Wrong length check in HMAC function

[alexdupre]

bitcore-lib/lib/crypto/hash.js

Line 56 in 026ddb4

} else if (key < blocksize) {

The above check always returns false, since it's missing .length, so the buffer copy/padding is never performed. Luckily/Accidentally accessing an out-of-index array in Javascript returns an undefined type that has the same property of a 0, in regard of the XOR operation.