diff options
Diffstat (limited to 'g10/mainproc.c')
-rw-r--r-- | g10/mainproc.c | 149 |
1 files changed, 118 insertions, 31 deletions
diff --git a/g10/mainproc.c b/g10/mainproc.c index 512d33c59..f2a28df74 100644 --- a/g10/mainproc.c +++ b/g10/mainproc.c @@ -245,46 +245,101 @@ add_signature (CTX c, PACKET *pkt) return 1; } -static int +static gpg_error_t symkey_decrypt_seskey (DEK *dek, byte *seskey, size_t slen) { + gpg_error_t err; gcry_cipher_hd_t hd; + unsigned int noncelen, keylen; + enum gcry_cipher_modes ciphermode; + + if (dek->use_aead) + { + err = openpgp_aead_algo_info (dek->use_aead, &ciphermode, &noncelen); + if (err) + return err; + } + else + { + ciphermode = GCRY_CIPHER_MODE_CFB; + noncelen = 0; + } - if(slen < 17 || slen > 33) + /* Check that the session key has a size of 16 to 32 bytes. */ + if ((dek->use_aead && (slen < (noncelen + 16 + 16) + || slen > (noncelen + 32 + 16))) + || (!dek->use_aead && (slen < 17 || slen > 33))) { log_error ( _("weird size for an encrypted session key (%d)\n"), (int)slen); - return GPG_ERR_BAD_KEY; + return gpg_error (GPG_ERR_BAD_KEY); } - if (openpgp_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1)) - BUG (); - if (gcry_cipher_setkey ( hd, dek->key, dek->keylen )) - BUG (); - gcry_cipher_setiv ( hd, NULL, 0 ); - gcry_cipher_decrypt ( hd, seskey, slen, NULL, 0 ); - gcry_cipher_close ( hd ); + err = openpgp_cipher_open (&hd, dek->algo, ciphermode, GCRY_CIPHER_SECURE); + if (!err) + err = gcry_cipher_setkey (hd, dek->key, dek->keylen); + if (!err) + err = gcry_cipher_setiv (hd, noncelen? seskey : NULL, noncelen); + if (err) + goto leave; - /* Now we replace the dek components with the real session key to - decrypt the contents of the sequencing packet. */ - - dek->keylen=slen-1; - dek->algo=seskey[0]; - - if(dek->keylen > DIM(dek->key)) - BUG (); - - memcpy(dek->key, seskey + 1, dek->keylen); + if (dek->use_aead) + { + byte ad[4]; + + ad[0] = (0xc0 | PKT_SYMKEY_ENC); + ad[1] = 5; + ad[2] = dek->algo; + ad[3] = dek->use_aead; + err = gcry_cipher_authenticate (hd, ad, 4); + if (err) + goto leave; + gcry_cipher_final (hd); + keylen = slen - noncelen - 16; + err = gcry_cipher_decrypt (hd, seskey+noncelen, keylen, NULL, 0); + if (err) + goto leave; + err = gcry_cipher_checktag (hd, seskey+noncelen+keylen, 16); + if (err) + goto leave; + /* Now we replace the dek components with the real session key to + * decrypt the contents of the sequencing packet. */ + if (keylen > DIM(dek->key)) + { + err = gpg_error (GPG_ERR_TOO_LARGE); + goto leave; + } + dek->keylen = keylen; + memcpy (dek->key, seskey + noncelen, dek->keylen); + } + else + { + gcry_cipher_decrypt (hd, seskey, slen, NULL, 0 ); + /* Now we replace the dek components with the real session key to + * decrypt the contents of the sequencing packet. */ + keylen = slen-1; + if (keylen > DIM(dek->key)) + { + err = gpg_error (GPG_ERR_TOO_LARGE); + goto leave; + } + dek->algo = seskey[0]; + dek->keylen = keylen; + memcpy (dek->key, seskey + 1, dek->keylen); + } /*log_hexdump( "thekey", dek->key, dek->keylen );*/ - return 0; + leave: + gcry_cipher_close (hd); + return err; } static void proc_symkey_enc (CTX c, PACKET *pkt) { + gpg_error_t err; PKT_symkey_enc *enc; enc = pkt->pkt.symkey_enc; @@ -294,19 +349,21 @@ proc_symkey_enc (CTX c, PACKET *pkt) { int algo = enc->cipher_algo; const char *s = openpgp_cipher_algo_name (algo); + const char *a = (enc->aead_algo ? openpgp_aead_algo_name (enc->aead_algo) + /**/ : "CFB"); if (!openpgp_cipher_test_algo (algo)) { if (!opt.quiet) { if (enc->seskeylen) - log_info (_("%s encrypted session key\n"), s ); + log_info (_("%s.%s encrypted session key\n"), s, a ); else - log_info (_("%s encrypted data\n"), s ); + log_info (_("%s.%s encrypted data\n"), s, a ); } } else - log_error (_("encrypted with unknown algorithm %d\n"), algo); + log_error (_("encrypted with unknown algorithm %d.