{"id":1908,"date":"2020-03-30T18:29:24","date_gmt":"2020-03-30T18:29:24","guid":{"rendered":"https:\/\/golangbyexamples.com\/?p=1908"},"modified":"2020-04-12T18:58:28","modified_gmt":"2020-04-12T18:58:28","slug":"generate-random-password-golang","status":"publish","type":"post","link":"https:\/\/golangbyexamples.com\/generate-random-password-golang\/","title":{"rendered":"Generate a random password in Go (Golang)"},"content":{"rendered":"\n<div id=\"ez-toc-container\" class=\"ez-toc-v2_0_17 counter-hierarchy counter-decimal ez-toc-light-blue\">\n<div class=\"ez-toc-title-container\">\n<p class=\"ez-toc-title\">Table of Contents<\/p>\n<span class=\"ez-toc-title-toggle\"><a class=\"ez-toc-pull-right ez-toc-btn ez-toc-btn-xs ez-toc-btn-default ez-toc-toggle\" style=\"display: none;\"><i class=\"ez-toc-glyphicon ez-toc-icon-toggle\"><\/i><\/a><\/span><\/div>\n<nav><ul class=\"ez-toc-list ez-toc-list-level-1\"><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-1\" href=\"https:\/\/golangbyexamples.com\/generate-random-password-golang\/#Overview\" title=\"Overview\">Overview<\/a><\/li><li class=\"ez-toc-page-1 ez-toc-heading-level-1\"><a class=\"ez-toc-link ez-toc-heading-2\" href=\"https:\/\/golangbyexamples.com\/generate-random-password-golang\/#Code\" title=\"Code\">Code<\/a><\/li><\/ul><\/nav><\/div>\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Overview\"><\/span><strong>Overview<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<p class=\"has-medium-font-size\"><strong>&#8216;math\/rand&#8217; <\/strong>package of golang contains an Intn function that can be used to generate a pseudo-random number between [0,n). The bracket at the end means that n is exclusive. This function can be utilized to generate a random password from a character set.<\/p>\n\n\n\n<p class=\"has-medium-font-size\"><br>To know more about what pseudo-random number means, check out this post &#8211; <a href=\"https:\/\/golangbyexamples.com\/generate-random-number-golang\">https:\/\/golangbyexamples.com\/generate-random-number-golang<\/a><\/p>\n\n\n\n<p class=\"has-medium-font-size\">Below is the signature of this method. It takes input a number n and will return a number x in range 0&lt;=x&lt;n.<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">func Intn(n int) int<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">In the code below we have first defined the character set from which to generate the password<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-\">lowerCharSet   = \"abcdedfghijklmnopqrst\"\nupperCharSet   = \"ABCDEFGHIJKLMNOPQRSTUVWXYZ\"\nspecialCharSet = \"!@#$%&*\"\nnumberSet      = \"0123456789\"\nallCharSet     = lowerCharSet + upperCharSet + specialCharSet + numberSet<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\">The below code also handles the case where the password can have minimum requirement of a specific number of special character, numeric or uppercase character.<\/p>\n\n\n\n<p class=\"has-medium-font-size\">Also please note once the password is generated with required criteria we shuffle it at the end. For shuffling, we convert it to a rune array first.  Please refer to this article to understand why for shuffling a string &#8211; <a href=\"https:\/\/golangbyexamples.com\/shuffle-string-golang\/\">https:\/\/golangbyexamples.com\/shuffle-string-golang\/<\/a><\/p>\n\n\n\n<p><\/p>\n\n\n\n<h1 class=\"wp-block-heading\"><span class=\"ez-toc-section\" id=\"Code\"><\/span><strong>Code<\/strong><span class=\"ez-toc-section-end\"><\/span><\/h1>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">package main\n\nimport (\n    \"fmt\"\n    \"math\/rand\"\n    \"strings\"\n    \"time\"\n)\n\nvar (\n    lowerCharSet   = \"abcdedfghijklmnopqrst\"\n    upperCharSet   = \"ABCDEFGHIJKLMNOPQRSTUVWXYZ\"\n    specialCharSet = \"!