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Add gen_random_uuid() to contrib/pgcrypto.
This function provides a way of generating version 4 (pseudorandom) UUIDs based on pgcrypto's PRNG. The main reason for doing this is that the OSSP UUID library depended on by contrib/uuid-ossp is becoming more and more of a porting headache, so we need an alternative for people who can't install that. A nice side benefit though is that this implementation is noticeably faster than uuid-ossp's uuid_generate_v4() function. Oskari Saarenmaa, reviewed by Emre Hasegeli
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9 files changed

+67
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‎contrib/pgcrypto/Makefile

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@@ -26,7 +26,7 @@ MODULE_big = pgcrypto
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OBJS = $(SRCS:.c=.o)
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EXTENSION = pgcrypto
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DATA = pgcrypto--1.0.sql pgcrypto--unpackaged--1.0.sql
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DATA = pgcrypto--1.1.sql pgcrypto--1.0--1.1.sql pgcrypto--unpackaged--1.0.sql
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REGRESS = init md5 sha1 hmac-md5 hmac-sha1 blowfish rijndael \
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$(CF_TESTS) \

‎contrib/pgcrypto/pgcrypto--1.0--1.1.sql

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/* contrib/pgcrypto/pgcrypto--1.0--1.1.sql */
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-- complain if script is sourced in psql, rather than via ALTER EXTENSION
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\echo Use "ALTER EXTENSION pgcrypto UPDATE TO '1.1'" to load this file. \quit
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CREATE FUNCTION gen_random_uuid()
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RETURNS uuid
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AS 'MODULE_PATHNAME', 'pg_random_uuid'
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LANGUAGE C VOLATILE;

‎contrib/pgcrypto/pgcrypto--1.0.sql renamed to ‎contrib/pgcrypto/pgcrypto--1.1.sql

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@@ -1,4 +1,4 @@
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/* contrib/pgcrypto/pgcrypto--1.0.sql */
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/* contrib/pgcrypto/pgcrypto--1.1.sql */
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-- complain if script is sourced in psql, rather than via CREATE EXTENSION
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\echo Use "CREATE EXTENSION pgcrypto" to load this file. \quit
@@ -63,6 +63,11 @@ RETURNS bytea
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AS 'MODULE_PATHNAME', 'pg_random_bytes'
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LANGUAGE C VOLATILE STRICT;
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CREATE FUNCTION gen_random_uuid()
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RETURNS uuid
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AS 'MODULE_PATHNAME', 'pg_random_uuid'
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LANGUAGE C VOLATILE;
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--
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-- pgp_sym_encrypt(data, key)
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--

‎contrib/pgcrypto/pgcrypto.c

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@@ -35,6 +35,7 @@
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#include "parser/scansup.h"
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#include "utils/builtins.h"
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#include "utils/uuid.h"
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#include "px.h"
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#include "px-crypt.h"
@@ -443,6 +444,32 @@ pg_random_bytes(PG_FUNCTION_ARGS)
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PG_RETURN_BYTEA_P(res);
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}
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/* SQL function: gen_random_uuid() returns uuid */
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PG_FUNCTION_INFO_V1(pg_random_uuid);
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Datum
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pg_random_uuid(PG_FUNCTION_ARGS)
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{
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uint8 *buf = (uint8 *) palloc(UUID_LEN);
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int err;
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/* generate random bits */
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err = px_get_pseudo_random_bytes(buf, UUID_LEN);
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if (err < 0)
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ereport(ERROR,
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(errcode(ERRCODE_EXTERNAL_ROUTINE_INVOCATION_EXCEPTION),
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errmsg("Random generator error: %s", px_strerror(err))));
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/*
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* Set magic numbers for a "version 4" (pseudorandom) UUID, see
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* http://tools.ietf.org/html/rfc4122#section-4.4
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*/
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buf[6] = (buf[6] & 0x0f) | 0x40; /* "version" field */
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buf[8] = (buf[8] & 0x3f) | 0x80; /* "variant" field */
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PG_RETURN_UUID_P((pg_uuid_t *) buf);
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}
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static void *
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find_provider(text *name,
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PFN provider_lookup,

‎contrib/pgcrypto/pgcrypto.control

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# pgcrypto extension
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comment = 'cryptographic functions'
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default_version = '1.0'
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default_version = '1.1'
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module_pathname = '$libdir/pgcrypto'
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relocatable = true

‎contrib/pgcrypto/pgcrypto.h

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@@ -45,5 +45,6 @@ Datum pg_decrypt(PG_FUNCTION_ARGS);
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Datum pg_encrypt_iv(PG_FUNCTION_ARGS);
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Datum pg_decrypt_iv(PG_FUNCTION_ARGS);
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Datum pg_random_bytes(PG_FUNCTION_ARGS);
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Datum pg_random_uuid(PG_FUNCTION_ARGS);
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#endif

‎doc/src/sgml/datatype.sgml

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suited for every application. The <xref
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linkend="uuid-ossp"> module
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provides functions that implement several standard algorithms.
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The <xref linkend="pgcrypto"> module also provides a generation
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function for random UUIDs.
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Alternatively, UUIDs could be generated by client applications or
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other libraries invoked through a server-side function.
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</para>

‎doc/src/sgml/pgcrypto.sgml

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@@ -1084,6 +1084,17 @@ gen_random_bytes(count integer) returns bytea
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At most 1024 bytes can be extracted at a time. This is to avoid
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draining the randomness generator pool.
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</para>
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<indexterm>
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<primary>gen_random_uuid</primary>
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</indexterm>
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<synopsis>
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gen_random_uuid() returns uuid
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</synopsis>
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<para>
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Returns a version 4 (random) UUID.
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</para>
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</sect2>
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<sect2>

‎doc/src/sgml/uuid-ossp.sgml

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<ulink url="http://www.ossp.org/pkg/lib/uuid/"></ulink>.
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</para>
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<note>
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<para>
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The OSSP UUID library is not well maintained, and is becoming increasingly
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difficult to port to newer platforms. If you only need randomly-generated
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(version 4) UUIDs, consider using the <function>gen_random_uuid()</>
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function from the <xref linkend="pgcrypto"> module instead.
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</para>
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</note>
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<sect2>
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<title><literal>uuid-ossp</literal> Functions</title>
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