1 /**
2  * \file pem.h
3  *
4  * \brief Privacy Enhanced Mail (PEM) decoding
5  */
6 /*
7  *  Copyright (C) 2006-2015, ARM Limited, All Rights Reserved
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  *  This file is part of mbed TLS (https://tls.mbed.org)
23  */
24 #ifndef MBEDTLS_PEM_H
25 #define MBEDTLS_PEM_H
26 
27 #include <stddef.h>
28 
29 /**
30  * \name PEM Error codes
31  * These error codes are returned in case of errors reading the
32  * PEM data.
33  * \{
34  */
35 #define MBEDTLS_ERR_PEM_NO_HEADER_FOOTER_PRESENT          -0x1080  /**< No PEM header or footer found. */
36 #define MBEDTLS_ERR_PEM_INVALID_DATA                      -0x1100  /**< PEM string is not as expected. */
37 #define MBEDTLS_ERR_PEM_ALLOC_FAILED                      -0x1180  /**< Failed to allocate memory. */
38 #define MBEDTLS_ERR_PEM_INVALID_ENC_IV                    -0x1200  /**< RSA IV is not in hex-format. */
39 #define MBEDTLS_ERR_PEM_UNKNOWN_ENC_ALG                   -0x1280  /**< Unsupported key encryption algorithm. */
40 #define MBEDTLS_ERR_PEM_PASSWORD_REQUIRED                 -0x1300  /**< Private key password can't be empty. */
41 #define MBEDTLS_ERR_PEM_PASSWORD_MISMATCH                 -0x1380  /**< Given private key password does not allow for correct decryption. */
42 #define MBEDTLS_ERR_PEM_FEATURE_UNAVAILABLE               -0x1400  /**< Unavailable feature, e.g. hashing/encryption combination. */
43 #define MBEDTLS_ERR_PEM_BAD_INPUT_DATA                    -0x1480  /**< Bad input parameters to function. */
44 /* \} name */
45 
46 #ifdef __cplusplus
47 extern "C" {
48 #endif
49 
50 #if defined(MBEDTLS_PEM_PARSE_C)
51 /**
52  * \brief       PEM context structure
53  */
54 typedef struct mbedtls_pem_context
55 {
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    header string to write
110  * \param footer    footer string to write
111  * \param der_data  DER data to write
112  * \param der_len   length of the DER data
113  * \param buf       buffer to write to
114  * \param buf_len   length of output buffer
115  * \param olen      total length written / required (if buf_len is not enough)
116  *
117  * \return          0 on success, or a specific PEM or BASE64 error code. On
118  *                  MBEDTLS_ERR_BASE64_BUFFER_TOO_SMALL olen is the required
119  *                  size.
120  */
121 int mbedtls_pem_write_buffer( const char *header, const char *footer,
122                       const unsigned char *der_data, size_t der_len,
123                       unsigned char *buf, size_t buf_len, size_t *olen );
124 #endif /* MBEDTLS_PEM_WRITE_C */
125 
126 #ifdef __cplusplus
127 }
128 #endif
129 
130 #endif /* pem.h */
131