/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2009 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 * Copyright 2018, Joyent, Inc.
 */

#include <pthread.h>
#include <stdlib.h>
#include <errno.h>
#include <sys/crypto/ioctl.h>
#include <security/cryptoki.h>
#include "kernelGlobal.h"
#include "kernelSession.h"
#include "kernelObject.h"


/*
 * Real decryptInit work. The caller doesn't hold the session lock.
 */
CK_RV
kernel_decrypt_init(kernel_session_t *session_p, kernel_object_t *key_p,
    CK_MECHANISM_PTR pMechanism)
{
        CK_RV rv;
        crypto_decrypt_init_t decrypt_init;
        crypto_mech_type_t k_mech_type;
        boolean_t ses_lock_held = B_FALSE;
        int r;
        CK_AES_CCM_PARAMS ccm_params = { 0 };

        /* Check to see if key object allows for decryption. */
        if (key_p->is_lib_obj && !(key_p->bool_attr_mask & DECRYPT_BOOL_ON)) {
                return (CKR_KEY_TYPE_INCONSISTENT);
        }

        /* Get the kernel's internal mechanism number. */
        rv = kernel_mech(pMechanism->mechanism, &k_mech_type);
        if (rv != CKR_OK)
                return (rv);

        (void) pthread_mutex_lock(&session_p->session_mutex);
        ses_lock_held = B_TRUE;

        /*
         * This active flag will remain ON until application calls either
         * C_Decrypt or C_DecryptFinal to actually obtain the final piece
         * of plaintext.
         */
        session_p->decrypt.flags = CRYPTO_OPERATION_ACTIVE;

        /* set up key data */
        if (!key_p->is_lib_obj) {
                decrypt_init.di_key.ck_format = CRYPTO_KEY_REFERENCE;
                decrypt_init.di_key.ck_obj_id = key_p->k_handle;
        } else {
                if (key_p->class == CKO_SECRET_KEY) {
                        decrypt_init.di_key.ck_format = CRYPTO_KEY_RAW;
                        decrypt_init.di_key.ck_data =
                            get_symmetric_key_value(key_p);
                        if (decrypt_init.di_key.ck_data == NULL) {
                                rv = CKR_HOST_MEMORY;
                                goto clean_exit;
                        }
                        /* KEF key lengths are expressed in bits */
                        decrypt_init.di_key.ck_length =
                            OBJ_SEC(key_p)->sk_value_len << 3;

                } else if (key_p->key_type == CKK_RSA) {
                        if (get_rsa_private_key(key_p, &decrypt_init.di_key) !=
                            CKR_OK) {
                                rv = CKR_HOST_MEMORY;
                                goto clean_exit;
                        }
                } else {
                        rv = CKR_KEY_TYPE_INCONSISTENT;
                        goto clean_exit;
                }
        }

        decrypt_init.di_session = session_p->k_session;
        session_p->decrypt.mech = *pMechanism;

        /* Cache this capability value for efficiency */
        if (INPLACE_MECHANISM(session_p->decrypt.mech.mechanism)) {
                session_p->decrypt.flags |= CRYPTO_OPERATION_INPLACE_OK;
        }
        (void) pthread_mutex_unlock(&session_p->session_mutex);

        ses_lock_held = B_FALSE;
        decrypt_init.di_mech.cm_type = k_mech_type;
        decrypt_init.di_mech.cm_param = pMechanism->pParameter;
        decrypt_init.di_mech.cm_param_len = pMechanism->ulParameterLen;

        /*
         * PKCS#11 uses CK_CCM_PARAMS as its mechanism parameter, while the
         * kernel uses CK_AES_CCM_PARAMS.  Unlike
         * CK_GCM_PARAMS / CK_AES_GCM_PARAMS, the two definitions are not
         * equivalent -- the fields are defined in different orders, so
         * we must translate.
         */
        if (session_p->decrypt.mech.mechanism == CKM_AES_CCM) {
                if (pMechanism->ulParameterLen != sizeof (CK_CCM_PARAMS)) {
                        rv = CKR_MECHANISM_PARAM_INVALID;
                        goto clean_exit;
                }
                p11_to_kernel_ccm_params(pMechanism->pParameter, &ccm_params);
                decrypt_init.di_mech.cm_param = (caddr_t)&ccm_params;
                decrypt_init.di_mech.cm_param_len = sizeof (ccm_params);
        }

        while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_INIT, &decrypt_init)) < 0) {
                if (errno != EINTR)
                        break;
        }
        if (r < 0) {
                rv = CKR_FUNCTION_FAILED;
        } else {
                rv = crypto2pkcs11_error_number(decrypt_init.di_return_value);
        }

