1 =pod
2 
3 =head1 NAME
4 
5 PEM_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 
20 PEM_bytes_read_bio() reads PEM-formatted (IETF RFC 1421 and IETF RFC 7468)
21 data from the BIO
22 I<bp> for the data type given in I<name> (RSA PRIVATE KEY, CERTIFICATE,
23 etc.).  If multiple PEM-encoded data structures are present in the same
24 stream, PEM_bytes_read_bio() will skip non-matching data types and
25 continue reading.  Non-PEM data present in the stream may cause an
26 error.
27 
28 The PEM header may indicate that the following data is encrypted; if so,
29 the data will be decrypted, waiting on user input to supply a passphrase
30 if needed.  The password callback I<cb> and rock I<u> are used to obtain
31 the decryption passphrase, if applicable.
32 
33 Some data types have compatibility aliases, such as a file containing
34 X509 CERTIFICATE matching a request for the deprecated type CERTIFICATE.
35 The actual type indicated by the file is returned in I<*pnm> if I<pnm> is
36 non-NULL.  The caller must free the storage pointed to by I<*pnm>.
37 
38 The returned data is the DER-encoded form of the requested type, in
39 I<*pdata> with length I<*plen>.  The caller must free the storage pointed
40 to by I<*pdata>.
41 
42 PEM_bytes_read_bio_secmem() is similar to PEM_bytes_read_bio(), but uses
43 memory from the secure heap for its temporary buffers and the storage
44 returned in I<*pdata> and I<*pnm>.  Accordingly, the caller must use
45 OPENSSL_secure_free() to free that storage.
46 
47 =head1 NOTES
48 
49 PEM_bytes_read_bio_secmem() only enforces that the secure heap is used for
50 storage allocated within the PEM processing stack.  The BIO stack from
51 which input is read may also use temporary buffers, which are not necessarily
52 allocated from the secure heap.  In cases where it is desirable to ensure
53 that the contents of the PEM file only appears in memory from the secure heap,
54 care is needed in generating the BIO passed as I<bp>.  In particular, the
55 use of BIO_s_file() indicates the use of the operating system stdio
56 functionality, which includes buffering as a feature; BIO_s_fd() is likely
57 to be more appropriate in such cases.
58 
59 These functions make no assumption regarding the pass phrase received from the
60 password callback.
61 It will simply be treated as a byte sequence.
62 
63 =head1 RETURN VALUES
64 
65 PEM_bytes_read_bio() and PEM_bytes_read_bio_secmem() return 1 for success or
66 0 for failure.
67 
68 =head1 SEE ALSO
69 
70 L<PEM_read_bio_ex(3)>,
71 L<passphrase-encoding(7)>
72 
73 =head1 HISTORY
74 
75 PEM_bytes_read_bio_secmem() was introduced in OpenSSL 1.1.1
76 
77 =head1 COPYRIGHT
78 
79 Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.
80 
81 Licensed under the Apache License 2.0 (the "License").  You may not use
82 this file except in compliance with the License.  You can obtain a copy
83 in the file LICENSE in the source distribution or at
84 L<https://www.openssl.org/source/license.html>.
85 
86 =cut
87