=pod

=encoding utf8

=head1 NAME

PAILLIER_new, PAILLIER_free,
i2d_PaillierPrivateKey, d2i_PaillierPrivateKey,
i2d_PaillierPublicKey, d2i_PaillierPublicKey,
PAILLIER_size, PAILLIER_security_bits
PAILLIER_generate_key, PAILLIER_check_key,
PAILLIER_encrypt, PAILLIER_decrypt,
PAILLIER_ciphertext_add, PAILLIER_ciphertext_scalar_mul,
PAILLIER_up_ref - Paillier Additive Homomorphic Encryption


=head1 SYNOPSIS

 #include <openssl/paillier.h>

 PAILLIER *PAILLIER_new(void);
 void PAILLIER_free(PAILLIER *key);


 int i2d_PaillierPrivateKey(const PaillierPrivateKey *sk, unsigned char **pp);
 PaillierPrivateKey *d2i_PaillierPrivateKey(PaillierPrivateKey **sk,
                                            const unsigned char **pp, long len);
 int i2d_PaillierPublicKey(const PaillierPublicKey *pk, unsigned char **pp);
 PaillierPublicKey *d2i_PaillierPublicKey(PaillierPublicKey **pk,
                                           const unsigned char **pp, long len);

 int PAILLIER_size(const PAILLIER *key);
 int PAILLIER_security_bits(const PAILLIER *key);

 int PAILLIER_generate_key(PAILLIER *key, int bits/* as RSA N */);
 int PAILLIER_check_key(PAILLIER *key);
 int PAILLIER_encrypt(BIGNUM *out, const BIGNUM *in, PAILLIER *key);
 int PAILLIER_decrypt(BIGNUM *out, const BIGNUM *in, PAILLIER *key);
 int PAILLIER_ciphertext_add(BIGNUM *r, const BIGNUM *a, const BIGNUM *b, PAILLIER *key);
 int PAILLIER_ciphertext_scalar_mul(BIGNUM *r, const BIGNUM *scalar, const BIGNUM *a, PAILLIER *key);

 int PAILLIER_up_ref(PAILLIER *key);

=head1 DESCRIPTION

Applications should use the higher level functions
L<EVP_DigestInit(3)> etc. instead of calling the hash
functions directly.

SM3 (ShangMi#3 Hash Algorithm) is a cryptographic hash function with a
256 bit output.

sm3() computes the SM3 message digest of the B<n>
bytes at B<d> and places it in B<md> (which must have space for
SHA_DIGEST_LENGTH == 20 bytes of output). If B<md> is NULL, the digest
is placed in a static array. Note: setting B<md> to NULL is B<not thread safe>.

The following functions may be used if the message is not completely
stored in memory:

sm3_nit() initializes a B<sm3_ctx_t> structure.

sm3_update() can be called repeatedly with chunks of the message to
be hashed (B<len> bytes at B<data>).

sm3_final() places the message digest in B<md>, which must have space
for SM3_DIGEST_LENGTH == 32 bytes of output, and erases the B<sm3_ctx_t>.

=head1 RETURN VALUES

sm3_init(), sm3_update(), sm3_final(), sm3_compress() and sm3() return void.

=head1 CONFORMING TO

GM/T 0004-2012 SM3 Cryptogrpahic Hash Algorithm.

=head1 SEE ALSO

L<EVP_DigestInit(3)>

=head1 COPYRIGHT

Copyright 2014-2019 The GmSSL Project. All Rights Reserved.

Licensed under the GmSSL license (the "License").  You may not use
this file except in compliance with the License.  You can obtain a copy
in the file LICENSE in the source distribution or at
L<http://gmssl.org/license.html>.

=cut