Objective-C：按照 mysql password() 的方式生成哈希

Question

根据this sitemysql使用：

SHA1(UNHEX(SHA1("this_is_a_random_string")))

生成其 password() 哈希。

...

我从另一个Whosebug post:

复制了这个函数

- (NSString *)sha1:(NSString *)str {
    const char *cStr = [str UTF8String];
    unsigned char result[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1(cStr, strlen(cStr), result);
    NSString *s = [NSString  stringWithFormat:
                  @"%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X%02X",
                  result[0], result[1], result[2], result[3], result[4],
                  result[5], result[6], result[7],
                  result[8], result[9], result[10], result[11], result[12],
                  result[13], result[14], result[15],
                  result[16], result[17], result[18], result[19]
                  ];

    return s;
}

生成 sh1 哈希。但正如第一个 link 所说：

the second SHA1() is applied to the binary data returned by the first SHA1() and not to its hex representation. Therefore in SQL I have to UNHEX() it before applying the second SHA1.

所以我必须做类似的事情：

NSString * a = [self sha1:@"abc"];
// convert a into binary data.
NSString * b = [self:sha1:a];

但无论我尝试什么，我都无法让它工作。

最简单的方法是什么？

Answer 1

- (NSString *)mysqlHashFromString:(NSString *)password{
    NSString *sha1String = [self sha1:password];
    NSData *sha1StringBinaryRepresentation = [self dataWithString:sha1String];
    NSString *finalHash = [self hexStringValue:[self SHA1Digest:sha1StringBinaryRepresentation ]];
    return finalHash;
} 

- (NSData *)dataWithString:(NSString *)string {
   NSString *command = [command stringByReplacingOccurrencesOfString:@" " withString:@""];
   NSMutableData *commandToSend = [NSMutableData new];
   unsigned char whole_byte;
   char byte_chars[3] = {'[=10=]','[=10=]','[=10=]'};
   int i;
   for (i=0; i < [command length]/2; i++) {
       byte_chars[0] = [command characterAtIndex:i*2];
       byte_chars[1] = [command characterAtIndex:i*2+1];
       whole_byte = strtol(byte_chars, NULL, 16);
       [commandToSend appendBytes:&whole_byte length:1]; 
   }
   return commandToSend;
}

- (NSString *)sha1:(NSString *)plainTextPasssword{
    NSData *data = [plainTextPasssword dataUsingEncoding:NSUTF8StringEncoding];
    uint8_t digest[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1(data.bytes, data.length, digest);
    NSMutableString *output = [NSMutableString stringWithCapacity:CC_SHA1_DIGEST_LENGTH * 2];
    for (int i = 0; i < CC_SHA1_DIGEST_LENGTH; i++) {
        [output appendFormat:@"%02x", digest[i]];
    }
    return output;
}

- (NSData *)SHA1Digest:(NSData *)data {
    unsigned char result[CC_SHA1_DIGEST_LENGTH];
    CC_SHA1([data bytes], [data length], result);
    return [NSData dataWithBytes:result length:CC_SHA1_DIGEST_LENGTH];
}

- (NSString *)hexStringValue:(NSData *)data {
    NSMutableString *stringBuffer = [NSMutableString stringWithCapacity:([data length] * 2)];
    const unsigned char *dataBuffer = [data bytes];
    for (int i = 0; i < [data length]; ++i) {
        [stringBuffer appendFormat:@"%02x", (unsigned long)dataBuffer[i]];
    }

    return [stringBuffer copy];
}

Creating SHA1 Hash from NSString
Converting HEX NSString To NSData
https://github.com/ali-rantakari/Tagger/blob/master/NSData%2BSHA1.m

Objective-C：按照 mysql password() 的方式生成哈希

Objective-C: Generate hash the way mysql password() does

mysql

hash

sha1

objective-c