apr_crypto_nss.c

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/* Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */
 
#include "apr_lib.h"
#include "apu.h"
#include "apu_config.h"
#include "apu_errno.h"
 
#include <ctype.h>
#include <stdlib.h>
 
#include "apr_strings.h"
#include "apr_time.h"
#include "apr_buckets.h"
 
#include "apr_crypto_internal.h"
 
#if APU_HAVE_CRYPTO
 
#include <prerror.h>
 
#ifdef HAVE_NSS_NSS_H
#include <nss/nss.h>
#endif
#ifdef HAVE_NSS_H
#include <nss.h>
#endif
 
#ifdef HAVE_NSS_PK11PUB_H
#include <nss/pk11pub.h>
#endif
#ifdef HAVE_PK11PUB_H
#include <pk11pub.h>
#endif
 
struct apr_crypto_t {
    apr_pool_t *pool;
    const apr_crypto_driver_t *provider;
    apu_err_t *result;
    apr_crypto_config_t *config;
    apr_hash_t *types;
    apr_hash_t *modes;
};
 
struct apr_crypto_config_t {
       void *opaque;
};
 
struct apr_crypto_key_t {
    apr_pool_t *pool;
    const apr_crypto_driver_t *provider;
    const apr_crypto_t *f;
    CK_MECHANISM_TYPE cipherMech;
    SECOidTag cipherOid;
    PK11SymKey *symKey;
    int ivSize;
    int keyLength;
};
 
struct apr_crypto_block_t {
    apr_pool_t *pool;
    const apr_crypto_driver_t *provider;
    const apr_crypto_t *f;
    PK11Context *ctx;
    apr_crypto_key_t *key;
    SECItem *secParam;
    int blockSize;
};
 
static struct apr_crypto_block_key_type_t key_types[] =
{
{ APR_KEY_3DES_192, 24, 8, 8 },
{ APR_KEY_AES_128, 16, 16, 16 },
{ APR_KEY_AES_192, 24, 16, 16 },
{ APR_KEY_AES_256, 32, 16, 16 } };
 
static struct apr_crypto_block_key_mode_t key_modes[] =
{
{ APR_MODE_ECB },
{ APR_MODE_CBC } };
 
/* sufficient space to wrap a key */
#define BUFFER_SIZE 128
 
static apr_status_t crypto_error(const apu_err_t **result,
        const apr_crypto_t *f)
{
    *result = f->result;
    return APR_SUCCESS;
}
 
static apr_status_t crypto_shutdown(void)
{
    if (NSS_IsInitialized()) {
        SECStatus s = NSS_Shutdown();
        if (s != SECSuccess) {
            fprintf(stderr, "NSS failed to shutdown, possible leak: %d: %s",
                PR_GetError(), PR_ErrorToName(s));
            return APR_EINIT;
        }
    }
    return APR_SUCCESS;
}
 
static apr_status_t crypto_shutdown_helper(void *data)
{
    return crypto_shutdown();
}
 
static apr_status_t crypto_init(apr_pool_t *pool, const char *params,
        const apu_err_t **result)
{
    SECStatus s;
    const char *dir = NULL;
    const char *keyPrefix = NULL;
    const char *certPrefix = NULL;
    const char *secmod = NULL;
    int noinit = 0;
    PRUint32 flags = 0;
 
    struct {
        const char *field;
        const char *value;
        int set;
    } fields[] = {
        { "dir", NULL, 0 },
        { "key3", NULL, 0 },
        { "cert7", NULL, 0 },
        { "secmod", NULL, 0 },
        { "noinit", NULL, 0 },
        { NULL, NULL, 0 }
    };
    const char *ptr;
    size_t klen;
    char **elts = NULL;
    char *elt;
    int i = 0, j;
    apr_status_t status;
 
