base64

Is a base64 encoded string unique?

由 假如想象 提交于 2019-12-28 12:15:12
问题 I can't find an answer to this. If I encode a string with Base64 will the encoded output be unique based on the string? I ask because I want to create a token which will contain user information so I need make sure the output will be unique depending on the information. For example if I encode "UnqUserId:987654321 Timestamp:01/02/03" will this be unique so no matter what other userid I put it in there will never be a collision? 回答1: Two years late, but here we go: The short answer is yes,

Node.js base64 encode a downloaded image for use in data URI

由 强颜欢笑 提交于 2019-12-28 12:05:43
问题 Using Node v0.2.0 I am trying to fetch an image from a server, convert it into a base64 string and then embed it on the page in an image tag. I have the following code: var express = require('express'), request = require('request'), sys = require('sys'); var app = express.createServer( express.logger(), express.bodyDecoder() ); app.get('/', function(req, res){ if(req.param("url")) { var url = unescape(req.param("url")); request({uri:url}, function (error, response, body) { if (!error &&

How to base64-decode large files in PHP

由 穿精又带淫゛_ 提交于 2019-12-28 11:56:25
问题 My PHP web application has an API that can recieve reasonably large files (up to 32 MB) which are base64 encoded. The goal is to write these files somewhere on my filesystem. Decoded of course. What would be the least resource intensive way of doing this? Edit: Recieving the files through an API means that I have a 32MB string in my PHP app, not a 32 MB source file somewhere on disk. I need to get that string decoded an onto the filesystem. Using PHP's own base64_decode() isn't cutting it

Out of memory when encoding file to base64

由 孤人 提交于 2019-12-28 01:56:07
问题 Using Base64 from Apache commons public byte[] encode(File file) throws FileNotFoundException, IOException { byte[] encoded; try (FileInputStream fin = new FileInputStream(file)) { byte fileContent[] = new byte[(int) file.length()]; fin.read(fileContent); encoded = Base64.encodeBase64(fileContent); } return encoded; } Exception in thread "AWT-EventQueue-0" java.lang.OutOfMemoryError: Java heap space at org.apache.commons.codec.binary.BaseNCodec.encode(BaseNCodec.java:342) at org.apache

忘记密码流程——UUID，AES

由 我只是一个虾纸丫 提交于 2019-12-27 21:13:50
忘记密码流程 1.进入忘记密码页面 2. 后台检验参数合法性（null，验证码，邮箱合法性） 3，生成更新密码链接，并将相关参数写入DB 　　link=urlBase（baseurl）+updatePassword？pwdid（相关参数在db中的id）&uuid（存于db中，用于步骤6检验外来链接的合法性） 4，发送邮件给客户 5. 客户点击邮件中的更新链接 6. 更新前参数的检验（status=1失效，status=2超过24小） 7，设置相关参数到更新页面（newpwd，repwd）； 其中用到的知识点：uuid，Aes加密 UUID是指在一台机器上生成的数字，它保证对在同一时空中的所有机器都是唯一的。使用UUID的好处在分布式的软件系统中（比如：DCE/RPC, COM+,CORBA）就能体现出来，它能保证每个节点所生成的标识都不会重复 UUID由以下几部分的组合： （1）当前日期和时间，UUID的第一个部分与时间有关，如果你在生成一个UUID之后，过几秒又生成一个UUID，则第一个部分不同，其余相同。 （2）时钟序列。 （3）全局唯一的IEEE机器识别号，如果有网卡，从网卡MAC地址获得，没有网卡以其他方式获得。 import java.util.UUID; UUID uuid = UUID.randomUUID(); 1.加密： 例：加密方式： AES128(CBC

Base64 length calculation?

由 允我心安 提交于 2019-12-27 10:59:49
问题 After reading the base64 wiki ... I'm trying to figure out how's the formula working : Given a string with length of n , the base64 length will be Which is : 4*Math.Ceiling(((double)s.Length/3))) I already know that base64 length must be %4==0 to allow the decoder know what was the original text length. The max number of padding for a sequence can be = or == . wiki :The number of output bytes per input byte is approximately 4 / 3 (33% overhead) Question: How does the information above settle

CSS网页中导入特殊字体@font-face属性详解

由 血红的双手。 提交于 2019-12-26 12:07:33
在最近移动端项目中用到了vux，感觉用着还习惯，当把vux使用到PC端的时候出现了IE浏览器出现，这样的错误信息： CSS3114: @font-face 未能完成 OpenType 嵌入权限检查。权限必须是可安装的。 文件: UwCtGsNCf5NCQ0N.... 然后在IE浏览器页面中的字体图标就没有显示。 原来在vux中weiui_font.less文件中，如下写法： @font-face { font-weight: normal; font-style: normal; font-family: "weui"; src: url('data:application/octet-stream;base64,AAE...省略') format('truetype'); } 于是想到了把base64格式字体转换为可用的字体文件。 实现步骤： 1. 获取到base64字符串并删除头部信息，在这里就是 data:font/opentype;base64 , 逗号也要删除，这样就获取到了字体信息。 比如： T1RUTwAJAIAAAwAQQ0ZGIBcEq...... 过长不展示 。 2. 访问 http://www.motobit.com/util/base64-decoder-encoder.asp 这个网站，将纯字体信息字符串粘贴进编辑区域

Passing base64-encoded data in php

由 被刻印的时光 ゝ 提交于 2019-12-25 18:30:07
问题 I have a page that receive via GET a base64 encoded data, it print data in an input hidden and it pass via get to another page. The problem is this: when i pass "Peuq/0X4XhFV+XNa8T06qFrP8lRadORUQBGJ1w6D4m33Jaqx/skKDEJIxjldBrcklboL/uB4C65cjz3BHMPmd3moEJ4GTK5k5Jwf9Ny4BA467bwgeaHJuOS+CjwFlIOzrhSWHTMVl4zWVvwMauuFAjhuMjOOj0/X5L12IcwGTTqLgHo" via GET it becomes "Peuq/0X4XhFV XNa8T06qFrP8lRadORUQBGJ1w6D4m33Jaqx/skKDEJIxjldBrcklboL/uB4C65cjz3BHMPmd3moEJ4GTK5k5Jwf9Ny4BA467bwgeaHJuOS

Concatenate two Base64 encoded strings

由 点点圈 提交于 2019-12-25 18:21:32
问题 I want to decode two Base64 encoded strings and combine them to make one 128 bit string. I am able to decode the Base64 encoded strings. Can some one guide me on how to combine these two decoded strings? This is the code I used for decoding the two encoded strings. NSData *decodedData_contentKey = [[NSData alloc] initWithBase64EncodedString:str_content options:0]; NSString *decodedString_contentKey = [[NSString alloc] initWithData:decodedData_contentKey encoding:NSUTF8StringEncoding]; NSLog(@

JSON parse error: Cannot deserialize instance of `byte[]` out of START_OBJECT token

由 限于喜欢 提交于 2019-12-25 18:06:35
问题 How to send a base64 image in postman json format. I was added image file in postman- body form data and it's encode details in json format but i got a bad request only in my attempts. [JSON parse error: Cannot deserialize instance of byte[] out of START_OBJECT token]. found that there is no error in source but the actual issue in json format in postman. SOURCE: https://github.com/arun0009/ocr-tess4j-rest I applied a stack overflow solution but it's repeating the same error. I was adding [] ,
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