> For the complete documentation index, see [llms.txt](https://developer.ivvy.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://developer.ivvy.com/development-reference/hmac-sha1.md).

# HMAC-SHA1

## Bash

The openssl package available in most linux distributions include a way of creating the HMAC-SHA1 string from the command line…

```javascript
echo -n "string to sign" | openssl dgst -sha1 -hmac "my secret key"
(stdin)= a993876ea1218921a1c8551923473da7b310dfae
```

## C\\

```javascript
Encoding encoding = Encoding.UTF8;
byte[] secretBytes = encoding.GetBytes(“my secret key”);
HMACSHA1 hmacsha1 = new HMACSHA1(secretBytes);
hmacsha1.ComputeHash(encoding.GetBytes(“string to sign”));
byte[] data = hmacsha1.Hash;
```

## Javascript

Cryptographic functions are available from the CryptJS libaray at <https://code.google.com/p/crypto-js/>.

```javascript
var stringToSign = “string to sign”;
var secret = “my secret key”;
var signature = CryptoJS.HmacSHA1(stringToSign, secret);
```

## NodeJS

This code assumes you have the crypto-js library installed (npm install crypto-js)

```javascript
$ cat hmacsha1.js 
var CryptoJS = require('crypto-js'),
    message = "string to sign",
    secret = "my secret key",
    sig = CryptoJS.HmacSHA1(message, secret);
console.log("" + sig);

$ node hmacsha1.js 
a993876ea1218921a1c8551923473da7b310dfae
```

## Objective-C

HMAC-SHA1 functionality can be be included in IOS code by first adding the CommonCrypto library to your target, and including the following function in your appDelegate (or appropriate class)

```javascript
#import <CommonCrypto/CommonDigest.h>
...
+(NSString*) hmac_sha1:(NSString*)input usingSecret:(NSString*)key
{
    const char *cKey = [key UTF8String];
    const char *cInput = [input UTF8String];
    unsigned char digest[CC_SHA1_DIGEST_LENGTH];
    if (cKey == nil || cInput == nil) {
        return @"";
    }
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
    CCHmac(kCCHmacAlgSHA1, cKey, strlen(cKey), cInput, strlen(cInput), digest);
    for (int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++) {
        [output appendFormat:@"%02x", digest[i]];
    }
    return output;
}
...
```

## PHP

Generating the HMAC-SHA1 in PHP can be done using the following code.

```javascript
<?php 
$stringToSign = “string to sign”;
$keySecret = “my secret key”;
$signature = hash_hmac(”sha1”, $stringToSign, $keySecret);
echo $signature;’
?>
```

This will generate an encrypted hash of the string. In this case the string will be

a993876ea1218921a1c8551923473da7b310dfae

## Ruby

Start up the ‘irb’ and try the following

```javascript
irb(main):001:0> require('openssl')
=> true
irb(main):002:0> OpenSSL::HMAC.hexdigest('sha1', 'my secret key', 'string to sign')
=> "a993876ea1218921a1c8551923473da7b310dfae"
```


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://developer.ivvy.com/development-reference/hmac-sha1.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.