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PKCS5_PBKDF2_HMAC(3) DragonFly Library Functions Manual PKCS5_PBKDF2_HMAC(3)
PKCS5_PBKDF2_HMAC, PKCS5_PBKDF2_HMAC_SHA1 -- password based derivation
routines with salt and iteration count
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);
PKCS5_PBKDF2_HMAC_SHA1(const char *pass, int passlen,
const unsigned char *salt, int saltlen, int iter, int keylen,
unsigned char *out);
PKCS5_PBKDF2_HMAC() derives a key from a password using a salt and itera-
tion count as specified in RFC 2898.
pass is the password used in the derivation of length passlen. pass is
an optional parameter and can be NULL. If passlen is -1, then the func-
tion will calculate the length of pass using strlen(3).
salt is the salt used in the derivation of length saltlen. If the salt
is NULL, then saltlen must be 0. The function will not attempt to calcu-
late the length of the salt because it is not assumed to be NUL termi-
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 iter
less than 1 is treated as a single iteration.
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(3).
The derived key will be written to out. The size of the out buffer is
specified via keylen.
A typical application of this function is to derive keying material for
an encryption algorithm from a password in the pass, a salt in salt, and
an iteration count.
Increasing the iter parameter slows down the algorithm which makes it
harder for an attacker to perform a brute force attack using a large num-
ber of candidate passwords.
PKCS5_PBKDF2_HMAC() and PBKCS5_PBKDF2_HMAC_SHA1() return 1 on success or
0 on error.
evp(3), EVP_BytesToKey(3), RAND_bytes(3)
PKCS5_PBKDF2_HMAC_SHA1() first appeared in OpenSSL 0.9.4 and has been
available since OpenBSD 2.6.
PKCS5_PBKDF2_HMAC() first appeared in OpenSSL 1.0.0 and has been avail-
able since OpenBSD 4.9.
DragonFly 5.5 March 23, 2018 DragonFly 5.5