pkcs11_kms/common/kmsDecrypt.c

/*
 * 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 (c) 2003, 2012, Oracle and/or its affiliates. All rights reserved.
 */

#include <string.h>
#include <strings.h>
#include <security/cryptoki.h>
#include "kmsGlobal.h"
#include "kmsCrypt.h"


/*
 * kms_decrypt_init()
 *
 * Arguments:
 *  session_p:  pointer to kms_session_t struct
 *  pMechanism: pointer to CK_MECHANISM struct provided by application
 *  key_p:      pointer to key kms_object_t struct
 *
 * Description:
 *  called by C_DecryptInit(). This function calls the corresponding
 *  decrypt init routine based on the mechanism.
 *
 * Returns:
 *  CKR_OK: success
 *  CKR_HOST_MEMORY: run out of system memory
 *  CKR_MECHANISM_PARAM_INVALID: invalid parameters in mechanism
 *  CKR_MECHANISM_INVALID: invalid mechanism type
 *  CKR_KEY_TYPE_INCONSISTENT: incorrect type of key to use
 *                 with the specified mechanism
 */
CK_RV
kms_decrypt_init(kms_session_t *session_p, CK_MECHANISM_PTR pMechanism,
    kms_object_t *key_p)
{

    CK_RV rv;

    switch (pMechanism->mechanism) {
    case CKM_AES_CBC:
    case CKM_AES_CBC_PAD:
    {
        kms_aes_ctx_t *kms_aes_ctx;

        if (key_p->key_type != CKK_AES) {
            return (CKR_KEY_TYPE_INCONSISTENT);
        }

        if ((pMechanism->pParameter == NULL) ||
            (pMechanism->ulParameterLen != AES_BLOCK_LEN)) {
            return (CKR_MECHANISM_PARAM_INVALID);
        }

        rv = kms_aes_crypt_init_common(session_p, pMechanism,
            key_p, B_FALSE);

        if (rv != CKR_OK)
            return (rv);

        (void) pthread_mutex_lock(&session_p->session_mutex);

        kms_aes_ctx = (kms_aes_ctx_t *)session_p->decrypt.context;

        /* Save Initialization Vector (IV) in the context. */
        (void) memcpy(kms_aes_ctx->ivec, pMechanism->pParameter,
            AES_BLOCK_LEN);

        /* Allocate a context for AES cipher-block chaining. */
        kms_aes_ctx->aes_cbc = (void *)aes_cbc_ctx_init(
            kms_aes_ctx->key_sched, kms_aes_ctx->keysched_len,
            kms_aes_ctx->ivec);

        if (kms_aes_ctx->aes_cbc == NULL) {
            bzero(kms_aes_ctx->key_sched,
                kms_aes_ctx->keysched_len);
            free(kms_aes_ctx->key_sched);
            free(session_p->decrypt.context);
            session_p->decrypt.context = NULL;
            (void) pthread_mutex_unlock(&session_p->session_mutex);
            return (CKR_HOST_MEMORY);
        }

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

        return (rv);
    }
    default:
        return (CKR_MECHANISM_INVALID);
    }
}

CK_RV
C_DecryptInit(CK_SESSION_HANDLE hSession, CK_MECHANISM_PTR pMechanism,
    CK_OBJECT_HANDLE hKey)
{
    CK_RV       rv;
    kms_session_t   *session_p;
    kms_object_t    *key_p;
    boolean_t   lock_held = B_FALSE;

    if (!kms_initialized)
        return (CKR_CRYPTOKI_NOT_INITIALIZED);

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

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

    /* Obtain the object pointer. */
    HANDLE2OBJECT(hKey, key_p, rv);
    if (rv != CKR_OK)
        goto clean_exit;

    /* Check to see if key object allows for decryption. */
    if (!(key_p->bool_attr_mask & DECRYPT_BOOL_ON)) {
        rv = CKR_KEY_FUNCTION_NOT_PERMITTED;
        goto clean_exit1;
    }

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

    /* Check to see if decrypt operation is already active. */
    if (session_p->decrypt.flags & CRYPTO_OPERATION_ACTIVE) {
        /* free the memory to avoid memory leak */
        kms_crypt_cleanup(session_p, B_FALSE, lock_held);
    }

    /*
     * 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;