    if (params) {
        if (APR_SUCCESS != (status = apr_tokenize_to_argv(params, &elts, pool))) {
            return status;
        }
        while ((elt = elts[i])) {
            ptr = strchr(elt, '=');
            if (ptr) {
                for (klen = ptr - elt; klen && apr_isspace(elt[klen - 1]); --klen)
                    ;
                ptr++;
            }
            else {
                for (klen = strlen(elt); klen && apr_isspace(elt[klen - 1]); --klen)
                    ;
            }
            elt[klen] = 0;
 
            for (j = 0; fields[j].field != NULL; ++j) {
                if (klen && !strcasecmp(fields[j].field, elt)) {
                    fields[j].set = 1;
                    if (ptr) {
                        fields[j].value = ptr;
                    }
                    break;
                }
            }
 
            i++;
        }
        dir = fields[0].value;
        keyPrefix = fields[1].value;
        certPrefix = fields[2].value;
        secmod = fields[3].value;
        noinit = fields[4].set;
    }
 
    /* if we've been asked to bypass, do so here */
    if (noinit) {
        return APR_SUCCESS;
    }
 
    /* sanity check - we can only initialise NSS once */
    if (NSS_IsInitialized()) {
        return APR_EREINIT;
    }
 
    if (keyPrefix || certPrefix || secmod) {
        s = NSS_Initialize(dir, certPrefix, keyPrefix, secmod, flags);
    }
    else if (dir) {
        s = NSS_InitReadWrite(dir);
    }
    else {
        s = NSS_NoDB_Init(NULL);
    }
    if (s != SECSuccess) {
        if (result) {
            /* Note: all memory must be owned by the caller, in case we're unloaded */
            apu_err_t *err = apr_pcalloc(pool, sizeof(apu_err_t));
            err->rc = PR_GetError();
            err->msg = apr_pstrdup(pool, PR_ErrorToName(s));
            err->reason = apr_pstrdup(pool, "Error during 'nss' initialisation");
            *result = err;
        }
 
        return APR_ECRYPT;
    }
 
    apr_pool_cleanup_register(pool, pool, crypto_shutdown_helper,
            apr_pool_cleanup_null);
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_cleanup(apr_crypto_block_t *block)
{
 
    if (block->secParam) {
        SECITEM_FreeItem(block->secParam, PR_TRUE);
        block->secParam = NULL;
    }
 
    if (block->ctx) {
        PK11_DestroyContext(block->ctx, PR_TRUE);
        block->ctx = NULL;
    }
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_cleanup_helper(void *data)
{
    apr_crypto_block_t *block = (apr_crypto_block_t *) data;
    return crypto_block_cleanup(block);
}
 
static apr_status_t crypto_key_cleanup(void *data)
{
    apr_crypto_key_t *key = data;
    if (key->symKey) {
        PK11_FreeSymKey(key->symKey);
        key->symKey = NULL;
    }
    return APR_SUCCESS;
}
static apr_status_t crypto_cleanup(apr_crypto_t *f)
{
    return APR_SUCCESS;
}
 
static apr_status_t crypto_cleanup_helper(void *data)
{
    apr_crypto_t *f = (apr_crypto_t *) data;
    return crypto_cleanup(f);
}
 
static apr_status_t crypto_make(apr_crypto_t **ff,
        const apr_crypto_driver_t *provider, const char *params,
        apr_pool_t *pool)
{
    apr_crypto_config_t *config = NULL;
    apr_crypto_t *f;
 
    f = apr_pcalloc(pool, sizeof(apr_crypto_t));
    if (!f) {
        return APR_ENOMEM;
    }
    *ff = f;
    f->pool = pool;
    f->provider = provider;
    config = f->config = apr_pcalloc(pool, sizeof(apr_crypto_config_t));
    if (!config) {
        return APR_ENOMEM;
    }
    f->result = apr_pcalloc(pool, sizeof(apu_err_t));
    if (!f->result) {
        return APR_ENOMEM;
    }
 
