Beispiel #1
0
static int pkey_hkdf_derive(EVP_PKEY_CTX *ctx, unsigned char *key,
                            size_t *keylen)
{
    HKDF_PKEY_CTX *kctx = ctx->data;

    if (kctx->md == NULL || kctx->key == NULL)
        return 0;

    switch (kctx->mode) {
    case EVP_PKEY_HKDEF_MODE_EXTRACT_AND_EXPAND:
        return HKDF(kctx->md, kctx->salt, kctx->salt_len, kctx->key,
                    kctx->key_len, kctx->info, kctx->info_len, key,
                    *keylen) != NULL;

    case EVP_PKEY_HKDEF_MODE_EXTRACT_ONLY:
        if (key == NULL) {
            *keylen = EVP_MD_size(kctx->md);
            return 1;
        }
        return HKDF_Extract(kctx->md, kctx->salt, kctx->salt_len, kctx->key,
                            kctx->key_len, key, keylen) != NULL;

    case EVP_PKEY_HKDEF_MODE_EXPAND_ONLY:
        return HKDF_Expand(kctx->md, kctx->key, kctx->key_len, kctx->info,
                           kctx->info_len, key, *keylen) != NULL;

    default:
        return 0;
    }
}
Beispiel #2
0
static unsigned char *HKDF(const EVP_MD *evp_md,
                           const unsigned char *salt, size_t salt_len,
                           const unsigned char *key, size_t key_len,
                           const unsigned char *info, size_t info_len,
                           unsigned char *okm, size_t okm_len)
{
    unsigned char prk[EVP_MAX_MD_SIZE];
    size_t prk_len;

    if (!HKDF_Extract(evp_md, salt, salt_len, key, key_len, prk, &prk_len))
        return NULL;

    return HKDF_Expand(evp_md, prk, prk_len, info, info_len, okm, okm_len);
}