Initial commit.

.gitignore

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+.idea
+vendor
+composer.lock

.travis.yml

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+language: php
+sudo: false
+
+matrix:
+  fast_finish: true
+  include:
+    - php: "7.0"
+    - php: "7.1"
+    - php: "nightly"
+  allow_failures:
+    - php: "nightly"
+
+install:
+    - composer self-update
+    - composer update
+
+script:
+    - vendor/bin/phpunit --bootstrap=phpunit-autoload.php
+    - php -dmbstring.func_overload=7 vendor/bin/phpunit --bootstrap=phpunit-autoload.php
+    - vendor/bin/psalm

LICENSE

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+The MIT License (MIT)
+
+Copyright (c) 2017 Paragon Initiative Enterprises
+
+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.
+

README.md

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+# Blakechain
+
+Blakechain is a simple hash-chain data structure based on the BLAKE2b hash function.
+
+Includes:
+
+* The `Blakechain` implementation, which chains together `Node` objects
+* A runtime `Verifier` class that validates the self-consistency of an entire chain

composer.json

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+{
+  "name": "paragonie/blakechain",
+  "description": "Hash chain using BLAKE2b",
+  "type": "library",
+  "require": {
+    "php": "^7",
+    "paragonie/constant_time_encoding": "^2",
+    "paragonie/sodium_compat": "^1"
+  },
+  "require-dev": {
+    "phpunit/phpunit": "^6",
+    "vimeo/psalm": "dev-master"
+  },
+  "autoload": {
+    "psr-4": {
+      "ParagonIE\\Blakechain\\": "src"
+    }
+  },
+  "license": "MIT",
+  "authors": [
+    {
+      "name": "Paragon Initiative Enterprises",
+      "email": "[email protected]"
+    }
+  ]
+}

phpunit-autoload.php

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+<?php
+require 'vendor/autoload.php';
+
+ParagonIE_Sodium_Compat::$fastMult = true;

phpunit.xml.dist

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+<?xml version="1.0" encoding="UTF-8"?>
+<phpunit
+    backupGlobals="true"
+    backupStaticAttributes="false"
+    bootstrap="vendor/autoload.php"
+    colors="true"
+    convertErrorsToExceptions="true"
+    convertNoticesToExceptions="true"
+    convertWarningsToExceptions="true"
+    processIsolation="false"
+    stopOnError="false"
+    stopOnFailure="false"
+    syntaxCheck="true"
+>
+    <testsuites>
+        <testsuite name="Unit Tests">
+            <directory suffix="Test.php">./tests</directory>
+        </testsuite>
+    </testsuites>
+    <filter>
+        <whitelist processUncoveredFilesFromWhitelist="true">
+            <directory suffix=".php">./src</directory>
+        </whitelist>
+    </filter>
+</phpunit>

psalm.xml

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+<?xml version="1.0"?>
+<psalm
+    stopOnFirstError="false"
+    useDocblockTypes="true"
+>
+    <projectFiles>
+        <directory name="src" />
+    </projectFiles>
+</psalm>

src/Blakechain.php

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+<?php
+declare(strict_types=1);
+namespace ParagonIE\Blakechain;
+
+/**
+ * Class Blakechain
+ * @package ParagonIE\Blakechain
+ */
+class Blakechain
+{
+    const HASH_SIZE = 32;
+
+    /**
+     * @var array<int, Node>
+     */
+    protected $nodes;
+
+    /**
+     * Blakechain constructor.
+     * @param array<int, Node> $nodes
+     * @throws \Error
+     */
+    public function __construct(Node ...$nodes)
+    {
+        $num = \count($nodes);
+        if ($num < 1) {
+            throw new \Error('Nodes expected.');
+        }
+        $prevHash = '';
+        for ($i = 0; $i < $num; ++$i) {
+            $thisNodesPrev = $nodes[$i]->getPrevHash();
+            if (empty($thisNodesPrev)) {
+                $nodes[$i]->setPrevHash($prevHash);
+            }
+            $prevHash = $nodes[$i]->getHash(true);
+        }
+        $this->nodes = $nodes;
+    }
+
+    /**
+     * @param bool $rawBinary
+     * @return string
+     */
+    public function getLastHash(bool $rawBinary = false): string
+    {
+        return $this->getLastNode()->getHash($rawBinary);
+    }
+
+    /**
+     * Append a new Node.
+     *
+     * @param string $data
+     * @return self
+     */
+    public function appendData(string $data): self
+    {
+        $last = $this->getLastNode();
+        $prevHash = $last->getHash(true);
+        $this->nodes[] = new Node($data, $prevHash);
+        return $this;
+    }
+
+    /**
+     * @return array<int, Node>
+     */
+    public function getNodes(): array
+    {
+        return \array_values($this->nodes);
+    }
+
+    /**
+     * @param int $offset
+     * @param int $limit
+     * @return array
+     */
+    public function getPartialChain(int $offset = 0, int $limit = PHP_INT_MAX): array
+    {
+        $chain = [];
+        $num = \count($this->nodes);
+        for ($i = 0; $i < $limit && $i < $num; ++$i) {
+            $chain[] = [
+                'prev' => $this->nodes[$offset]->getPrevHash(),
+                'data' => $this->nodes[$offset]->getData(),
+                'hash' => $this->nodes[$offset]->getHash()
+            ];
+            ++$offset;
+        }
+        return $chain;
+    }
+
+    /**
+     * @return Node
+     */
+    public function getLastNode(): Node
+    {
+        if (empty($this->nodes)) {
+            throw new \Error('Blakechain has no nodes');
+        }
+        $keys = \array_keys($this->nodes);
+        $last = \array_pop($keys);
+        return $this->nodes[$last];
+    }
+}

src/Node.php

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+<?php
+declare(strict_types=1);
+namespace ParagonIE\Blakechain;
+
+use ParagonIE\ConstantTime\Base64UrlSafe;
+
+/**
+ * Class Node
+ * @package ParagonIE\Blakechain
+ */
+class Node
+{
+    /**
+     * @var string
+     */
+    protected $prevHash;
+
+    /**
+     * @var string
+     */
+    protected $data;
+
+    /**
+     * @var string
+     */
+    protected $hash;
+
+    /**
+     * Node constructor.
+     *
+     * @param string $data
+     * @param string $prevHash
+     */
+    public function __construct(string $data, string $prevHash = '')
+    {
+        $this->data = $data;
+        $this->prevHash = $prevHash;
+    }
+
+    /**
+     * @param bool $rawBinary
+     * @return string
+     */
+    public function getPrevHash(bool $rawBinary = false): string
+    {
+        if ($rawBinary) {
+            return $this->prevHash;
+        }
+        return Base64UrlSafe::encode($this->prevHash);
+    }
+
+    /**
+     * @param bool $rawBinary
+     * @return string
+     */
+    public function getHash(bool $rawBinary = false): string
+    {
+        if (empty($this->hash)) {
+            $this->hash = \ParagonIE_Sodium_Compat::crypto_generichash(
+                $this->data,
+                $this->prevHash,
+                Blakechain::HASH_SIZE
+            );
+        }
+        if ($rawBinary) {
+            return $this->hash;
+        }
+        return Base64UrlSafe::encode($this->hash);
+    }
+
+    /**
+     * @return string
+     */
+    public function getData(): string
+    {
+        return $this->data;
+    }
+
+    /**
+     * @param string $prevHash
+     * @return self
+     */
+    public function setPrevHash(string $prevHash): self
+    {
+        $this->prevHash = $prevHash;
+        $this->hash = '';
+        return $this;
+    }
+}