AOT: crypto.createHash('sha1').digest() returns a number, not a Buffer #86

Environment

• perry 0.5.95
• macOS arm64 (darwin 25.4.0)

Problem

crypto.createHash(...).update(buf).digest() under the AOT binary returns a value with typeof === 'number' instead of a 20-byte Buffer. instanceof Uint8Array is false, .length is undefined.

Other Buffer-producing paths (Buffer.alloc, Buffer.from) work correctly from the same cross-module context, so this is specific to the crypto Hash wrapper.

Reproduction

// repro.ts
import * as crypto from 'node:crypto';

const h = crypto.createHash('sha1');
h.update(Buffer.from('hello', 'utf8'));
const d = h.digest();

console.log('typeof=' + typeof d);                           // 'number' (bug); expect 'object'
console.log('length=' + (d as { length?: number }).length);  // undefined; expect 20
console.log('instanceof Uint8Array=' + (d instanceof Uint8Array)); // false; expect true

perry compile repro.ts -o /tmp/hashrepro && /tmp/hashrepro
# Observed:
#   typeof=number
#   length=undefined
#   instanceof Uint8Array=false
#
# Expected (Node):
#   typeof=object
#   length=20
#   instanceof Uint8Array=true

Scope / blast radius

Any Node crypto API that returns a Buffer via the Hash object is affected. This breaks:

• mysql_native_password: SHA1(pw) XOR SHA1(challenge ++ SHA1(SHA1(pw)))
• caching_sha2_password: SHA256(pw) XOR SHA256(SHA256(SHA256(pw)) ++ challenge)
• Any protocol that needs SHA-1 / SHA-256 / SHA-512 digests in-process.

Workarounds are painful — you'd have to reimplement the hash by hand, which defeats the point of having crypto in the stdlib.

Hit in real code

@perry/mysql's auth plugins (src/auth/native-password.ts, src/auth/caching-sha2.ts) compute the auth-response via h.digest(). Under the AOT binary the digest buffer has length === 0 by the time it reaches the outer nativeScramble, so the driver ends up sending an empty auth_response field in HandshakeResponse41 and the server rejects with errno 1045 "Access denied (using password: NO)".

Same source, run under Bun or Node, authenticates correctly against MySQL 8.

Expected

hash.digest() returns a Buffer of length matching the algorithm (20 for SHA-1, 32 for SHA-256, 64 for SHA-512), with Buffer.isBuffer(d) === true and d instanceof Uint8Array === true.