BlockSig checks the predicate against b.
(b *bc.Block, predicate *bc.Predicate)
| 27 | |
| 28 | // BlockSig checks the predicate against b. |
| 29 | func BlockSig(b *bc.Block, predicate *bc.Predicate) error { |
| 30 | if predicate.Version != 1 { |
| 31 | return errors.WithDetailf(errBadPredicate, "predicate version %d", predicate.Version) |
| 32 | } |
| 33 | if predicate.Quorum < 0 { |
| 34 | return errors.WithDetailf(errBadPredicate, "predicate quorum %d", predicate.Quorum) |
| 35 | } |
| 36 | if int(predicate.Quorum) > len(predicate.Pubkeys) { |
| 37 | return errors.WithDetailf(errBadPredicate, "predicate quorum %d, pubkeys %d", predicate.Quorum, len(predicate.Pubkeys)) |
| 38 | } |
| 39 | if len(b.Arguments) != len(predicate.Pubkeys) { |
| 40 | return errors.WithDetailf(errBadArguments, "pubkeys %d, signatures %d", len(predicate.Pubkeys), len(b.Arguments)) |
| 41 | } |
| 42 | |
| 43 | var ( |
| 44 | sigCount int32 |
| 45 | hash = b.Hash() |
| 46 | ) |
| 47 | |
| 48 | for i := 0; i < len(b.Arguments); i++ { |
| 49 | pk := predicate.Pubkeys[i] |
| 50 | if len(pk) != ed25519.PublicKeySize { |
| 51 | return errors.WithDetailf(errBadPredicate, "public key length %d", len(pk)) |
| 52 | } |
| 53 | |
| 54 | sig, ok := b.Arguments[i].([]byte) |
| 55 | if !ok { |
| 56 | return errors.WithDetailf(errBadArguments, "invalid signature type %T", b.Arguments[i]) |
| 57 | } |
| 58 | |
| 59 | if len(sig) == 0 { |
| 60 | continue |
| 61 | } |
| 62 | |
| 63 | if len(sig) != ed25519.SignatureSize { |
| 64 | return errors.WithDetailf(errBadArguments, "invalid signature length %d", len(sig)) |
| 65 | } |
| 66 | |
| 67 | if !ed25519.Verify(pk, hash.Bytes(), sig) { |
| 68 | return errors.WithDetailf(errBadArguments, "message %x, public key %x, signature %x", hash.Bytes(), pk, sig) |
| 69 | } |
| 70 | |
| 71 | sigCount++ |
| 72 | } |
| 73 | |
| 74 | if sigCount != predicate.Quorum { |
| 75 | return errors.WithDetail(errBadArguments, "insufficient signatures for quorum") |
| 76 | } |
| 77 | |
| 78 | return nil |
| 79 | } |
| 80 | |
| 81 | // Block validates a block and the transactions within. |
| 82 | // It does not check the predicate; for that, see ValidateBlockSig. |