Common encryption algorithms for iOS

In iOS development, the content is often encrypted for data security, and here we summarize the commonly used cryptographic algorithms:

1, MD5

<span style= "FONT-SIZE:18PX;" >+ (NSString *) Md5hash: (NSString *) str {    const char *cstr = [str utf8string];    unsigned char result[16];    CC_MD5 (CStr, strlen (CSTR), result);    NSString *md5result = [NSString stringWithFormat:                           @ "%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%02x%0 2x%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]                           ];    return md5result;} </span>

2. SHA1 digital Signature Algorithm

<span style= "FONT-SIZE:18PX;" >const char *cstr = [str cstringusingencoding:nsutf8stringencoding];    NSData *data = [NSData datawithbytes:cstr length:str.length];        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;</span>

3.AES Encryption Algorithm

<span style= "FONT-SIZE:18PX;"    >-(NSData *) Aes256encryptwithkey: (NSString *) key {//encryption char keyptr[kcckeysizeaes256+1];    Bzero (keyptr, sizeof (KEYPTR));    [Key Getcstring:keyptr maxlength:sizeof (KEYPTR) encoding:nsutf8stringencoding];    Nsuinteger datalength = [self length];    size_t buffersize = datalength + kCCBlockSizeAES128;    void *buffer = malloc (buffersize);    size_t numbytesencrypted = 0; Cccryptorstatus cryptstatus = Cccrypt (Kccencrypt, kCCAlgorithmAES128, KCCOPTIONPK cs7padding |                                          Kccoptionecbmode, Keyptr, kCCBlockSizeAES128, NULL, [self bytes], datalength, BU    Ffer, buffersize, &numbytesencrypted);    if (Cryptstatus = = kccsuccess) {return [NSData datawithbytesnocopy:buffer length:numbytesencrypted]; } FREE (buffer); return nil;}    -(NSData *) Aes256decryptwithkey: (NSString *) key {//decrypt char keyptr[kcckeysizeaes256+1];    Bzero (keyptr, sizeof (KEYPTR));    [Key Getcstring:keyptr maxlength:sizeof (KEYPTR) encoding:nsutf8stringencoding];    Nsuinteger datalength = [self length];    size_t buffersize = datalength + kCCBlockSizeAES128;    void *buffer = malloc (buffersize);    size_t numbytesdecrypted = 0; Cccryptorstatus cryptstatus = Cccrypt (Kccdecrypt, kCCAlgorithmAES128, KCCOPTIONPK cs7padding |                                          Kccoptionecbmode, Keyptr, kCCBlockSizeAES128, NULL, [self bytes], datalength, BU    Ffer, buffersize, &numbytesdecrypted);    if (Cryptstatus = = kccsuccess) {return [NSData datawithbytesnocopy:buffer length:numbytesdecrypted]; } Free (BuffER); return nil;} </span>

4,BASE64 code

<span style= "FONT-SIZE:18PX;" >+ (nsstring*) encodebase64string: (NSString *) input {nsdata *data = [input datausingencoding:nsutf8stringencoding     Allowlossyconversion:yes];     data = [GTMBase64 encodedata:data]; NSString *base64string = [[[NSString Alloc] initwithdata:data encoding:nsutf8stringencoding] autorelease]; return base64string;} + (nsstring*) decodebase64string: (NSString *) input {nsdata *data = [input datausingencoding:nsutf8stringencoding allo     Wlossyconversion:yes];     data = [GTMBase64 decodedata:data]; NSString *base64string = [[[NSString Alloc] initwithdata:data encoding:nsutf8stringencoding] autorelease]; return base64string;}     + (nsstring*) Encodebase64data: (NSData *) data {data = [GTMBase64 encodedata:data]; NSString *base64string = [[[NSString Alloc] Initwithdata:data encoding:nsutf8stringencoding] Autorelease];return base64string;}     + (nsstring*) Decodebase64data: (NSData *) data {data = [GTMBase64 decodedata:data]; NSString *base64string = [[[NS]String alloc] Initwithdata:data encoding:nsutf8stringencoding] Autorelease];return base64string;} </span>