pgp-mpi-openssl.c File Reference

#include "postgres.h"
#include <openssl/bn.h>
#include "pgp.h"
#include "px.h"

Include dependency graph for pgp-mpi-openssl.c:

Go to the source code of this file.

Functions
static BIGNUM *	mpi_to_bn (PGP_MPI *n)
static PGP_MPI *	bn_to_mpi (BIGNUM *bn)
static int	decide_k_bits (int p_bits)
int	pgp_elgamal_encrypt (PGP_PubKey *pk, PGP_MPI *_m, PGP_MPI **c1_p, PGP_MPI **c2_p)
int	pgp_elgamal_decrypt (PGP_PubKey *pk, PGP_MPI *_c1, PGP_MPI *_c2, PGP_MPI **msg_p)
int	pgp_rsa_encrypt (PGP_PubKey *pk, PGP_MPI *_m, PGP_MPI **c_p)
int	pgp_rsa_decrypt (PGP_PubKey *pk, PGP_MPI *_c, PGP_MPI **m_p)

Function Documentation

bn_to_mpi()

static PGP_MPI* bn_to_mpi ( BIGNUM *  bn )

static

Definition at line 56 of file pgp-mpi-openssl.c.

{
    int         res;
    PGP_MPI    *n;
 
    res = pgp_mpi_alloc(BN_num_bits(bn), &n);
    if (res < 0)
        return NULL;
 
    if (BN_num_bytes(bn) != n->bytes)
    {
        px_debug("bn_to_mpi: bignum conversion failed: bn=%d, mpi=%d",
                 BN_num_bytes(bn), n->bytes);
        pgp_mpi_free(n);
        return NULL;
    }
    BN_bn2bin(bn, n->data);
    return n;
}

References PGP_MPI::bytes, PGP_MPI::data, pgp_mpi_alloc(), pgp_mpi_free(), px_debug(), and res.

Referenced by pgp_elgamal_decrypt(), pgp_elgamal_encrypt(), pgp_rsa_decrypt(), and pgp_rsa_encrypt().

decide_k_bits()

static int decide_k_bits ( int  p_bits )

static

Definition at line 92 of file pgp-mpi-openssl.c.

{
    if (p_bits <= 5120)
        return p_bits / 10 + 160;
    else
        return (p_bits / 8 + 200) * 3 / 2;
}

Referenced by pgp_elgamal_encrypt().

mpi_to_bn()

static BIGNUM* mpi_to_bn ( PGP_MPI *  n )

static

Definition at line 39 of file pgp-mpi-openssl.c.

{
    BIGNUM     *bn = BN_bin2bn(n->data, n->bytes, NULL);
 
    if (!bn)
        return NULL;
    if (BN_num_bits(bn) != n->bits)
    {
        px_debug("mpi_to_bn: bignum conversion failed: mpi=%d, bn=%d",
                 n->bits, BN_num_bits(bn));
        BN_clear_free(bn);
        return NULL;
    }
    return bn;
}

References PGP_MPI::bits, PGP_MPI::bytes, PGP_MPI::data, and px_debug().

Referenced by pgp_elgamal_decrypt(), pgp_elgamal_encrypt(), pgp_rsa_decrypt(), and pgp_rsa_encrypt().

pgp_elgamal_decrypt()

int pgp_elgamal_decrypt	(	PGP_PubKey *	pk,
		PGP_MPI *	_c1,
		PGP_MPI *	_c2,
		PGP_MPI **	msg_p
	)

Definition at line 164 of file pgp-mpi-openssl.c.

{
    int         res = PXE_PGP_MATH_FAILED;
    BIGNUM     *c1 = mpi_to_bn(_c1);
    BIGNUM     *c2 = mpi_to_bn(_c2);
    BIGNUM     *p = mpi_to_bn(pk->pub.elg.p);
    BIGNUM     *x = mpi_to_bn(pk->sec.elg.x);
    BIGNUM     *c1x = BN_new();
    BIGNUM     *div = BN_new();
    BIGNUM     *m = BN_new();
    BN_CTX     *tmp = BN_CTX_new();
 
    if (!c1 || !c2 || !p || !x || !c1x || !div || !m || !tmp)
        goto err;
 
    /*
     * m = c2 / (c1^x)
     */
    if (!BN_mod_exp(c1x, c1, x, p, tmp))
        goto err;
    if (!BN_mod_inverse(div, c1x, p, tmp))
        goto err;
    if (!BN_mod_mul(m, c2, div, p, tmp))
        goto err;
 
    /* result */
    *msg_p = bn_to_mpi(m);
    if (*msg_p)
        res = 0;
err:
    if (tmp)
        BN_CTX_free(tmp);
    if (m)
        BN_clear_free(m);
    if (div)
        BN_clear_free(div);
    if (c1x)
        BN_clear_free(c1x);
    if (x)
        BN_clear_free(x);
    if (p)
        BN_clear_free(p);
    if (c2)
        BN_clear_free(c2);
    if (c1)
        BN_clear_free(c1);
    return res;
}

References bn_to_mpi(), PGP_PubKey::elg, err(), mpi_to_bn(), PGP_PubKey::pub, PXE_PGP_MATH_FAILED, res, PGP_PubKey::sec, and x.