    f->types = apr_hash_make(pool);
    if (!f->types) {
        return APR_ENOMEM;
    }
    apr_hash_set(f->types, "3des192", APR_HASH_KEY_STRING, &(key_types[0]));
    apr_hash_set(f->types, "aes128", APR_HASH_KEY_STRING, &(key_types[1]));
    apr_hash_set(f->types, "aes192", APR_HASH_KEY_STRING, &(key_types[2]));
    apr_hash_set(f->types, "aes256", APR_HASH_KEY_STRING, &(key_types[3]));
 
    f->modes = apr_hash_make(pool);
    if (!f->modes) {
        return APR_ENOMEM;
    }
    apr_hash_set(f->modes, "ecb", APR_HASH_KEY_STRING, &(key_modes[0]));
    apr_hash_set(f->modes, "cbc", APR_HASH_KEY_STRING, &(key_modes[1]));
 
    apr_pool_cleanup_register(pool, f, crypto_cleanup_helper,
            apr_pool_cleanup_null);
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_get_block_key_types(apr_hash_t **types,
        const apr_crypto_t *f)
{
    *types = f->types;
    return APR_SUCCESS;
}
 
static apr_status_t crypto_get_block_key_modes(apr_hash_t **modes,
        const apr_crypto_t *f)
{
    *modes = f->modes;
    return APR_SUCCESS;
}
 
/*
 * Work out which mechanism to use.
 */
static apr_status_t crypto_cipher_mechanism(apr_crypto_key_t *key,
        const apr_crypto_block_key_type_e type,
        const apr_crypto_block_key_mode_e mode, const int doPad)
{
 
    /* decide on what cipher mechanism we will be using */
    switch (type) {
 
    case (APR_KEY_3DES_192):
        if (APR_MODE_CBC == mode) {
            key->cipherOid = SEC_OID_DES_EDE3_CBC;
        }
        else if (APR_MODE_ECB == mode) {
            return APR_ENOCIPHER;
            /* No OID for CKM_DES3_ECB; */
        }
        key->keyLength = 24;
        break;
    case (APR_KEY_AES_128):
        if (APR_MODE_CBC == mode) {
            key->cipherOid = SEC_OID_AES_128_CBC;
        }
        else {
            key->cipherOid = SEC_OID_AES_128_ECB;
        }
        key->keyLength = 16;
        break;
    case (APR_KEY_AES_192):
        if (APR_MODE_CBC == mode) {
            key->cipherOid = SEC_OID_AES_192_CBC;
        }
        else {
            key->cipherOid = SEC_OID_AES_192_ECB;
        }
        key->keyLength = 24;
        break;
    case (APR_KEY_AES_256):
        if (APR_MODE_CBC == mode) {
            key->cipherOid = SEC_OID_AES_256_CBC;
        }
        else {
            key->cipherOid = SEC_OID_AES_256_ECB;
        }
        key->keyLength = 32;
        break;
    default:
        /* unknown key type, give up */
        return APR_EKEYTYPE;
    }
 
    /* AES_128_CBC --> CKM_AES_CBC --> CKM_AES_CBC_PAD */
    key->cipherMech = PK11_AlgtagToMechanism(key->cipherOid);
    if (key->cipherMech == CKM_INVALID_MECHANISM) {
        return APR_ENOCIPHER;
    }
    if (doPad) {
        CK_MECHANISM_TYPE paddedMech;
        paddedMech = PK11_GetPadMechanism(key->cipherMech);
        if (CKM_INVALID_MECHANISM == paddedMech
                || key->cipherMech == paddedMech) {
            return APR_EPADDING;
        }
        key->cipherMech = paddedMech;
    }
 
    key->ivSize = PK11_GetIVLength(key->cipherMech);
 