        /* Free memory allocated for decrypt_init.di_key */
        if (key_p->is_lib_obj) {
                if (key_p->class == CKO_SECRET_KEY) {
                        free(decrypt_init.di_key.ck_data);
                } else if (key_p->key_type == CKK_RSA) {
                        free_key_attributes(&decrypt_init.di_key);
                }
        }

clean_exit:
        /*
         * ccm_params does not contain any key material -- just lengths and
         * pointers, therefore it does not need to be zeroed on exit.
         */
        if (!ses_lock_held) {
                (void) pthread_mutex_lock(&session_p->session_mutex);
                ses_lock_held = B_TRUE;
        }

        if (rv != CKR_OK)
                session_p->decrypt.flags &= ~CRYPTO_OPERATION_ACTIVE;

        if (ses_lock_held) {
                (void) pthread_mutex_unlock(&session_p->session_mutex);
                ses_lock_held = B_FALSE;
        }

        return (rv);
}

CK_RV
C_DecryptInit(CK_SESSION_HANDLE hSession, CK_MECHANISM_PTR pMechanism,
    CK_OBJECT_HANDLE hKey)
{

        CK_RV rv;
        kernel_session_t *session_p;
        kernel_object_t *key_p;
        boolean_t ses_lock_held = B_FALSE;

        if (!kernel_initialized)
                return (CKR_CRYPTOKI_NOT_INITIALIZED);

        if (pMechanism == NULL) {
                return (CKR_ARGUMENTS_BAD);
        }

        /* Obtain the session pointer. */
        rv = handle2session(hSession, &session_p);
        if (rv != CKR_OK)
                return (rv);

        /* Obtain the object pointer. */
        HANDLE2OBJECT(hKey, key_p, rv);
        if (rv == CKR_OK) {
                rv = kernel_decrypt_init(session_p, key_p, pMechanism);
                OBJ_REFRELE(key_p);
        }

        REFRELE(session_p, ses_lock_held);
        return (rv);
}



/*
 * Real decrypt work. The caller doesn't hold the session lock.
 */
CK_RV
kernel_decrypt(kernel_session_t *session_p, CK_BYTE_PTR pEncryptedData,
    CK_ULONG ulEncryptedData, CK_BYTE_PTR pData, CK_ULONG_PTR pulDataLen)
{
        crypto_decrypt_t decrypt;
        boolean_t ses_lock_held = B_FALSE;
        boolean_t inplace;
        CK_RV rv;
        int r;

        (void) pthread_mutex_lock(&session_p->session_mutex);
        ses_lock_held = B_TRUE;

        /* Application must call C_DecryptInit before calling C_Decrypt. */
        if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
                rv = CKR_OPERATION_NOT_INITIALIZED;
                goto clean_exit;
        }

        /*
         * C_Decrypt must be called without intervening C_DecryptUpdate
         * calls.
         */
        if (session_p->decrypt.flags & CRYPTO_OPERATION_UPDATE) {
                /*
                 * C_Decrypt cannot be used to terminate a multiple-part
                 * operation, so we'll leave the active decrypt operation
                 * flag on and let the application continue with the
                 * decrypt update operation.
                 */
                rv = CKR_FUNCTION_FAILED;
                goto clean_exit;
        }

        decrypt.cd_session = session_p->k_session;

