signstate.c

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/*
 * Copyright (C) 2016 Southern Storm Software, Pty Ltd.
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * the rights to use, copy, modify, merge, publish, distribute, sublicense,
 * and/or sell copies of the Software, and to permit persons to whom the
 * Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice shall be included
 * in all copies or substantial portions of the Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
 * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
 * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
 * DEALINGS IN THE SOFTWARE.
 */

#include "internal.h"
#include <string.h>

int noise_signstate_new_by_id(NoiseSignState **state, int id)
{
    /* The "state" argument must be non-NULL */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;

    /* Create the SignState object for the "id" */
    *state = 0;
    switch (id) {
    case NOISE_SIGN_ED25519:
        *state = noise_ed25519_new();
        break;

    default:
        return NOISE_ERROR_UNKNOWN_ID;
    }

    /* Bail out if insufficient memory */
    if (!(*state))
        return NOISE_ERROR_NO_MEMORY;

    /* Ready to go */
    return NOISE_ERROR_NONE;
}

int noise_signstate_new_by_name(NoiseSignState **state, const char *name)
{
    int id;

    /* The "state" and "name" arguments must be non-NULL */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;
    *state = 0;
    if (!name)
        return NOISE_ERROR_INVALID_PARAM;

    /* Map the name and create the corresponding object */
    id = noise_name_to_id(NOISE_SIGN_CATEGORY, name, strlen(name));
    if (id)
        return noise_signstate_new_by_id(state, id);

    /* We don't know what this is */
    return NOISE_ERROR_UNKNOWN_NAME;
}

int noise_signstate_free(NoiseSignState *state)
{
    /* Bail out if no sign state */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;

    /* Call the backend-specific destroy function if necessary */
    if (state->destroy)
        (*(state->destroy))(state);

    /* Clean and free the memory */
    noise_free(state, state->size);
    return NOISE_ERROR_NONE;
}

int noise_signstate_get_sign_id(const NoiseSignState *state)
{
    return state ? state->sign_id : NOISE_SIGN_NONE;
}

size_t noise_signstate_get_public_key_length(const NoiseSignState *state)
{
    return state ? state->public_key_len : 0;
}

size_t noise_signstate_get_private_key_length(const NoiseSignState *state)
{
    return state ? state->private_key_len : 0;
}

size_t noise_signstate_get_signature_length(const NoiseSignState *state)
{
    return state ? state->signature_len : 0;
}

int noise_signstate_has_keypair(const NoiseSignState *state)
{
    if (state)
        return state->key_type == NOISE_KEY_TYPE_KEYPAIR;
    else
        return 0;
}

int noise_signstate_has_public_key(const NoiseSignState *state)
{
    if (state)
        return state->key_type != NOISE_KEY_TYPE_NO_KEY;
    else
        return 0;
}

int noise_signstate_generate_keypair(NoiseSignState *state)
{
    /* Validate the parameter */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;

    /* Generate the new keypair */
    (*(state->generate_keypair))(state);
    state->key_type = NOISE_KEY_TYPE_KEYPAIR;
    return NOISE_ERROR_NONE;
}

int noise_signstate_set_keypair
    (NoiseSignState *state, const uint8_t *private_key, size_t private_key_len,
     const uint8_t *public_key, size_t public_key_len)
{
    int err;

    /* Validate the parameters */
    if (!state || !private_key || !public_key)
        return NOISE_ERROR_INVALID_PARAM;
    if (private_key_len != state->private_key_len)
        return NOISE_ERROR_INVALID_LENGTH;
    if (public_key_len != state->public_key_len)
        return NOISE_ERROR_INVALID_LENGTH;

    /* Validate the keypair */
    err = (*(state->validate_keypair))(state, private_key, public_key);
    if (err != NOISE_ERROR_NONE)
        return err;

    /* Copy the key into place */
    memcpy(state->private_key, private_key, state->private_key_len);
    memcpy(state->public_key, public_key, state->public_key_len);
    state->key_type = NOISE_KEY_TYPE_KEYPAIR;
    return NOISE_ERROR_NONE;
}

int noise_signstate_set_keypair_private
    (NoiseSignState *state, const uint8_t *private_key, size_t private_key_len)
{
    int err;

    /* Validate the parameters */
    if (!state || !private_key)
        return NOISE_ERROR_INVALID_PARAM;
    if (private_key_len != state->private_key_len)
        return NOISE_ERROR_INVALID_LENGTH;

    /* Derive the public key from the private key */
    err = (*(state->derive_public_key))
        (state, private_key, state->public_key);
    if (err != NOISE_ERROR_NONE) {
        noise_signstate_clear_key(state);
        return err;
    }

    /* Copy the private key into place */
    memcpy(state->private_key, private_key, state->private_key_len);
    state->key_type = NOISE_KEY_TYPE_KEYPAIR;
    return NOISE_ERROR_NONE;
}

int noise_signstate_get_keypair
    (const NoiseSignState *state, uint8_t *private_key, size_t private_key_len,
     uint8_t *public_key, size_t public_key_len)
{
    /* Validate the parameters */
    if (!state || !private_key || !public_key)
        return NOISE_ERROR_INVALID_PARAM;
    if (private_key_len != state->private_key_len)
        return NOISE_ERROR_INVALID_LENGTH;
    if (public_key_len != state->public_key_len)
        return NOISE_ERROR_INVALID_LENGTH;