    return APR_SUCCESS;
}
 
static apr_status_t crypto_key(apr_crypto_key_t **k,
        const apr_crypto_key_rec_t *rec, const apr_crypto_t *f, apr_pool_t *p)
{
    apr_status_t rv = APR_SUCCESS;
    PK11SlotInfo *slot, *tslot;
    PK11SymKey *tkey;
    SECItem secretItem;
    SECItem wrappedItem;
    SECItem *secParam;
    PK11Context *ctx;
    SECStatus s;
    SECItem passItem;
    SECItem saltItem;
    SECAlgorithmID *algid;
    void *wincx = NULL; /* what is wincx? */
    apr_crypto_key_t *key;
    int blockSize;
    int remainder;
 
    key = *k;
    if (!key) {
        *k = key = apr_pcalloc(p, sizeof *key);
        if (!key) {
            return APR_ENOMEM;
        }
        apr_pool_cleanup_register(p, key, crypto_key_cleanup,
                                  apr_pool_cleanup_null);
    }
 
    key->f = f;
    key->provider = f->provider;
 
    /* decide on what cipher mechanism we will be using */
    rv = crypto_cipher_mechanism(key, rec->type, rec->mode, rec->pad);
    if (APR_SUCCESS != rv) {
        return rv;
    }
 
    switch (rec->ktype) {
 
    case APR_CRYPTO_KTYPE_PASSPHRASE: {
 
        /* Turn the raw passphrase and salt into SECItems */
        passItem.data = (unsigned char*) rec->k.passphrase.pass;
        passItem.len = rec->k.passphrase.passLen;
        saltItem.data = (unsigned char*) rec->k.passphrase.salt;
        saltItem.len = rec->k.passphrase.saltLen;
 
        /* generate the key */
        /* pbeAlg and cipherAlg are the same. */
        algid = PK11_CreatePBEV2AlgorithmID(key->cipherOid, key->cipherOid,
                SEC_OID_HMAC_SHA1, key->keyLength,
                rec->k.passphrase.iterations, &saltItem);
        if (algid) {
            slot = PK11_GetBestSlot(key->cipherMech, wincx);
            if (slot) {
                key->symKey = PK11_PBEKeyGen(slot, algid, &passItem, PR_FALSE,
                        wincx);
                PK11_FreeSlot(slot);
            }
            SECOID_DestroyAlgorithmID(algid, PR_TRUE);
        }
 
        break;
    }
 
    case APR_CRYPTO_KTYPE_SECRET: {
 
        /*
         * NSS is by default in FIPS mode, which disallows the use of unencrypted
         * symmetrical keys. As per http://permalink.gmane.org/gmane.comp.mozilla.crypto/7947
         * we do the following:
         *
         * 1. Generate a (temporary) symmetric key in NSS.
         * 2. Use that symmetric key to encrypt your symmetric key as data.
         * 3. Unwrap your wrapped symmetric key, using the symmetric key
         * you generated in Step 1 as the unwrapping key.
         *
         * http://permalink.gmane.org/gmane.comp.mozilla.crypto/7947
         */
 
        /* generate the key */
        slot = PK11_GetBestSlot(key->cipherMech, NULL);
        if (slot) {
            unsigned char data[BUFFER_SIZE];
 
            /* sanity check - key correct size? */
            if (rec->k.secret.secretLen != key->keyLength) {
                PK11_FreeSlot(slot);
                return APR_EKEYLENGTH;
            }
 
            tslot = PK11_GetBestSlot(CKM_AES_ECB, NULL);
            if (tslot) {
 
                /* generate a temporary wrapping key */
                tkey = PK11_KeyGen(tslot, CKM_AES_ECB, 0, PK11_GetBestKeyLength(tslot, CKM_AES_ECB), 0);
 
                /* prepare the key to wrap */
                secretItem.data = (unsigned char *) rec->k.secret.secret;
                secretItem.len = rec->k.secret.secretLen;
 
                /* ensure our key matches the blocksize */
                secParam = PK11_GenerateNewParam(CKM_AES_ECB, tkey);
                blockSize = PK11_GetBlockSize(CKM_AES_ECB, secParam);
                remainder = rec->k.secret.secretLen % blockSize;
                if (remainder) {
                    secretItem.data =
                            apr_pcalloc(p, rec->k.secret.secretLen + remainder);
                    apr_crypto_clear(p, secretItem.data,
                            rec->k.secret.secretLen);
                    memcpy(secretItem.data, rec->k.secret.secret,
                            rec->k.secret.secretLen);
                    secretItem.len += remainder;
                }
 
