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Use BLAKE2b-256 for the outer personalized hash

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str4d 2018-01-10 01:08:33 +01:00
parent 3d2923933d
commit 9f5dc6d729
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1 changed files with 5 additions and 6 deletions
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11
drafts/str4d-overwinter-sighash/draft1.rst
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@ -61,7 +61,7 @@ Specification
A new transaction digest algorithm is defined, but only applicable from the Overwinter upgrade block height
[#ZIP0000]_::
[TODO: Pick one] BLAKE2[b-256|s] of the serialization of:
BLAKE2b-256 of the serialization of:
1. nVersion of the transaction (4-byte little endian)
2. hashPrevouts (32-byte hash)
3. hashSequence (32-byte hash)
@ -75,9 +75,9 @@ A new transaction digest algorithm is defined, but only applicable from the Over
c. value of the output spent by this input (8-byte little endian)
d. nSequence of the input (4-byte little endian)
The BLAKE2[b-256|s] personalization field will be set to::
The BLAKE2b-256 personalization field will be set to::
["ZcashSigHash"|"ZcSH"] || BRANCH_ID
"ZcashSigHash" || BRANCH_ID
Semantics of the original sighash types remain unchanged, except the followings:
@ -192,10 +192,9 @@ Refer to the reference implementation, reproduced below, for the precise algorit
hashJoinSplits = ss.GetHash();
}
// TODO: Update after choosing outer hash function
unsigned char personalization[16] = {};
memcpy(personalization, "ZcashSigHash", 8);
memcpy(personalization, branchId, 4);
memcpy(personalization, "ZcashSigHash", 12);
memcpy(personalization+12, branchId, 4);
CBlake2HashWriter ss(SER_GETHASH, 0, personalization);
// Version