NAME

       crypto - OpenSSL cryptographic library

SYNOPSIS

DESCRIPTION

       The OpenSSL crypto library implements a wide range of cryptographic algorithms used in
       various Internet standards. The services provided by this library are used by the OpenSSL
       implementations of SSL, TLS and S/MIME, and they have also been used to implement SSH,
       OpenPGP, and other cryptographic standards.

OVERVIEW

       libcrypto consists of a number of sub-libraries that implement the individual algorithms.

       The functionality includes symmetric encryption, public key cryptography and key
       agreement, certificate handling, cryptographic hash functions and a cryptographic pseudo-
       random number generator.

       SYMMETRIC CIPHERS
           blowfish(3), cast(3), des(3), idea(3), rc2(3), rc4(3), rc5(3)

       PUBLIC KEY CRYPTOGRAPHY AND KEY AGREEMENT
           dsa(3), dh(3), rsa(3)

       CERTIFICATES
           x509(3), x509v3(3)

       AUTHENTICATION CODES, HASH FUNCTIONS
           hmac(3), md2(3), md4(3), md5(3), mdc2(3), ripemd(3), sha(3)

       AUXILIARY FUNCTIONS
           err(3), threads(3), rand(3), OPENSSL_VERSION_NUMBER(3)

       INPUT/OUTPUT, DATA ENCODING
           asn1(3), bio(3), evp(3), pem(3), pkcs7(3), pkcs12(3)

       INTERNAL FUNCTIONS
           bn(3), buffer(3), lhash(3), objects(3), stack(3), txt_db(3)

NOTES

       Some of the newer functions follow a naming convention using the numbers 0 and 1. For
       example the functions:

        int X509_CRL_add0_revoked(X509_CRL *crl, X509_REVOKED *rev);
        int X509_add1_trust_object(X509 *x, ASN1_OBJECT *obj);

       The 0 version uses the supplied structure pointer directly in the parent and it will be
       freed up when the parent is freed.  In the above example crl would be freed but rev would
       not.

       The 1 function uses a copy of the supplied structure pointer (or in some cases increases
       its link count) in the parent and so both (x and obj above) should be freed up.

SEE ALSO

       openssl(1), ssl(3)