security-and-privacy/gnupg
security-and-privacy/gnupg
1
0
Fork 0
mirror of git://git.gnupg.org/gnupg.git synced 2025-07-02 22:46:30 +02:00
Code Activity

Output armor works, RSA keygen works.

Browse source
This commit is contained in:
Werner Koch 1997-11-19 13:12:23 +00:00
parent 5393dd53c5
commit 25c8f1a3d7
21 changed files with 395 additions and 115 deletions
Download patch file Download diff file Expand all files Collapse all files

37
cipher/rsa.c
View file

@ -91,50 +91,57 @@ rsa_generate( RSA_public_key *pk, RSA_secret_key *sk, unsigned nbits )
MPI n; /* the public key */
MPI e; /* the exponent */
MPI phi; /* helper: (p-a)(q-1) */
MPI g;
MPI f;
/* select two (very secret) primes */
p = generate_random_prime( nbits / 2 );
q = generate_random_prime( nbits / 2 );
if( mpi_cmp( p, q ) > 0 ) /* p shall be smaller than q */
if( mpi_cmp( p, q ) > 0 ) /* p shall be smaller than q (for calc of u)*/
mpi_swap(p,q);
/* calculate phi = (p-1)(q-1) */
/* calculate Euler totient: phi = (p-1)(q-1) */
t1 = mpi_alloc_secure( mpi_get_nlimbs(p) );
t2 = mpi_alloc_secure( mpi_get_nlimbs(p) );
phi = mpi_alloc_secure( nbits / BITS_PER_MPI_LIMB );
g = mpi_alloc_secure( nbits / BITS_PER_MPI_LIMB );
f = mpi_alloc_secure( nbits / BITS_PER_MPI_LIMB );
mpi_sub_ui( t1, p, 1 );
mpi_sub_ui( t2, q, 1 );
mpi_mul( phi, t1, t2 );
mpi_gcd(g, t1, t2);
mpi_fdiv_q(f, phi, g);
/* multiply them to make the private key */
n = mpi_alloc( nbits / BITS_PER_MPI_LIMB );
mpi_mul( n, p, q );
/* find a public exponent */
e = mpi_alloc(1);
mpi_set_ui( e, 17); /* start with 17 */
while( !mpi_gcd(t1, e, phi) ) { /* (while gcd is not 1) */
if( DBG_CIPHER )
log_mpidump("trying e=", e);
while( !mpi_gcd(t1, e, phi) ) /* (while gcd is not 1) */
mpi_add_ui( e, e, 2);
}
/* calculate the secret key d = e^1 mod phi */
d = mpi_alloc( nbits / BITS_PER_MPI_LIMB );
mpi_inv_mod(d, e, phi );
mpi_inv_mod(d, e, f );
/* calculate the inverse of p and q (used for chinese remainder theorem)*/
u = mpi_alloc( nbits / BITS_PER_MPI_LIMB );
mpi_inv_mod(u, p, q );
if( DBG_CIPHER ) {
log_mpidump("p=", p );
log_mpidump("q=", q );
log_mpidump("phi=", phi );
log_mpidump("n=", n );
log_mpidump("e=", e );
log_mpidump("d=", d );
log_mpidump("u=", u );
log_mpidump(" p= ", p );
log_mpidump(" q= ", q );
log_mpidump("phi= ", phi );
log_mpidump(" g= ", g );
log_mpidump(" f= ", f );
log_mpidump(" n= ", n );
log_mpidump(" e= ", e );
log_mpidump(" d= ", d );
log_mpidump(" u= ", u );
}
mpi_free(t1);
mpi_free(t2);
mpi_free(phi);
mpi_free(f);
mpi_free(g);
pk->n = mpi_copy(n);
pk->e = mpi_copy(e);
@ -146,7 +153,7 @@ rsa_generate( RSA_public_key *pk, RSA_secret_key *sk, unsigned nbits )
sk->u = u;
/* now we can test our keys (this should never fail!) */
test_keys( pk, sk, nbits - 16 );
test_keys( pk, sk, nbits - 64 );
}