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Diffstat (limited to 'doc/man3/PKCS5_PBKDF2_HMAC.pod')
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diff --git a/doc/man3/PKCS5_PBKDF2_HMAC.pod b/doc/man3/PKCS5_PBKDF2_HMAC.pod new file mode 100644 index 0000000000..5cc2caa5fb --- /dev/null +++ b/doc/man3/PKCS5_PBKDF2_HMAC.pod @@ -0,0 +1,73 @@ +=pod + +=head1 NAME + +PKCS5_PBKDF2_HMAC, PKCS5_PBKDF2_HMAC_SHA1 - password based derivation routines with salt and iteration count + +=head1 SYNOPSIS + + #include <openssl/evp.h> + + int PKCS5_PBKDF2_HMAC(const char *pass, int passlen, + const unsigned char *salt, int saltlen, int iter, + const EVP_MD *digest, + int keylen, unsigned char *out); + +int PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen, + const unsigned char *salt, int saltlen, int iter, + int keylen, unsigned char *out); + +=head1 DESCRIPTION + +PKCS5_PBKDF2_HMAC() derives a key from a password using a salt and iteration count +as specified in RFC 2898. + +B<pass> is the password used in the derivation of length B<passlen>. B<pass> +is an optional parameter and can be NULL. If B<passlen> is -1, then the +function will calculate the length of B<pass> using strlen(). + +B<salt> is the salt used in the derivation of length B<saltlen>. If the +B<salt> is NULL, then B<saltlen> must be 0. The function will not +attempt to calculate the length of the B<salt> because it is not assumed to +be NULL terminated. + +B<iter> is the iteration count and its value should be greater than or +equal to 1. RFC 2898 suggests an iteration count of at least 1000. Any +B<iter> less than 1 is treated as a single iteration. + +B<digest> is the message digest function used in the derivation. Values include +any of the EVP_* message digests. PKCS5_PBKDF2_HMAC_SHA1() calls +PKCS5_PBKDF2_HMAC() with EVP_sha1(). + +The derived key will be written to B<out>. The size of the B<out> buffer +is specified via B<keylen>. + +=head1 NOTES + +A typical application of this function is to derive keying material for an +encryption algorithm from a password in the B<pass>, a salt in B<salt>, +and an iteration count. + +Increasing the B<iter> parameter slows down the algorithm which makes it +harder for an attacker to perform a brute force attack using a large number +of candidate passwords. + +=head1 RETURN VALUES + +PKCS5_PBKDF2_HMAC() and PBKCS5_PBKDF2_HMAC_SHA1() return 1 on success or 0 on error. + +=head1 SEE ALSO + +L<evp(3)>, L<rand(3)>, +L<EVP_BytesToKey(3)> + +=head1 COPYRIGHT + +Copyright 2014-2016 The OpenSSL Project Authors. All Rights Reserved. + +Licensed under the OpenSSL 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<https://www.openssl.org/source/license.html>. + +=cut |