pem.h

00001 /**
00002  * \file pem.h
00003  *
00004  * \brief Privacy Enhanced Mail (PEM) decoding
00005  */
00006 /*
00007  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
00008  *  SPDX-License-Identifier: Apache-2.0
00009  *
00010  *  Licensed under the Apache License, Version 2.0 (the "License"); you may
00011  *  not use this file except in compliance with the License.
00012  *  You may obtain a copy of the License at
00013  *
00014  *  http://www.apache.org/licenses/LICENSE-2.0
00015  *
00016  *  Unless required by applicable law or agreed to in writing, software
00017  *  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
00018  *  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
00019  *  See the License for the specific language governing permissions and
00020  *  limitations under the License.
00021  *
00022  *  This file is part of mbed TLS (https://tls.mbed.org)
00023  */
00024 #ifndef MBEDTLS_PEM_H
00025 #define MBEDTLS_PEM_H
00026 
00027 #include <stddef.h>
00028 
00029 /**
00030  * \name PEM Error codes
00031  * These error codes are returned in case of errors reading the
00032  * PEM data.
00033  * \{
00034  */
00035 #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT          -0x1080  /**< No PEM header or footer found. */
00036 #define MBEDTLS_ERR_PEM_INVALID_DATA                      -0x1100  /**< PEM string is not as expected. */
00037 #define MBEDTLS_ERR_PEM_ALLOC_FAILED                      -0x1180  /**< Failed to allocate memory. */
00038 #define MBEDTLS_ERR_PEM_INVALID_ENC_IV                    -0x1200  /**< RSA IV is not in hex-format. */
00039 #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG                   -0x1280  /**< Unsupported key encryption algorithm. */
00040 #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED                 -0x1300  /**< Private key password can't be empty. */
00041 #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH                 -0x1380  /**< Given private key password does not allow for correct decryption. */
00042 #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE               -0x1400  /**< Unavailable feature, e.g. hashing/encryption combination. */
00043 #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA                    -0x1480  /**< Bad input parameters to function. */
00044 /* \} name */
00045 
00046 #ifdef __cplusplus
00047 extern "C" {
00048 #endif
00049 
00050 #if defined(MBEDTLS_PEM_PARSE_C)
00051 /**
00052  * \brief       PEM context structure
00053  */
00054 typedef struct
00055 {
00056     unsigned char *buf ;     /*!< buffer for decoded data             */
00057     size_t buflen ;          /*!< length of the buffer                */
00058     unsigned char *info ;    /*!< buffer for extra header information */
00059 }
00060 mbedtls_pem_context;
00061 
00062 /**
00063  * \brief       PEM context setup
00064  *
00065  * \param ctx   context to be initialized
00066  */
00067 void mbedtls_pem_init( mbedtls_pem_context *ctx );
00068 
00069 /**
00070  * \brief       Read a buffer for PEM information and store the resulting
00071  *              data into the specified context buffers.
00072  *
00073  * \param ctx       context to use
00074  * \param header    header string to seek and expect
00075  * \param footer    footer string to seek and expect
00076  * \param data      source data to look in (must be nul-terminated)
00077  * \param pwd       password for decryption (can be NULL)
00078  * \param pwdlen    length of password
00079  * \param use_len   destination for total length used (set after header is
00080  *                  correctly read, so unless you get
00081  *                  MBEDTLS_ERR_PEM_BAD_INPUT_DATA or
00082  *                  MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT, use_len is
00083  *                  the length to skip)
00084  *
00085  * \note            Attempts to check password correctness by verifying if
00086  *                  the decrypted text starts with an ASN.1 sequence of
00087  *                  appropriate length
00088  *
00089  * \return          0 on success, or a specific PEM error code
00090  */
00091 int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer,
00092                      const unsigned char *data,
00093                      const unsigned char *pwd,
00094                      size_t pwdlen, size_t *use_len );
00095 
00096 /**
00097  * \brief       PEM context memory freeing
00098  *
00099  * \param ctx   context to be freed
00100  */
00101 void mbedtls_pem_free( mbedtls_pem_context *ctx );
00102 #endif /* MBEDTLS_PEM_PARSE_C */
00103 
00104 #if defined(MBEDTLS_PEM_WRITE_C)
00105 /**
00106  * \brief           Write a buffer of PEM information from a DER encoded
00107  *                  buffer.
00108  *
00109  * \param header    header string to write
00110  * \param footer    footer string to write
00111  * \param der_data  DER data to write
00112  * \param der_len   length of the DER data
00113  * \param buf       buffer to write to
00114  * \param buf_len   length of output buffer
00115  * \param olen      total length written / required (if buf_len is not enough)
00116  *
00117  * \return          0 on success, or a specific PEM or BASE64 error code. On
00118  *                  MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL olen is the required
00119  *                  size.
00120  */
00121 int mbedtls_pem_write_buffer( const char *header, const char *footer,
00122                       const unsigned char *der_data, size_t der_len,
00123                       unsigned char *buf, size_t buf_len, size_t *olen );
00124 #endif /* MBEDTLS_PEM_WRITE_C */
00125 
00126 #ifdef __cplusplus
00127 }
00128 #endif
00129 
00130 #endif /* pem.h */