diff options
Diffstat (limited to 'g10/sign.c')
| -rw-r--r-- | g10/sign.c | 106 |
1 files changed, 106 insertions, 0 deletions
diff --git a/g10/sign.c b/g10/sign.c index bb1f2679a..645d676af 100644 --- a/g10/sign.c +++ b/g10/sign.c @@ -24,6 +24,7 @@ #include <string.h> #include <errno.h> #include <assert.h> +#include <unistd.h> /* need sleep() */ #include "options.h" #include "packet.h" @@ -905,3 +906,108 @@ make_keysig_packet( PKT_signature **ret_sig, PKT_public_key *pk, } + +/**************** + * Create a new signature packet based on an existing one. + * Only user ID signatureare supportted for now. + * TODO: Merge this with make_keysig_packet. + */ +int +update_keysig_packet( PKT_signature **ret_sig, + PKT_signature *orig_sig, + PKT_public_key *pk, + PKT_user_id *uid, + PKT_secret_key *sk, + int (*mksubpkt)(PKT_signature *, void *), + void *opaque + ) +{ + PKT_signature *sig; + int rc=0; + MD_HANDLE md; + + if (!orig_sig || !pk || !uid || !sk) + return G10ERR_GENERAL; + if (orig_sig->sig_class < 0x10 || orig_sig->sig_class > 0x13 ) + return G10ERR_GENERAL; + + md = md_open( orig_sig->digest_algo, 0 ); + + /* hash the public key certificate and the user id */ + hash_public_key( md, pk ); + if( orig_sig->version >= 4 ) { + byte buf[5]; + buf[0] = 0xb4; /* indicates a userid packet */ + buf[1] = uid->len >> 24; /* always use 4 length bytes */ + buf[2] = uid->len >> 16; + buf[3] = uid->len >> 8; + buf[4] = uid->len; + md_write( md, buf, 5 ); + } + md_write( md, uid->name, uid->len ); + + /* create a new signature packet */ + sig = copy_signature (NULL, orig_sig); + if ( sig->version >= 4 && mksubpkt) + rc = (*mksubpkt)(sig, opaque); + + /* we increasethe timestamp by one second so that a future import + of this key will replace the existing one. We make sure that + we don't produce a timestamp in the future */ + sig->timestamp++; + while (sig->timestamp >= make_timestamp()) + sleep (1); + /* put the updated timestamp back into the data */ + if( sig->version >= 4 ) + build_sig_subpkt_from_sig( sig ); + + if (!rc) { + if (sig->version >= 4) + md_putc (md, sig->version); + md_putc (md, sig->sig_class); + if (sig->version < 4) { + u32 a = sig->timestamp; + md_putc( md, (a >> 24) & 0xff ); + md_putc( md, (a >> 16) & 0xff ); + md_putc( md, (a >> 8) & 0xff ); + md_putc( md, a & 0xff ); + } + else { + byte buf[6]; + size_t n; + + md_putc( md, sig->pubkey_algo ); + md_putc( md, sig->digest_algo ); + if( sig->hashed_data ) { + n = (sig->hashed_data[0] << 8) | sig->hashed_data[1]; + md_write( md, sig->hashed_data, n+2 ); + n += 6; + } + else { + md_putc( md, 0 ); /* always hash the length of the subpacket*/ + md_putc( md, 0 ); + n = 6; + } + /* add some magic */ + buf[0] = sig->version; + buf[1] = 0xff; + buf[2] = n >> 24; /* hmmm, n is only 16 bit, so this is always 0 */ + buf[3] = n >> 16; + buf[4] = n >> 8; + buf[5] = n; + md_write( md, buf, 6 ); + } + md_final(md); + + rc = complete_sig( sig, sk, md ); + } + + md_close (md); + if( rc ) + free_seckey_enc (sig); + else + *ret_sig = sig; + return rc; +} + + |