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 /** Invalid input parameter(s). */ 45 #define MBEDTLS_ERR_POLY1305_BAD_INPUT_DATA -0x0057 46 47 /* MBEDTLS_ERR_POLY1305_FEATURE_UNAVAILABLE is deprecated and should not be 48 * used. */ 49 /** Feature not available. For example, s part of the API is not implemented. */ 50 #define MBEDTLS_ERR_POLY1305_FEATURE_UNAVAILABLE -0x0059 51 52 /* MBEDTLS_ERR_POLY1305_HW_ACCEL_FAILED is deprecated and should not be used. 53 */ 54 /** Poly1305 hardware accelerator failed. */ 55 #define MBEDTLS_ERR_POLY1305_HW_ACCEL_FAILED -0x005B 56 57 #ifdef __cplusplus 58 extern "C" { 59 #endif 60 61 #if !defined(MBEDTLS_POLY1305_ALT) 62 63 typedef struct mbedtls_poly1305_context 64 { 65 uint32_t r[4]; /** The value for 'r' (low 128 bits of the key). */ 66 uint32_t s[4]; /** The value for 's' (high 128 bits of the key). */ 67 uint32_t acc[5]; /** The accumulator number. */ 68 uint8_t queue[16]; /** The current partial block of data. */ 69 size_t queue_len; /** The number of bytes stored in 'queue'. */ 70 } 71 mbedtls_poly1305_context; 72 73 #else /* MBEDTLS_POLY1305_ALT */ 74 #include "poly1305_alt.h" 75 #endif /* MBEDTLS_POLY1305_ALT */ 76 77 /** 78 * \brief This function initializes the specified Poly1305 context. 79 * 80 * It must be the first API called before using 81 * the context. 82 * 83 * It is usually followed by a call to 84 * \c mbedtls_poly1305_starts(), then one or more calls to 85 * \c mbedtls_poly1305_update(), then one call to 86 * \c mbedtls_poly1305_finish(), then finally 87 * \c mbedtls_poly1305_free(). 88 * 89 * \param ctx The Poly1305 context to initialize. This must 90 * not be \c NULL. 91 */ 92 void mbedtls_poly1305_init( mbedtls_poly1305_context *ctx ); 93 94 /** 95 * \brief This function releases and clears the specified 96 * Poly1305 context. 97 * 98 * \param ctx The Poly1305 context to clear. This may be \c NULL, in which 99 * case this function is a no-op. If it is not \c NULL, it must 100 * point to an initialized Poly1305 context. 101 */ 102 void mbedtls_poly1305_free( mbedtls_poly1305_context *ctx ); 103 104 /** 105 * \brief This function sets the one-time authentication key. 106 * 107 * \warning The key must be unique and unpredictable for each 108 * invocation of Poly1305. 109 * 110 * \param ctx The Poly1305 context to which the key should be bound. 111 * This must be initialized. 112 * \param key The buffer containing the \c 32 Byte (\c 256 Bit) key. 113 * 114 * \return \c 0 on success. 115 * \return A negative error code on failure. 116 */ 117 int mbedtls_poly1305_starts( mbedtls_poly1305_context *ctx, 118 const unsigned char key[32] ); 119 120 /** 121 * \brief This functions feeds an input buffer into an ongoing 122 * Poly1305 computation. 123 * 124 * It is called between \c mbedtls_cipher_poly1305_starts() and 125 * \c mbedtls_cipher_poly1305_finish(). 126 * It can be called repeatedly to process a stream of data. 127 * 128 * \param ctx The Poly1305 context to use for the Poly1305 operation. 129 * This must be initialized and bound to a key. 130 * \param ilen The length of the input data in Bytes. 131 * Any value is accepted. 132 * \param input The buffer holding the input data. 133 * This pointer can be \c NULL if `ilen == 0`. 134 * 135 * \return \c 0 on success. 136 * \return A negative error code on failure. 137 */ 138 int mbedtls_poly1305_update( mbedtls_poly1305_context *ctx, 139 const unsigned char *input, 140 size_t ilen ); 141 142 /** 143 * \brief This function generates the Poly1305 Message 144 * Authentication Code (MAC). 145 * 146 * \param ctx The Poly1305 context to use for the Poly1305 operation. 147 * This must be initialized and bound to a key. 148 * \param mac The buffer to where the MAC is written. This must 149 * be a writable buffer of length \c 16 Bytes. 150 * 151 * \return \c 0 on success. 152 * \return A negative error code on failure. 153 */ 154 int mbedtls_poly1305_finish( mbedtls_poly1305_context *ctx, 155 unsigned char mac[16] ); 156 157 /** 158 * \brief This function calculates the Poly1305 MAC of the input 159 * buffer with the provided key. 160 * 161 * \warning The key must be unique and unpredictable for each 162 * invocation of Poly1305. 163 * 164 * \param key The buffer containing the \c 32 Byte (\c 256 Bit) key. 165 * \param ilen The length of the input data in Bytes. 166 * Any value is accepted. 167 * \param input The buffer holding the input data. 168 * This pointer can be \c NULL if `ilen == 0`. 169 * \param mac The buffer to where the MAC is written. This must be 170 * a writable buffer of length \c 16 Bytes. 171 * 172 * \return \c 0 on success. 173 * \return A negative error code on failure. 174 */ 175 int mbedtls_poly1305_mac( const unsigned char key[32], 176 const unsigned char *input, 177 size_t ilen, 178 unsigned char mac[16] ); 179 180 #if defined(MBEDTLS_SELF_TEST) 181 /** 182 * \brief The Poly1305 checkup routine. 183 * 184 * \return \c 0 on success. 185 * \return \c 1 on failure. 186 */ 187 int mbedtls_poly1305_self_test( int verbose ); 188 #endif /* MBEDTLS_SELF_TEST */ 189 190 #ifdef __cplusplus 191 } 192 #endif 193 194 #endif /* MBEDTLS_POLY1305_H */ 195