text: /****************************************************************************
   *
   * Copyright 2017 Samsung Electronics All Rights Reserved.
   *
   * Licensed under the Apache License, Version 2.0 (the "License");
   * you may not use this file except in compliance with the License.
   * You may obtain a copy of the License at
   *
   * http://www.apache.org/licenses/LICENSE-2.0
   *
   * Unless required by applicable law or agreed to in writing,
   * software distributed under the License is distributed on an
   * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
   * either express or implied. See the License for the specific
   * language governing permissions and limitations under the License.
   *
   ****************************************************************************/
  /**
   * \file pem.h
   *
   * \brief Privacy Enhanced Mail (PEM) decoding
   *
   *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
   *  SPDX-License-Identifier: Apache-2.0
   *
   *  Licensed under the Apache License, Version 2.0 (the "License"); you may
   *  not use this file except in compliance with the License.
   *  You may obtain a copy of the License at
   *
   *  http://www.apache.org/licenses/LICENSE-2.0
   *
   *  Unless required by applicable law or agreed to in writing, software
   *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
   *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
   *  See the License for the specific language governing permissions and
   *  limitations under the License.
   *
   *  This file is part of mbed TLS (https://tls.mbed.org)
   */
  #ifndef MBEDTLS_PEM_H
  #define MBEDTLS_PEM_H
  
  #include <stddef.h>
  
  /**
   * \name PEM Error codes
   * These error codes are returned in case of errors reading the
   * PEM data.
   * \{
   */
  #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT          -0x1080  /**< No PEM header or footer found. */
  #define MBEDTLS_ERR_PEM_INVALID_DATA                      -0x1100  /**< PEM string is not as expected. */
  #define MBEDTLS_ERR_PEM_ALLOC_FAILED                      -0x1180  /**< Failed to allocate memory. */
  #define MBEDTLS_ERR_PEM_INVALID_ENC_IV                    -0x1200  /**< RSA IV is not in hex-format. */
  #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG                   -0x1280  /**< Unsupported key encryption algorithm. */
  #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED                 -0x1300  /**< Private key password can't be empty. */
  #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH                 -0x1380  /**< Given private key password does not allow for correct decryption. */
  #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE               -0x1400  /**< Unavailable feature, e.g. hashing/encryption combination. */
  #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA                    -0x1480  /**< Bad input parameters to function. */
  /* \} name */
  
  #ifdef __cplusplus
  extern "C" {
  #endif
  
  #if defined(MBEDTLS_PEM_PARSE_C)
  /**
   * \brief       PEM context structure
   */
  typedef struct
  {
      unsigned char *buf;     /*!< buffer for decoded data             */
      size_t buflen;          /*!< length of the buffer                */
      unsigned char *info;    /*!< buffer for extra header information */
  }
  mbedtls_pem_context;
  
  /**
   * \brief       PEM context setup
   *
   * \param ctx   context to be initialized
   */
  void mbedtls_pem_init( mbedtls_pem_context *ctx );
  
  /**
   * \brief       Read a buffer for PEM information and store the resulting
   *              data into the specified context buffers.
   *
   * \param ctx       context to use
   * \param header    header string to seek and expect
   * \param footer    footer string to seek and expect
   * \param data      source data to look in (must be nul-terminated)
   * \param pwd       password for decryption (can be NULL)
   * \param pwdlen    length of password
   * \param use_len   destination for total length used (set after header is
   *                  correctly read, so unless you get
   *                  MBEDTLS_ERR_PEM_BAD_INPUT_DATA or
   *                  MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT, use_len is
   *                  the length to skip)
   *
   * \note            Attempts to check password correctness by verifying if
   *                  the decrypted text starts with an ASN.1 sequence of
   *                  appropriate length
   *
   * \return          0 on success, or a specific PEM error code
   */
  int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer,
                       const unsigned char *data,
                       const unsigned char *pwd,
                       size_t pwdlen, size_t *use_len );
  
  /**
   * \brief       PEM context memory freeing
   *
   * \param ctx   context to be freed
   */
  void mbedtls_pem_free( mbedtls_pem_context *ctx );
  #endif /* MBEDTLS_PEM_PARSE_C */
  
  #if defined(MBEDTLS_PEM_WRITE_C)
  /**
   * \brief           Write a buffer of PEM information from a DER encoded
   *                  buffer.
   *
   * \param header    header string to write
   * \param footer    footer string to write
   * \param der_data  DER data to write
   * \param der_len   length of the DER data
   * \param buf       buffer to write to
   * \param buf_len   length of output buffer
   * \param olen      total length written / required (if buf_len is not enough)
   *
   * \return          0 on success, or a specific PEM or BASE64 error code. On
   *                  MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL olen is the required
   *                  size.
   */
  int mbedtls_pem_write_buffer( const char *header, const char *footer,
                        const unsigned char *der_data, size_t der_len,
                        unsigned char *buf, size_t buf_len, size_t *olen );
  #endif /* MBEDTLS_PEM_WRITE_C */
  
  #ifdef __cplusplus
  }
  #endif
  
  #endif /* pem.h */
  