Only pull in the small subset of crypto-browserify that is used by the SDK

[jeskew]

This PR replaces the SDK's dependency on crypto-browserify with direct dependencies on the portions of the crypto API on which the SDK depends, namely createHash and createHmac. As a result, we are no longer pulling in any form of CSPRNG or AES implementation, which should reduce the size of the SDK's bundle somewhat.

Resolves #1602

[codecov-io]

Codecov Report

Merging #1857 into master will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #1857   +/-   ##
=======================================
  Coverage   95.91%   95.91%           
=======================================
  Files         214      214           
  Lines        6933     6933           
  Branches     1364     1364           
=======================================
  Hits         6650     6650           
  Misses        283      283

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[KurtPattyn]

Great!

[WChoy]

Breaking the crypto in ReactNative and Browser. "Unable to resolve module 'stream'."

create-hmac and create-hash use a hash-base module. That does a
"var Transform = require('stream').Transform". That was defined in node.js core (NOT a standard JS function, see https://nodejs.org/api/stream.html#stream_new_stream_transform_options)

Reproducible in https://github.com/awslabs/aws-mobile-react-native-starter

[lock]

This thread has been automatically locked since there has not been any recent activity after it was closed. Please open a new issue for related bugs and link to relevant comments in this thread.