objective c SHA256 암호화

#import <CommonCrypto/CommonHMAC.h>

-(NSString*) sha256{  

NSString* home = [@"~" stringByExpandingTildeInPath];

// NSLog(@"home===============%@",home);

NSString *mergePdfPath= [NSString stringWithFormat:@"%@/Documents/C0105.pdf",home];

// const char *s  = [data  cStringUsingEncoding:NSASCIIStringEncoding];  

// NSData *keyData=[NSData dataWithBytes:s length:strlen(s)];  

NSData *data = [[[NSData alloc] initWithContentsOfFile:mergePdfPath] autorelease];

uint8_t digest[CC_SHA256_DIGEST_LENGTH]={0};  

CC_SHA256(data.bytes, data.length, digest);  

NSData *out = [NSData dataWithBytes:digest length:CC_SHA256_DIGEST_LENGTH];  

NSString *hash=[out description];  

hash = [hash stringByReplacingOccurrencesOfString:@" " withString:@""];

hash = [hash stringByReplacingOccurrencesOfString:@"<" withString:@""];

hash = [hash stringByReplacingOccurrencesOfString:@">" withString:@""];

NSLog(@"hash====================%@",hash);

// NSLog(@"ha len ============%d",[hash length]);

return hash;  

}

출처 : http://blog.naver.com/clubbboy?Redirect=Log&logNo=157383561