1 files changed, 284 insertions, 0 deletions
diff --git a/contrib/pgcrypto/pgp-mpi-openssl.c b/contrib/pgcrypto/pgp-mpi-openssl.c
new file mode 100644
index 0000000..75e4c8b
--- /dev/null
+++ b/contrib/pgcrypto/pgp-mpi-openssl.c
@@ -0,0 +1,284 @@
+/*
+ * pgp-mpi-openssl.c
+ *	  OpenPGP MPI functions using OpenSSL BIGNUM code.
+ *
+ * Copyright (c) 2005 Marko Kreen
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ *	  notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ *	  notice, this list of conditions and the following disclaimer in the
+ *	  documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ *
+ * contrib/pgcrypto/pgp-mpi-openssl.c
+ */
+#include "postgres.h"
+
+#include <openssl/bn.h>
+
+#include "pgp.h"
+#include "px.h"
+
+static BIGNUM *
+mpi_to_bn(PGP_MPI *n)
+{
+	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;
+}
+
+static PGP_MPI *
+bn_to_mpi(BIGNUM *bn)
+{
+	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;
+}
+
+/*
+ * Decide the number of bits in the random component k
+ *
+ * It should be in the same range as p for signing (which
+ * is deprecated), but can be much smaller for encrypting.
+ *
+ * Until I research it further, I just mimic gpg behaviour.
+ * It has a special mapping table, for values <= 5120,
+ * above that it uses 'arbitrary high number'.  Following
+ * algorithm hovers 10-70 bits above gpg values.  And for
+ * larger p, it uses gpg's algorithm.
+ *
+ * The point is - if k gets large, encryption will be
+ * really slow.  It does not matter for decryption.
+ */
+static int
+decide_k_bits(int p_bits)
+{
+	if (p_bits <= 5120)
+		return p_bits / 10 + 160;
+	else
+		return (p_bits / 8 + 200) * 3 / 2;
+}
+
+int
+pgp_elgamal_encrypt(PGP_PubKey *pk, PGP_MPI *_m,
+					PGP_MPI **c1_p, PGP_MPI **c2_p)
+{
+	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;
+}
+
+int
+pgp_elgamal_decrypt(PGP_PubKey *pk, PGP_MPI *_c1, PGP_MPI *_c2,
+					PGP_MPI **msg_p)
+{
+	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;
+}
+
+int
+pgp_rsa_encrypt(PGP_PubKey *pk, PGP_MPI *_m, PGP_MPI **c_p)
+{
+	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;
+}
+
+int
+pgp_rsa_decrypt(PGP_PubKey *pk, PGP_MPI *_c, PGP_MPI **m_p)
+{
+	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;
+}