        /*
         * Certain mechanisms, where the length of the plaintext is
         * same as the transformed ciphertext, can be optimized
         * by the kernel into an in-place operation. Unfortunately,
         * some applications use a plaintext buffer that is larger
         * than it needs to be. We fix that here.
         */
        inplace = (session_p->decrypt.flags & CRYPTO_OPERATION_INPLACE_OK) != 0;

        if (ulEncryptedData < *pulDataLen && inplace) {
                decrypt.cd_datalen = ulEncryptedData;
        } else {
                decrypt.cd_datalen = *pulDataLen;
        }
        (void) pthread_mutex_unlock(&session_p->session_mutex);
        ses_lock_held = B_FALSE;

        decrypt.cd_databuf = (char *)pData;
        decrypt.cd_encrlen = ulEncryptedData;
        decrypt.cd_encrbuf = (char *)pEncryptedData;
        decrypt.cd_flags =
            ((inplace && (pData != NULL)) || (pData == pEncryptedData)) &&
            (decrypt.cd_datalen == decrypt.cd_encrlen) ?
            CRYPTO_INPLACE_OPERATION : 0;

        while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT, &decrypt)) < 0) {
                if (errno != EINTR)
                        break;
        }
        if (r < 0) {
                rv = CKR_FUNCTION_FAILED;
        } else {
                rv = crypto2pkcs11_error_number(decrypt.cd_return_value);
        }

        if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL)
                *pulDataLen = decrypt.cd_datalen;

clean_exit:

        if (ses_lock_held)
                (void) pthread_mutex_unlock(&session_p->session_mutex);

        return (rv);
}

CK_RV
C_Decrypt(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pEncryptedData,
    CK_ULONG ulEncryptedData, CK_BYTE_PTR pData, CK_ULONG_PTR pulDataLen)
{
        CK_RV rv;
        kernel_session_t *session_p;
        boolean_t ses_lock_held = B_FALSE;

        if (!kernel_initialized)
                return (CKR_CRYPTOKI_NOT_INITIALIZED);

        /* Obtain the session pointer. */
        rv = handle2session(hSession, &session_p);
        if (rv != CKR_OK)
                return (rv);

        /*
         * No need to check pData because application might
         * just want to know the length of decrypted data.
         */
        if (pulDataLen == NULL) {
                rv = CKR_ARGUMENTS_BAD;
                goto clean_exit;
        }

        rv = kernel_decrypt(session_p, pEncryptedData, ulEncryptedData, pData,
            pulDataLen);

        if ((rv == CKR_BUFFER_TOO_SMALL) ||
            (rv == CKR_OK && pData == NULL)) {
                /*
                 * We will not terminate the active decrypt operation flag,
                 * when the application-supplied buffer is too small, or
                 * the application asks for the length of buffer to hold
                 * the plaintext.
                 */
                REFRELE(session_p, ses_lock_held);
                return (rv);
        }

clean_exit:
        /*
         * Terminates the active decrypt operation.
         * Application needs to call C_DecryptInit again for next
         * decrypt operation.
         */
        (void) pthread_mutex_lock(&session_p->session_mutex);
        session_p->decrypt.flags = 0;
        ses_lock_held = B_TRUE;
        REFRELE(session_p, ses_lock_held);

        return (rv);
}


CK_RV
C_DecryptUpdate(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pEncryptedPart,
    CK_ULONG ulEncryptedPartLen, CK_BYTE_PTR pPart,
    CK_ULONG_PTR pulPartLen)
{

        CK_RV rv;
        kernel_session_t *session_p;
        boolean_t ses_lock_held = B_FALSE;
        boolean_t inplace;
        crypto_decrypt_update_t decrypt_update;
        int r;

        if (!kernel_initialized)
                return (CKR_CRYPTOKI_NOT_INITIALIZED);

        /* Obtain the session pointer. */
        rv = handle2session(hSession, &session_p);
        if (rv != CKR_OK)
                return (rv);

        if (pEncryptedPart == NULL) {
                rv = CKR_ARGUMENTS_BAD;
                goto clean_exit;
        }

        /*
         * Only check if pulPartLen is NULL.
         * No need to check if pPart is NULL because application
         * might just ask for the length of buffer to hold the
         * recovered data.
         */
        if (pulPartLen == NULL) {
                rv = CKR_ARGUMENTS_BAD;
                goto clean_exit;
        }

        (void) pthread_mutex_lock(&session_p->session_mutex);
        ses_lock_held = B_TRUE;

