DESCRIPTIONBIO_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.
NOTESBecause of the format of base64 encoding the end of the encoded
block cannot always be reliably determined. RETURN VALUESBIO_f_base64() returns the base64 BIO method. EXAMPLESBase64 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 = BIO_push(b64, bio);
BIO_write(bio, message, strlen(message));
BIO_flush(bio);
BIO_free_all(bio);
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;
b64 = BIO_new(BIO_f_base64());
bio = BIO_new_fp(stdin, BIO_NOCLOSE);
bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
bio = BIO_push(b64, bio);
while((inlen = BIO_read(bio, inbuf, 512) > 0)
BIO_write(bio_out, inbuf, inlen);
BIO_free_all(bio);
RestrictionsThe 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).
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