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// Copyright (c) 2018, Compiler Explorer Authors
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
//
// * Redistributions of source code must retain the above copyright notice,
// this list of conditions and the following disclaimer.
// * Redistributions in binary form must reproduce the above copyright
// notice, this list of conditions and the following disclaimer in the
// documentation and/or other materials provided with the distribution.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
// AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
// IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
// ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
// LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
// CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
// SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
// INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
// CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
// ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
import * as express from 'express';
import {profanities} from 'profanities';
import {logger} from '../logger.js';
import {CompilerProps} from '../properties.js';
import * as utils from '../utils.js';
const FILE_HASH_VERSION = 'Compiler Explorer Config Hasher 2';
/* How long a string to check for possible unusable hashes (Profanities or confusing text)
Note that a Hash might end up being longer than this!
*/
const USABLE_HASH_CHECK_LENGTH = 9; // Quite generous
const MAX_TRIES = 4;
export abstract class StorageBase {
constructor(protected readonly httpRootDir: string, protected readonly compilerProps: CompilerProps) {}
/**
* Encode a buffer as a URL-safe string.
*/
static encodeBuffer(buffer: Buffer): string {
return utils.base32Encode(buffer);
}
static isCleanText(text: string) {
const lowercased = text.toLowerCase();
return !profanities.some(badWord => lowercased.includes(badWord));
}
static getRawConfigHash(config) {
return StorageBase.encodeBuffer(utils.getBinaryHash(JSON.stringify(config), FILE_HASH_VERSION));
}
static getSafeHash(config) {
// Keep rehashing until a usable text is found
let configHash = StorageBase.getRawConfigHash(config);
let tries = 1;
while (!StorageBase.isCleanText(configHash.substr(0, USABLE_HASH_CHECK_LENGTH))) {
// Shake up the hash a bit by adding, or incrementing a nonce value.
config.nonce = tries;
logger.info(`Unusable text found in full hash ${configHash} - Trying again (${tries})`);
if (tries <= MAX_TRIES) {
configHash = StorageBase.getRawConfigHash(config);
++tries;
} else {
logger.warn(`Gave up trying to find clean text for ${configHash}`);
break;
}
}
// And stringify it for the rest of the request
config = JSON.stringify(config);
return {config, configHash};
}
static configFor(req: express.Request) {
if (req.body.config) {
return req.body.config;
} else if (req.body.sessions) {
return req.body;
}
return null;
}
handler(req: express.Request, res: express.Response) {
// Get the desired config and check for profanities in its hash
const origConfig = StorageBase.configFor(req);
if (!origConfig) {
logger.error('No configuration found');
res.status(500);
res.send('Missing config parameter');
return;
}
const {config, configHash} = StorageBase.getSafeHash(origConfig);
this.findUniqueSubhash(configHash)
.then(result => {
logger.info(
`Unique subhash '${result.uniqueSubHash}' ` +
`(${result.alreadyPresent ? 'was already present' : 'newly-created'})`,
);
if (result.alreadyPresent) {
return result;
} else {
const storedObject = {
prefix: result.prefix,
uniqueSubHash: result.uniqueSubHash,
fullHash: configHash,
config: config,
};
return this.storeItem(storedObject, req);
}
})
.then(result => {
res.send({url: `${req.protocol}://${req.get('host')}${this.httpRootDir}z/${result.uniqueSubHash}`});
})
.catch(err => {
logger.error(err);
res.status(500);
res.send(err.message);
});
}
abstract storeItem(item, req: express.Request): Promise<any>;
abstract findUniqueSubhash(hash: string): Promise<any>;
abstract expandId(id: string): Promise<{config: string; specialMetadata: any}>;
abstract incrementViewCount(id): Promise<any>;
}
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