common/mbedtls/pem.h

   1 /**
   2  * \file pem.h
   3  *
   4  * \brief Privacy Enhanced Mail (PEM) decoding
   5  */
   6 /*
   7  *  Copyright The Mbed TLS Contributors
   8  *  SPDX-License-Identifier: Apache-2.0
   9  *
  10  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
  11  *  not use this file except in compliance with the License.
  12  *  You may obtain a copy of the License at
  13  *
  14  *  http://www.apache.org/licenses/LICENSE-2.0
  15  *
  16  *  Unless required by applicable law or agreed to in writing, software
  17  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  18  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  19  *  See the License for the specific language governing permissions and
  20  *  limitations under the License.
  21  */
  22 #ifndef MBEDTLS_PEM_H
  23 #define MBEDTLS_PEM_H
  24
  25 #if !defined(MBEDTLS_CONFIG_FILE)
  26 #include "mbedtls/config.h"
  27 #else
  28 #include MBEDTLS_CONFIG_FILE
  29 #endif
  30
  31 #include <stddef.h>
  32
  33 /**
  34  * \name PEM Error codes
  35  * These error codes are returned in case of errors reading the
  36  * PEM data.
  37  * \{
  38  */
  39 #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT          -0x1080  /**< No PEM header or footer found. */
  40 #define MBEDTLS_ERR_PEM_INVALID_DATA                      -0x1100  /**< PEM string is not as expected. */
  41 #define MBEDTLS_ERR_PEM_ALLOC_FAILED                      -0x1180  /**< Failed to allocate memory. */
  42 #define MBEDTLS_ERR_PEM_INVALID_ENC_IV                    -0x1200  /**< RSA IV is not in hex-format. */
  43 #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG                   -0x1280  /**< Unsupported key encryption algorithm. */
  44 #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED                 -0x1300  /**< Private key password can't be empty. */
  45 #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH                 -0x1380  /**< Given private key password does not allow for correct decryption. */
  46 #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE               -0x1400  /**< Unavailable feature, e.g. hashing/encryption combination. */
  47 #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA                    -0x1480  /**< Bad input parameters to function. */
  48 /* \} name */
  49
  50 #ifdef __cplusplus
  51 extern "C" {
  52 #endif
  53
  54 #if defined(MBEDTLS_PEM_PARSE_C)
  55 /**
  56  * \brief       PEM context structure
  57  */
  58 typedef struct mbedtls_pem_context {
  59     unsigned char *buf;     /*!< buffer for decoded data             */
  60     size_t buflen;          /*!< length of the buffer                */
  61     unsigned char *info;    /*!< buffer for extra header information */
  62 }
  63 mbedtls_pem_context;
  64
  65 /**
  66  * \brief       PEM context setup
  67  *
  68  * \param ctx   context to be initialized
  69  */
  70 void mbedtls_pem_init(mbedtls_pem_context *ctx);
  71
  72 /**
  73  * \brief       Read a buffer for PEM information and store the resulting
  74  *              data into the specified context buffers.
  75  *
  76  * \param ctx       context to use
  77  * \param header    header string to seek and expect
  78  * \param footer    footer string to seek and expect
  79  * \param data      source data to look in (must be nul-terminated)
  80  * \param pwd       password for decryption (can be NULL)
  81  * \param pwdlen    length of password
  82  * \param use_len   destination for total length used (set after header is
  83  *                  correctly read, so unless you get
  84  *                  MBEDTLS_ERR_PEM_BAD_INPUT_DATA or
  85  *                  MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT, use_len is
  86  *                  the length to skip)
  87  *
  88  * \note            Attempts to check password correctness by verifying if
  89  *                  the decrypted text starts with an ASN.1 sequence of
  90  *                  appropriate length
  91  *
  92  * \return          0 on success, or a specific PEM error code
  93  */
  94 int mbedtls_pem_read_buffer(mbedtls_pem_context *ctx, const char *header, const char *footer,
  95                             const unsigned char *data,
  96                             const unsigned char *pwd,
  97                             size_t pwdlen, size_t *use_len);
  98
  99 /**
 100  * \brief       PEM context memory freeing
 101  *
 102  * \param ctx   context to be freed
 103  */
 104 void mbedtls_pem_free(mbedtls_pem_context *ctx);
 105 #endif /* MBEDTLS_PEM_PARSE_C */
 106
 107 #if defined(MBEDTLS_PEM_WRITE_C)
 108 /**
 109  * \brief           Write a buffer of PEM information from a DER encoded
 110  *                  buffer.
 111  *
 112  * \param header    The header string to write.
 113  * \param footer    The footer string to write.
 114  * \param der_data  The DER data to encode.
 115  * \param der_len   The length of the DER data \p der_data in Bytes.
 116  * \param buf       The buffer to write to.
 117  * \param buf_len   The length of the output buffer \p buf in Bytes.
 118  * \param olen      The address at which to store the total length written
 119  *                  or required (if \p buf_len is not enough).
 120  *
 121  * \note            You may pass \c NULL for \p buf and \c 0 for \p buf_len
 122  *                  to request the length of the resulting PEM buffer in
 123  *                  `*olen`.
 124  *
 125  * \note            This function may be called with overlapping \p der_data
 126  *                  and \p buf buffers.
 127  *
 128  * \return          \c 0 on success.
 129  * \return          #MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL if \p buf isn't large
 130  *                  enough to hold the PEM buffer. In  this case, `*olen` holds
 131  *                  the required minimum size of \p buf.
 132  * \return          Another PEM or BASE64 error code on other kinds of failure.
 133  */
 134 int mbedtls_pem_write_buffer(const char *header, const char *footer,
 135                              const unsigned char *der_data, size_t der_len,
 136                              unsigned char *buf, size_t buf_len, size_t *olen);
 137 #endif /* MBEDTLS_PEM_WRITE_C */
 138
 139 #ifdef __cplusplus
 140 }
 141 #endif
 142
 143 #endif /* pem.h */