Hello,
While trying to download reports with the amazon sellers partner api we encountered an issue. While downloading the file an error occured:
FunctionError: ‘crypto’ module: buffer is not a supported output encoding
We tried to reproduce the error locally by using the same node version like Realm but could not reproduce it.
We are using the ‘amazon-sp-api’ npm package. The problem seems to occur inside the package when calling:
let decipher = crypto.createDecipheriv(
‘aes-256-cbc’,
Buffer.from(details.encryptionDetails.key, ‘base64’),
Buffer.from(details.encryptionDetails.initializationVector, ‘base64’)
);
Since it is the only place where the crypto library is used inside the call. On function side we just call
await sellingPartner.download(res, { json: true });
With the correct parameters. The call worked locally with the same node version (10.18.1).
Now we have no idea what is happening there, since inside the built-in support documentation every from crypto that is needed is marked as supported.
Best Regards,
Daniel
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When calling the function without a trycatch we got the following stacktrace:
‘crypto’ module: buffer is not a supported output encoding
trace:
FunctionError: ‘crypto’ module: buffer is not a supported output encoding
at github.com/10gen/stitch/function/execution/vm.gojaFunc.func1 (native)
at update (:193:37(32))
at download$ (node_modules/amazon-sp-api/lib/SellingPartner.js:829:64(187))
at tryCatch (:55:50(9))
at invoke (:281:30(112))
at :107:28(6)
at tryCatch (:55:50(9))
at invoke (:145:28(15))
at :155:19(7)
We managed to specify the issue to the line inside the amazon-sp-api:
let decrypted_buffer = Buffer.concat([decipher.update(encrypted_buffer), decipher.final()]);
The update function is the root cause. The function is returning a buffer by default which makes sense. But MongDB backend is not allowing as output encoding buffer somehow? This is strange since buffers are explicitly allowed by the docu:
https://nodejs.org/api/crypto.html#crypto_decipher_update_data_inputencoding_outputencoding
Experimenting with other output encodings has shown that only buffer as output encoding is an issue here.
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We also have encountered an issue when using the csvtojson npm package. Is it possible that there are problems with using Buffers in MongoDB Realm Functions?
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