(Objective-C) Compute Glacier SHA256 Tree Hash of a File

Computes the Amazon Glacier SHA256 tree hash for a file.

Note: This example requires Chilkat v9.5.0.78 or greater.

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#import <CkoCrypt2.h>
#import <NSString.h>

// This example requires the Chilkat API to have been previously unlocked.
// See Global Unlock Sample for sample code.

CkoCrypt2 *crypt = [[CkoCrypt2 alloc] init];

// For more information about Amazon Glacier tree hashes, see Computing Glacier Checksums
// Chilkat added the "sha256-tree-hash" algorithm in v9.5.0.78 to make it easy to compute the Glacier tree hash checksum
// of a file or from bytes in memory.
crypt.HashAlgorithm = @"sha256-tree-hash";

// Return the hash in lowercase hexidecimal format.
crypt.EncodingMode = @"hexlower";

NSString *treeHashHex = [crypt HashFileENC: @"qa_data/jpg/penguins.jpg"];
NSLog(@"%@%@",@"SHA256 tree hash = ",treeHashHex);