Common iOS encryption algorithms

1, MD5//because the category is used, the parameters of the wood are passed in.-(NSString *) stringFromMD5 {if(self = nil | | [self length] = =0) {        returnNil; }    Const Char*value =[self utf8string]; unsignedCharOutputbuffer[cc_md5_digest_length];    CC_MD5 (value, strlen (value), OutputBuffer); Nsmutablestring*outputstring = [[Nsmutablestring alloc] Initwithcapacity:cc_md5_digest_length *2];  for(Nsinteger count =0; Count < Cc_md5_digest_length; count++) {[outputstring AppendFormat:@"%02x", Outputbuffer[count]]; }    return[outputstring autorelease];}2, Base64+ (NSString *) Base64encodedata: (NSData *) Objdata {ConstUnsignedChar* Objrawdata =[objdata bytes];Char*ObjPointer;Char*strresult;//Get the Raw data length and ensure we actually have dataintIntlength =[objdata length];if(Intlength = =0)returnNil;//Setup the string-based Result placeholder and pointer within that placeholderStrresult = (Char*) Calloc ((Intlength +2) /3) *4,sizeof(Char)); ObjPointer=strresult;//Iterate through everything while(Intlength >2) {//keep going until we have less than bits*objpointer++ = _base64encodingtable[objrawdata[0] >>2];*objpointer++ = _base64encodingtable[((objrawdata[0] &0x03) <<4) + (objrawdata[1] >>4)];*objpointer++ = _base64encodingtable[((objrawdata[1] &0x0f) <<2) + (objrawdata[2] >>6)];*objpointer++ = _base64encodingtable[objrawdata[2] &0x3f];//we just handled 3 octets (bits) of dataObjrawdata + =3; Intlength-=3;}//Now deal with the tail end of thingsif(Intlength! =0) {*objpointer++ = _base64encodingtable[objrawdata[0] >>2];if(Intlength >1) {*objpointer++ = _base64encodingtable[((objrawdata[0] &0x03) <<4) + (objrawdata[1] >>4)];*objpointer++ = _base64encodingtable[(objrawdata[1] &0x0f) <<2];*objpointer++ ='=';} Else {*objpointer++ = _base64encodingtable[(objrawdata[0] &0x03) <<4];*objpointer++ ='=';*objpointer++ ='=';}}//Terminate the string-based result*objpointer =' /'; NSString*rststr =[NSString Stringwithcstring:strresult encoding:nsasciistringencoding];    Free (ObjPointer); returnrststr;}3, AES-(nsdata*) Encryptaes: (NSString *) Key {Charkeyptr[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, kccoptionpkcs7padding|Kccoptionecbmode, Keyptr, kCCBlockSizeAES128,                                          NULL, [self bytes], datalength, Buffer, buffersize,&numbytesencrypted); if(Cryptstatus = =kccsuccess) {        return[NSData Datawithbytesnocopy:buffer length:numbytesencrypted];    } free (buffer); returnNil;}4, RSA-(NSData *) Encryptwithdata: (NSData *) content {size_t Plainlen=[content length]; if(Plainlen >Maxplainlen) {NSLog (@"content (%LD) is too long, must <%LD", Plainlen, Maxplainlen); returnNil; }    void*plain =malloc (Plainlen);    [Content Getbytes:plain Length:plainlen]; size_t Cipherlen= -;//currently RSA key length is set to bytes    void*cipher =malloc (Cipherlen); Osstatus ReturnCode=Seckeyencrypt (PublicKey, kSecPaddingPKCS1, Plain, Plainlen, cipher,&Cipherlen); NSData*result =Nil; if(ReturnCode! =0) {NSLog (@"Seckeyencrypt fail. Error Code:%ld", ReturnCode); }    Else{result=[NSData Datawithbytes:cipher Length:cipherlen];    } free (plain);    Free (cipher); returnresult;} Well, this is the article, if you want to know more, you can follow Sina Blog: blog.sina.com/zhongxiaoqiu

Common iOS encryption algorithms