diff options
Diffstat (limited to 'g10/pubkey-enc.c')
| -rw-r--r-- | g10/pubkey-enc.c | 40 |
1 files changed, 37 insertions, 3 deletions
diff --git a/g10/pubkey-enc.c b/g10/pubkey-enc.c index a5224e20a..24411e8a1 100644 --- a/g10/pubkey-enc.c +++ b/g10/pubkey-enc.c @@ -147,14 +147,16 @@ get_it (PKT_pubkey_enc *enc, DEK *dek, PKT_public_key *sk, u32 *keyid) char *keygrip; byte fp[MAX_FINGERPRINT_LEN]; size_t fpn; + const int gcry_pkalgo = map_pk_openpgp_to_gcry( sk->pubkey_algo ); /* Get the keygrip. */ err = hexkeygrip_from_pk (sk, &keygrip); if (err) goto leave; + /* Convert the data to an S-expression. */ - if (sk->pubkey_algo == GCRY_PK_ELG || sk->pubkey_algo == GCRY_PK_ELG_E) + if (gcry_pkalgo == GCRY_PK_ELG ||gcry_pkalgo == GCRY_PK_ELG_E) { if (!enc->data[0] || !enc->data[1]) err = gpg_error (GPG_ERR_BAD_MPI); @@ -162,7 +164,7 @@ get_it (PKT_pubkey_enc *enc, DEK *dek, PKT_public_key *sk, u32 *keyid) err = gcry_sexp_build (&s_data, NULL, "(enc-val(elg(a%m)(b%m)))", enc->data[0], enc->data[1]); } - else if (sk->pubkey_algo == GCRY_PK_RSA || sk->pubkey_algo == GCRY_PK_RSA_E) + else if (gcry_pkalgo == GCRY_PK_RSA || gcry_pkalgo == GCRY_PK_RSA_E) { if (!enc->data[0]) err = gpg_error (GPG_ERR_BAD_MPI); @@ -170,6 +172,14 @@ get_it (PKT_pubkey_enc *enc, DEK *dek, PKT_public_key *sk, u32 *keyid) err = gcry_sexp_build (&s_data, NULL, "(enc-val(rsa(a%m)))", enc->data[0]); } + else if (gcry_pkalgo == GCRY_PK_ECDH ) + { + if (!enc->data[0] || !enc->data[1]) + err = gpg_error (GPG_ERR_BAD_MPI); + else + err = gcry_sexp_build (&s_data, NULL, "(enc-val(ecdh(a%m)(b%m)))", + enc->data[0], enc->data[1]); + } else err = gpg_error (GPG_ERR_BUG); @@ -181,7 +191,7 @@ get_it (PKT_pubkey_enc *enc, DEK *dek, PKT_public_key *sk, u32 *keyid) /* Decrypt. */ desc = gpg_format_keydesc (sk, 0, 1); - err = agent_pkdecrypt (NULL, keygrip, desc, s_data, fp, &frame, &nframe); + err = agent_pkdecrypt (NULL, keygrip, desc, s_data, &frame, &nframe); xfree (desc); gcry_sexp_release (s_data); if (err) @@ -233,6 +243,30 @@ get_it (PKT_pubkey_enc *enc, DEK *dek, PKT_public_key *sk, u32 *keyid) } } else { + gcry_mpi_t shared_mpi; + gcry_mpi_t decoded; + + /* at the beginning the frame is the bytes of shared point MPI */ + + err = gcry_mpi_scan (&shared_mpi, GCRYMPI_FMT_USG, frame, nframe, NULL); + if (err) { + log_fatal ("mpi_scan failed: %s\n", gpg_strerror (err)); + goto leave; + } + + err = pk_ecdh_decrypt (&decoded, fp, enc->data[1]/*encr data as an MPI*/, shared_mpi, sk->pkey); + mpi_release( shared_mpi ); + if( err ) + goto leave; + + /* reuse nframe, which size is sufficient to include the session key */ + err = gcry_mpi_print (GCRYMPI_FMT_USG, frame, nframe, &nframe, decoded); + mpi_release( decoded ); + if( err ) + goto leave; + + /* Now the frame is the bytes decrypted but padded session key */ + /* Allow double padding for the benefit of DEK size concealment. * Higher than this is wasteful. */ |