Bitcoin Forum

Bitcoin => Development & Technical Discussion => Topic started by: kokjo on July 10, 2011, 03:14:56 PM



Title: [SOLVED] possible hack, in the scripting. drops the public key hash.
Post by: kokjo on July 10, 2011, 03:14:56 PM
example:
sigscript: <sig> <pub> OP_1 OP_1 OP_PUSHDATA1 21
explanation:
OP_1 OP_1: to fool OP_EQUALVERIFY
OP_PUSHDATA1 21: the next 21 bytes of data is to be pushed, its all the "OP_DUP OP_HASH160 xxxxxxxx..."

scriptpubkey: OP_DUP OP_HASH160 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx75 OP_EQUALVERIFY OP_CHECKSIG
explanation:
0x75 is 117 in decimal, and also the OP_DROP opcode.
so when this both is put togther:

<sig> <pub> OP_1 OP_1 OP_PUSHDATA1 21 OP_DUP OP_HASH160 xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx75 OP_EQUALVERIFY OP_CHECKSIG

<sig> <pub> OP_1 OP_1 <21 bytes of data> OP_DROP OP_EQUALVERIFY OP_CHECKSIG

then the public key is indifferent. and you could put a bogus in instead.

will this work?

im worried.


Title: Re: [SOLVED] possible hack, in the scripting. drops the public key hash.
Post by: kokjo on July 10, 2011, 03:40:52 PM
FALSE ALARM.
https://github.com/bitcoin/bitcoin/blob/master/src/script.cpp#L1152