1=pod
2
3=head1 NAME
4
5crypto - OpenSSL cryptographic library
6
7=head1 SYNOPSIS
8
9=head1 DESCRIPTION
10
11The OpenSSL B<crypto> library implements a wide range of cryptographic
12algorithms used in various Internet standards. The services provided
13by this library are used by the OpenSSL implementations of SSL, TLS
14and S/MIME, and they have also been used to implement SSH, OpenPGP, and
15other cryptographic standards.
16
17=head1 OVERVIEW
18
19B<libcrypto> consists of a number of sub-libraries that implement the
20individual algorithms.
21
22The functionality includes symmetric encryption, public key
23cryptography and key agreement, certificate handling, cryptographic
24hash functions and a cryptographic pseudo-random number generator.
25
26=over 4
27
28=item SYMMETRIC CIPHERS
29
30L<blowfish(3)|blowfish(3)>, L<cast(3)|cast(3)>, L<des(3)|des(3)>,
31L<idea(3)|idea(3)>, L<rc2(3)|rc2(3)>, L<rc4(3)|rc4(3)>, L<rc5(3)|rc5(3)> 
32
33=item PUBLIC KEY CRYPTOGRAPHY AND KEY AGREEMENT
34
35L<dsa(3)|dsa(3)>, L<dh(3)|dh(3)>, L<rsa(3)|rsa(3)>
36
37=item CERTIFICATES
38
39L<x509(3)|x509(3)>, L<x509v3(3)|x509v3(3)>
40
41=item AUTHENTICATION CODES, HASH FUNCTIONS
42
43L<hmac(3)|hmac(3)>, L<md2(3)|md2(3)>, L<md4(3)|md4(3)>,
44L<md5(3)|md5(3)>, L<mdc2(3)|mdc2(3)>, L<ripemd(3)|ripemd(3)>,
45L<sha(3)|sha(3)>
46
47=item AUXILIARY FUNCTIONS
48
49L<err(3)|err(3)>, L<threads(3)|threads(3)>, L<rand(3)|rand(3)>,
50L<OPENSSL_VERSION_NUMBER(3)|OPENSSL_VERSION_NUMBER(3)>
51
52=item INPUT/OUTPUT, DATA ENCODING
53
54L<asn1(3)|asn1(3)>, L<bio(3)|bio(3)>, L<evp(3)|evp(3)>, L<pem(3)|pem(3)>,
55L<pkcs7(3)|pkcs7(3)>, L<pkcs12(3)|pkcs12(3)> 
56
57=item INTERNAL FUNCTIONS
58
59L<bn(3)|bn(3)>, L<buffer(3)|buffer(3)>, L<lhash(3)|lhash(3)>,
60L<objects(3)|objects(3)>, L<stack(3)|stack(3)>,
61L<txt_db(3)|txt_db(3)> 
62
63=back
64
65=head1 NOTES
66
67Some of the newer functions follow a naming convention using the numbers
68B<0> and B<1>. For example the functions:
69
70 int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev);
71 int X509_add1_trust_object(X509 *x, ASN1_OBJECT *obj);
72
73The B<0> version uses the supplied structure pointer directly
74in the parent and it will be freed up when the parent is freed.
75In the above example B<crl> would be freed but B<rev> would not.
76
77The B<1> function uses a copy of the supplied structure pointer
78(or in some cases increases its link count) in the parent and
79so both (B<x> and B<obj> above) should be freed up.
80
81=head1 SEE ALSO
82
83L<openssl(1)|openssl(1)>, L<ssl(3)|ssl(3)>
84
85=cut
86