diff options
Diffstat (limited to 'g10/build-packet.c')
| -rw-r--r-- | g10/build-packet.c | 105 |
1 files changed, 66 insertions, 39 deletions
diff --git a/g10/build-packet.c b/g10/build-packet.c index d138e0614..e2bbdb511 100644 --- a/g10/build-packet.c +++ b/g10/build-packet.c @@ -178,17 +178,44 @@ mpi_write (iobuf_t out, gcry_mpi_t a) return rc; } -/* Write the name OID, encoded as an mpi, to OUT. The format of the - * content of the MPI is one byte LEN, following by LEN bytes that are - * DER representation of an ASN.1 OID. This is true for each of the 3 - * following functions. */ -#define iobuf_name_oid_write iobuf_write_size_body_mpi -/* Write the value of KEK fields for ECDH. */ -#define ecdh_kek_params_write iobuf_write_size_body_mpi +/* + * Write a special size+body mpi A, to OUT. The format of the content + * of the MPI is one byte LEN, following by LEN bytes. + */ +gpg_error_t +write_size_body_mpi (iobuf_t out, gcry_mpi_t a) +{ + gpg_error_t err; + byte buffer[256]; /* Fixed buffer for a public parameter, max possible */ + size_t nbytes = (mpi_get_nbits (a)+7)/8; + + if (nbytes > sizeof(buffer)) + { + log_error("mpi with size+body is too large (%u bytes)\n", nbytes); + return gpg_error (GPG_ERR_TOO_LARGE); + } -/* Write the value of encrypted filed for ECDH. */ -#define ecdh_esk_write iobuf_write_size_body_mpi + err = gcry_mpi_print (GCRYMPI_FMT_USG, buffer, sizeof(buffer), &nbytes, a); + if (err) + { + log_error ("failed to exported size+body mpi\n"); + return err; + } + if (nbytes < 2 || buffer[0] != nbytes-1) + { + if (nbytes > 2) + log_error ("internal size mismatch in mpi size+body: " + "%02x != %02x (other bytes: %02x %02x ... %02x %02x)\n", + buffer[0], nbytes-1, buffer[1], buffer[2], buffer[nbytes-2], + buffer[nbytes-1]); + else + log_error ("internal size mismatch in mpi size+body: " + "only %d bytes\n", nbytes); + return gpg_error (GPG_ERR_INV_DATA); + } + return iobuf_write (out, buffer, nbytes); +} /* Calculate the length of a packet described by PKT. */ @@ -228,11 +255,11 @@ calc_packet_length( PACKET *pkt ) static void write_fake_data (IOBUF out, gcry_mpi_t a) { - if (a) + if (a) { unsigned int n; void *p; - + p = gcry_mpi_get_opaque ( a, &n ); iobuf_write (out, p, (n+7)/8 ); } @@ -281,18 +308,18 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) ndays = 0; write_16(a, ndays); } - + iobuf_put (a, pk->pubkey_algo ); - + /* Get number of secret and public parameters. They are held in one array first the public ones, then the secret ones. */ nskey = pubkey_get_nskey (pk->pubkey_algo); npkey = pubkey_get_npkey (pk->pubkey_algo); - + /* If we don't have any public parameters - which is the case if we don't know the algorithm used - the parameters are stored as one blob in a faked (opaque) MPI. */ - if (!npkey) + if (!npkey) { write_fake_data (a, pk->pkey[0]); goto leave; @@ -305,7 +332,7 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) || pk->pubkey_algo == PUBKEY_ALGO_ECDH) { /* Write DER of OID with preceeding length byte. */ - err = iobuf_name_oid_write (a, pk->pkey[0]); + err = write_size_body_mpi (a, pk->pkey[0]); if (err) goto leave; /* Write point Q, the public key. */ @@ -316,7 +343,7 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) /* Write one more public field for ECDH. */ if (pk->pubkey_algo == PUBKEY_ALGO_ECDH) { - err = ecdh_kek_params_write(a,pk->pkey[2]); + err = write_size_body_mpi (a, pk->pkey[2]); if (err) goto leave; } @@ -328,14 +355,14 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) goto leave; } - + if (pk->seckey_info) { /* This is a secret key packet. */ struct seckey_info *ski = pk->seckey_info; /* Build the header for protected (encrypted) secret parameters. */ - if (ski->is_protected) + if (ski->is_protected) { if ( is_RSA (pk->pubkey_algo) && pk->version < 4 && !ski->s2k.mode ) { @@ -355,12 +382,12 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) viewed as a private/experimental extension (this is not specified in rfc2440 but the same scheme is used