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Diffstat (limited to '')
| -rw-r--r-- | g10/sig-check.c | 28 |
1 files changed, 28 insertions, 0 deletions
diff --git a/g10/sig-check.c b/g10/sig-check.c index 0eb29eafb..4cb1ea65e 100644 --- a/g10/sig-check.c +++ b/g10/sig-check.c @@ -64,6 +64,34 @@ signature_check( PKT_signature *sig, MD_HANDLE digest ) rc = do_check( pk, sig, digest ); free_public_key( pk ); + + if( !rc && is_status_enabled() + && ( sig->pubkey_algo == PUBKEY_ALGO_DSA + || sig->pubkey_algo == PUBKEY_ALGO_ELGAMAL ) ) { + /* If we are using these public key algorithms we can + * calculate an unique signature id, which may be useful + * in an application to prevent replac attacks */ + MD_HANDLE md; + int i, nsig = pubkey_get_nsig( sig->pubkey_algo ); + byte *p; + + md = md_open( DIGEST_ALGO_RMD160, 0); + for(i=0; i < nsig; i++ ) { + unsigned n = mpi_get_nbits( sig->data[i]); + + md_putc( md, n>>8); + md_putc( md, n ); + p = mpi_get_buffer( sig->data[i], &n, NULL ); + md_write( md, p, n ); + m_free(p); + } + md_final( md ); + p = make_radix64_string( md_read( md, 0 ), 20 ); + write_status_text( STATUS_SIG_ID, p ); + m_free(p); + md_close(md); + } + return rc; } |