1PEM_READ(3ossl) OpenSSL PEM_READ(3ossl)
2
6 PEM_write, PEM_write_bio, PEM_read, PEM_read_bio, PEM_do_header,
7 PEM_get_EVP_CIPHER_INFO - PEM encoding routines
8
10 #include <openssl/pem.h>
11 int PEM_write(FILE *fp, const char *name, const char *header,
13 const unsigned char *data, long len);
14 int PEM_write_bio(BIO *bp, const char *name, const char *header,
15 const unsigned char *data, long len);
16 int PEM_read(FILE *fp, char **name, char **header,
18 unsigned char **data, long *len);
19 int PEM_read_bio(BIO *bp, char **name, char **header,
20 unsigned char **data, long *len);
21 int PEM_get_EVP_CIPHER_INFO(char *header, EVP_CIPHER_INFO *cinfo);
23 int PEM_do_header(EVP_CIPHER_INFO *cinfo, unsigned char *data, long *len,
24 pem_password_cb *cb, void *u);
25
27 These functions read and write PEM-encoded objects, using the PEM type
28 name, any additional header information, and the raw data of length
29 len.
30 PEM is the term used for binary content encoding first defined in IETF
32 RFC 1421. The content is a series of base64-encoded lines, surrounded
33 by begin/end markers each on their own line. For example:
34 -----BEGIN PRIVATE KEY-----
36 MIICdg....
37 ... bhTQ==
38 -----END PRIVATE KEY-----
39 Optional header line(s) may appear after the begin line, and their
41 existence depends on the type of object being written or read.
42 PEM_write() writes to the file fp, while PEM_write_bio() writes to the
44 BIO bp. The name is the name to use in the marker, the header is the
45 header value or NULL, and data and len specify the data and its length.
46 The final data buffer is typically an ASN.1 object which can be decoded
48 with the d2i function appropriate to the type name; see d2i_X509(3) for
49 examples.
50 PEM_read() reads from the file fp, while PEM_read_bio() reads from the
52 BIO bp. Both skip any non-PEM data that precedes the start of the next
53 PEM object. When an object is successfully retrieved, the type name
54 from the "----BEGIN <type>-----" is returned via the name argument, any
55 encapsulation headers are returned in header and the base64-decoded
56 content and its length are returned via data and len respectively. The
57 name, header and data pointers are allocated via OPENSSL_malloc() and
58 should be freed by the caller via OPENSSL_free() when no longer needed.
59 PEM_get_EVP_CIPHER_INFO() can be used to determine the data returned by
61 PEM_read() or PEM_read_bio() is encrypted and to retrieve the
62 associated cipher and IV. The caller passes a pointer to structure of
63 type EVP_CIPHER_INFO via the cinfo argument and the header returned via
64 PEM_read() or PEM_read_bio(). If the call is successful 1 is returned
65 and the cipher and IV are stored at the address pointed to by cinfo.
66 When the header is malformed, or not supported or when the cipher is
67 unknown or some internal error happens 0 is returned. This function is
68 deprecated, see NOTES below.
69 PEM_do_header() can then be used to decrypt the data if the header
71 indicates encryption. The cinfo argument is a pointer to the structure
72 initialized by the previous call to PEM_get_EVP_CIPHER_INFO(). The
73 data and len arguments are those returned by the previous call to
74 PEM_read() or PEM_read_bio(). The cb and u arguments make it possible
75 to override the default password prompt function as described in
76 PEM_read_PrivateKey(3). On successful completion the data is decrypted
77 in place, and len is updated to indicate the plaintext length. This
78 function is deprecated, see NOTES below.
79 If the data is a priori known to not be encrypted, then neither
81 PEM_do_header() nor PEM_get_EVP_CIPHER_INFO() need be called.
82
84 PEM_read() and PEM_read_bio() return 1 on success and 0 on failure, the
85 latter includes the case when no more PEM objects remain in the input
86 file. To distinguish end of file from more serious errors the caller
87 must peek at the error stack and check for PEM_R_NO_START_LINE, which
88 indicates that no more PEM objects were found. See
89 ERR_peek_last_error(3), ERR_GET_REASON(3).
90 PEM_get_EVP_CIPHER_INFO() and PEM_do_header() return 1 on success, and
92 0 on failure. The data is likely meaningless if these functions fail.
93
95 The PEM_get_EVP_CIPHER_INFO() and PEM_do_header() functions are
96 deprecated. This is because the underlying PEM encryption format is
97 obsolete, and should be avoided. It uses an encryption format with an
98 OpenSSL-specific key-derivation function, which employs MD5 with an
99 iteration count of 1! Instead, private keys should be stored in PKCS#8
100 form, with a strong PKCS#5 v2.0 PBE. See PEM_write_PrivateKey(3) and
101 d2i_PKCS8PrivateKey_bio(3).
102 PEM_do_header() makes no assumption regarding the pass phrase received
104 from the password callback. It will simply be treated as a byte
105 sequence.
106
108 ERR_peek_last_error(3), ERR_GET_LIB(3), d2i_PKCS8PrivateKey_bio(3),
109 passphrase-encoding(7)
110
112 Copyright 1998-2020 The OpenSSL Project Authors. All Rights Reserved.
113 Licensed under the Apache License 2.0 (the "License"). You may not use
115 this file except in compliance with the License. You can obtain a copy
116 in the file LICENSE in the source distribution or at
117 <https://www.openssl.org/source/license.html>.
1183.1.1 2023-08-31 PEM_READ(3ossl)