NAME¶

EVP_KDF-ARGON2 - The Argon2 EVP KDF implementation

DESCRIPTION¶

Support for computing the argon2 password-based KDF through the EVP_KDF API.

The EVP_KDF-ARGON2 algorithm implements the Argon2 password-based key derivation function, as described in IETF RFC 9106. It is memory-hard in the sense that it deliberately requires a significant amount of RAM for efficient computation. The intention of this is to render brute forcing of passwords on systems that lack large amounts of main memory (such as GPUs or ASICs) computationally infeasible.

Argon2d (Argon2i) uses data-dependent (data-independent) memory access and primary seek to address trade-off (side-channel) attacks.

Argon2id is a hybrid construction which, in the first two slices of the first pass, generates reference addresses data-independently as in Argon2i, whereas in later slices and next passes it generates them data-dependently as in Argon2d.

Sbox-hardened version Argon2ds is not supported.

For more information, please refer to RFC 9106.

EXAMPLES¶

This example uses Argon2d with password "1234567890", salt "saltsalt", using 2 lanes, 2 threads, and memory cost of 65536:

 #include <string.h>                 /* strlen               */
 #include <openssl/core_names.h>     /* OSSL_KDF_*           */
 #include <openssl/params.h>         /* OSSL_PARAM_*         */
 #include <openssl/thread.h>         /* OSSL_set_max_threads */
 #include <openssl/kdf.h>            /* EVP_KDF_*            */
 int main(void)
 {
     int retval = 1;
     EVP_KDF *kdf = NULL;
     EVP_KDF_CTX *kctx = NULL;
     OSSL_PARAM params[6], *p = params;
     /* argon2 params, please refer to RFC9106 for recommended defaults */
     uint32_t lanes = 2, threads = 2, memcost = 65536;
     char pwd[] = "1234567890", salt[] = "saltsalt";
     /* derive result */
     size_t outlen = 128;
     unsigned char result[outlen];
     /* required if threads > 1 */
     if (OSSL_set_max_threads(NULL, threads) != 1)
         goto fail;
     p = params;
     *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_THREADS, &threads);
     *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_ARGON2_LANES,
                                        &lanes);
     *p++ = OSSL_PARAM_construct_uint32(OSSL_KDF_PARAM_ARGON2_MEMCOST,
                                        &memcost);
     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_SALT,
                                              salt,
                                              strlen((const char *)salt));
     *p++ = OSSL_PARAM_construct_octet_string(OSSL_KDF_PARAM_PASSWORD,
                                              pwd,
                                              strlen((const char *)pwd));
     *p++ = OSSL_PARAM_construct_end();
     if ((kdf = EVP_KDF_fetch(NULL, "ARGON2D", NULL)) == NULL)
         goto fail;
     if ((kctx = EVP_KDF_CTX_new(kdf)) == NULL)
         goto fail;
     if (EVP_KDF_derive(kctx, &result[0], outlen, params) != 1)
         goto fail;
     printf("Output = %s\n", OPENSSL_buf2hexstr(result, outlen));
     retval = 0;
 fail:
     EVP_KDF_free(kdf);
     EVP_KDF_CTX_free(kctx);
     OSSL_set_max_threads(NULL, 0);
     return retval;
 }

NOTES¶

"ARGON2I", "ARGON2D", and "ARGON2ID" are the names for this implementation; it can be used with the EVP_KDF_fetch() function.

CONFORMING TO¶

RFC 9106 Argon2, see <https://www.rfc-editor.org/rfc/rfc9106.txt>.

SEE ALSO¶

EVP_KDF(3), EVP_KDF_CTX_new(3), EVP_KDF_CTX_free(3), EVP_KDF_CTX_set_params(3), EVP_KDF_derive(3), "PARAMETERS" in EVP_KDF(3)

HISTORY¶

This functionality was added to OpenSSL 3.2.

COPYRIGHT¶

Copyright 2022-2024 The OpenSSL Project Authors. All Rights Reserved.

Licensed under the Apache License 2.0 (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 <https://www.openssl.org/source/license.html>.