xref: /onnv-gate/usr/src/common/openssl/doc/crypto/BIO_f_base64.pod (revision 2175:b0b2f052a486)
1*2175Sjp161948=pod
2*2175Sjp161948
3*2175Sjp161948=head1 NAME
4*2175Sjp161948
5*2175Sjp161948BIO_f_base64 - base64 BIO filter
6*2175Sjp161948
7*2175Sjp161948=head1 SYNOPSIS
8*2175Sjp161948
9*2175Sjp161948 #include <openssl/bio.h>
10*2175Sjp161948 #include <openssl/evp.h>
11*2175Sjp161948
12*2175Sjp161948 BIO_METHOD *	BIO_f_base64(void);
13*2175Sjp161948
14*2175Sjp161948=head1 DESCRIPTION
15*2175Sjp161948
16*2175Sjp161948BIO_f_base64() returns the base64 BIO method. This is a filter
17*2175Sjp161948BIO that base64 encodes any data written through it and decodes
18*2175Sjp161948any data read through it.
19*2175Sjp161948
20*2175Sjp161948Base64 BIOs do not support BIO_gets() or BIO_puts().
21*2175Sjp161948
22*2175Sjp161948BIO_flush() on a base64 BIO that is being written through is
23*2175Sjp161948used to signal that no more data is to be encoded: this is used
24*2175Sjp161948to flush the final block through the BIO.
25*2175Sjp161948
26*2175Sjp161948The flag BIO_FLAGS_BASE64_NO_NL can be set with BIO_set_flags()
27*2175Sjp161948to encode the data all on one line or expect the data to be all
28*2175Sjp161948on one line.
29*2175Sjp161948
30*2175Sjp161948=head1 NOTES
31*2175Sjp161948
32*2175Sjp161948Because of the format of base64 encoding the end of the encoded
33*2175Sjp161948block cannot always be reliably determined.
34*2175Sjp161948
35*2175Sjp161948=head1 RETURN VALUES
36*2175Sjp161948
37*2175Sjp161948BIO_f_base64() returns the base64 BIO method.
38*2175Sjp161948
39*2175Sjp161948=head1 EXAMPLES
40*2175Sjp161948
41*2175Sjp161948Base64 encode the string "Hello World\n" and write the result
42*2175Sjp161948to standard output:
43*2175Sjp161948
44*2175Sjp161948 BIO *bio, *b64;
45*2175Sjp161948 char message[] = "Hello World \n";
46*2175Sjp161948
47*2175Sjp161948 b64 = BIO_new(BIO_f_base64());
48*2175Sjp161948 bio = BIO_new_fp(stdout, BIO_NOCLOSE);
49*2175Sjp161948 bio = BIO_push(b64, bio);
50*2175Sjp161948 BIO_write(bio, message, strlen(message));
51*2175Sjp161948 BIO_flush(bio);
52*2175Sjp161948
53*2175Sjp161948 BIO_free_all(bio);
54*2175Sjp161948
55*2175Sjp161948Read Base64 encoded data from standard input and write the decoded
56*2175Sjp161948data to standard output:
57*2175Sjp161948
58*2175Sjp161948 BIO *bio, *b64, *bio_out;
59*2175Sjp161948 char inbuf[512];
60*2175Sjp161948 int inlen;
61*2175Sjp161948
62*2175Sjp161948 b64 = BIO_new(BIO_f_base64());
63*2175Sjp161948 bio = BIO_new_fp(stdin, BIO_NOCLOSE);
64*2175Sjp161948 bio_out = BIO_new_fp(stdout, BIO_NOCLOSE);
65*2175Sjp161948 bio = BIO_push(b64, bio);
66*2175Sjp161948 while((inlen = BIO_read(bio, inbuf, 512) > 0)
67*2175Sjp161948	BIO_write(bio_out, inbuf, inlen);
68*2175Sjp161948
69*2175Sjp161948 BIO_free_all(bio);
70*2175Sjp161948
71*2175Sjp161948=head1 BUGS
72*2175Sjp161948
73*2175Sjp161948The ambiguity of EOF in base64 encoded data can cause additional
74*2175Sjp161948data following the base64 encoded block to be misinterpreted.
75*2175Sjp161948
76*2175Sjp161948There should be some way of specifying a test that the BIO can perform
77*2175Sjp161948to reliably determine EOF (for example a MIME boundary).
78*2175Sjp161948
79*2175Sjp161948=head1 SEE ALSO
80*2175Sjp161948
81*2175Sjp161948TBA
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