No One Here Gets OAuth Alive (flickr)

No One Here Gets OAuth Alive (flickr)

I love web services, I love API, I can’t say the same for OAuth!

It’s frustrating at times, when you’re not using any of the existing libraries to get the entire flow running.

If you have a headless server, with a terminal console and limited programming languages at hand, one of the best options you have is cURL.

There’s a lot of documentation out there about this tool, and the official manual is more than enough to start with.

I’ll try to guide you through the Kafkaesque OAuth process using a web service API that still uses the 1.0 revision of OAuth: flickr

To follow the steps all you need is cURL, openssl and sed. I am using Amazon Linux on EC2. I assume you already have a flickr account.

1. Get an API Key

api_key

2. Get a Request Token:

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

timestamp="$(/bin/date +%s)"
nonce="$(/bin/date +%s%T%N | /usr/bin/openssl base64 | /bin/sed -e s’/[+=/]//g’)"

request_url="GET&https%3A%2F%2Fwww.flickr.com%2Fservices%2Foauth%2Frequest_token"

consumerkey=b284fdada……f2fbbe1145
consumersecret=17a……..c36

basestring="$(echo ${request_url}’&oauth_callback%3Doob%26oauth_consumer_key%3D’${consumerkey}’%26oauth_nonce%3D’${nonce}’%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D’${timestamp}’%26oauth_version%3D1.0′)"
echo ‘basestring=’${basestring}

signature="$(echo -n ${basestring} | openssl dgst -sha1 -hmac ${consumersecret}’&’ -binary | /usr/bin/openssl base64 | /bin/sed -e s’/+/%2B/’ -e s’///%2F/’ -e s’/=/%3D/’)"
echo ‘signature=’${signature}

request_output="$(/usr/bin/curl –compressed -s -H "Accept-Encoding: gzip,deflate" "https://www.flickr.com/services/oauth/request_token?oauth_callback=oob&oauth_consumer_key="${consumerkey}"&oauth_nonce="${nonce}"&oauth_signature="${signature}"&oauth_signature_method=HMAC-SHA1&oauth_timestamp="${timestamp}"&oauth_version=1.0")"
# echo ‘request_output = ‘"${request_output}"
echo ${request_output} | awk -F'[;&]’ ‘{print $1}’
oauth_token="$(echo ${request_output} | awk -F'[;&]’ ‘{print $2}’)"
oauth_token_secret="$(echo ${request_output} | awk -F'[;&]’ ‘{print $3}’)"

echo ${oauth_token}
echo ${oauth_token_secret}
echo ”
echo "Please ask your user to open this url: ‘https://www.flickr.com/services/oauth/authorize?"${oauth_token}"’"

[/code]

3. Get User Authorization:

From step 2 you need to note down the oauth_token and oauth_token_secret, you’ll need them later. Open in a browser window the url resulting from the step 2. Once you authorize it, you’ll get a code, this is the oauth_verifier:

verifier

4. Get an Access Token:

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

timestamp="$(/bin/date +%s)"
nonce="$(/bin/date +%s%T%N | /usr/bin/openssl base64 | /bin/sed -e s’/[+=/]//g’)"

request_url="GET&https%3A%2F%2Fwww.flickr.com%2Fservices%2Foauth%2Faccess_token"

consumerkey=b284fdada……f2fbbe1145
consumersecret=17a……..c36
oauth_token=72157651980726063-9ee23f2f77cc1edb
oauth_token_secret=f448f55629f2092e
oauth_verifier=518-883-896

basestring="$(echo ${request_url}’&oauth_consumer_key%3D’${consumerkey}’%26oauth_nonce%3D’${nonce}’%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D’${timestamp}’%26oauth_token%3D’${oauth_token}’%26oauth_verifier%3D’${oauth_verifier}’%26oauth_version%3D1.0′)"
echo ‘basestring = ‘${basestring}

signature="$(echo -n ${basestring} | openssl dgst -sha1 -hmac ${consumersecret}’&’${oauth_token_secret} -binary | /usr/bin/openssl base64 | /bin/sed -e s’/+/%2B/’ -e s’///%2F/’ -e s’/=/%3D/’)"
echo ‘signature = ‘${signature}

request_output="$(/usr/bin/curl –compressed -s -H "Accept-Encoding: gzip,deflate" "https://www.flickr.com/services/oauth/access_token?oauth_consumer_key="${consumerkey}"&oauth_nonce="${nonce}"&oauth_signature="${signature}"&oauth_signature_method=HMAC-SHA1&oauth_timestamp="${timestamp}"&oauth_token="${oauth_token}"&oauth_verifier="${oauth_verifier}"&oauth_version=1.0")"
echo ‘request_output = ‘"${request_output}"

oauth_token="$(echo ${request_output} | awk -F'[;&]’ ‘{print $2}’)"
oauth_token_secret="$(echo ${request_output} | awk -F'[;&]’ ‘{print $3}’)"

echo ${oauth_token}
echo ${oauth_token_secret}

[/code]

5. Use the Access Token with API calls:

According to the OAuth 1.0 spec the Access Token should never expire. So you only need to do the steps 1-4 one time.

With every API call you should use the oauth_token you received in step 4, in this example I’m using the flickr.test.login

[code language=”bash” gutter=”true” light=”false”]
#!/bin/bash

timestamp="$(/bin/date +%s)"
nonce="$(/bin/date +%s%T%N | /usr/bin/openssl base64 | /bin/sed -e s’/[+=/]//g’)"

request_url="GET&https%3A%2F%2Fwww.flickr.com%2Fservices%2Frest"

consumerkey=b284fdada……f2fbbe1145
consumersecret=17a……..c36
oauth_token=721576519…..393-c6255e48d9fed8b7
oauth_token_secret=8547b…..1524ff0a

basestring="$(echo ${request_url}’&format%3Djson%26method%3Dflickr.test.login%26nojsoncallback%3D1%26oauth_consumer_key%3D’${consumerkey}’%26oauth_nonce%3D’${nonce}’%26oauth_signature_method%3DHMAC-SHA1%26oauth_timestamp%3D’${timestamp}’%26oauth_token%3D’${oauth_token}’%26oauth_version%3D1.0′)"
echo ‘basestring = ‘${basestring}

signature="$(echo -n ${basestring} | openssl dgst -sha1 -hmac ${consumersecret}’&’${oauth_token_secret} -binary | /usr/bin/openssl base64 | /bin/sed -e s’/+/%2B/’ -e s’///%2F/’ -e s’/=/%3D/’)"
echo ‘signature = ‘${signature}

request_output="$(/usr/bin/curl –compressed -s -H "Accept-Encoding: gzip,deflate" "https://www.flickr.com/services/rest?format=json&method=flickr.test.login&nojsoncallback=1&oauth_consumer_key="${consumerkey}"&oauth_nonce="${nonce}"&oauth_signature="${signature}"&oauth_signature_method=HMAC-SHA1&oauth_timestamp="${timestamp}"&oauth_token="${oauth_token}"&oauth_version=1.0")"
echo ‘request_output = ‘
echo "${request_output}" | /usr/bin/jq .
[/code]

if the call is successful you’ll receive your user id and username

output

# standing on the shoulders of giants: thanks to https://twittercommunity.com/t/can-you-get-public-timeline-using-oauth-by-only-using-curl-and-openssl-in-unix-shell/1476/2

Leave a Reply

4 thoughts on “No One Here Gets OAuth Alive (flickr)

Leave a Reply