BIO_f_base64(3)

BIO_f_base64(3)              OpenSSL              BIO_f_base64(3)

NAME

     BIO_f_base64 - base64 BIO filter

SYNOPSIS

      #include <openssl/bio.h>
      #include <openssl/evp.h>

      BIO_METHOD *   BIO_f_base64(void);

DESCRIPTION

     BIO_f_base64() returns the base64 BIO method. This is a
     filter BIO that base64 encodes any data written through it
     and decodes any data read through it.

     Base64 BIOs do not support BIO_gets() or BIO_puts().

     BIO_flush() on a base64 BIO that is being written through is
     used to signal that no more data is to be encoded: this is
     used to flush the final block through the BIO.

     The flag BIO_FLAGS_BASE64_NO_NL can be set with
     BIO_set_flags() to encode the data all on one line or expect
     the data to be all on one line.

NOTES

     Because of the format of base64 encoding the end of the
     encoded block cannot always be reliably determined.

RETURN VALUES

     BIO_f_base64() returns the base64 BIO method.

EXAMPLES

     Base64 encode the string "Hello World\n" and write the
     result to standard output:

      BIO *bio, *b64;
      char message[] = "Hello World \n";

      b64 = BIO_new(BIO_f_base64());
      bio = BIO_new_fp(stdout, BIO_NOCLOSE);
      BIO_push(b64, bio);
      BIO_write(b64, message, strlen(message));
      BIO_flush(b64);

      BIO_free_all(b64);

     Read Base64 encoded data from standard input and write the
     decoded data to standard output:

      BIO *bio, *b64, *bio_out;
      char inbuf[512];
      int inlen;

1.0.2t               Last change: 2019-09-10                    1

BIO_f_base64(3)              OpenSSL              BIO_f_base64(3)

      b64 = BIO_new(BIO_f_base64());
      bio = BIO_new_fp(stdin, BIO_NOCLOSE);
      bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
      BIO_push(b64, bio);
      while((inlen = BIO_read(b64, inbuf, 512)) > 0)
             BIO_write(bio_out, inbuf, inlen);

      BIO_flush(bio_out);
      BIO_free_all(b64);

BUGS

     The ambiguity of EOF in base64 encoded data can cause
     additional data following the base64 encoded block to be
     misinterpreted.

     There should be some way of specifying a test that the BIO
     can perform to reliably determine EOF (for example a MIME
     boundary).

SEE ALSO

     TBA

1.0.2t               Last change: 2019-09-10                    2