                /* prepare a space for the wrapped key */
                wrappedItem.data = data;
 
                /* wrap the key */
                ctx = PK11_CreateContextBySymKey(CKM_AES_ECB, CKA_ENCRYPT, tkey,
                        secParam);
                if (ctx) {
                    s = PK11_CipherOp(ctx, wrappedItem.data,
                            (int *) (&wrappedItem.len), BUFFER_SIZE,
                            secretItem.data, secretItem.len);
                    if (s == SECSuccess) {
 
                        /* unwrap the key again */
                        key->symKey = PK11_UnwrapSymKeyWithFlags(tkey,
                                CKM_AES_ECB, NULL, &wrappedItem,
                                key->cipherMech, CKA_ENCRYPT,
                                rec->k.secret.secretLen, 0);
 
                    }
 
                    PK11_DestroyContext(ctx, PR_TRUE);
                }
 
                /* clean up */
                SECITEM_FreeItem(secParam, PR_TRUE);
                PK11_FreeSymKey(tkey);
                PK11_FreeSlot(tslot);
 
            }
 
            PK11_FreeSlot(slot);
        }
 
        break;
    }
 
    default: {
 
        return APR_ENOKEY;
 
    }
    }
 
    /* sanity check? */
    if (!key->symKey) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            f->result->rc = perr;
            f->result->msg = PR_ErrorToName(perr);
            rv = APR_ENOKEY;
        }
    }
 
    return rv;
}
 
static apr_status_t crypto_passphrase(apr_crypto_key_t **k, apr_size_t *ivSize,
        const char *pass, apr_size_t passLen, const unsigned char * salt,
        apr_size_t saltLen, const apr_crypto_block_key_type_e type,
        const apr_crypto_block_key_mode_e mode, const int doPad,
        const int iterations, const apr_crypto_t *f, apr_pool_t *p)
{
    apr_status_t rv = APR_SUCCESS;
    PK11SlotInfo * slot;
    SECItem passItem;
    SECItem saltItem;
    SECAlgorithmID *algid;
    void *wincx = NULL; /* what is wincx? */
    apr_crypto_key_t *key = *k;
 
    if (!key) {
        *k = key = apr_pcalloc(p, sizeof *key);
        if (!key) {
            return APR_ENOMEM;
        }
        apr_pool_cleanup_register(p, key, crypto_key_cleanup,
                                  apr_pool_cleanup_null);
    }
 
    key->f = f;
    key->provider = f->provider;
 
    /* decide on what cipher mechanism we will be using */
    rv = crypto_cipher_mechanism(key, type, mode, doPad);
    if (APR_SUCCESS != rv) {
        return rv;
    }
 
    /* Turn the raw passphrase and salt into SECItems */
    passItem.data = (unsigned char*) pass;
    passItem.len = passLen;
    saltItem.data = (unsigned char*) salt;
    saltItem.len = saltLen;
 
    /* generate the key */
    /* pbeAlg and cipherAlg are the same. */
    algid = PK11_CreatePBEV2AlgorithmID(key->cipherOid, key->cipherOid,
            SEC_OID_HMAC_SHA1, key->keyLength, iterations, &saltItem);
    if (algid) {
        slot = PK11_GetBestSlot(key->cipherMech, wincx);
        if (slot) {
            key->symKey = PK11_PBEKeyGen(slot, algid, &passItem, PR_FALSE,
                    wincx);
            PK11_FreeSlot(slot);
        }
        SECOID_DestroyAlgorithmID(algid, PR_TRUE);
    }
 
