Why the end of signatures is 0x01 | Bitcointalksearch.org

zzkjliu

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Look at this:https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623

Code:

https://en.bitcoin.it/wiki/OP_CHECKSIG
Hashtype Values (from script.h):
Name 	Value
SIGHASH_ALL 	              0x00000001
SIGHASH_NONE 	              0x00000002
SIGHASH_SINGLE     	      0x00000003
SIGHASH_ANYONECANPAY 	0x00000080 


https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623
Enochian said "......, 
A signature is a pair of bignum integers, (r,s), so it consists of 0x30, 
which indicates a sequence of one or more things, an octet count of 
what follows, followed by two encoded integers.  In addition, bitcoin 
appends the hashtype, which is always "1", to the end.
 ......"

which is always "1", is this right?

kjj

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Shit, you're right. I should have checked the source instead of my notes.

Peter Todd

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Quote from: kjj on March 11, 2014, 06:50:17 AM

It is a varint. For values between 0 and 253, a varint has a single byte representation.

It will probably be many, many years before we see a three byte hashtype.

That's incorrect; from CheckSig():

Code:

    if (nHashType == 0)
        nHashType = vchSig.back();
    else if (nHashType != vchSig.back())
        return false;
    vchSig.pop_back();

vchSig is a vector of 8-bit unsigned char's, so it really is just a single byte and encoding a varint would cause the signature to fail. In particular, changing to that in the future would not be a backwards compatible change.

kjj

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It is a varint. For values between 0 and 253, a varint has a single byte representation.

It will probably be many, many years before we see a three byte hashtype.

Edit (2014-03-11): Totally wrong, see next post

zzkjliu

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Thanks

DannyHamilton

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Quote from: zzkjliu on March 10, 2014, 11:07:48 AM

Quote from: btchip on March 10, 2014, 10:44:03 AM

It's the hashtype, which is not part of the signature - check https://en.bitcoin.it/wiki/OP_CHECKSIG

You are wrong? hashtype is 4 bytes, and in the TxOut. But the 0x01 is in the scriptSig in TxIn

Code:

Hashtype Values (from script.h):
Name 	Value
SIGHASH_ALL 	0x00000001
SIGHASH_NONE 	0x00000002
SIGHASH_SINGLE 	0x00000003
SIGHASH_ANYONECANPAY 	0x00000080

Does step 5 here answer your question?
https://en.bitcoin.it/w/images/en/7/70/Bitcoin_OpCheckSig_InDetail.png

zzkjliu

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Quote from: btchip on March 10, 2014, 10:44:03 AM

It's the hashtype, which is not part of the signature - check https://en.bitcoin.it/wiki/OP_CHECKSIG

You are wrong? hashtype is 4 bytes, and in the TxOut. But the 0x01 is in the scriptSig in TxIn

Code:

Hashtype Values (from script.h):
Name 	Value
SIGHASH_ALL 	0x00000001
SIGHASH_NONE 	0x00000002
SIGHASH_SINGLE 	0x00000003
SIGHASH_ANYONECANPAY 	0x00000080

btchip

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CTO, Ledger

It's the hashtype, which is not part of the signature - check https://en.bitcoin.it/wiki/OP_CHECKSIG

zzkjliu

newbie

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Merit: 0

Hello all!

If you look at this transaction(http://blockexplorer.com/rawtx/d2b04f28dfe36bbd7f6228519725f4560b6d7eef0eb9c1b1d4c718f2ba4548f5) you can see that one of the signatures is:

Code:

3045 0220
316eb3cad8b66fcf1494a6e6f9542c3555addbf337f04b62bf4758483fdc881d          this is r
022100
bf46d26cef45d998a2cb5d2d0b8342d70973fa7c3c37ae72234696524b2bc812      this is s
01


"scriptSig":"30450220316eb3cad8b66fcf1494a6e6f9542c3555addbf337f04b62bf4758483fdc881d022100bf46d26cef45d998a2cb5d2d0b8342d70973fa7c3c37ae72234696524b2bc81201"

Why the end of the character is 0x01?

Topic: Why the end of signatures is 0x01 (Read 751 times)