md5

Attached are two small patches to expose md5 as a user function -- including
documentation and regression test mods. It seemed small and unobtrusive enough
to not require a specific proposal on the hackers list -- but if not, let me
know and I'll make a pitch. Otherwise, if there are no objections please apply.

Joe
Index: src/test/regress/expected/strings.out
===================================================================
RCS file: /opt/src/cvs/pgsql-server/src/test/regress/expected/strings.out,v
retrieving revision 1.19
diff -c -r1.19 strings.out
*** src/test/regress/expected/strings.out    22 Sep 2002 17:27:25 -0000    1.19
--- src/test/regress/expected/strings.out    5 Dec 2002 05:35:41 -0000
***************
*** 777,779 ****
--- 777,825 ----
   ffffffff
  (1 row)

+ --
+ -- MD5 test suite - from IETF RFC 1321
+ -- (see: ftp://ftp.rfc-editor.org/in-notes/rfc1321.txt)
+ --
+ select md5('') = 'd41d8cd98f00b204e9800998ecf8427e' AS "TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('a') = '0cc175b9c0f1b6a831c399e269772661' AS "TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('abc') = '900150983cd24fb0d6963f7d28e17f72' AS "TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('message digest') = 'f96b697d7cb7938d525a2f31aaf161d0' AS "TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('abcdefghijklmnopqrstuvwxyz') = 'c3fcd3d76192e4007dfb496cca67e13b' AS "TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789') = 'd174ab98d277d9f5a5611c2c9f419d9f' AS
"TRUE";
+  TRUE
+ ------
+  t
+ (1 row)
+
+ select md5('12345678901234567890123456789012345678901234567890123456789012345678901234567890') =
'57edf4a22be3c955ac49da2e2107b67a'AS "TRUE"; 
+  TRUE
+ ------
+  t
+ (1 row)
+
Index: src/test/regress/sql/strings.sql
===================================================================
RCS file: /opt/src/cvs/pgsql-server/src/test/regress/sql/strings.sql,v
retrieving revision 1.13
diff -c -r1.13 strings.sql
*** src/test/regress/sql/strings.sql    22 Sep 2002 17:27:25 -0000    1.13
--- src/test/regress/sql/strings.sql    5 Dec 2002 05:35:09 -0000
***************
*** 313,315 ****
--- 313,333 ----
  select to_hex(256*256*256 - 1) AS "ffffff";

  select to_hex(256::bigint*256::bigint*256::bigint*256::bigint - 1) AS "ffffffff";
+
+ --
+ -- MD5 test suite - from IETF RFC 1321
+ -- (see: ftp://ftp.rfc-editor.org/in-notes/rfc1321.txt)
+ --
+ select md5('') = 'd41d8cd98f00b204e9800998ecf8427e' AS "TRUE";
+
+ select md5('a') = '0cc175b9c0f1b6a831c399e269772661' AS "TRUE";
+
+ select md5('abc') = '900150983cd24fb0d6963f7d28e17f72' AS "TRUE";
+
+ select md5('message digest') = 'f96b697d7cb7938d525a2f31aaf161d0' AS "TRUE";
+
+ select md5('abcdefghijklmnopqrstuvwxyz') = 'c3fcd3d76192e4007dfb496cca67e13b' AS "TRUE";
+
+ select md5('ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789') = 'd174ab98d277d9f5a5611c2c9f419d9f' AS
"TRUE";
+
+ select md5('12345678901234567890123456789012345678901234567890123456789012345678901234567890') =
'57edf4a22be3c955ac49da2e2107b67a'AS "TRUE"; 
Index: doc/src/sgml/func.sgml
===================================================================
RCS file: /opt/src/cvs/pgsql-server/doc/src/sgml/func.sgml,v
retrieving revision 1.133
diff -c -r1.133 func.sgml
*** doc/src/sgml/func.sgml    5 Dec 2002 04:38:29 -0000    1.133
--- doc/src/sgml/func.sgml    5 Dec 2002 05:16:55 -0000
***************
*** 1140,1145 ****
--- 1140,1155 ----
        </row>

