pem.h

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