the input data. If \p length is greater + * than zero, \p input must be a readable buffer of at least + * that length. + * \param output The buffer holding the output data. If \p length is greater + * than zero, \p output must be a writable buffer of at least + * that length. + * \param tag The buffer holding the authentication field. This must be a + * readable buffer of at least \p tag_len Bytes. + * \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. 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_auth_decrypt(mbedtls_ccm_context *ctx, size_t length, + const unsigned char *iv, size_t iv_len, + const unsigned char *ad, size_t ad_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. + * + * \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. This must be + * initialized and bound to a key. + * \param length The length of the input data in Bytes. + * For tag length = 0, input length is ignored. + * \param iv The initialization vector (nonce). This must be a readable + * buffer of at least \p iv_len Bytes. + * \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 ad The additional data field. This must be a readable buffer of + * at least that \p ad_len Bytes. + * \param ad_len The length of additional data in Bytes. + * This must be less than 2^16 - 2^8. + * \param input The buffer holding the input data. If \p length is greater + * than zero, \p input must be a readable buffer of at least + * that length. + * \param output The buffer holding the output data. If \p length is greater + * than zero, \p output must be a writable buffer of at least + * that length. + * \param tag The buffer holding the authentication field. This must be a + * readable buffer of at least \p tag_len Bytes. + * \param tag_len The length of the authentication field in Bytes. + * 0, 4, 6, 8, 10, 12, 14 or 16. + * + * \warning Passing \c 0 as \p tag_len means that the message is nos + * 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 *ad, size_t ad_len, + const unsigned char *input, unsigned char *output, + const unsigned char *tag, size_t tag_len); + +/** + * \brief This function starts a CCM encryption or decryption + * operation. + * + * This function and mbedtls_ccm_set_lengths() must be called + * before calling mbedtls_ccm_update_ad() or + * mbedtls_ccm_update(). This function can be called before + * or after mbedtls_ccm_set_lengths(). + * + * \note This function is not implemented in Mbed TLS yet. + * + * \param ctx The CCM context. This must be initialized. + * \param mode The operation to perform: #MBEDTLS_CCM_ENCRYPT or + * #MBEDTLS_CCM_DECRYPT or #MBEDTLS_CCM_STAR_ENCRYPT or + * #MBEDTLS_CCM_STAR_DECRYPT. + * \param iv The initialization vector. This must be a readable buffer + * of at least \p iv_len Bytes. + * \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. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure: + * \p ctx is in an invalid state, + * \p mode is invalid, + * \p iv_len is invalid (lower than \c 7 or greater than + * \c 13). + */ +int mbedtls_ccm_starts(mbedtls_ccm_context *ctx, + int mode, + const unsigned char *iv, + size_t iv_len); + +/** + * \brief This function declares the lengths of the message + * and additional data for a CCM encryption or decryption + * operation. + * + * This function and mbedtls_ccm_starts() must be called + * before calling mbedtls_ccm_update_ad() or + * mbedtls_ccm_update(). This function can be called before + * or after mbedtls_ccm_starts(). + * + * \note This function is not implemented in Mbed TLS yet. + * + * \param ctx The CCM context. This must be initialized. + * \param total_ad_len The total length of additional data in bytes. + * This must be less than `2^16 - 2^8`. + * \param plaintext_len The length in bytes of the plaintext to encrypt or + * result of the decryption (thus not encompassing the + * additional data that are not encrypted). + * \param tag_len The length of the tag to generate in Bytes: + * 4, 6, 8, 10, 12, 14 or 16. + * For CCM*, zero is also valid. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure: + * \p ctx is in an invalid state, + * \p total_ad_len is greater than \c 0xFF00. + */ +int mbedtls_ccm_set_lengths(mbedtls_ccm_context *ctx, + size_t total_ad_len, + size_t plaintext_len, + size_t tag_len); + +/** + * \brief This function feeds an input buffer as associated data + * (authenticated but not encrypted data) in a CCM + * encryption or decryption operation. + * + * You may call this function zero, one or more times + * to pass successive parts of the additional data. The + * lengths \p ad_len of the data parts should eventually add + * up exactly to the total length of additional data + * \c total_ad_len passed to mbedtls_ccm_set_lengths(). You + * may not call this function after calling + * mbedtls_ccm_update(). + * + * \note This function is not implemented in Mbed TLS yet. + * + * \param ctx The CCM context. This must have been started with + * mbedtls_ccm_starts(), the lengths of the message and + * additional data must have been declared with + * mbedtls_ccm_set_lengths() and this must not have yet + * received any input with mbedtls_ccm_update(). + * \param ad The buffer holding the additional data, or \c NULL + * if \p ad_len is \c 0. + * \param ad_len The length of the additional data. If \c 0, + * \p ad may be \c NULL. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure: + * \p ctx is in an invalid state, + * total input length too long. + */ +int mbedtls_ccm_update_ad(mbedtls_ccm_context *ctx, + const unsigned char *ad, + size_t ad_len); + +/** + * \brief This function feeds an input buffer into an ongoing CCM + * encryption or decryption operation. + * + * You may call this function zero, one or more times + * to pass successive parts of the input: the plaintext to + * encrypt, or the ciphertext (not including the tag) to + * decrypt. After the last part of the input, call + * mbedtls_ccm_finish(). The lengths \p input_len of the + * data parts should eventually add up exactly to the + * plaintext length \c plaintext_len passed to + * mbedtls_ccm_set_lengths(). + * + * This function may produce output in one of the following + * ways: + * - Immediate output: the output length is always equal + * to the input length. + * - Buffered output: except for the last part of input data, + * the output consists of a whole number of 16-byte blocks. + * If the total input length so far (not including + * associated data) is 16 \* *B* + *A* with *A* < 16 then + * the total output length is 16 \* *B*. + * For the last part of input data, the output length is + * equal to the input length plus the number of bytes (*A*) + * buffered in the previous call to the function (if any). + * The function uses the plaintext length + * \c plaintext_len passed to mbedtls_ccm_set_lengths() + * to detect the last part of input data. + * + * In particular: + * - It is always correct to call this function with + * \p output_size >= \p input_len + 15. + * - If \p input_len is a multiple of 16 for all the calls + * to this function during an operation (not necessary for + * the last one) then it is correct to use \p output_size + * =\p input_len. + * + * \note This function is not implemented in Mbed TLS yet. + * + * \param ctx The CCM context. This must have been started with + * mbedtls_ccm_starts() and the lengths of the message and + * additional data must have been declared with + * mbedtls_ccm_set_lengths(). + * \param input The buffer holding the input data. If \p input_len + * is greater than zero, this must be a readable buffer + * of at least \p input_len bytes. + * \param input_len The length of the input data in bytes. + * \param output The buffer for the output data. If \p output_size + * is greater than zero, this must be a writable buffer of + * at least \p output_size bytes. + * \param output_size The size of the output buffer in bytes. + * See the function description regarding the output size. + * \param output_len On success, \p *output_len contains the actual + * length of the output written in \p output. + * On failure, the content of \p *output_len is + * unspecified. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure: + * \p ctx is in an invalid state, + * total input length too long, + * or \p output_size too small. + */ +int mbedtls_ccm_update(mbedtls_ccm_context *ctx, + const unsigned char *input, size_t input_len, + unsigned char *output, size_t output_size, + size_t *output_len); + +/** + * \brief This function finishes the CCM operation and generates + * the authentication tag. + * + * It wraps up the CCM stream, and generates the + * tag. The tag can have a maximum length of 16 Bytes. + * + * \note This function is not implemented in Mbed TLS yet. + * + * \param ctx The CCM context. This must have been started with + * mbedtls_ccm_starts() and the lengths of the message and + * additional data must have been declared with + * mbedtls_ccm_set_lengths(). + * \param tag The buffer for holding the tag. If \p tag_len is greater + * than zero, this must be a writable buffer of at least \p + * tag_len Bytes. + * \param tag_len The length of the tag. Must match the tag length passed to + * mbedtls_ccm_set_lengths() function. + * + * \return \c 0 on success. + * \return #MBEDTLS_ERR_CCM_BAD_INPUT on failure: + * \p ctx is in an invalid state, + * invalid value of \p tag_len, + * the total amount of additional data passed to + * mbedtls_ccm_update_ad() was lower than the total length of + * additional data \c total_ad_len passed to + * mbedtls_ccm_set_lengths(), + * the total amount of input data passed to + * mbedtls_ccm_update() was lower than the plaintext length + * \c plaintext_len passed to mbedtls_ccm_set_lengths(). + */ +int mbedtls_ccm_finish(mbedtls_ccm_context *ctx, + unsigned char *tag, size_t tag_len); + +#if defined(MBEDTLS_SELF_TEST) && defined(MBEDTLS_AES_C) +/** + * \brief The CCM checkup routine. + * + * \return \c 0 on success. + * \return \c 1 on failure. + */ +int mbedtls_ccm_self_test(int verbose); +#endif /* MBEDTLS_SELF_TEST && MBEDTLS_AES_C */ + +#ifdef __cplusplus +} +#endif + +#endif /* MBEDTLS_CCM_H */ |