        <row>
+        <entry><function>md5</function>(<parameter>string</parameter> <type>text</type>)</entry>
+        <entry><type>text</type></entry>
+        <entry>
+         Calculates the MD5 hash of given string, returning the result in hex.
+        </entry>
+        <entry><literal>md5('abc')</literal></entry>
+        <entry><literal>900150983cd24fb0d6963f7d28e17f72</literal></entry>
+       </row>
+
+       <row>
         <entry><function>pg_client_encoding</function>()</entry>
         <entry><type>name</type></entry>
         <entry>
Index: src/backend/utils/adt/varlena.c
===================================================================
RCS file: /opt/src/cvs/pgsql-server/src/backend/utils/adt/varlena.c,v
retrieving revision 1.93
diff -c -r1.93 varlena.c
*** src/backend/utils/adt/varlena.c    17 Nov 2002 23:01:30 -0000    1.93
--- src/backend/utils/adt/varlena.c    5 Dec 2002 04:36:11 -0000
***************
*** 23,28 ****
--- 23,29 ----
  #include "utils/builtins.h"
  #include "utils/pg_locale.h"

+ extern bool md5_hash(const void *buff, size_t len, char *hexsum);

  typedef struct varlena unknown;

***************
*** 1837,1841 ****
--- 1838,1868 ----
      } while (ptr > buf && value);

      result_text = PG_STR_GET_TEXT(ptr);
+     PG_RETURN_TEXT_P(result_text);
+ }
+
+ /*
+  * Create an md5 hash of a text string and return it as hex
+  *
+  * md5 produces a 16 byte (128 bit) hash; double it for hex
+  */
+ #define MD5_HASH_LEN  32
+
+ Datum
+ md5_text(PG_FUNCTION_ARGS)
+ {
+     char       *buff = PG_TEXT_GET_STR(PG_GETARG_TEXT_P(0));
+     size_t        len = strlen(buff);
+     char       *hexsum;
+     text       *result_text;
+
+     /* leave room for the terminating '\0' */
+     hexsum = (char *) palloc(MD5_HASH_LEN + 1);
+
+     /* get the hash result */
+     md5_hash((void *) buff, len, hexsum);
+
+     /* convert to text and return it */
+     result_text = PG_STR_GET_TEXT(hexsum);
      PG_RETURN_TEXT_P(result_text);
  }
Index: src/include/catalog/pg_proc.h
===================================================================
RCS file: /opt/src/cvs/pgsql-server/src/include/catalog/pg_proc.h,v
retrieving revision 1.278
diff -c -r1.278 pg_proc.h
*** src/include/catalog/pg_proc.h    5 Dec 2002 04:38:30 -0000    1.278
--- src/include/catalog/pg_proc.h    5 Dec 2002 04:44:54 -0000
***************
*** 3121,3126 ****
--- 3121,3129 ----
  DATA(insert OID = 2307 (  opaque_out        PGNSP PGUID 12 f f t f i 1 2275 "2282"    opaque_out - _null_ ));
  DESCR("(internal)");

+ /* cryptographic */
+ DATA(insert OID =  2311 (  md5       PGNSP PGUID 12 f f t f i 1 25 "25"  md5_text - _null_ ));
+ DESCR("calculates md5 hash");

  /*
   * Symbolic values for provolatile column: these indicate whether the result
Index: src/include/utils/builtins.h
===================================================================
RCS file: /opt/src/cvs/pgsql-server/src/include/utils/builtins.h,v
retrieving revision 1.205
diff -c -r1.205 builtins.h
*** src/include/utils/builtins.h    8 Nov 2002 17:37:52 -0000    1.205
--- src/include/utils/builtins.h    5 Dec 2002 04:56:37 -0000
***************
*** 482,487 ****
--- 482,488 ----
  extern Datum split_text(PG_FUNCTION_ARGS);
  extern Datum to_hex32(PG_FUNCTION_ARGS);
  extern Datum to_hex64(PG_FUNCTION_ARGS);
+ extern Datum md5_text(PG_FUNCTION_ARGS);

  extern Datum unknownin(PG_FUNCTION_ARGS);
  extern Datum unknownout(PG_FUNCTION_ARGS);