    (void) pthread_mutex_unlock(&session_p->session_mutex);
    lock_held = B_FALSE;

    rv = kms_decrypt_init(session_p, pMechanism, key_p);

    if (rv != CKR_OK) {
        (void) pthread_mutex_lock(&session_p->session_mutex);
        session_p->decrypt.flags &= ~CRYPTO_OPERATION_ACTIVE;
        lock_held = B_TRUE;
    }

clean_exit1:
    OBJ_REFRELE(key_p);
clean_exit:
    REFRELE(session_p, lock_held);
    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;
    kms_session_t   *session_p;
    boolean_t   lock_held = B_FALSE;

    if (!kms_initialized)
        return (CKR_CRYPTOKI_NOT_INITIALIZED);

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

    /*
     * Only check if input buffer is null.  How to handle zero input
     * length depends on the mechanism in use.  For secret key mechanisms,
     * unpadded ones yield zero length output, but padded ones always
     * result in smaller than original, possibly zero, length output.
     */
    if (pEncryptedData == NULL) {
        rv = CKR_ARGUMENTS_BAD;
        goto clean_exit;
    }

    /*
     * 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;
    }

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

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

    /*
     * C_Decrypt must be called without intervening C_DecryptUpdate
     * calls.
     */
    if (session_p->decrypt.flags & CRYPTO_OPERATION_UPDATE) {
        /*
         * C_Decrypt can not be used to terminate a multi-part
         * operation, so we'll leave the active decrypt operation
         * flag on and let the application continue with the
         * decrypt update operation.
         */
        REFRELE(session_p, lock_held);
        return (CKR_FUNCTION_FAILED);
    }

    (void) pthread_mutex_unlock(&session_p->session_mutex);
    lock_held = B_FALSE;

    rv = kms_aes_decrypt_common(session_p, pEncryptedData,
        ulEncryptedData, pData, pulDataLen, FALSE);

    if ((rv == CKR_BUFFER_TOO_SMALL) ||
        (pData == NULL && rv == CKR_OK)) {
        /*
         * 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, lock_held);
        return (rv);
    }

clean_exit:
    /* Clear context, free key, and release session counter */
    kms_crypt_cleanup(session_p, B_FALSE, B_FALSE);

    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;
    kms_session_t   *session_p;
    boolean_t   lock_held = B_FALSE;

    if (!kms_initialized)
        return (CKR_CRYPTOKI_NOT_INITIALIZED);

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

    /*
     * Only check if input buffer is null.  How to handle zero input
     * length depends on the mechanism in use.  For secret key mechanisms,
     * unpadded ones yield zero length output, but padded ones always
     * result in smaller than original, possibly zero, length output.
     */
    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);
    lock_held = B_TRUE;

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

    session_p->decrypt.flags |= CRYPTO_OPERATION_UPDATE;

    (void) pthread_mutex_unlock(&session_p->session_mutex);
    lock_held = B_FALSE;

    rv = kms_aes_decrypt_common(session_p, pEncryptedPart,
        ulEncryptedPartLen, pPart, pulPartLen, B_TRUE);

    /*
     * If CKR_OK or CKR_BUFFER_TOO_SMALL, don't terminate the
     * current decryption operation.
     */
    if ((rv == CKR_OK) || (rv == CKR_BUFFER_TOO_SMALL)) {
        REFRELE(session_p, lock_held);
        return (rv);
    }

clean_exit:
    /*
     * After an error occurred, terminate the current decrypt
     * operation by resetting the active and update flags.
     */
    kms_crypt_cleanup(session_p, B_FALSE, lock_held);

    return (rv);
}

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

    CK_RV       rv;
    kms_session_t   *session_p;
    boolean_t   lock_held = B_FALSE;

    if (!kms_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);
    lock_held = B_TRUE;

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

    (void) pthread_mutex_unlock(&session_p->session_mutex);
    lock_held = B_FALSE;

    rv = kms_aes_decrypt_final(session_p, pLastPart, pulLastPartLen);

    if ((rv == CKR_BUFFER_TOO_SMALL) ||
        (pLastPart == NULL && rv == CKR_OK)) {
        /*
         * 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, lock_held);
        return (rv);
    }

    /* Terminates the active encrypt operation. */
    (void) pthread_mutex_lock(&session_p->session_mutex);
    session_p->decrypt.flags = 0;
    lock_held = B_TRUE;
    REFRELE(session_p, lock_held);
    return (rv);

clean_exit:
    /* Terminates the active decrypt operation */
    kms_crypt_cleanup(session_p, B_FALSE, lock_held);

    return (rv);
}