Movatterモバイル変換

[0]ホーム
URL:

Skip to content

Navigation Menu

Sign in
Appearance settings

Search code, repositories, users, issues, pull requests...

Provide feedback

We read every piece of feedback, and take your input very seriously.

Saved searches

Use saved searches to filter your results more quickly

 Sign up
Appearance settings

Commit188f359

Browse files
committed
pgcrypto: support changing S2K iteration count
pgcrypto already supports key-stretching during symmetric encryption,including the salted-and-iterated method; but the number of iterationswas not configurable. This commit implements a new s2k-count parameterto pgp_sym_encrypt() which permits selecting a larger number ofiterations.Author: Jeff Janes
1 parentb6fb647 commit188f359

File tree

9 files changed

+98
-16
lines changed

9 files changed

+98
-16
lines changed

‎contrib/pgcrypto/expected/pgp-encrypt.out

Lines changed: 19 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -103,6 +103,25 @@ select pgp_sym_decrypt(
103103
Secret.
104104
(1 row)
105105

106+
-- s2k count change
107+
select pgp_sym_decrypt(
108+
pgp_sym_encrypt('Secret.', 'key', 's2k-count=1024'),
109+
'key', 'expect-s2k-count=1024');
110+
pgp_sym_decrypt
111+
-----------------
112+
Secret.
113+
(1 row)
114+
115+
-- s2k_count rounds up
116+
select pgp_sym_decrypt(
117+
pgp_sym_encrypt('Secret.', 'key', 's2k-count=65000000'),
118+
'key', 'expect-s2k-count=65000000');
119+
NOTICE: pgp_decrypt: unexpected s2k_count: expected 65000000 got 65011712
120+
pgp_sym_decrypt
121+
-----------------
122+
Secret.
123+
(1 row)
124+
106125
-- s2k digest change
107126
select pgp_sym_decrypt(
108127
pgp_sym_encrypt('Secret.', 'key', 's2k-digest-algo=md5'),

‎contrib/pgcrypto/pgp-decrypt.c

Lines changed: 1 addition & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -643,6 +643,7 @@ parse_symenc_sesskey(PGP_Context *ctx, PullFilter *src)
643643
if (res<0)
644644
returnres;
645645
ctx->s2k_mode=ctx->s2k.mode;
646+
ctx->s2k_count=s2k_decode_count(ctx->s2k.iter);
646647
ctx->s2k_digest_algo=ctx->s2k.digest_algo;
647648

648649
/*

‎contrib/pgcrypto/pgp-encrypt.c

Lines changed: 1 addition & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -567,7 +567,7 @@ init_s2k_key(PGP_Context *ctx)
567567
if (ctx->s2k_cipher_algo<0)
568568
ctx->s2k_cipher_algo=ctx->cipher_algo;
569569

570-
res=pgp_s2k_fill(&ctx->s2k,ctx->s2k_mode,ctx->s2k_digest_algo);
570+
res=pgp_s2k_fill(&ctx->s2k,ctx->s2k_mode,ctx->s2k_digest_algo,ctx->s2k_count);
571571
if (res<0)
572572
returnres;
573573

‎contrib/pgcrypto/pgp-pgsql.c

Lines changed: 10 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -181,6 +181,7 @@ struct debug_expect
181181
intexpect;
182182
intcipher_algo;
183183
ints2k_mode;
184+
ints2k_count;
184185
ints2k_cipher_algo;
185186
ints2k_digest_algo;
186187
intcompress_algo;
@@ -196,6 +197,7 @@ fill_expect(struct debug_expect * ex, int text_mode)
196197
ex->expect=0;
197198
ex->cipher_algo=-1;
198199
ex->s2k_mode=-1;
200+
ex->s2k_count=-1;
199201
ex->s2k_cipher_algo=-1;
200202
ex->s2k_digest_algo=-1;
201203
ex->compress_algo=-1;
@@ -218,6 +220,7 @@ check_expect(PGP_Context *ctx, struct debug_expect * ex)
218220
{
219221
EX_CHECK(cipher_algo);
220222
EX_CHECK(s2k_mode);
223+
EX_CHECK(s2k_count);
221224
EX_CHECK(s2k_digest_algo);
222225
EX_CHECK(use_sess_key);
223226
if (ctx->use_sess_key)
@@ -247,6 +250,8 @@ set_arg(PGP_Context *ctx, char *key, char *val,
247250
res=pgp_set_sess_key(ctx,atoi(val));
248251
elseif (strcmp(key,"s2k-mode")==0)
249252
res=pgp_set_s2k_mode(ctx,atoi(val));
253+
elseif (strcmp(key,"s2k-count")==0)
254+
res=pgp_set_s2k_count(ctx,atoi(val));
250255
elseif (strcmp(key,"s2k-digest-algo")==0)
251256
res=pgp_set_s2k_digest_algo(ctx,val);
252257
elseif (strcmp(key,"s2k-cipher-algo")==0)
@@ -286,6 +291,11 @@ set_arg(PGP_Context *ctx, char *key, char *val,
286291
ex->expect=1;
287292
ex->s2k_mode=atoi(val);
288293
}
294+
elseif (ex!=NULL&&strcmp(key,"expect-s2k-count")==0)
295+
{
296+
ex->expect=1;
297+
ex->s2k_count=atoi(val);
298+
}
289299
elseif (ex!=NULL&&strcmp(key,"expect-s2k-digest-algo")==0)
290300
{
291301
ex->expect=1;

