xref: /freebsd/crypto/openssl/doc/man3/PEM_bytes_read_bio.pod (revision cddbc3b40812213ff00041f79174cac0be360a2a)
1=pod
2
3=head1 NAME
4
5PEM_bytes_read_bio, PEM_bytes_read_bio_secmem - read a PEM-encoded data structure from a BIO
6
7=head1 SYNOPSIS
8
9 #include <openssl/pem.h>
10
11 int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
12                        const char *name, BIO *bp, pem_password_cb *cb,
13                        void *u);
14 int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
15                               const char *name, BIO *bp, pem_password_cb *cb,
16                               void *u);
17
18=head1 DESCRIPTION
19
20PEM_bytes_read_bio() reads PEM-formatted (RFC 1421) data from the BIO
21I<bp> for the data type given in I<name> (RSA PRIVATE KEY, CERTIFICATE,
22etc.).  If multiple PEM-encoded data structures are present in the same
23stream, PEM_bytes_read_bio() will skip non-matching data types and
24continue reading.  Non-PEM data present in the stream may cause an
25error.
26
27The PEM header may indicate that the following data is encrypted; if so,
28the data will be decrypted, waiting on user input to supply a passphrase
29if needed.  The password callback I<cb> and rock I<u> are used to obtain
30the decryption passphrase, if applicable.
31
32Some data types have compatibility aliases, such as a file containing
33X509 CERTIFICATE matching a request for the deprecated type CERTIFICATE.
34The actual type indicated by the file is returned in I<*pnm> if I<pnm> is
35non-NULL.  The caller must free the storage pointed to by I<*pnm>.
36
37The returned data is the DER-encoded form of the requested type, in
38I<*pdata> with length I<*plen>.  The caller must free the storage pointed
39to by I<*pdata>.
40
41PEM_bytes_read_bio_secmem() is similar to PEM_bytes_read_bio(), but uses
42memory from the secure heap for its temporary buffers and the storage
43returned in I<*pdata> and I<*pnm>.  Accordingly, the caller must use
44OPENSSL_secure_free() to free that storage.
45
46=head1 NOTES
47
48PEM_bytes_read_bio_secmem() only enforces that the secure heap is used for
49storage allocated within the PEM processing stack.  The BIO stack from
50which input is read may also use temporary buffers, which are not necessarily
51allocated from the secure heap.  In cases where it is desirable to ensure
52that the contents of the PEM file only appears in memory from the secure heap,
53care is needed in generating the BIO passed as I<bp>.  In particular, the
54use of BIO_s_file() indicates the use of the operating system stdio
55functionality, which includes buffering as a feature; BIO_s_fd() is likely
56to be more appropriate in such cases.
57
58These functions make no assumption regarding the pass phrase received from the
59password callback.
60It will simply be treated as a byte sequence.
61
62=head1 RETURN VALUES
63
64PEM_bytes_read_bio() and PEM_bytes_read_bio_secmem() return 1 for success or
650 for failure.
66
67=head1 SEE ALSO
68
69L<PEM(3)>,
70L<PEM_read_bio_ex(3)>,
71L<passphrase-encoding(7)>
72
73=head1 HISTORY
74
75PEM_bytes_read_bio_secmem() was introduced in OpenSSL 1.1.1
76
77=head1 COPYRIGHT
78
79Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
80
81Licensed under the OpenSSL license (the "License").  You may not use
82this file except in compliance with the License.  You can obtain a copy
83in the file LICENSE in the source distribution or at
84L<https://www.openssl.org/source/license.html>.
85
86=cut
87