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authorlloyd <[email protected]>2006-05-18 18:33:19 +0000
committerlloyd <[email protected]>2006-05-18 18:33:19 +0000
commita2c99d3270eb73ef2db5704fc54356c6b75096f8 (patch)
treead3d6c4fcc8dd0f403f8105598943616246fe172 /src/make_prm.cpp
Initial checkin1.5.6
Diffstat (limited to 'src/make_prm.cpp')
-rw-r--r--src/make_prm.cpp177
1 files changed, 177 insertions, 0 deletions
diff --git a/src/make_prm.cpp b/src/make_prm.cpp
new file mode 100644
index 000000000..2874cb365
--- /dev/null
+++ b/src/make_prm.cpp
@@ -0,0 +1,177 @@
+/*************************************************
+* Prime Generation Source File *
+* (C) 1999-2006 The Botan Project *
+*************************************************/
+
+#include <botan/numthry.h>
+#include <botan/lookup.h>
+#include <botan/bit_ops.h>
+#include <botan/parsing.h>
+#include <botan/rng.h>
+#include <botan/ui.h>
+#include <algorithm>
+#include <memory>
+
+namespace Botan {
+
+namespace {
+
+/*************************************************
+* Increment the seed by one *
+*************************************************/
+void increment(SecureVector<byte>& seed)
+ {
+ for(u32bit j = seed.size(); j > 0; --j)
+ if(++seed[j-1])
+ break;
+ }
+
+}
+
+/*************************************************
+* Attempt DSA prime generation with given seed *
+*************************************************/
+bool generate_dsa_primes(BigInt& p, BigInt& q, const byte const_seed[],
+ u32bit seed_len, u32bit pbits, u32bit counter_start)
+ {
+ if(seed_len < 20)
+ throw Invalid_Argument("DSA prime generation needs a seed "
+ "at least 160 bits long");
+ if((pbits % 64 != 0) || (pbits > 1024) || (pbits < 512))
+ throw Invalid_Argument("DSA prime generation algorithm does not support "
+ "prime size " + to_string(pbits));
+
+ std::auto_ptr<HashFunction> sha1(get_hash("SHA-1"));
+
+ SecureVector<byte> seed(const_seed, seed_len);
+
+ SecureVector<byte> qhash = sha1->process(seed);
+ increment(seed);
+ SecureVector<byte> qhash2 = sha1->process(seed);
+ xor_buf(qhash, qhash2, qhash.size());
+
+ qhash[0] |= 0x80;
+ qhash[19] |= 0x01;
+ q.binary_decode(qhash, qhash.size());
+ if(!is_prime(q))
+ return false;
+ UI::pulse(UI::PRIME_FOUND);
+
+ u32bit n = (pbits-1) / 160, b = (pbits-1) % 160;
+ SecureVector<byte> W(20 * (n+1));
+ BigInt X;
+
+ for(u32bit j = 0; j != counter_start; ++j)
+ for(u32bit k = 0; k != n + 1; ++k)
+ increment(seed);
+
+ for(u32bit j = 0; j != 4096 - counter_start; ++j)
+ {
+ UI::pulse(UI::PRIME_SEARCHING);
+
+ for(u32bit k = 0; k != n + 1; ++k)
+ {
+ increment(seed);
+ sha1->update(seed);
+ sha1->final(W + 20 * (n-k));
+ }
+ X.binary_decode(W + (20 - 1 - b/8), W.size() - (20 - 1 - b/8));
+ X.set_bit(pbits-1);
+
+ p = X - (X % (2*q) - 1);
+
+ if(p.bits() == pbits && is_prime(p))
+ {
+ UI::pulse(UI::PRIME_FOUND);
+ return true;
+ }
+ }
+ return false;
+ }
+
+/*************************************************
+* Generate DSA Primes *
+*************************************************/
+SecureVector<byte> generate_dsa_primes(BigInt& p, BigInt& q, u32bit pbits)
+ {
+ SecureVector<byte> seed(20);
+
+ while(true)
+ {
+ Global_RNG::randomize(seed, seed.size());
+ UI::pulse(UI::PRIME_SEARCHING);
+ if(generate_dsa_primes(p, q, seed, seed.size(), pbits))
+ return seed;
+ }
+ }
+
+/*************************************************
+* Generate a random prime *
+*************************************************/
+BigInt random_prime(u32bit bits, const BigInt& coprime,
+ u32bit equiv, u32bit modulo)
+ {
+ if(bits <= 48)
+ throw Invalid_Argument("random_prime: Can't make a prime of " +
+ to_string(bits) + " bits");
+
+ if(coprime <= 0)
+ throw Invalid_Argument("random_prime: coprime must be > 0");
+ if(modulo % 2 == 1 || modulo == 0)
+ throw Invalid_Argument("random_prime: Invalid modulo value");
+ if(equiv >= modulo || equiv % 2 == 0)
+ throw Invalid_Argument("random_prime: equiv must be < modulo, and odd");
+
+ while(true)
+ {
+ UI::pulse(UI::PRIME_SEARCHING);
+
+ BigInt p = random_integer(bits);
+ p.set_bit(bits - 2);
+ p.set_bit(0);
+
+ if(p % modulo != equiv)
+ p += (modulo - p % modulo) + equiv;
+
+ const u32bit sieve_size = std::min(bits / 2, PRIME_TABLE_SIZE);
+ SecureVector<u32bit> sieve(sieve_size);
+
+ for(u32bit j = 0; j != sieve.size(); ++j)
+ {
+ sieve[j] = p % PRIMES[j];
+ UI::pulse(UI::PRIME_SIEVING);
+ }
+
+ u32bit counter = 0;
+ while(true)
+ {
+ if(counter == 4096 || p.bits() > bits)
+ break;
+
+ UI::pulse(UI::PRIME_SEARCHING);
+
+ bool passes_sieve = true;
+ ++counter;
+ p += modulo;
+
+ for(u32bit j = 0; j != sieve.size(); ++j)
+ {
+ sieve[j] = (sieve[j] + modulo) % PRIMES[j];
+ UI::pulse(UI::PRIME_SIEVING);
+ if(sieve[j] == 0)
+ passes_sieve = false;
+ }
+
+ if(!passes_sieve || gcd(p - 1, coprime) != 1)
+ continue;
+ UI::pulse(UI::PRIME_PASSED_SIEVE);
+ if(passes_mr_tests(p))
+ {
+ UI::pulse(UI::PRIME_FOUND);
+ return p;
+ }
+ }
+ }
+ }
+
+}