‎contrib/pgcrypto/pgp-s2k.c

Lines changed: 24 additions & 13 deletions
Original file line numberDiff line numberDiff line change
@@ -132,12 +132,10 @@ calc_s2k_iter_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
132132
unsignedpreload=0;
133133
unsignedremain,
134134
c,
135-
cval,
136135
curcnt,
137136
count;
138137

139-
cval=s2k->iter;
140-
count= ((unsigned)16+ (cval&15)) << ((cval >>4)+6);
138+
count=s2k_decode_count(s2k->iter);
141139

142140
md_rlen=px_md_result_size(md);
143141

@@ -195,21 +193,34 @@ calc_s2k_iter_salted(PGP_S2K *s2k, PX_MD *md, const uint8 *key,
195193
}
196194

197195
/*
198-
* DecideS2K_ISALTED iteration count
196+
* DecidePGP_S2K_ISALTED iteration count (in OpenPGP one-byte representation)
199197
*
200198
* Too small: weak
201199
* Too big: slow
202200
* gpg defaults to 96 => 65536 iters
203-
* let it float a bit: 96 + 32 => 262144 iters
201+
*
202+
* For our default (count=-1) we let it float a bit: 96 + 32 => between 65536
203+
* and 262144 iterations.
204+
*
205+
* Otherwise, find the smallest number which provides at least the specified
206+
* iteration count.
204207
*/
205-
staticint
206-
decide_count(unsignedrand_byte)
208+
staticuint8
209+
decide_s2k_iter(unsignedrand_byte,intcount)
207210
{
208-
return96+ (rand_byte&0x1F);
211+
intiter;
212+
213+
if (count==-1)
214+
return96+ (rand_byte&0x1F);
215+
/* this is a bit brute-force, but should be quick enough */
216+
for (iter=0;iter <=255;iter++)
217+
if (s2k_decode_count(iter) >=count)
218+
returniter;
219+
return255;
209220
}
210221

211222
int
212-
pgp_s2k_fill(PGP_S2K*s2k,intmode,intdigest_algo)
223+
pgp_s2k_fill(PGP_S2K*s2k,intmode,intdigest_algo,intcount)
213224
{
214225
intres=0;
215226
uint8tmp;
@@ -219,19 +230,19 @@ pgp_s2k_fill(PGP_S2K *s2k, int mode, int digest_algo)
219230

220231
switch (s2k->mode)
221232
{
222-
case0:
233+
casePGP_S2K_SIMPLE:
223234
break;
224-
case1:
235+
casePGP_S2K_SALTED:
225236
res=px_get_pseudo_random_bytes(s2k->salt,PGP_S2K_SALT);
226237
break;
227-
case3:
238+
casePGP_S2K_ISALTED:
228239
res=px_get_pseudo_random_bytes(s2k->salt,PGP_S2K_SALT);
229240
if (res<0)
230241
break;
231242
res=px_get_pseudo_random_bytes(&tmp,1);
232243
if (res<0)
233244
break;
234-
s2k->iter=decide_count(tmp);
245+
s2k->iter=decide_s2k_iter(tmp,count);
235246
break;
236247
default:
237248
res=PXE_PGP_BAD_S2K_MODE;

‎contrib/pgcrypto/pgp.c

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -40,6 +40,7 @@
4040
staticintdef_cipher_algo=PGP_SYM_AES_128;
4141
staticintdef_s2k_cipher_algo=-1;
4242
staticintdef_s2k_mode=PGP_S2K_ISALTED;
43+
staticintdef_s2k_count=-1;
4344
staticintdef_s2k_digest_algo=PGP_DIGEST_SHA1;
4445
staticintdef_compress_algo=PGP_COMPR_NONE;
4546
staticintdef_compress_level=6;
@@ -206,6 +207,7 @@ pgp_init(PGP_Context **ctx_p)
206207
ctx->cipher_algo=def_cipher_algo;
207208
ctx->s2k_cipher_algo=def_s2k_cipher_algo;
208209
ctx->s2k_mode=def_s2k_mode;
210+
ctx->s2k_count=def_s2k_count;
209211
ctx->s2k_digest_algo=def_s2k_digest_algo;
210212
ctx->compress_algo=def_compress_algo;
211213
ctx->compress_level=def_compress_level;
@@ -269,6 +271,17 @@ pgp_set_s2k_mode(PGP_Context *ctx, int mode)
269271
returnerr;
270272
}
271273

