IOS计算MD5值
#import <Foundation/Foundation.h>
#import <CommonCrypto/CommonDigest.h>
#define FileHashDefaultChunkSizeForReadingData 1024*8 // 8K
@interface QQYMD5Util : NSObject
//计算NSData的MD5值
+(NSString*)getMD5WithData:(NSData*)data;
//计算字符串的MD5值，
+(NSString*)getmd5WithString:(NSString*)string;
//计算大文件的MD5值
+(NSString*)getFileMD5WithPath:(NSString*)path;
@end
#import “QQYMD5Util.h”
@implementation QQYMD5Util
+ (NSString*)getmd5WithString:(NSString *)string
{
const char* original_str=[string UTF8String];
unsigned char digist[CC_MD5_DIGEST_LENGTH]; //CC_MD5_DIGEST_LENGTH = 16
CC_MD5(original_str, strlen(original_str), digist);
NSMutableString* outPutStr = [NSMutableString stringWithCapacity:10];
for(int i =0; i<CC_MD5_DIGEST_LENGTH;i++){
[outPutStr appendFormat:@”%02x”, digist[i]];//小写x表示输出的是小写MD5，大写X表示输出的是大写MD5
}
return [outPutStr lowercaseString];
}
+ (NSString*)getMD5WithData:(NSData *)data{
const char* original_str = (const char *)[data bytes];
unsigned char digist[CC_MD5_DIGEST_LENGTH]; //CC_MD5_DIGEST_LENGTH = 16
CC_MD5(original_str, strlen(original_str), digist);
NSMutableString* outPutStr = [NSMutableString stringWithCapacity:10];
for(int i =0; i<CC_MD5_DIGEST_LENGTH;i++){
[outPutStr appendFormat:@”%02x”,digist[i]];//小写x表示输出的是小写MD5，大写X表示输出的是大写MD5
}
//也可以定义一个字节数组来接收计算得到的MD5值
// Byte byte[16];
// CC_MD5(original_str, strlen(original_str), byte);
// NSMutableString* outPutStr = [NSMutableString stringWithCapacity:10];
// for(int i = 0; i<CC_MD5_DIGEST_LENGTH;i++){
// [outPutStr appendFormat:@”%02x”,byte[i]];
// }
// [temp release];
return [outPutStr lowercaseString];
}
+(NSString*)getFileMD5WithPath:(NSString*)path
{
return ( NSString *)FileMD5HashCreateWithPath((__bridge CFStringRef)path,FileHashDefaultChunkSizeForReadingData);
}
CFStringRef FileMD5HashCreateWithPath(CFStringRef filePath,
size_t chunkSizeForReadingData) {
// Declare needed variables
CFStringRef result = NULL;
CFReadStreamRef readStream = NULL;
// Get the file URL
CFURLRef fileURL =
CFURLCreateWithFileSystemPath(kCFAllocatorDefault,
(CFStringRef)filePath,
kCFURLPOSIXPathStyle,
(Boolean)false);
CC_MD5_CTX hashObject;
bool hasMoreData = true;
bool didSucceed;
if (!fileURL) goto done;
// Create and open the read stream
readStream = CFReadStreamCreateWithFile(kCFAllocatorDefault,
(CFURLRef)fileURL);
if (!readStream) goto done;
didSucceed = (bool)CFReadStreamOpen(readStream);
if (!didSucceed) goto done;
// Initialize the hash object
CC_MD5_Init(&hashObject);
// Make sure chunkSizeForReadingData is valid
if (!chunkSizeForReadingData) {
chunkSizeForReadingData = FileHashDefaultChunkSizeForReadingData;
}
// Feed the data to the hash object
while (hasMoreData) {
uint8_t buffer[chunkSizeForReadingData];
CFIndex readBytesCount = CFReadStreamRead(readStream,
(UInt8 *)buffer,
(CFIndex)sizeof(buffer));
if (readBytesCount == -1)break;
if (readBytesCount == 0) {
hasMoreData =false;
continue;
}
CC_MD5_Update(&hashObject,(const void *)buffer,(CC_LONG)readBytesCount);
}
// Check if the read operation succeeded
didSucceed = !hasMoreData;
// Compute the hash digest
unsigned char digest[CC_MD5_DIGEST_LENGTH];
CC_MD5_Final(digest, &hashObject);
// Abort if the read operation failed
if (!didSucceed) goto done;
// Compute the string result
char hash[2 *sizeof(digest) + 1];
for (size_t i =0; i < sizeof(digest); ++i) {
snprintf(hash + (2 * i),3, “%02x”, (int)(digest[i]));
}
result = CFStringCreateWithCString(kCFAllocatorDefault,
(const char *)hash,
kCFStringEncodingUTF8);
done:
if (readStream) {
CFReadStreamClose(readStream);
CFRelease(readStream);
}
if (fileURL) {
CFRelease(fileURL);
}
return result;
}
@end
调用事例:
#include “QQYMD5Util.h”
NSString* filePath;
NSString* fileMD5 = [QQYMD5Util getFileMD5WithPath:filePath];