Hyperledger Fabric - How to Decode data_hash to return the actual data?
0
I have been involved in developing Blockchain application using hyperledger fabric.
I made use of fabric-node-sdk to interact with blockchain layer.
Right now I have few data that were inserted into blocks & we are able to see them in CouchDB & query the same to retrieve data.
When channel.queryBlock(1) is called we get data_hash as its response, Is there a way to decode data_hash to get the actual data ?
The data_hash would look like this : 0dafabc38a7d216426b9a9ab71057fe6c8b984c9e44f92b7265fbd3e2785e26c
Any suggestion would be a helpful.
Thank You!
hyperledger-fabric hyperledger hyperledger-fabric-ca
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
add a comment |
0
I have been involved in developing Blockchain application using hyperledger fabric.
I made use of fabric-node-sdk to interact with blockchain layer.
Right now I have few data that were inserted into blocks & we are able to see them in CouchDB & query the same to retrieve data.
When channel.queryBlock(1) is called we get data_hash as its response, Is there a way to decode data_hash to get the actual data ?
The data_hash would look like this : 0dafabc38a7d216426b9a9ab71057fe6c8b984c9e44f92b7265fbd3e2785e26c
Any suggestion would be a helpful.
Thank You!
hyperledger-fabric hyperledger hyperledger-fabric-ca
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
add a comment |
0
0
0
I have been involved in developing Blockchain application using hyperledger fabric.
I made use of fabric-node-sdk to interact with blockchain layer.
Right now I have few data that were inserted into blocks & we are able to see them in CouchDB & query the same to retrieve data.
When channel.queryBlock(1) is called we get data_hash as its response, Is there a way to decode data_hash to get the actual data ?
The data_hash would look like this : 0dafabc38a7d216426b9a9ab71057fe6c8b984c9e44f92b7265fbd3e2785e26c
Any suggestion would be a helpful.
Thank You!
hyperledger-fabric hyperledger hyperledger-fabric-ca
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
I have been involved in developing Blockchain application using hyperledger fabric.
I made use of fabric-node-sdk to interact with blockchain layer.
Right now I have few data that were inserted into blocks & we are able to see them in CouchDB & query the same to retrieve data.
When channel.queryBlock(1) is called we get data_hash as its response, Is there a way to decode data_hash to get the actual data ?
The data_hash would look like this : 0dafabc38a7d216426b9a9ab71057fe6c8b984c9e44f92b7265fbd3e2785e26c
Any suggestion would be a helpful.
Thank You!
hyperledger-fabric hyperledger hyperledger-fabric-ca
hyperledger-fabric hyperledger hyperledger-fabric-ca
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
asked Nov 28 '18 at 11:20
Faizul HassanFaizul Hassan
33
33
add a comment |
add a comment |
1 Answer
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As per the Fabric SDK docs, Channel.queryBlock returns a Promise for a Block. The Block object returned can be interrogated to extract various fields, e.g.
channel = client.getChannel(channelName);
return channel.queryBlock(blockNumber);
}).then((block) => {
console.log('Block Number: ' + block.header.number);
console.log('Previous Hash: ' + block.header.previous_hash);
console.log('Data Hash: ' + block.header.data_hash);
console.log('Transactions: ' + block.data.data.length);
block.data.data.forEach(transaction => {
console.log('Transaction ID: ' + transaction.payload.header.channel_header.tx_id);
console.log('Creator ID: ' + transaction.payload.header.signature_header.creator.Mspid);
console.log('Data: ');
console.log(JSON.stringify(transaction.payload.data));
});
});
Some sample output:
Block Number: 4
Previous Hash: b794ee910514f989c0bcb54c2d26d907fca65eb9dd60e86047b3c3c78b96cb96
Data Hash: 1e267340a5f57ea687bfd6b57aec51b5e16420921fb50f980d08f1302bd289be
Transactions: 1
Transaction ID: 49c1333402977a53ec2532a4d425ef8bd6e3efa546358d3d2e3be645ee32b6c0
Creator ID: Org1MSP
Data:
{"actions":[{"header":{"creator":{"Mspid":"Org1MSP","IdBytes":"-----BEGIN CERTIFICATE-----...
The structure of the Block object is fully documented here.
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
add a comment |
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1 Answer
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oldest
votes
1 Answer
1
active
oldest
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active
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0
As per the Fabric SDK docs, Channel.queryBlock returns a Promise for a Block. The Block object returned can be interrogated to extract various fields, e.g.
channel = client.getChannel(channelName);
return channel.queryBlock(blockNumber);
}).then((block) => {
console.log('Block Number: ' + block.header.number);
console.log('Previous Hash: ' + block.header.previous_hash);
console.log('Data Hash: ' + block.header.data_hash);
console.log('Transactions: ' + block.data.data.length);
block.data.data.forEach(transaction => {
console.log('Transaction ID: ' + transaction.payload.header.channel_header.tx_id);
console.log('Creator ID: ' + transaction.payload.header.signature_header.creator.Mspid);
console.log('Data: ');
console.log(JSON.stringify(transaction.payload.data));
});
});
Some sample output:
Block Number: 4
Previous Hash: b794ee910514f989c0bcb54c2d26d907fca65eb9dd60e86047b3c3c78b96cb96
Data Hash: 1e267340a5f57ea687bfd6b57aec51b5e16420921fb50f980d08f1302bd289be
Transactions: 1
Transaction ID: 49c1333402977a53ec2532a4d425ef8bd6e3efa546358d3d2e3be645ee32b6c0
Creator ID: Org1MSP
Data:
{"actions":[{"header":{"creator":{"Mspid":"Org1MSP","IdBytes":"-----BEGIN CERTIFICATE-----...