    /* sanity check? */
    if (!key->symKey) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            f->result->rc = perr;
            f->result->msg = PR_ErrorToName(perr);
            rv = APR_ENOKEY;
        }
    }
 
    if (ivSize) {
        *ivSize = key->ivSize;
    }
 
    return rv;
}
 
static apr_status_t crypto_block_encrypt_init(apr_crypto_block_t **ctx,
        const unsigned char **iv, const apr_crypto_key_t *key,
        apr_size_t *blockSize, apr_pool_t *p)
{
    PRErrorCode perr;
    SECItem ivItem;
    unsigned char * usedIv;
    apr_crypto_block_t *block = *ctx;
    if (!block) {
        *ctx = block = apr_pcalloc(p, sizeof(apr_crypto_block_t));
    }
    if (!block) {
        return APR_ENOMEM;
    }
    block->f = key->f;
    block->pool = p;
    block->provider = key->provider;
 
    apr_pool_cleanup_register(p, block, crypto_block_cleanup_helper,
            apr_pool_cleanup_null);
 
    if (key->ivSize) {
        if (iv == NULL) {
            return APR_ENOIV;
        }
        if (*iv == NULL) {
            SECStatus s;
            usedIv = apr_pcalloc(p, key->ivSize);
            if (!usedIv) {
                return APR_ENOMEM;
            }
            apr_crypto_clear(p, usedIv, key->ivSize);
            s = PK11_GenerateRandom(usedIv, key->ivSize);
            if (s != SECSuccess) {
                return APR_ENOIV;
            }
            *iv = usedIv;
        }
        else {
            usedIv = (unsigned char *) *iv;
        }
        ivItem.data = usedIv;
        ivItem.len = key->ivSize;
        block->secParam = PK11_ParamFromIV(key->cipherMech, &ivItem);
    }
    else {
        block->secParam = PK11_GenerateNewParam(key->cipherMech, key->symKey);
    }
    block->blockSize = PK11_GetBlockSize(key->cipherMech, block->secParam);
    block->ctx = PK11_CreateContextBySymKey(key->cipherMech, CKA_ENCRYPT,
            key->symKey, block->secParam);
 
    /* did an error occur? */
    perr = PORT_GetError();
    if (perr || !block->ctx) {
        key->f->result->rc = perr;
        key->f->result->msg = PR_ErrorToName(perr);
        return APR_EINIT;
    }
 
    if (blockSize) {
        *blockSize = PK11_GetBlockSize(key->cipherMech, block->secParam);
    }
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_encrypt(unsigned char **out,
        apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
        apr_crypto_block_t *block)
{
 
    unsigned char *buffer;
    int outl = (int) *outlen;
    SECStatus s;
    if (!out) {
        *outlen = inlen + block->blockSize;
        return APR_SUCCESS;
    }
    if (!*out) {
        buffer = apr_palloc(block->pool, inlen + block->blockSize);
        if (!buffer) {
            return APR_ENOMEM;
        }
        apr_crypto_clear(block->pool, buffer, inlen + block->blockSize);
        *out = buffer;
    }
 
    s = PK11_CipherOp(block->ctx, *out, &outl, inlen, (unsigned char*) in,
            inlen);
    if (s != SECSuccess) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            block->f->result->rc = perr;
            block->f->result->msg = PR_ErrorToName(perr);
        }
        return APR_ECRYPT;
    }
    *outlen = outl;
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_encrypt_finish(unsigned char *out,
        apr_size_t *outlen, apr_crypto_block_t *block)
{
 
    apr_status_t rv = APR_SUCCESS;
    unsigned int outl = *outlen;
 
    SECStatus s = PK11_DigestFinal(block->ctx, out, &outl, block->blockSize);
    *outlen = outl;
 
    if (s != SECSuccess) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            block->f->result->rc = perr;
            block->f->result->msg = PR_ErrorToName(perr);
        }
        rv = APR_ECRYPT;
    }
    crypto_block_cleanup(block);
 
    return rv;
 