@#$%&*\"\n    numberSet      = \"0123456789\"\n    allCharSet     = lowerCharSet + upperCharSet + specialCharSet + numberSet\n)\n\nfunc main() {\n    rand.Seed(time.Now().Unix())\n    minSpecialChar := 1\n    minNum := 1\n    minUpperCase := 1\n    passwordLength := 8\n    password := generatePassword(passwordLength, minSpecialChar, minNum, minUpperCase)\n    fmt.Println(password)\n\n    minSpecialChar = 2\n    minNum = 2\n    minUpperCase = 2\n    passwordLength = 20\n    password = generatePassword(passwordLength, minSpecialChar, minNum, minUpperCase)\n    fmt.Println(password)\n}\n\nfunc generatePassword(passwordLength, minSpecialChar, minNum, minUpperCase int) string {\n    var password strings.Builder\n\n    \/\/Set special character\n    for i := 0; i < minSpecialChar; i++ {\n        random := rand.Intn(len(specialCharSet))\n        password.WriteString(string(specialCharSet[random]))\n    }\n\n    \/\/Set numeric\n    for i := 0; i < minNum; i++ {\n        random := rand.Intn(len(numberSet))\n        password.WriteString(string(numberSet[random]))\n    }\n\n    \/\/Set uppercase\n    for i := 0; i < minUpperCase; i++ {\n        random := rand.Intn(len(upperCharSet))\n        password.WriteString(string(upperCharSet[random]))\n    }\n\n    remainingLength := passwordLength - minSpecialChar - minNum - minUpperCase\n    for i := 0; i < remainingLength; i++ {\n        random := rand.Intn(len(allCharSet))\n        password.WriteString(string(allCharSet[random]))\n    }\n    inRune := []rune(password.String())\n\trand.Shuffle(len(inRune), func(i, j int) {\n\t\tinRune[i], inRune[j] = inRune[j], inRune[i]\n\t})\n\treturn string(inRune)\n}<\/code><\/pre>\n\n\n\n<p class=\"has-medium-font-size\"><strong>Output<\/strong><\/p>\n\n\n\n<p class=\"has-medium-font-size\">Output will be different on your machine<\/p>\n\n\n\n<pre class=\"wp-block-prismatic-blocks\"><code class=\"language-go\">e$e&tD19\n4T$&Qmg2rA4DXD5a2OGs<\/code><\/pre>\n","protected":false},"excerpt":{"rendered":"<p>Table of Contents OverviewCode Overview &#8216;math\/rand&#8217; package of golang contains an Intn function that can be used to generate a pseudo-random number between [0,n). The bracket at the end means that n&#8230;<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"spay_email":"","footnotes":"","jetpack_publicize_message":"","jetpack_is_tweetstorm":false},"categories":[1],"tags":[3,4,258],"class_list":["post-1908","post","type-post","status-publish","format-standard","hentry","category-tech","tag-go","tag-golang","tag-random-password"],"yoast_head":"<!-- This site is optimized with the Yoast SEO plugin v22.7 - https:\/\/yoast.com\/wordpress\/plugins\/seo\/ -->\n<title>Generate a random password in Go (Golang) - Welcome To Golang By Example<\/title>\n<meta name=\"robots\" content=\"index, follow, max-snippet:-1, max-image-preview:large, max-video-preview:-1\" \/>\n<link rel=\"canonical\" href=\"https:\/\/golangbyexamples.com\/generate-random-password-golang\/\" \/>\n<meta property=\"og:locale\" content=\"en_US\" \/>\n<meta property=\"og:type\" content=\"article\" \/>\n<meta property=\"og:title\" content=\"Generate a random password in Go (Golang) - Welcome To Golang By Example\" \/>\n<meta property=\"og:description\" content=\"Table of Contents OverviewCode Overview &#8216;math\/rand&#8217; package of golang contains an Intn function that can be used to generate a pseudo-random number between [0,n). 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