53 lines
1.5 KiB
R
53 lines
1.5 KiB
R
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## ----setup, include=FALSE-----------------------------------------------------
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library(openssl)
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knitr::opts_chunk$set(echo = TRUE)
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## -----------------------------------------------------------------------------
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# create a bignum
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y <- bignum("123456789123456789")
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z <- bignum("D41D8CD98F00B204E9800998ECF8427E", hex = TRUE)
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# size grows
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print(y * z)
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# Basic arithmetic
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div <- z %/% y
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mod <- z %% y
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z2 <- div * y + mod
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stopifnot(z2 == z)
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stopifnot(div < z)
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## -----------------------------------------------------------------------------
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(key <- rsa_keygen(512))
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(pubkey <- key$pubkey)
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## -----------------------------------------------------------------------------
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msg <- charToRaw("hello world")
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ciphertext <- rsa_encrypt(msg, pubkey)
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rawToChar(rsa_decrypt(ciphertext, key))
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## -----------------------------------------------------------------------------
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key$data
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## -----------------------------------------------------------------------------
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pubkey$data
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## -----------------------------------------------------------------------------
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m <- bignum(charToRaw("hello world"))
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print(m)
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## -----------------------------------------------------------------------------
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e <- pubkey$data$e
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n <- pubkey$data$n
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c <- (m ^ e) %% n
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print(c)
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## -----------------------------------------------------------------------------
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base64_encode(c)
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## -----------------------------------------------------------------------------
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d <- key$data$d
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out <- bignum_mod_exp(c, d, n)
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rawToChar(out)
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