diff options
Diffstat (limited to 'rsa.cpp')
| -rw-r--r-- | rsa.cpp | 55 |
1 files changed, 26 insertions, 29 deletions
@@ -1,3 +1,4 @@ +#include <algorithm> #include <cstdint> #include <cassert> #include "base64.h" @@ -10,55 +11,51 @@ using namespace std; namespace RSA{ - Bigint encrypt(Bigint msg,const PublicKey &pubkey){ + Bigint encrypt(Bigint msg,const Key &pubkey){ assert(msg>1&&msg<pubkey.mod); return expmod(msg,pubkey.exp,pubkey.mod); } - Bigint decrypt(Bigint encr,const PrivateKey &privkey){ - return expmod(encr,privkey.pexp,privkey.pub.mod); + Bigint decrypt(Bigint encr,const Key &privkey){ + return expmod(encr,privkey.exp,privkey.mod); } - PrivateKey genkey(int nbits,Rng &rng){ + pair<Key,Key> genkeys(int nbits,Rng &rng){ pair<Bigint,Bigint> pq=genprimepair(rng,nbits); - PrivateKey key; - key.pub.mod=pq.first*pq.second; - key.pub.exp=65537; + Key pubkey,privkey; + pubkey.mod=privkey.mod=pq.first*pq.second; + pubkey.exp=65537; Bigint x; - egcd((pq.first-Bigint::one)*(pq.second-Bigint::one),key.pub.exp,x,key.pexp); - return key; + assert(egcd((pq.first-Bigint::one)*(pq.second-Bigint::one),pubkey.exp,x,privkey.exp)==1); + return make_pair(pubkey,privkey); } - PrivateKey genkey(int nbits){ + pair<Key,Key> genkeys(int nbits){ CryptoRng rng; - return genkey(nbits,rng); + return genkeys(nbits,rng); } - PrivateKey genkey(int nbits,const string &password){ + pair<Key,Key> genkeys(int nbits,const string &password){ KeyRng rng(password); - return genkey(nbits,rng); + return genkeys(nbits,rng); } - pair<string,string> exportkey(const PrivateKey &key){ - string modser=key.pub.mod.serialiseMantissa(); + string exportKey(const Key &key){ + string modser=key.mod.serialiseMantissa(); int32_t modlen=modser.size(); string modlenstr{(char)(modlen&0xff),(char)((modlen>>8)&0xff),(char)((modlen>>16)&0xff),(char)((modlen>>24)&0xff)}; - return make_pair( - Base64::encode(modlenstr + modser + key.pub.exp.serialiseMantissa()), - Base64::encode(modlenstr + modser + key.pexp.serialiseMantissa())); + return Base64::encode(modlenstr + modser + key.exp.serialiseMantissa()); } - PrivateKey importkey(const string &pub,const string &priv){ - string pubdeser=Base64::decode(pub); - assert(pubdeser.size()>4); - int modlen=(uint8_t)pubdeser[0]+((uint8_t)pubdeser[1]<<8)+ - ((uint8_t)pubdeser[2]<<16)+((uint8_t)pubdeser[3]<<24); - assert((int)pubdeser.size()-4>modlen); - PrivateKey key; - key.pub.mod.deserialiseMantissa(string(pubdeser.begin()+4,pubdeser.begin()+(4+modlen))); - key.pub.exp.deserialiseMantissa(string(pubdeser.begin()+(4+modlen),pubdeser.end())); - string privdeser=Base64::decode(priv); - key.pexp.deserialiseMantissa(string(privdeser.begin()+(4+modlen),privdeser.end())); + Key importKey(const string &repr){ + string deser=Base64::decode(repr); + if(deser.size()<=4)throw invalid_argument("Invalid key string length"); + int modlen=(uint8_t)deser[0]+((uint8_t)deser[1]<<8)+ + ((uint8_t)deser[2]<<16)+((uint8_t)deser[3]<<24); + if((int)deser.size()-4-modlen<=0)throw invalid_argument("Key string incomplete"); + Key key; + key.mod.deserialiseMantissa(string(deser.begin()+4,deser.begin()+(4+modlen))); + key.exp.deserialiseMantissa(string(deser.begin()+(4+modlen),deser.end())); return key; } |