    /* Is this actually a keypair? */
    if (state->key_type != NOISE_KEY_TYPE_KEYPAIR) {
        memset(private_key, 0, private_key_len);
        memset(public_key, 0, public_key_len);
        return NOISE_ERROR_INVALID_STATE;
    }

    /* Copy the keypair out */
    memcpy(private_key, state->private_key, private_key_len);
    memcpy(public_key, state->public_key, public_key_len);
    return NOISE_ERROR_NONE;
}

int noise_signstate_set_public_key
    (NoiseSignState *state, const uint8_t *public_key, size_t public_key_len)
{
    int err;

    /* Validate the parameters */
    if (!state || !public_key)
        return NOISE_ERROR_INVALID_PARAM;
    if (public_key_len != state->public_key_len)
        return NOISE_ERROR_INVALID_LENGTH;

    /* Validate the public key with the back end */
    err = (*(state->validate_public_key))(state, public_key);
    if (err != NOISE_ERROR_NONE)
        return err;

    /* Copy the public key into place and clear the private key */
    memcpy(state->public_key, public_key, public_key_len);
    memset(state->private_key, 0, state->private_key_len);
    state->key_type = NOISE_KEY_TYPE_PUBLIC;
    return NOISE_ERROR_NONE;
}

int noise_signstate_get_public_key
    (const NoiseSignState *state, uint8_t *public_key, size_t public_key_len)
{
    /* Validate the parameters */
    if (!state || !public_key)
        return NOISE_ERROR_INVALID_PARAM;
    if (public_key_len != state->public_key_len)
        return NOISE_ERROR_INVALID_LENGTH;
    if (state->key_type == NOISE_KEY_TYPE_NO_KEY)
        return NOISE_ERROR_INVALID_STATE;

    /* Copy the public key out */
    memcpy(public_key, state->public_key, public_key_len);
    return NOISE_ERROR_NONE;
}

int noise_signstate_clear_key(NoiseSignState *state)
{
    /* Validate the parameter */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;

    /* Clear the key to all-zeroes */
    memset(state->public_key, 0, state->public_key_len);
    memset(state->private_key, 0, state->private_key_len);

    /* There is no key in the object now */
    state->key_type = NOISE_KEY_TYPE_NO_KEY;
    return NOISE_ERROR_NONE;
}

int noise_signstate_sign
    (const NoiseSignState *state, const uint8_t *message, size_t message_len,
     uint8_t *signature, size_t signature_len)
{
    /* Validate the parameters */
    if (!state || !message || !signature)
        return NOISE_ERROR_INVALID_PARAM;
    if (signature_len != state->signature_len)
        return NOISE_ERROR_INVALID_LENGTH;
    if (state->key_type != NOISE_KEY_TYPE_KEYPAIR)
        return NOISE_ERROR_INVALID_PRIVATE_KEY;

    /* Create the digial signature */
    return (*(state->sign))(state, message, message_len, signature);
}

int noise_signstate_verify
    (const NoiseSignState *state, const uint8_t *message, size_t message_len,
     const uint8_t *signature, size_t signature_len)
{
    /* Validate the parameters */
    if (!state || !message || !signature)
        return NOISE_ERROR_INVALID_PARAM;
    if (signature_len != state->signature_len)
        return NOISE_ERROR_INVALID_LENGTH;
    if (state->key_type == NOISE_KEY_TYPE_NO_KEY)
        return NOISE_ERROR_INVALID_PUBLIC_KEY;

    /* Verify the digial signature */
    return (*(state->verify))(state, message, message_len, signature);
}

int noise_signstate_copy(NoiseSignState *state, const NoiseSignState *from)
{
    /* Validate the parameters */
    if (!state || !from)
        return NOISE_ERROR_INVALID_PARAM;
    if (state->sign_id != from->sign_id)
        return NOISE_ERROR_NOT_APPLICABLE;

    /* Copy the key information across */
    if (state != from) {
        state->key_type = from->key_type;
        memcpy(state->private_key, from->private_key, from->private_key_len);
        memcpy(state->public_key, from->public_key, from->public_key_len);
    }
    return NOISE_ERROR_NONE;
}

int noise_signstate_format_fingerprint
    (const NoiseSignState *state, int fingerprint_type,
     char *buffer, size_t len)
{
    /* Validate the parameters */
    if (!buffer)
        return NOISE_ERROR_INVALID_PARAM;
    if (!len)
        return NOISE_ERROR_INVALID_LENGTH;
    *buffer = '\0'; /* In case we bail out with an error later */
    if (!state)
        return NOISE_ERROR_INVALID_PARAM;
    if (state->key_type == NOISE_KEY_TYPE_NO_KEY)
        return NOISE_ERROR_INVALID_STATE;

    /* Format the fingerprint */
    return noise_format_fingerprint
        (fingerprint_type, buffer, len,
         state->public_key, state->public_key_len);
}

int noise_signstate_get_max_key_length(void)
{
    return 32;
}

int noise_signstate_get_max_signature_length(void)
{
    return 64;
}