Add missing pgcrypto files from previous commit.

contrib/pgcrypto/pgp-pubdec.c

@@ -0,0 +1,193 @@
+/*
+ * pgp-pubdec.c
+ *	  Decrypt public-key encrypted session key.
+ *
+ * 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.
+ *
+ * $PostgreSQL: pgsql/contrib/pgcrypto/pgp-pubdec.c,v 1.1 2005/07/10 13:46:29 momjian Exp $
+ */
+#include <postgres.h>
+
+#include <openssl/bn.h>
+
+#include "px.h"
+#include "mbuf.h"
+#include "pgp.h"
+
+/*
+ * padded msg = 02 || PS || 00 || M 
+ * PS - pad bytes
+ * M - msg
+ */
+static uint8 *
+check_eme_pkcs1_v15(uint8 *data, int len)
+{
+	uint8 *data_end = data + len;
+	uint8 *p = data;
+	int rnd = 0;
+
+	if (len < 1 + 8 + 1)
+		return NULL;
+
+	if (*p++ != 2)
+		return NULL;
+	
+	while (p < data_end && *p) {
+		p++;
+		rnd++;
+	}
+
+	if (p == data_end)
+		return NULL;
+	if (*p != 0)
+		return NULL;
+	if (rnd < 8)
+		return NULL;
+	return p + 1;
+}
+
+/*
+ * secret message: 1 byte algo, sesskey, 2 byte cksum
+ * ignore algo in cksum
+ */
+static int
+control_cksum(uint8 *msg, int msglen)
+{
+	int i;
+	unsigned my_cksum, got_cksum;
+
+	if (msglen < 3)
+		return PXE_PGP_CORRUPT_DATA;
+
+	my_cksum = 0;
+	for (i = 1; i < msglen - 2; i++)
+		my_cksum += msg[i];
+	my_cksum &= 0xFFFF;
+	got_cksum = ((unsigned)(msg[msglen-2]) << 8) + msg[msglen-1];
+	if (my_cksum != got_cksum) {
+		px_debug("pubenc cksum failed");
+		return PXE_PGP_CORRUPT_DATA;
+	}
+	return 0;
+}
+
+/* key id is missing - user is expected to try all keys */
+static const uint8
+any_key[] = {0, 0, 0, 0, 0, 0, 0, 0};
+
+int
+pgp_parse_pubenc_sesskey(PGP_Context *ctx, PullFilter *pkt)
+{
+	int ver;
+	int algo;
+	int res;
+	uint8 key_id[8];
+	PGP_MPI *c1, *c2;
+	PGP_PubKey *pk;
+	uint8 *msg;
+	int msglen;
+	PGP_MPI *m;
+
+	pk = ctx->pub_key;
+	if (pk == NULL) {
+		px_debug("no pubkey?");
+		return PXE_BUG;
+	}
+	if (!pk->elg_p || !pk->elg_g || !pk->elg_y || !pk->elg_x) {
+		px_debug("seckey not loaded?");
+		return PXE_BUG;
+	}
+	
+	GETBYTE(pkt, ver);
+	if (ver != 3) {
+		px_debug("unknown pubenc_sesskey pkt ver=%d", ver);
+		return PXE_PGP_CORRUPT_DATA;
+	}
+
+	/*
+	 * check if keyid's match - user-friendly msg
+	 */
+	res = pullf_read_fixed(pkt, 8, key_id);
+	if (res < 0)
+		return res;
+	if (memcmp(key_id, any_key, 8) != 0
+	 && memcmp(key_id, pk->key_id, 8) != 0)
+	{
+		px_debug("key_id's does not match");
+		return PXE_PGP_WRONG_KEYID;
+	}
+
+	GETBYTE(pkt, algo);
+	if (algo != PGP_PUB_ELG_ENCRYPT)
+	{
+		px_debug("unknown public-key algo=%d", algo);
+		if (algo == PGP_PUB_RSA_ENCRYPT || algo == PGP_PUB_RSA_ENCRYPT_SIGN)
+			return PXE_PGP_RSA_UNSUPPORTED;
+		else
+			return PXE_PGP_UNKNOWN_PUBALGO;
+	}
+
+	/*
+	 * read elgamal encrypted data
+	 */
+	res = pgp_mpi_read(pkt, &c1);
+	if (res < 0)
+		return res;
+	res = pgp_mpi_read(pkt, &c2);
+	if (res < 0)
+		return res;
+
+	/*
+	 * decrypt
+	 */
+	res = pgp_elgamal_decrypt(pk, c1, c2, &m);
+	if (res < 0)
+		return res;
+
+	/*
+	 * extract message
+	 */
+	msg = check_eme_pkcs1_v15(m->data, m->bytes);
+	if (msg == NULL) {
+		px_debug("check_eme_pkcs1_v15 failed");
+		return PXE_PGP_CORRUPT_DATA;
+	}
+	msglen = m->bytes - (msg - m->data);
+
+	res = control_cksum(msg, msglen);
+	if (res < 0)
+		return res;
+
+	/*
+	 * got sesskey
+	 */
+	ctx->cipher_algo = *msg;
+	ctx->sess_key_len = msglen - 3;
+	memcpy(ctx->sess_key, msg + 1, ctx->sess_key_len);
+
+	return pgp_expect_packet_end(pkt);
+}
+
+