diff options
Diffstat (limited to 'g10/pkclist.c')
| -rw-r--r-- | g10/pkclist.c | 48 |
1 files changed, 31 insertions, 17 deletions
diff --git a/g10/pkclist.c b/g10/pkclist.c index da33159db..ba36a0ca1 100644 --- a/g10/pkclist.c +++ b/g10/pkclist.c @@ -1,6 +1,6 @@ /* pkclist.c - create a list of public keys * Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, - * 2008, 2009 Free Software Foundation, Inc. + * 2008, 2009, 2010 Free Software Foundation, Inc. * * This file is part of GnuPG. * @@ -1303,9 +1303,8 @@ select_algo_from_prefs(PK_LIST pk_list, int preftype, u32 bits[8]; const prefitem_t *prefs; int result=-1,i; - unsigned int best=-1; - byte scores[256]; - + u16 scores[256]; + if( !pk_list ) return -1; @@ -1367,7 +1366,13 @@ select_algo_from_prefs(PK_LIST pk_list, int preftype, { if( prefs[i].type == preftype ) { - scores[prefs[i].value]+=rank; + /* Make sure all scores don't add up past 0xFFFF + (and roll around) */ + if(rank+scores[prefs[i].value]<=0xFFFF) + scores[prefs[i].value]+=rank; + else + scores[prefs[i].value]=0xFFFF; + mask[prefs[i].value/32] |= 1<<(prefs[i].value%32); rank++; @@ -1434,10 +1439,31 @@ select_algo_from_prefs(PK_LIST pk_list, int preftype, if(result==-1) { + unsigned int best=-1; + /* At this point, we have not selected an algorithm due to a special request or via personal prefs. Pick the highest ranked algorithm (i.e. the one with the lowest score). */ + if(preftype==PREFTYPE_HASH && scores[DIGEST_ALGO_MD5]) + { + /* "If you are building an authentication system, the recipient + may specify a preferred signing algorithm. However, the + signer would be foolish to use a weak algorithm simply + because the recipient requests it." (RFC4880:14). If any + other hash algorithm is available, pretend that MD5 isn't. + Note that if the user intentionally chose MD5 by putting it + in their personal prefs, then we do what the user said (as we + never reach this code). */ + + for(i=DIGEST_ALGO_MD5+1;i<256;i++) + if(scores[i]) + { + scores[DIGEST_ALGO_MD5]=0; + break; + } + } + for(i=0;i<256;i++) { /* Note the '<' here. This means in case of a tie, we will @@ -1455,18 +1481,6 @@ select_algo_from_prefs(PK_LIST pk_list, int preftype, result=i; } } - - /* "If you are building an authentication system, the recipient - may specify a preferred signing algorithm. However, the - signer would be foolish to use a weak algorithm simply - because the recipient requests it." (RFC4880:14). If we - settle on MD5, and SHA1 is also available, use SHA1 instead. - Note that if the user intentionally chose MD5 by putting it - in their personal prefs, then we do what the user said (as we - never reach this code). */ - if(preftype==PREFTYPE_HASH && result==DIGEST_ALGO_MD5 - && (bits[0] & (1<<DIGEST_ALGO_SHA1))) - result=DIGEST_ALGO_SHA1; } return result; |