        /*
         * Application must call C_DecryptInit before calling
         * C_DecryptUpdate.
         */
        if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
                REFRELE(session_p, ses_lock_held);
                return (CKR_OPERATION_NOT_INITIALIZED);
        }

        session_p->decrypt.flags |= CRYPTO_OPERATION_UPDATE;

        decrypt_update.du_session = session_p->k_session;
        (void) pthread_mutex_unlock(&session_p->session_mutex);
        ses_lock_held = B_FALSE;

        decrypt_update.du_datalen = *pulPartLen;
        decrypt_update.du_databuf = (char *)pPart;
        decrypt_update.du_encrlen = ulEncryptedPartLen;
        decrypt_update.du_encrbuf = (char *)pEncryptedPart;

        inplace = (session_p->decrypt.flags & CRYPTO_OPERATION_INPLACE_OK) != 0;
        decrypt_update.du_flags =
            ((inplace && (pPart != NULL)) || (pPart == pEncryptedPart)) &&
            (decrypt_update.du_datalen == decrypt_update.du_encrlen) ?
            CRYPTO_INPLACE_OPERATION : 0;

        while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_UPDATE,
            &decrypt_update)) < 0) {
                if (errno != EINTR)
                        break;
        }
        if (r < 0) {
                rv = CKR_FUNCTION_FAILED;
        } else {
                rv = crypto2pkcs11_error_number(
                    decrypt_update.du_return_value);
        }

        /*
         * If CKR_OK or CKR_BUFFER_TOO_SMALL, set the output length.
         * We don't terminate the current decryption operation.
         */
        if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL) {
                *pulPartLen = decrypt_update.du_datalen;
                REFRELE(session_p, ses_lock_held);
                return (rv);
        }

clean_exit:
        /*
         * After an error occurred, terminate the current decrypt
         * operation by resetting the active and update flags.
         */
        (void) pthread_mutex_lock(&session_p->session_mutex);
        session_p->decrypt.flags = 0;
        ses_lock_held = B_TRUE;
        REFRELE(session_p, ses_lock_held);

        return (rv);
}


CK_RV
C_DecryptFinal(CK_SESSION_HANDLE hSession, CK_BYTE_PTR pLastPart,
    CK_ULONG_PTR pulLastPartLen)
{

        CK_RV rv;
        kernel_session_t *session_p;
        boolean_t ses_lock_held = B_FALSE;
        crypto_decrypt_final_t decrypt_final;
        int r;

        if (!kernel_initialized)
                return (CKR_CRYPTOKI_NOT_INITIALIZED);

        /* Obtain the session pointer. */
        rv = handle2session(hSession, &session_p);
        if (rv != CKR_OK)
                return (rv);

        if (pulLastPartLen == NULL) {
                rv = CKR_ARGUMENTS_BAD;
                goto clean_exit;
        }

        (void) pthread_mutex_lock(&session_p->session_mutex);
        ses_lock_held = B_TRUE;

        /*
         * Application must call C_DecryptInit before calling
         * C_DecryptFinal.
         */
        if (!(session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE)) {
                REFRELE(session_p, ses_lock_held);
                return (CKR_OPERATION_NOT_INITIALIZED);
        }

        decrypt_final.df_session = session_p->k_session;
        (void) pthread_mutex_unlock(&session_p->session_mutex);
        ses_lock_held = B_FALSE;

        decrypt_final.df_datalen = *pulLastPartLen;
        decrypt_final.df_databuf = (char *)pLastPart;

        while ((r = ioctl(kernel_fd, CRYPTO_DECRYPT_FINAL,
            &decrypt_final)) < 0) {
                if (errno != EINTR)
                        break;
        }
        if (r < 0) {
                rv = CKR_FUNCTION_FAILED;
        } else {
                rv = crypto2pkcs11_error_number(decrypt_final.df_return_value);
        }

        if (rv == CKR_OK || rv == CKR_BUFFER_TOO_SMALL)
                *pulLastPartLen = decrypt_final.df_datalen;

        if (rv == CKR_BUFFER_TOO_SMALL ||
            (rv == CKR_OK && pLastPart == NULL)) {
                /*
                 * We will not terminate the active decrypt operation flag,
                 * when the application-supplied buffer is too small, or
                 * the application asks for the length of buffer to hold
                 * the plaintext.
                 */
                REFRELE(session_p, ses_lock_held);
                return (rv);
        }

clean_exit:
        /* Terminates the active decrypt operation */
        (void) pthread_mutex_lock(&session_p->session_mutex);
        session_p->decrypt.flags = 0;
        ses_lock_held = B_TRUE;
        REFRELE(session_p, ses_lock_held);

        return (rv);
}