274+
int
275+
pgp_set_s2k_count(PGP_Context*ctx,intcount)
276+
{
277+
if (ctx->s2k_mode==PGP_S2K_ISALTED&&count >=1024&&count <=65011712)
278+
{
279+
ctx->s2k_count=count;
280+
returnPXE_OK;
281+
}
282+
returnPXE_ARGUMENT_ERROR;
283+
}
284+
272285
int
273286
pgp_set_compress_algo(PGP_Context*ctx,intalgo)
274287
{

‎contrib/pgcrypto/pgp.h

Lines changed: 8 additions & 2 deletions
Original file line numberDiff line numberDiff line change
@@ -124,7 +124,7 @@ struct PGP_S2K
124124
uint8mode;
125125
uint8digest_algo;
126126
uint8salt[8];
127-
uint8iter;
127+
uint8iter;/* encoded (one-octet) count */
128128
/* calculated: */
129129
uint8key[PGP_MAX_KEY];
130130
uint8key_len;
@@ -138,6 +138,7 @@ struct PGP_Context
138138
*/
139139
PGP_S2Ks2k;
140140
ints2k_mode;
141+
ints2k_count;/* 4-byte decoded count */
141142
ints2k_digest_algo;
142143
ints2k_cipher_algo;
143144
intcipher_algo;
@@ -171,6 +172,10 @@ struct PGP_Context
171172
unsignedsess_key_len;
172173
};
173174

175+
/* from RFC 4880 3.7.1.3 */
176+
#defines2k_decode_count(cval) \
177+
(((unsigned) 16 + (cval & 15)) << ((cval >> 4) + 6))
178+
174179
structPGP_MPI
175180
{
176181
uint8*data;
@@ -243,6 +248,7 @@ const char *pgp_get_cipher_name(int code);
243248

244249
intpgp_set_cipher_algo(PGP_Context*ctx,constchar*name);
245250
intpgp_set_s2k_mode(PGP_Context*ctx,inttype);
251+
intpgp_set_s2k_count(PGP_Context*ctx,intcount);
246252
intpgp_set_s2k_cipher_algo(PGP_Context*ctx,constchar*name);
247253
intpgp_set_s2k_digest_algo(PGP_Context*ctx,constchar*name);
248254
intpgp_set_convert_crlf(PGP_Context*ctx,intdoit);
@@ -267,7 +273,7 @@ intpgp_load_cipher(int c, PX_Cipher **res);
267273
intpgp_get_cipher_key_size(intc);
268274
intpgp_get_cipher_block_size(intc);
269275

270-
intpgp_s2k_fill(PGP_S2K*s2k,intmode,intdigest_algo);
276+
intpgp_s2k_fill(PGP_S2K*s2k,intmode,intdigest_algo,intcount);
271277
intpgp_s2k_read(PullFilter*src,PGP_S2K*s2k);
272278
intpgp_s2k_process(PGP_S2K*s2k,intcipher,constuint8*key,intklen);
273279

‎contrib/pgcrypto/sql/pgp-encrypt.sql

Lines changed: 9 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -55,6 +55,15 @@ select pgp_sym_decrypt(
5555
pgp_sym_encrypt('Secret.','key','s2k-mode=3'),
5656
'key','expect-s2k-mode=3');
5757

58+
-- s2k count change
59+
select pgp_sym_decrypt(
60+
pgp_sym_encrypt('Secret.','key','s2k-count=1024'),
61+
'key','expect-s2k-count=1024');
62+
-- s2k_count rounds up
63+
select pgp_sym_decrypt(
64+
pgp_sym_encrypt('Secret.','key','s2k-count=65000000'),
65+
'key','expect-s2k-count=65000000');
66+
5867
-- s2k digest change
5968
select pgp_sym_decrypt(
6069
pgp_sym_encrypt('Secret.','key','s2k-digest-algo=md5'),

‎doc/src/sgml/pgcrypto.sgml

Lines changed: 13 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -858,6 +858,19 @@ Applies to: pgp_sym_encrypt
858858
</literallayout>
859859
</sect4>
860860

861+
<sect4>
862+
<title>s2k-count</title>
863+
864+
<para>
865+
The number of iterations of the S2K algorithm to use. It must
866+
be a value between 1024 and 65011712, inclusive.
867+
</para>
868+
<literallayout>
869+
Default: A random value bewteen 65536 and 253952
870+
Applies to: pgp_sym_encrypt, only with s2k-mode=3
871+
</literallayout>
872+
</sect4>
873+
861874
<sect4>
862875
<title>s2k-digest-algo</title>
863876

0 commit comments

Comments
 (0)
[8]ページ先頭
©2009-2025 Movatter.jp