Updated: 2022/Sep/29

Please read Privacy Policy. It's for your privacy.

PEM_bytes_read_bio(3)               OpenSSL              PEM_bytes_read_bio(3)

       PEM_bytes_read_bio, PEM_bytes_read_bio_secmem - read a PEM-encoded data
       structure from a BIO

       libcrypto, -lcrypto

        #include <openssl/pem.h>

        int PEM_bytes_read_bio(unsigned char **pdata, long *plen, char **pnm,
                               const char *name, BIO *bp, pem_password_cb *cb,
                               void *u);
        int PEM_bytes_read_bio_secmem(unsigned char **pdata, long *plen, char **pnm,
                                      const char *name, BIO *bp, pem_password_cb *cb,
                                      void *u);

       PEM_bytes_read_bio() reads PEM-formatted (IETF RFC 1421 and IETF RFC
       7468) data from the BIO bp for the data type given in name (RSA PRIVATE
       KEY, CERTIFICATE, etc.).  If multiple PEM-encoded data structures are
       present in the same stream, PEM_bytes_read_bio() will skip non-matching
       data types and continue reading.  Non-PEM data present in the stream
       may cause an error.

       The PEM header may indicate that the following data is encrypted; if
       so, the data will be decrypted, waiting on user input to supply a
       passphrase if needed.  The password callback cb and rock u are used to
       obtain the decryption passphrase, if applicable.

       Some data types have compatibility aliases, such as a file containing
       X509 CERTIFICATE matching a request for the deprecated type
       CERTIFICATE. The actual type indicated by the file is returned in *pnm
       if pnm is non-NULL.  The caller must free the storage pointed to by

       The returned data is the DER-encoded form of the requested type, in
       *pdata with length *plen.  The caller must free the storage pointed to
       by *pdata.

       PEM_bytes_read_bio_secmem() is similar to PEM_bytes_read_bio(), but
       uses memory from the secure heap for its temporary buffers and the
       storage returned in *pdata and *pnm.  Accordingly, the caller must use
       OPENSSL_secure_free() to free that storage.

       PEM_bytes_read_bio_secmem() only enforces that the secure heap is used
       for storage allocated within the PEM processing stack.  The BIO stack
       from which input is read may also use temporary buffers, which are not
       necessarily allocated from the secure heap.  In cases where it is
       desirable to ensure that the contents of the PEM file only appears in
       memory from the secure heap, care is needed in generating the BIO
       passed as bp.  In particular, the use of BIO_s_file() indicates the use
       of the operating system stdio functionality, which includes buffering
       as a feature; BIO_s_fd() is likely to be more appropriate in such

       These functions make no assumption regarding the pass phrase received
       from the password callback.  It will simply be treated as a byte

       PEM_bytes_read_bio() and PEM_bytes_read_bio_secmem() return 1 for
       success or 0 for failure.

       PEM_read_bio_ex(3), passphrase-encoding(7)

       PEM_bytes_read_bio_secmem() was introduced in OpenSSL 1.1.1

       Copyright 2017-2018 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the OpenSSL license (the "License").  You may not use
       this file except in compliance with the License.  You can obtain a copy
       in the file LICENSE in the source distribution or at

1.1.1i                            2020-03-22             PEM_bytes_read_bio(3)