Referenced by decrypt_elgamal().

pgp_elgamal_encrypt()

int pgp_elgamal_encrypt	(	PGP_PubKey *	pk,
		PGP_MPI *	_m,
		PGP_MPI **	c1_p,
		PGP_MPI **	c2_p
	)

Definition at line 101 of file pgp-mpi-openssl.c.

{
    int         res = PXE_PGP_MATH_FAILED;
    int         k_bits;
    BIGNUM     *m = mpi_to_bn(_m);
    BIGNUM     *p = mpi_to_bn(pk->pub.elg.p);
    BIGNUM     *g = mpi_to_bn(pk->pub.elg.g);
    BIGNUM     *y = mpi_to_bn(pk->pub.elg.y);
    BIGNUM     *k = BN_new();
    BIGNUM     *yk = BN_new();
    BIGNUM     *c1 = BN_new();
    BIGNUM     *c2 = BN_new();
    BN_CTX     *tmp = BN_CTX_new();
 
    if (!m || !p || !g || !y || !k || !yk || !c1 || !c2 || !tmp)
        goto err;
 
    /*
     * generate k
     */
    k_bits = decide_k_bits(BN_num_bits(p));
    if (!BN_rand(k, k_bits, 0, 0))
        goto err;
 
    /*
     * c1 = g^k c2 = m * y^k
     */
    if (!BN_mod_exp(c1, g, k, p, tmp))
        goto err;
    if (!BN_mod_exp(yk, y, k, p, tmp))
        goto err;
    if (!BN_mod_mul(c2, m, yk, p, tmp))
        goto err;
 
    /* result */
    *c1_p = bn_to_mpi(c1);
    *c2_p = bn_to_mpi(c2);
    if (*c1_p && *c2_p)
        res = 0;
err:
    if (tmp)
        BN_CTX_free(tmp);
    if (c2)
        BN_clear_free(c2);
    if (c1)
        BN_clear_free(c1);
    if (yk)
        BN_clear_free(yk);
    if (k)
        BN_clear_free(k);
    if (y)
        BN_clear_free(y);
    if (g)
        BN_clear_free(g);
    if (p)
        BN_clear_free(p);
    if (m)
        BN_clear_free(m);
    return res;
}

References bn_to_mpi(), decide_k_bits(), PGP_PubKey::elg, err(), mpi_to_bn(), PGP_PubKey::pub, PXE_PGP_MATH_FAILED, res, and y.

Referenced by encrypt_and_write_elgamal().

pgp_rsa_decrypt()

int pgp_rsa_decrypt	(	PGP_PubKey *	pk,
		PGP_MPI *	_c,
		PGP_MPI **	m_p
	)

Definition at line 251 of file pgp-mpi-openssl.c.

{
    int         res = PXE_PGP_MATH_FAILED;
    BIGNUM     *c = mpi_to_bn(_c);
    BIGNUM     *d = mpi_to_bn(pk->sec.rsa.d);
    BIGNUM     *n = mpi_to_bn(pk->pub.rsa.n);
    BIGNUM     *m = BN_new();
    BN_CTX     *tmp = BN_CTX_new();
 
    if (!m || !d || !n || !c || !tmp)
        goto err;
 
    /*
     * m = c ^ d
     */
    if (!BN_mod_exp(m, c, d, n, tmp))
        goto err;
 
    *m_p = bn_to_mpi(m);
    if (*m_p)
        res = 0;
err:
    if (tmp)
        BN_CTX_free(tmp);
    if (m)
        BN_clear_free(m);
    if (n)
        BN_clear_free(n);
    if (d)
        BN_clear_free(d);
    if (c)
        BN_clear_free(c);
    return res;
}

References bn_to_mpi(), err(), mpi_to_bn(), PGP_PubKey::pub, PXE_PGP_MATH_FAILED, res, PGP_PubKey::rsa, and PGP_PubKey::sec.

Referenced by decrypt_rsa().

pgp_rsa_encrypt()

int pgp_rsa_encrypt	(	PGP_PubKey *	pk,
		PGP_MPI *	_m,
		PGP_MPI **	c_p
	)

Definition at line 215 of file pgp-mpi-openssl.c.

{
    int         res = PXE_PGP_MATH_FAILED;
    BIGNUM     *m = mpi_to_bn(_m);
    BIGNUM     *e = mpi_to_bn(pk->pub.rsa.e);
    BIGNUM     *n = mpi_to_bn(pk->pub.rsa.n);
    BIGNUM     *c = BN_new();
    BN_CTX     *tmp = BN_CTX_new();
 
    if (!m || !e || !n || !c || !tmp)
        goto err;
 
    /*
     * c = m ^ e
     */
    if (!BN_mod_exp(c, m, e, n, tmp))
        goto err;
 
    *c_p = bn_to_mpi(c);
    if (*c_p)
        res = 0;
err:
    if (tmp)
        BN_CTX_free(tmp);
    if (c)
        BN_clear_free(c);
    if (n)
        BN_clear_free(n);
    if (e)
        BN_clear_free(e);
    if (m)
        BN_clear_free(m);
    return res;
}

References bn_to_mpi(), err(), mpi_to_bn(), PGP_PubKey::pub, PXE_PGP_MATH_FAILED, res, and PGP_PubKey::rsa.

Referenced by encrypt_and_write_rsa().