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 #include "mbedtls/private_access.h" 25 26 #include "mbedtls/build_info.h" 27 28 #include <stddef.h> 29 30 /** 31 * \name PEM Error codes 32 * These error codes are returned in case of errors reading the 33 * PEM data. 34 * \{ 35 */ 36 /** No PEM header or footer found. */ 37 #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT -0x1080 38 /** PEM string is not as expected. */ 39 #define MBEDTLS_ERR_PEM_INVALID_DATA -0x1100 40 /** Failed to allocate memory. */ 41 #define MBEDTLS_ERR_PEM_ALLOC_FAILED -0x1180 42 /** RSA IV is not in hex-format. */ 43 #define MBEDTLS_ERR_PEM_INVALID_ENC_IV -0x1200 44 /** Unsupported key encryption algorithm. */ 45 #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG -0x1280 46 /** Private key password can't be empty. */ 47 #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED -0x1300 48 /** Given private key password does not allow for correct decryption. */ 49 #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH -0x1380 50 /** Unavailable feature, e.g. hashing/encryption combination. */ 51 #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE -0x1400 52 /** Bad input parameters to function. */ 53 #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA -0x1480 54 /* \} name */ 55 56 #ifdef __cplusplus 57 extern "C" { 58 #endif 59 60 #if defined(MBEDTLS_PEM_PARSE_C) 61 /** 62 * \brief PEM context structure 63 */ 64 typedef struct mbedtls_pem_context 65 { 66 unsigned char *MBEDTLS_PRIVATE(buf); /*!< buffer for decoded data */ 67 size_t MBEDTLS_PRIVATE(buflen); /*!< length of the buffer */ 68 unsigned char *MBEDTLS_PRIVATE(info); /*!< buffer for extra header information */ 69 } 70 mbedtls_pem_context; 71 72 /** 73 * \brief PEM context setup 74 * 75 * \param ctx context to be initialized 76 */ 77 void mbedtls_pem_init( mbedtls_pem_context *ctx ); 78 79 /** 80 * \brief Read a buffer for PEM information and store the resulting 81 * data into the specified context buffers. 82 * 83 * \param ctx context to use 84 * \param header header string to seek and expect 85 * \param footer footer string to seek and expect 86 * \param data source data to look in (must be nul-terminated) 87 * \param pwd password for decryption (can be NULL) 88 * \param pwdlen length of password 89 * \param use_len destination for total length used (set after header is 90 * correctly read, so unless you get 91 * MBEDTLS_ERR_PEM_BAD_INPUT_DATA or 92 * MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT, use_len is 93 * the length to skip) 94 * 95 * \note Attempts to check password correctness by verifying if 96 * the decrypted text starts with an ASN.1 sequence of 97 * appropriate length 98 * 99 * \return 0 on success, or a specific PEM error code 100 */ 101 int mbedtls_pem_read_buffer( mbedtls_pem_context *ctx, const char *header, const char *footer, 102 const unsigned char *data, 103 const unsigned char *pwd, 104 size_t pwdlen, size_t *use_len ); 105 106 /** 107 * \brief PEM context memory freeing 108 * 109 * \param ctx context to be freed 110 */ 111 void mbedtls_pem_free( mbedtls_pem_context *ctx ); 112 #endif /* MBEDTLS_PEM_PARSE_C */ 113 114 #if defined(MBEDTLS_PEM_WRITE_C) 115 /** 116 * \brief Write a buffer of PEM information from a DER encoded 117 * buffer. 118 * 119 * \param header The header string to write. 120 * \param footer The footer string to write. 121 * \param der_data The DER data to encode. 122 * \param der_len The length of the DER data \p der_data in Bytes. 123 * \param buf The buffer to write to. 124 * \param buf_len The length of the output buffer \p buf in Bytes. 125 * \param olen The address at which to store the total length written 126 * or required (if \p buf_len is not enough). 127 * 128 * \note You may pass \c NULL for \p buf and \c 0 for \p buf_len 129 * to request the length of the resulting PEM buffer in 130 * `*olen`. 131 * 132 * \note This function may be called with overlapping \p der_data 133 * and \p buf buffers. 134 * 135 * \return \c 0 on success. 136 * \return #MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL if \p buf isn't large 137 * enough to hold the PEM buffer. In this case, `*olen` holds 138 * the required minimum size of \p buf. 139 * \return Another PEM or BASE64 error code on other kinds of failure. 140 */ 141 int mbedtls_pem_write_buffer( const char *header, const char *footer, 142 const unsigned char *der_data, size_t der_len, 143 unsigned char *buf, size_t buf_len, size_t *olen ); 144 #endif /* MBEDTLS_PEM_WRITE_C */ 145 146 #ifdef __cplusplus 147 } 148 #endif 149 150 #endif /* pem.h */ 151