mirror of
https://git.sr.ht/~tsileo/microblog.pub
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54 lines
1.6 KiB
Python
54 lines
1.6 KiB
Python
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from pyld import jsonld
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import hashlib
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from datetime import datetime
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from Crypto.Signature import PKCS1_v1_5
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from Crypto.Hash import SHA256
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import base64
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def options_hash(doc):
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doc = dict(doc['signature'])
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for k in ['type', 'id', 'signatureValue']:
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if k in doc:
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del doc[k]
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doc['@context'] = 'https://w3id.org/identity/v1'
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normalized = jsonld.normalize(doc, {'algorithm': 'URDNA2015', 'format': 'application/nquads'})
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h = hashlib.new('sha256')
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h.update(normalized.encode('utf-8'))
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return h.hexdigest()
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def doc_hash(doc):
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doc = dict(doc)
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if 'signature' in doc:
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del doc['signature']
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normalized = jsonld.normalize(doc, {'algorithm': 'URDNA2015', 'format': 'application/nquads'})
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h = hashlib.new('sha256')
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h.update(normalized.encode('utf-8'))
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return h.hexdigest()
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def verify_signature(doc, pubkey):
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to_be_signed = options_hash(doc) + doc_hash(doc)
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signature = doc['signature']['signatureValue']
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signer = PKCS1_v1_5.new(pubkey)
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digest = SHA256.new()
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digest.update(to_be_signed.encode('utf-8'))
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return signer.verify(digest, base64.b64decode(signature))
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def generate_signature(doc, privkey):
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options = {
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'type': 'RsaSignature2017',
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'creator': doc['actor'] + '#main-key',
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'created': datetime.utcnow().replace(microsecond=0).isoformat() + 'Z',
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}
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doc['signature'] = options
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to_be_signed = options_hash(doc) + doc_hash(doc)
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signer = PKCS1_v1_5.new(privkey)
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digest = SHA256.new()
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digest.update(to_be_signed.encode('utf-8'))
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sig = base64.b64encode(signer.sign(digest))
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options['signatureValue'] = sig.decode('utf-8')
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