src: refactor DH groups to delete crypto_groups.h

[tniessen]

Rewrite FindDiffieHellmanGroup() using OpenSSL helper functions to obtain the required constants directly, instead of loading them from our own crypto_groups.h and converting them to BIGNUMs.

This also removes the need for the struct modp_group, so we can delete crypto_groups.h altogether.

cc @nodejs/cpp-reviewers

[nodejs-github-bot]

Review requested:

• @nodejs/crypto

[nodejs-github-bot]

CI: https://ci.nodejs.org/job/node-test-pull-request/45548/

[tniessen]

@nodejs/cpp-reviewers @nodejs/crypto To aid reviews: this PR mainly changes how we obtain the large prime numbers making up standardized DH groups. Instead of defining these constants in crypto_groups.h, we can retrieve the values from OpenSSL.

An existing test guarantees that the constants remain correct:

node/test/pummel/test-crypto-dh-hash.js

Lines 40 to 59 in dffcfdd

	consthashes={
	modp1: '630e9acd2cc63f7e80d8507624ba60ac0757201a',
	modp2: '18f7aa964484137f57bca64b21917a385b6a0b60',
	modp5: 'c0a8eec0c2c8a5ec2f9c26f9661eb339a010ec61',
	modp14: 'af5455606fe74cec49782bb374e4c63c9b1d132c',
	modp15: '7bdd39e5cdbb9748113933e5c2623b559c534e74',
	modp16: 'daea5277a7ad0116e734a8e0d2f297ef759d1161',
	modp17: '3b62aaf0142c2720f0bf26a9589b0432c00eadc1',
	modp18: 'a870b491bbbec9b131ae9878d07449d32e54f160',
	};
	for(constnameinhashes){
	constgroup=crypto.getDiffieHellman(name);
	constprivate_key=group.getPrime('hex');
	consthash1=hashes[name];
	consthash2=crypto.createHash('sha1')
	.update(private_key.toUpperCase()).digest('hex');
	assert.strictEqual(hash1,hash2);
	assert.strictEqual(group.getGenerator('hex'),'02');
	}

[nodejs-github-bot]

Landed in 3e6e908