The structure of the Block object is fully documented here.
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
add a comment |
0
As per the Fabric SDK docs, Channel.queryBlock returns a Promise for a Block. The Block object returned can be interrogated to extract various fields, e.g.
channel = client.getChannel(channelName);
return channel.queryBlock(blockNumber);
}).then((block) => {
console.log('Block Number: ' + block.header.number);
console.log('Previous Hash: ' + block.header.previous_hash);
console.log('Data Hash: ' + block.header.data_hash);
console.log('Transactions: ' + block.data.data.length);
block.data.data.forEach(transaction => {
console.log('Transaction ID: ' + transaction.payload.header.channel_header.tx_id);
console.log('Creator ID: ' + transaction.payload.header.signature_header.creator.Mspid);
console.log('Data: ');
console.log(JSON.stringify(transaction.payload.data));
});
});
Some sample output:
Block Number: 4
Previous Hash: b794ee910514f989c0bcb54c2d26d907fca65eb9dd60e86047b3c3c78b96cb96
Data Hash: 1e267340a5f57ea687bfd6b57aec51b5e16420921fb50f980d08f1302bd289be
Transactions: 1
Transaction ID: 49c1333402977a53ec2532a4d425ef8bd6e3efa546358d3d2e3be645ee32b6c0
Creator ID: Org1MSP
Data:
{"actions":[{"header":{"creator":{"Mspid":"Org1MSP","IdBytes":"-----BEGIN CERTIFICATE-----...
The structure of the Block object is fully documented here.
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
add a comment |
0
0
0
As per the Fabric SDK docs, Channel.queryBlock returns a Promise for a Block. The Block object returned can be interrogated to extract various fields, e.g.
channel = client.getChannel(channelName);
return channel.queryBlock(blockNumber);
}).then((block) => {
console.log('Block Number: ' + block.header.number);
console.log('Previous Hash: ' + block.header.previous_hash);
console.log('Data Hash: ' + block.header.data_hash);
console.log('Transactions: ' + block.data.data.length);
block.data.data.forEach(transaction => {
console.log('Transaction ID: ' + transaction.payload.header.channel_header.tx_id);
console.log('Creator ID: ' + transaction.payload.header.signature_header.creator.Mspid);
console.log('Data: ');
console.log(JSON.stringify(transaction.payload.data));
});
});
Some sample output:
Block Number: 4
Previous Hash: b794ee910514f989c0bcb54c2d26d907fca65eb9dd60e86047b3c3c78b96cb96
Data Hash: 1e267340a5f57ea687bfd6b57aec51b5e16420921fb50f980d08f1302bd289be
Transactions: 1
Transaction ID: 49c1333402977a53ec2532a4d425ef8bd6e3efa546358d3d2e3be645ee32b6c0
Creator ID: Org1MSP
Data:
{"actions":[{"header":{"creator":{"Mspid":"Org1MSP","IdBytes":"-----BEGIN CERTIFICATE-----...
The structure of the Block object is fully documented here.
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
As per the Fabric SDK docs, Channel.queryBlock returns a Promise for a Block. The Block object returned can be interrogated to extract various fields, e.g.
channel = client.getChannel(channelName);
return channel.queryBlock(blockNumber);
}).then((block) => {
console.log('Block Number: ' + block.header.number);
console.log('Previous Hash: ' + block.header.previous_hash);
console.log('Data Hash: ' + block.header.data_hash);
console.log('Transactions: ' + block.data.data.length);
block.data.data.forEach(transaction => {
console.log('Transaction ID: ' + transaction.payload.header.channel_header.tx_id);
console.log('Creator ID: ' + transaction.payload.header.signature_header.creator.Mspid);
console.log('Data: ');
console.log(JSON.stringify(transaction.payload.data));
});
});
Some sample output:
Block Number: 4
Previous Hash: b794ee910514f989c0bcb54c2d26d907fca65eb9dd60e86047b3c3c78b96cb96
Data Hash: 1e267340a5f57ea687bfd6b57aec51b5e16420921fb50f980d08f1302bd289be
Transactions: 1
Transaction ID: 49c1333402977a53ec2532a4d425ef8bd6e3efa546358d3d2e3be645ee32b6c0
Creator ID: Org1MSP
Data:
{"actions":[{"header":{"creator":{"Mspid":"Org1MSP","IdBytes":"-----BEGIN CERTIFICATE-----...
The structure of the Block object is fully documented here.
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
answered Nov 29 '18 at 9:44
Paul RussellPaul Russell
39028
39028
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
add a comment |
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
Thanks much for taking time to write @PaulRussel :) yes have gone through this and I want that particular data_hash value to be decoded to form the actual data. Is there a way to do so ?
– Faizul Hassan
Nov 29 '18 at 9:57
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
No. This is a cryptographic hash, which is a one-way function used to convert data of an arbitrary size to a hash value of a fixed size. You cannot reconstruct the original data from the hash value.
– Paul Russell
Nov 29 '18 at 10:09
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
Just to be completely correct, if you know that no bits have been discarded (i.e. the number of bits in the original data is small enough), it is theoretically possible (given sufficient time and computing power) to reconstruct the original data from the hash. However, in the case of a Hyperledger block, I doubt this would ever be the case.
– Paul Russell
Nov 29 '18 at 10:18
add a comment |
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