1 /** 2 * \file poly1305.h 3 * 4 * \brief This file contains Poly1305 definitions and functions. 5 * 6 * Poly1305 is a one-time message authenticator that can be used to 7 * authenticate messages. Poly1305-AES was created by Daniel 8 * Bernstein https://cr.yp.to/mac/poly1305-20050329.pdf The generic 9 * Poly1305 algorithm (not tied to AES) was also standardized in RFC 10 * 7539. 11 * 12 * \author Daniel King <damaki.gh@gmail.com> 13 */ 14 15 /* 16 * Copyright The Mbed TLS Contributors 17 * SPDX-License-Identifier: Apache-2.0 18 * 19 * Licensed under the Apache License, Version 2.0 (the "License"); you may 20 * not use this file except in compliance with the License. 21 * You may obtain a copy of the License at 22 * 23 * http://www.apache.org/licenses/LICENSE-2.0 24 * 25 * Unless required by applicable law or agreed to in writing, software 26 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT 27 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 28 * See the License for the specific language governing permissions and 29 * limitations under the License. 30 */ 31 32 #ifndef MBEDTLS_POLY1305_H 33 #define MBEDTLS_POLY1305_H 34 35 #if !defined(MBEDTLS_CONFIG_FILE) 36 #include "mbedtls/config.h" 37 #else 38 #include MBEDTLS_CONFIG_FILE 39 #endif 40 41 #include <stdint.h> 42 #include <stddef.h> 43 44 #define MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA -0x0057 /**< Invalid input parameter(s). */ 45 46 /* MBEDTLS_ERR_POLY1305_FEATURE_UNAVAILABLE is deprecated and should not be 47 * used. */ 48 #define MBEDTLS_ERR_POLY1305_FEATURE_UNAVAILABLE -0x0059 /**< Feature not available. For example, s part of the API is not implemented. */ 49 50 /* MBEDTLS_ERR_POLY1305_HW_ACCEL_FAILED is deprecated and should not be used. 51 */ 52 #define MBEDTLS_ERR_POLY1305_HW_ACCEL_FAILED -0x005B /**< Poly1305 hardware accelerator failed. */ 53 54 #ifdef __cplusplus 55 extern "C" { 56 #endif 57 58 #if !defined(MBEDTLS_POLY1305_ALT) 59 60 typedef struct mbedtls_poly1305_context 61 { 62 uint32_t r[4]; /** The value for 'r' (low 128 bits of the key). */ 63 uint32_t s[4]; /** The value for 's' (high 128 bits of the key). */ 64 uint32_t acc[5]; /** The accumulator number. */ 65 uint8_t queue[16]; /** The current partial block of data. */ 66 size_t queue_len; /** The number of bytes stored in 'queue'. */ 67 } 68 mbedtls_poly1305_context; 69 70 #else /* MBEDTLS_POLY1305_ALT */ 71 #include "poly1305_alt.h" 72 #endif /* MBEDTLS_POLY1305_ALT */ 73 74 /** 75 * \brief This function initializes the specified Poly1305 context. 76 * 77 * It must be the first API called before using 78 * the context. 79 * 80 * It is usually followed by a call to 81 * \c mbedtls_poly1305_starts(), then one or more calls to 82 * \c mbedtls_poly1305_update(), then one call to 83 * \c mbedtls_poly1305_finish(), then finally 84 * \c mbedtls_poly1305_free(). 85 * 86 * \param ctx The Poly1305 context to initialize. This must 87 * not be \c NULL. 88 */ 89 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx ); 90 91 /** 92 * \brief This function releases and clears the specified 93 * Poly1305 context. 94 * 95 * \param ctx The Poly1305 context to clear. This may be \c NULL, in which 96 * case this function is a no-op. If it is not \c NULL, it must 97 * point to an initialized Poly1305 context. 98 */ 99 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx ); 100 101 /** 102 * \brief This function sets the one-time authentication key. 103 * 104 * \warning The key must be unique and unpredictable for each 105 * invocation of Poly1305. 106 * 107 * \param ctx The Poly1305 context to which the key should be bound. 108 * This must be initialized. 109 * \param key The buffer containing the \c 32 Byte (\c 256 Bit) key. 110 * 111 * \return \c 0 on success. 112 * \return A negative error code on failure. 113 */ 114 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx, 115 const unsigned char key[32] ); 116 117 /** 118 * \brief This functions feeds an input buffer into an ongoing 119 * Poly1305 computation. 120 * 121 * It is called between \c mbedtls_cipher_poly1305_starts() and 122 * \c mbedtls_cipher_poly1305_finish(). 123 * It can be called repeatedly to process a stream of data. 124 * 125 * \param ctx The Poly1305 context to use for the Poly1305 operation. 126 * This must be initialized and bound to a key. 127 * \param ilen The length of the input data in Bytes. 128 * Any value is accepted. 129 * \param input The buffer holding the input data. 130 * This pointer can be \c NULL if `ilen == 0`. 131 * 132 * \return \c 0 on success. 133 * \return A negative error code on failure. 134 */ 135 int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx, 136 const unsigned char *input, 137 size_t ilen ); 138 139 /** 140 * \brief This function generates the Poly1305 Message 141 * Authentication Code (MAC). 142 * 143 * \param ctx The Poly1305 context to use for the Poly1305 operation. 144 * This must be initialized and bound to a key. 145 * \param mac The buffer to where the MAC is written. This must 146 * be a writable buffer of length \c 16 Bytes. 147 * 148 * \return \c 0 on success. 149 * \return A negative error code on failure. 150 */ 151 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx, 152 unsigned char mac[16] ); 153 154 /** 155 * \brief This function calculates the Poly1305 MAC of the input 156 * buffer with the provided key. 157 * 158 * \warning The key must be unique and unpredictable for each 159 * invocation of Poly1305. 160 * 161 * \param key The buffer containing the \c 32 Byte (\c 256 Bit) key. 162 * \param ilen The length of the input data in Bytes. 163 * Any value is accepted. 164 * \param input The buffer holding the input data. 165 * This pointer can be \c NULL if `ilen == 0`. 166 * \param mac The buffer to where the MAC is written. This must be 167 * a writable buffer of length \c 16 Bytes. 168 * 169 * \return \c 0 on success. 170 * \return A negative error code on failure. 171 */ 172 int mbedtls_poly1305_mac( const unsigned char key[32], 173 const unsigned char *input, 174 size_t ilen, 175 unsigned char mac[16] ); 176 177 #if defined(MBEDTLS_SELF_TEST) 178 /** 179 * \brief The Poly1305 checkup routine. 180 * 181 * \return \c 0 on success. 182 * \return \c 1 on failure. 183 */ 184 int mbedtls_poly1305_self_test( int verbose ); 185 #endif /* MBEDTLS_SELF_TEST */ 186 187 #ifdef __cplusplus 188 } 189 #endif 190 191 #endif /* MBEDTLS_POLY1305_H */ 192