Hashing functions from Marko Kreen <marko@l-t.ee>

1 files changed, 155 insertions, 0 deletions

diff --git a/contrib/pgcrypto/pgcrypto.c b/contrib/pgcrypto/pgcrypto.c
new file mode 100644
index 00000000000..4897edb9d25
--- /dev/null
+++ b/contrib/pgcrypto/pgcrypto.c
@@ -0,0 +1,155 @@
+/*
+ * pgcrypto.c
+ *		Cryptographic digests for PostgreSQL.
+ * 
+ * Copyright (c) 2000 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.
+ *
+ * $Id: pgcrypto.c,v 1.1 2000/10/31 13:11:28 petere Exp $
+ */
+
+#include <postgres.h>
+#include <utils/builtins.h>
+
+#include "pgcrypto.h"
+
+/*
+ * maximum length of digest for internal buffers
+ */
+#define MAX_DIGEST_LENGTH	128
+
+/*
+ * NAMEDATALEN is used for hash names
+ */
+#if NAMEDATALEN < 16
+#error "NAMEDATALEN < 16: too small"
+#endif
+
+
+/* exported functions */
+Datum digest(PG_FUNCTION_ARGS);
+Datum digest_exists(PG_FUNCTION_ARGS);
+
+/* private stuff */
+static char *
+to_hex(uint8 *src, uint len, char *dst);
+static pg_digest *
+find_digest(pg_digest *hbuf, text *name, int silent);
+
+
+/* SQL function: hash(text, text) returns text */
+Datum
+digest(PG_FUNCTION_ARGS)
+{
+	text *arg;
+	text *name;
+	uint8 *p, buf[MAX_DIGEST_LENGTH];
+	uint len, hlen;
+	pg_digest *h, _hbuf;
+	text *res;
+	
+	if (PG_ARGISNULL(0) || PG_ARGISNULL(1))
+		PG_RETURN_NULL();
+	
+	name = PG_GETARG_TEXT_P(1);	
+	h = find_digest(&_hbuf, name, 0); /* will give error if fails */
+
+	hlen = h->length(h);
+	if (hlen > MAX_DIGEST_LENGTH)
+		elog(ERROR, "Hash length overflow: %d", hlen);
+	
+	res = (text *)palloc(hlen*2 + VARHDRSZ);
+	VARATT_SIZEP(res) = hlen*2 + VARHDRSZ;
+	
+	arg = PG_GETARG_TEXT_P(0);
+	len = VARSIZE(arg) - VARHDRSZ;
+	
+	p = h->digest(h, VARDATA(arg), len, buf);
+	to_hex(p, hlen, VARDATA(res));
+	
+	PG_FREE_IF_COPY(arg, 0);
+	PG_FREE_IF_COPY(name, 0);	// unnecessary i guess
+	
+	PG_RETURN_TEXT_P(res);
+}
+
+/* check if given hash exists */
+Datum
+digest_exists(PG_FUNCTION_ARGS)
+{
+	text *name;
+	pg_digest _hbuf, *res;
+
+	if (PG_ARGISNULL(0))
+		PG_RETURN_NULL();
+	
+	name = PG_GETARG_TEXT_P(0);
+	
+	res = find_digest(&_hbuf, name, 1);
+	
+	PG_FREE_IF_COPY(name, 0);	// unnecessary i guess
+
+	if (res != NULL)
+		PG_RETURN_BOOL(true);
+	PG_RETURN_BOOL(false);
+}
+
+static pg_digest *
+find_digest(pg_digest *hbuf, text *name, int silent)
+{
+	pg_digest *p;
+	char buf[NAMEDATALEN];
+	uint len;
+	
+	len = VARSIZE(name) - VARHDRSZ;
+	if (len >= NAMEDATALEN) {
+		if (silent)
+			return NULL;
+		elog(ERROR, "Hash type does not exist (name too long)");
+	}
+		
+	memcpy(buf, VARDATA(name), len);
+	buf[len] = 0;
+	
+	p = pg_find_digest(hbuf, buf);
+
+	if (p == NULL && !silent)
+		elog(ERROR, "Hash type does not exist: '%s'", buf);
+	return p;
+}
+
+static unsigned char *hextbl = "0123456789abcdef";
+
+/* dumps binary to hex...  Note that it does not null-terminate  */
+static char *
+to_hex(uint8 *buf, uint len, char *dst)
+{
+	uint i;
+	for (i = 0; i < len; i++) {
+		dst[i*2] = hextbl[(buf[i] >> 4) & 0xF];
+		dst[i*2 + 1] = hextbl[buf[i] & 0xF];
+	}
+	return dst;
+}
+