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 OR GPL-2.0-or-later 9 */ 10 #ifndef MBEDTLS_PEM_H 11 #define MBEDTLS_PEM_H 12 13 #if !defined(MBEDTLS_CONFIG_FILE) 14 #include "mbedtls/config.h" 15 #else 16 #include MBEDTLS_CONFIG_FILE 17 #endif 18 19 #include <stddef.h> 20 21 /** 22 * \name PEM Error codes 23 * These error codes are returned in case of errors reading the 24 * PEM data. 25 * \{ 26 */ 27 /** No PEM header or footer found. */ 28 #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT -0x1080 29 /** PEM string is not as expected. */ 30 #define MBEDTLS_ERR_PEM_INVALID_DATA -0x1100 31 /** Failed to allocate memory. */ 32 #define MBEDTLS_ERR_PEM_ALLOC_FAILED -0x1180 33 /** RSA IV is not in hex-format. */ 34 #define MBEDTLS_ERR_PEM_INVALID_ENC_IV -0x1200 35 /** Unsupported key encryption algorithm. */ 36 #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG -0x1280 37 /** Private key password can't be empty. */ 38 #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED -0x1300 39 /** Given private key password does not allow for correct decryption. */ 40 #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH -0x1380 41 /** Unavailable feature, e.g. hashing/encryption combination. */ 42 #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE -0x1400 43 /** Bad input parameters to function. */ 44 #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA -0x1480 45 /** \} name PEM Error codes */ 46 47 #ifdef __cplusplus 48 extern "C" { 49 #endif 50 51 #if defined(MBEDTLS_PEM_PARSE_C) 52 /** 53 * \brief PEM context structure 54 */ 55 typedef struct mbedtls_pem_context { 56 unsigned char *buf; /*!< buffer for decoded data */ 57 size_t buflen; /*!< length of the buffer */ 58 unsigned char *info; /*!< buffer for extra header information */ 59 } 60 mbedtls_pem_context; 61 62 /** 63 * \brief PEM context setup 64 * 65 * \param ctx context to be initialized 66 */ 67 void mbedtls_pem_init(mbedtls_pem_context *ctx); 68 69 /** 70 * \brief Read a buffer for PEM information and store the resulting 71 * data into the specified context buffers. 72 * 73 * \param ctx context to use 74 * \param header header string to seek and expect 75 * \param footer footer string to seek and expect 76 * \param data source data to look in (must be nul-terminated) 77 * \param pwd password for decryption (can be NULL) 78 * \param pwdlen length of password 79 * \param use_len destination for total length used (set after header is 80 * correctly read, so unless you get 81 * MBEDTLS_ERR_PEM_BAD_INPUT_DATA or 82 * MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT, use_len is 83 * the length to skip) 84 * 85 * \note Attempts to check password correctness by verifying if 86 * the decrypted text starts with an ASN.1 sequence of 87 * appropriate length 88 * 89 * \return 0 on success, or a specific PEM error code 90 */ 91 int mbedtls_pem_read_buffer(mbedtls_pem_context *ctx, const char *header, const char *footer, 92 const unsigned char *data, 93 const unsigned char *pwd, 94 size_t pwdlen, size_t *use_len); 95 96 /** 97 * \brief PEM context memory freeing 98 * 99 * \param ctx context to be freed 100 */ 101 void mbedtls_pem_free(mbedtls_pem_context *ctx); 102 #endif /* MBEDTLS_PEM_PARSE_C */ 103 104 #if defined(MBEDTLS_PEM_WRITE_C) 105 /** 106 * \brief Write a buffer of PEM information from a DER encoded 107 * buffer. 108 * 109 * \param header The header string to write. 110 * \param footer The footer string to write. 111 * \param der_data The DER data to encode. 112 * \param der_len The length of the DER data \p der_data in Bytes. 113 * \param buf The buffer to write to. 114 * \param buf_len The length of the output buffer \p buf in Bytes. 115 * \param olen The address at which to store the total length written 116 * or required (if \p buf_len is not enough). 117 * 118 * \note You may pass \c NULL for \p buf and \c 0 for \p buf_len 119 * to request the length of the resulting PEM buffer in 120 * `*olen`. 121 * 122 * \note This function may be called with overlapping \p der_data 123 * and \p buf buffers. 124 * 125 * \return \c 0 on success. 126 * \return #MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL if \p buf isn't large 127 * enough to hold the PEM buffer. In this case, `*olen` holds 128 * the required minimum size of \p buf. 129 * \return Another PEM or BASE64 error code on other kinds of failure. 130 */ 131 int mbedtls_pem_write_buffer(const char *header, const char *footer, 132 const unsigned char *der_data, size_t der_len, 133 unsigned char *buf, size_t buf_len, size_t *olen); 134 #endif /* MBEDTLS_PEM_WRITE_C */ 135 136 #ifdef __cplusplus 137 } 138 #endif 139 140 #endif /* pem.h */ 141