%s\n"), algo, a); if (openpgp_md_test_algo (enc->s2k.hash_algo)) { @@ -334,6 +391,7 @@ proc_symkey_enc (CTX c, PACKET *pkt) if (c->dek) { c->dek->symmetric = 1; + c->dek->use_aead = enc->aead_algo; /* FIXME: This doesn't work perfectly if a symmetric key comes before a public key in the message - if the @@ -344,9 +402,24 @@ proc_symkey_enc (CTX c, PACKET *pkt) come later. */ if (enc->seskeylen) { - if (symkey_decrypt_seskey (c->dek, - enc->seskey, enc->seskeylen)) + err = symkey_decrypt_seskey (c->dek, + enc->seskey, enc->seskeylen); + if (err) { + log_info ("decryption of the symmetrically encrypted" + " session key failed: %s\n", + gpg_strerror (err)); + if (gpg_err_code (err) != GPG_ERR_BAD_KEY + && gpg_err_code (err) != GPG_ERR_CHECKSUM) + log_fatal ("process terminated to be bug compatible" + " with GnuPG <= 2.2\n"); + if (c->dek->s2k_cacheid[0]) + { + if (opt.debug) + log_debug ("cleared passphrase cached with ID:" + " %s\n", c->dek->s2k_cacheid); + passphrase_clear_cache (c->dek->s2k_cacheid); + } xfree (c->dek); c->dek = NULL; } @@ -650,6 +723,7 @@ proc_encrypted (CTX c, PACKET *pkt) else if (!result && !opt.ignore_mdc_error && !pkt->pkt.encrypted->mdc_method + && !pkt->pkt.encrypted->aead_algo && openpgp_cipher_get_algo_blklen (c->dek->algo) != 8 && c->dek->algo != CIPHER_ALGO_TWOFISH) { @@ -664,17 +738,25 @@ proc_encrypted (CTX c, PACKET *pkt) write_status (STATUS_DECRYPTION_FAILED); } else if (!result || (gpg_err_code (result) == GPG_ERR_BAD_SIGNATURE + && !pkt->pkt.encrypted->aead_algo && opt.ignore_mdc_error)) { + /* All is fine or for an MDC message the MDC failed but the + * --ignore-mdc-error option is active. For compatibility + * reasons we issue GOODMDC also for AEAD messages. */ write_status (STATUS_DECRYPTION_OKAY); if (opt.verbose > 1) log_info(_("decryption okay\n")); - if (pkt->pkt.encrypted->mdc_method && !result) + + if (pkt->pkt.encrypted->aead_algo) + write_status (STATUS_GOODMDC); + else if (pkt->pkt.encrypted->mdc_method && !result) write_status (STATUS_GOODMDC); else if (!opt.no_mdc_warn) log_info (_("WARNING: message was not integrity protected\n")); } - else if (gpg_err_code (result) == GPG_ERR_BAD_SIGNATURE) + else if (gpg_err_code (result) == GPG_ERR_BAD_SIGNATURE + || gpg_err_code (result) == GPG_ERR_TRUNCATED) { glo_ctrl.lasterr = result; log_error (_("WARNING: encrypted message has been manipulated!\n")); @@ -684,6 +766,7 @@ proc_encrypted (CTX c, PACKET *pkt) else { if ((gpg_err_code (result) == GPG_ERR_BAD_KEY + || gpg_err_code (result) == GPG_ERR_CHECKSUM || gpg_err_code (result) == GPG_ERR_CIPHER_ALGO) && *c->dek->s2k_cacheid != '\0') { @@ -1393,7 +1476,8 @@ do_proc_packets (ctrl_t ctrl, CTX c, iobuf_t a) case PKT_PUBKEY_ENC: proc_pubkey_enc (ctrl, c, pkt); break; case PKT_SYMKEY_ENC: proc_symkey_enc (c, pkt); break; case PKT_ENCRYPTED: - case PKT_ENCRYPTED_MDC: proc_encrypted (c, pkt); break; + case PKT_ENCRYPTED_MDC: + case PKT_ENCRYPTED_AEAD:proc_encrypted (c, pkt); break; case PKT_COMPRESSED: rc = proc_compressed (c, pkt); break; default: newpkt = 0; break; } @@ -1409,6 +1493,7 @@ do_proc_packets (ctrl_t ctrl, CTX c, iobuf_t a) case PKT_PUBKEY_ENC: case PKT_ENCRYPTED: case PKT_ENCRYPTED_MDC: + case PKT_ENCRYPTED_AEAD: write_status_text( STATUS_UNEXPECTED, "0" ); rc = GPG_ERR_UNEXPECTED; goto leave; @@ -1436,7 +1521,8 @@ do_proc_packets (ctrl_t ctrl, CTX c, iobuf_t a) case PKT_SYMKEY_ENC: proc_symkey_enc (c, pkt); break; case PKT_PUBKEY_ENC: proc_pubkey_enc (ctrl, c, pkt); break; case PKT_ENCRYPTED: - case PKT_ENCRYPTED_MDC: proc_encrypted (c, pkt); break; + case PKT_ENCRYPTED_MDC: + case PKT_ENCRYPTED_AEAD: proc_encrypted (c, pkt); break; case PKT_PLAINTEXT: proc_plaintext (c, pkt); break; case PKT_COMPRESSED: rc = proc_compressed (c, pkt); break; case PKT_ONEPASS_SIG: newpkt = add_onepass_sig (c, pkt); break; @@ -1463,7 +1549,8 @@ do_proc_packets (ctrl_t ctrl, CTX c, iobuf_t a) case PKT_PUBKEY_ENC: proc_pubkey_enc (ctrl, c, pkt); break; case PKT_SYMKEY_ENC: proc_symkey_enc (c, pkt); break; case PKT_ENCRYPTED: - case PKT_ENCRYPTED_MDC: proc_encrypted (c, pkt); break; + case PKT_ENCRYPTED_MDC: + case PKT_ENCRYPTED_AEAD: proc_encrypted (c, pkt); break; case PKT_PLAINTEXT: proc_plaintext (c, pkt); break; case PKT_COMPRESSED: rc = proc_compressed (c, pkt); break; case PKT_ONEPASS_SIG: newpkt = add_onepass_sig (c, pkt); break; |