for all other algorithm identifiers). */ - iobuf_put (a, 101); + iobuf_put (a, 101); iobuf_put (a, ski->s2k.hash_algo); iobuf_write (a, "GNU", 3 ); iobuf_put (a, ski->s2k.mode - 1000); } - else + else { iobuf_put (a, ski->s2k.mode); iobuf_put (a, ski->s2k.hash_algo); @@ -370,7 +397,7 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) iobuf_write (a, ski->s2k.salt, 8); if (ski->s2k.mode == 3) - iobuf_put (a, ski->s2k.count); + iobuf_put (a, ski->s2k.count); /* For our special modes 1001, 1002 we do not need an IV. */ if (ski->s2k.mode != 1001 && ski->s2k.mode != 1002) @@ -381,10 +408,10 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) iobuf_put (a, 0 ); if (ski->s2k.mode == 1001) - ; /* GnuPG extension - don't write a secret key at all. */ + ; /* GnuPG extension - don't write a secret key at all. */ else if (ski->s2k.mode == 1002) - { - /* GnuPG extension - divert to OpenPGP smartcard. */ + { + /* GnuPG extension - divert to OpenPGP smartcard. */ /* Length of the serial number or 0 for no serial number. */ iobuf_put (a, ski->ivlen ); /* The serial number gets stored in the IV field. */ @@ -395,19 +422,19 @@ do_key (iobuf_t out, int ctb, PKT_public_key *pk) /* The secret key is protected - write it out as it is. */ byte *p; unsigned int ndatabits; - + assert (gcry_mpi_get_flag (pk->pkey[npkey], GCRYMPI_FLAG_OPAQUE)); p = gcry_mpi_get_opaque (pk->pkey[npkey], &ndatabits); iobuf_write (a, p, (ndatabits+7)/8 ); } - else if (ski->is_protected) + else if (ski->is_protected) { /* The secret key is protected the old v4 way. */ - for ( ; i < nskey; i++ ) + for ( ; i < nskey; i++ ) { byte *p; unsigned int ndatabits; - + assert (gcry_mpi_get_flag (pk->pkey[i], GCRYMPI_FLAG_OPAQUE)); p = gcry_mpi_get_opaque (pk->pkey[i], &ndatabits); iobuf_write (a, p, (ndatabits+7)/8); @@ -476,9 +503,9 @@ do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc ) int rc = 0; int n, i; IOBUF a = iobuf_temp(); - + write_version( a, ctb ); - if ( enc->throw_keyid ) + if ( enc->throw_keyid ) { write_32(a, 0 ); /* Don't tell Eve who can decrypt the message. */ write_32(a, 0 ); @@ -500,7 +527,7 @@ do_pubkey_enc( IOBUF out, int ctb, PKT_pubkey_enc *enc ) assert (n == 2); rc = mpi_write (a, enc->data[0]); if (!rc) - rc = ecdh_esk_write (a, enc->data[1]); + rc = write_size_body_mpi (a, enc->data[1]); } else { @@ -545,7 +572,7 @@ do_plaintext( IOBUF out, int ctb, PKT_plaintext *pt ) for(i=0; i < pt->namelen; i++ ) iobuf_put(out, pt->name[i] ); rc = write_32(out, pt->timestamp ); - if (rc) + if (rc) return rc; n = 0; @@ -661,7 +688,7 @@ delete_sig_subpkt (subpktarea_t *area, sigsubpkttype_t reqtype ) } if( buflen < n ) break; - + type = *buffer & 0x7f; if( type == reqtype ) { buffer++; @@ -695,7 +722,7 @@ delete_sig_subpkt (subpktarea_t *area, sigsubpkttype_t reqtype ) * Note: All pointers into sig->[un]hashed (e.g. returned by * parse_sig_subpkt) are not valid after a call to this function. The * data to put into the subpaket should be in a buffer with a length - * of buflen. + * of buflen. */ void build_sig_subpkt (PKT_signature *sig, sigsubpkttype_t type, @@ -798,7 +825,7 @@ build_sig_subpkt (PKT_signature *sig, sigsubpkttype_t type, case SIGSUBPKT_SIGNATURE: hashed = 0; break; - default: + default: hashed = 1; break; } @@ -849,7 +876,7 @@ build_sig_subpkt (PKT_signature *sig, sigsubpkttype_t type, memcpy (p, buffer, buflen); } - if (hashed) + if (hashed) sig->hashed = newarea; else sig->unhashed = newarea; @@ -1135,7 +1162,7 @@ do_signature( IOBUF out, int ctb, PKT_signature *sig ) if ( sig->version < 4 ) iobuf_put (a, 5 ); /* Constant */ iobuf_put (a, sig->sig_class ); - if ( sig->version < 4 ) + if ( sig->version < 4 ) { write_32(a, sig->timestamp ); write_32(a, sig->keyid[0] ); @@ -1143,7 +1170,7 @@ do_signature( IOBUF out, int ctb, PKT_signature *sig ) } iobuf_put(a, sig->pubkey_algo ); iobuf_put(a, sig->digest_algo ); - if ( sig->version >= 4 ) + if ( sig->version >= 4 ) { size_t nn; /* Timestamp and keyid must have been packed into the subpackets |