}
 
static apr_status_t crypto_block_decrypt_init(apr_crypto_block_t **ctx,
        apr_size_t *blockSize, const unsigned char *iv,
        const apr_crypto_key_t *key, apr_pool_t *p)
{
    PRErrorCode perr;
    apr_crypto_block_t *block = *ctx;
    if (!block) {
        *ctx = block = apr_pcalloc(p, sizeof(apr_crypto_block_t));
    }
    if (!block) {
        return APR_ENOMEM;
    }
    block->f = key->f;
    block->pool = p;
    block->provider = key->provider;
 
    apr_pool_cleanup_register(p, block, crypto_block_cleanup_helper,
            apr_pool_cleanup_null);
 
    if (key->ivSize) {
        SECItem ivItem;
        if (iv == NULL) {
            return APR_ENOIV; /* Cannot initialise without an IV */
        }
        ivItem.data = (unsigned char*) iv;
        ivItem.len = key->ivSize;
        block->secParam = PK11_ParamFromIV(key->cipherMech, &ivItem);
    }
    else {
        block->secParam = PK11_GenerateNewParam(key->cipherMech, key->symKey);
    }
    block->blockSize = PK11_GetBlockSize(key->cipherMech, block->secParam);
    block->ctx = PK11_CreateContextBySymKey(key->cipherMech, CKA_DECRYPT,
            key->symKey, block->secParam);
 
    /* did an error occur? */
    perr = PORT_GetError();
    if (perr || !block->ctx) {
        key->f->result->rc = perr;
        key->f->result->msg = PR_ErrorToName(perr);
        return APR_EINIT;
    }
 
    if (blockSize) {
        *blockSize = PK11_GetBlockSize(key->cipherMech, block->secParam);
    }
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_decrypt(unsigned char **out,
        apr_size_t *outlen, const unsigned char *in, apr_size_t inlen,
        apr_crypto_block_t *block)
{
 
    unsigned char *buffer;
    int outl = (int) *outlen;
    SECStatus s;
    if (!out) {
        *outlen = inlen + block->blockSize;
        return APR_SUCCESS;
    }
    if (!*out) {
        buffer = apr_palloc(block->pool, inlen + block->blockSize);
        if (!buffer) {
            return APR_ENOMEM;
        }
        apr_crypto_clear(block->pool, buffer, inlen + block->blockSize);
        *out = buffer;
    }
 
    s = PK11_CipherOp(block->ctx, *out, &outl, inlen, (unsigned char*) in,
            inlen);
    if (s != SECSuccess) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            block->f->result->rc = perr;
            block->f->result->msg = PR_ErrorToName(perr);
        }
        return APR_ECRYPT;
    }
    *outlen = outl;
 
    return APR_SUCCESS;
 
}
 
static apr_status_t crypto_block_decrypt_finish(unsigned char *out,
        apr_size_t *outlen, apr_crypto_block_t *block)
{
 
    apr_status_t rv = APR_SUCCESS;
    unsigned int outl = *outlen;
 
    SECStatus s = PK11_DigestFinal(block->ctx, out, &outl, block->blockSize);
    *outlen = outl;
 
    if (s != SECSuccess) {
        PRErrorCode perr = PORT_GetError();
        if (perr) {
            block->f->result->rc = perr;
            block->f->result->msg = PR_ErrorToName(perr);
        }
        rv = APR_ECRYPT;
    }
    crypto_block_cleanup(block);
 
    return rv;
 
}
 
APU_MODULE_DECLARE_DATA const apr_crypto_driver_t apr_crypto_nss_driver = {
    "nss", crypto_init, crypto_make, crypto_get_block_key_types,
    crypto_get_block_key_modes, crypto_passphrase,
    crypto_block_encrypt_init, crypto_block_encrypt,
    crypto_block_encrypt_finish, crypto_block_decrypt_init,
    crypto_block_decrypt, crypto_block_decrypt_finish,
    crypto_block_cleanup, crypto_cleanup, crypto_shutdown, crypto_error,
    crypto_key
};
 
#endif