so using r pki package, simon urbanek, , trying understand application of signing message. can figure out how sign something.
require(pki) # generate 2048-bit rsa key key <- pki.genrsakey(bits = 2048l) # extract private , public parts pem priv.pem <- pki.save.key(key) pub.pem <- pki.save.key(key, private=false) # load public key separately pub.k <- pki.load.key(pub.pem) # encrypt public key x <- pki.encrypt(chartoraw("hello, world!"), pub.k) # decrypt private key rawtochar(pki.decrypt(x, key)) # straight package examples have public , private keys. # additionally, same can sign message x <- chartoraw("my message sign") sig <- pki.sign(x, key) pki.verify(x, sig, key) # slight change exapmles verify public key can verify pki.verify(x, sig, pub.k) pub.pem can written file as
puk<-paste(pub.pem, collapse="") and can later reconstructed via
pub.pem<-substring(puk, c(1, 27, 91, 155, 219, 283, 347, 411, 419), c(26, 90,154,218,282,346,410,418,442)) pub.k <- pki.load.key(pub.pem) and verified again
pki.verify(x, sig, pub.k) however, sig raw
str(sig) and when written file get
sig<-paste(sig, collapse=" " ) but can no longer verify signature string , not raw , chartoraw not recreate original signature. can part of way there not correctly formatted raw vector verify signature
sigraw<-rawtochar(sig2, multiple = true) str(sapply(sigraw, fun=chartoraw)) so there way can write signature file , again verify signature?
not sure direct answer question allow text sting can written file , reformatted.
library("bms") library("pki") library("pack") # generate 2048-bit rsa key key <- pki.genrsakey(bits = 2048l) # extract private , public parts pem priv.pem <- pki.save.key(key) pub.pem <- pki.save.key(key, private=false) # load public key separately pub.k <- pki.load.key(pub.pem) x <- chartoraw("my message sign") sig <- pki.sign(x, key) pki.verify(x, sig, key) bits<-rawtobits(sig) ### part can skipped, long way make character vector & ### pbitsb<-paste(bits) back<-sapply(pbitsb, fun=as.raw) back==bits sigbits<-packbits(bits, type="raw") sigback<-packbits(back, type="raw") sig==sigbits&sigbits==sigback pki.verify(x,sigback,key) #can make more compressed character vector hexsig<-bin2hex(as.numeric(bits)) #this value shared in text file proof of signature #the remaineder needs executed recipient binsig<-hex2bin(hexsig) backbin<-sapply(binsig, fun=as.raw) sigbin<-packbits(backbin, type="raw") pki.verify(x,sigbin,key) sig==sigbits&sigbits==sigback&sigback==sigbin 