diff options
| -rw-r--r-- | g10/encrypt.c | 156 | ||||
| -rw-r--r-- | g10/gpgcompose.c | 8 | ||||
| -rw-r--r-- | g10/main.h | 3 |
3 files changed, 113 insertions, 54 deletions
diff --git a/g10/encrypt.c b/g10/encrypt.c index 856849799..ab745cee8 100644 --- a/g10/encrypt.c +++ b/g10/encrypt.c @@ -67,45 +67,75 @@ encrypt_store (const char *filename) } -/* *SESKEY contains the unencrypted session key ((*SESKEY)->KEY) and - the algorithm that will be used to encrypt the contents of the SED - packet ((*SESKEY)->ALGO). If *SESKEY is NULL, then a random - session key that is appropriate for DEK->ALGO is generated and - stored there. - - Encrypt that session key using DEK and store the result in ENCKEY, - which must be large enough to hold (*SESKEY)->KEYLEN + 1 bytes. */ -void -encrypt_seskey (DEK *dek, DEK **seskey, byte *enckey) +/* Encrypt a session key using DEK and store a pointer to the result + * at R_ENCKEY and its length at R_ENCKEYLEN. + * + * R_SESKEY points to the unencrypted session key (.KEY, >KEYLEN) and + * the algorithm that will be used to encrypt the contents of the + * SKESK packet (.ALGO). If R_SESKEY points to NULL, then a random + * session key that is appropriate for DEK->ALGO is generated and + * stored at R_SESKEY. + */ +gpg_error_t +encrypt_seskey (DEK *dek, DEK **r_seskey, void **r_enckey, size_t *r_enckeylen) { - gcry_cipher_hd_t hd; - byte buf[33]; + gpg_error_t err; + gcry_cipher_hd_t hd = NULL; + byte *buf = NULL; + DEK *seskey; + + *r_enckey = NULL; + *r_enckeylen = 0; - log_assert ( dek->keylen <= 32 ); - if (!*seskey) + if (*r_seskey) + seskey = *r_seskey; + else { - *seskey=xmalloc_clear(sizeof(DEK)); - (*seskey)->algo=dek->algo; - make_session_key(*seskey); + seskey = xtrycalloc (1, sizeof(DEK)); + if (!seskey) + { + err = gpg_error_from_syserror (); + goto leave; + } + seskey->algo = dek->algo; + make_session_key (seskey); /*log_hexdump( "thekey", c->key, c->keylen );*/ } + buf = xtrymalloc_secure (1 + seskey->keylen); + if (!buf) + { + err = gpg_error_from_syserror (); + goto leave; + } + /* The encrypted session key is prefixed with a one-octet algorithm id. */ - buf[0] = (*seskey)->algo; - memcpy( buf + 1, (*seskey)->key, (*seskey)->keylen ); - - /* We only pass already checked values to the following function, - thus we consider any failure as fatal. */ - 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_encrypt (hd, buf, (*seskey)->keylen + 1, NULL, 0); - gcry_cipher_close (hd); + buf[0] = seskey->algo; + memcpy (buf + 1, seskey->key, seskey->keylen); + + err = openpgp_cipher_open (&hd, dek->algo, GCRY_CIPHER_MODE_CFB, 1); + if (!err) + err = gcry_cipher_setkey (hd, dek->key, dek->keylen); + if (!err) + err = gcry_cipher_setiv (hd, NULL, 0); + if (!err) + err = gcry_cipher_encrypt (hd, buf, seskey->keylen + 1, NULL, 0); + if (err) + goto leave; + + *r_enckey = buf; + buf = NULL; + *r_enckeylen = seskey->keylen + 1; + /* Return the session key in case we allocated it. */ + *r_seskey = seskey; + seskey = NULL; - memcpy( enckey, buf, (*seskey)->keylen + 1 ); - wipememory( buf, sizeof buf ); /* burn key */ + leave: + gcry_cipher_close (hd); + if (seskey != *r_seskey) + xfree (seskey); + xfree (buf); + return err; } @@ -218,9 +248,9 @@ encrypt_simple (const char *filename, int mode, int use_seskey) PACKET pkt; PKT_plaintext *pt = NULL; STRING2KEY *s2k = NULL; - byte enckey[33]; + void *enckey = NULL; + size_t enckeylen = 0; int rc = 0; - int seskeylen = 0; u32 filesize; cipher_filter_context_t cfx; armor_filter_context_t *afx = NULL; @@ -273,6 +303,7 @@ encrypt_simple (const char *filename, int mode, int use_seskey) if ( mode ) { int canceled; + aead_algo_t aead_algo; s2k = xmalloc_clear( sizeof *s2k ); s2k->mode = opt.s2k_mode; @@ -296,21 +327,33 @@ encrypt_simple (const char *filename, int mode, int use_seskey) "due to the S2K mode\n")); } + /* See whether we want to use AEAD. */ + aead_algo = use_aead (NULL, cfx.dek->algo)? default_aead_algo () : 0; + if ( use_seskey ) { DEK *dek = NULL; - seskeylen = openpgp_cipher_get_algo_keylen (default_cipher_algo ()); - encrypt_seskey( cfx.dek, &dek, enckey ); - xfree( cfx.dek ); cfx.dek = dek; + rc = encrypt_seskey (cfx.dek, &dek, &enckey, &enckeylen); + if (rc) + { + xfree (cfx.dek); + xfree (s2k); + iobuf_close (inp); + release_progress_context (pfx); + return rc; + } + /* Replace key in DEK. */ + xfree (cfx.dek); + cfx.dek = dek; } if (opt.verbose) log_info(_("using cipher %s\n"), openpgp_cipher_algo_name (cfx.dek->algo)); - if (use_aead (NULL, cfx.dek->algo)) - cfx.dek->use_aead = default_aead_algo (); + if (aead_algo) + cfx.dek->use_aead = aead_algo; else cfx.dek->use_mdc = !!use_mdc (NULL, cfx.dek->algo); } @@ -342,20 +385,23 @@ encrypt_simple (const char *filename, int mode, int use_seskey) if ( s2k ) { - PKT_symkey_enc *enc = xmalloc_clear( sizeof *enc + seskeylen + 1 ); + /* Fixme: This is quite similar to write_symkey_enc. */ + PKT_symkey_enc *enc = xmalloc_clear (sizeof *enc + enckeylen); enc->version = 4; enc->cipher_algo = cfx.dek->algo; enc->s2k = *s2k; - if ( use_seskey && seskeylen ) + if (enckeylen) { - enc->seskeylen = seskeylen + 1; /* algo id */ - memcpy (enc->seskey, enckey, seskeylen + 1 ); + enc->seskeylen = enckeylen; + memcpy (enc->seskey, enckey, enckeylen); } pkt.pkttype = PKT_SYMKEY_ENC; pkt.pkt.symkey_enc = enc; if ((rc = build_packet( out, &pkt ))) log_error("build symkey packet failed: %s\n", gpg_strerror (rc) ); xfree (enc); + xfree (enckey); + enckey = NULL; } if (!opt.no_literal) @@ -459,6 +505,7 @@ encrypt_simple (const char *filename, int mode, int use_seskey) if (pt) pt->buf = NULL; free_packet (&pkt, NULL); + xfree (enckey); xfree (cfx.dek); xfree (s2k); release_armor_context (afx); @@ -493,20 +540,29 @@ static int write_symkey_enc (STRING2KEY *symkey_s2k, DEK *symkey_dek, DEK *dek, iobuf_t out) { - int rc, seskeylen = openpgp_cipher_get_algo_keylen (dek->algo); - + int rc; + void *enckey; + size_t enckeylen; PKT_symkey_enc *enc; - byte enckey[33]; PACKET pkt; - enc=xmalloc_clear(sizeof(PKT_symkey_enc)+seskeylen+1); - encrypt_seskey(symkey_dek,&dek,enckey); + rc = encrypt_seskey (symkey_dek, &dek, &enckey, &enckeylen); + if (rc) + return rc; + enc = xtrycalloc (1, sizeof (PKT_symkey_enc) + enckeylen); + if (!enc) + { + rc = gpg_error_from_syserror (); + xfree (enckey); + return rc; + } enc->version = 4; enc->cipher_algo = opt.s2k_cipher_algo; enc->s2k = *symkey_s2k; - enc->seskeylen = seskeylen + 1; /* algo id */ - memcpy( enc->seskey, enckey, seskeylen + 1 ); + enc->seskeylen = enckeylen; + memcpy (enc->seskey, enckey, enckeylen); + xfree (enckey); pkt.pkttype = PKT_SYMKEY_ENC; pkt.pkt.symkey_enc = enc; @@ -514,7 +570,7 @@ write_symkey_enc (STRING2KEY *symkey_s2k, DEK *symkey_dek, DEK *dek, if ((rc=build_packet(out,&pkt))) log_error("build symkey_enc packet failed: %s\n",gpg_strerror (rc)); - xfree(enc); + xfree (enc); return rc; } diff --git a/g10/gpgcompose.c b/g10/gpgcompose.c index f87983802..f22c7c202 100644 --- a/g10/gpgcompose.c +++ b/g10/gpgcompose.c @@ -2283,9 +2283,11 @@ sk_esk (const char *option, int argc, char *argv[], void *cookie) DEK *sesdekp = &sesdek; /* Now encrypt the session key (or rather, the algorithm used to - encrypt the SED plus the session key) using ENCKEY. */ - ske->seskeylen = 1 + sesdek.keylen; - encrypt_seskey (&s2kdek, &sesdekp, ske->seskey); + encrypt the SKESK plus the session key) using ENCKEY. */ + err = encrypt_seskey (&s2kdek, &sesdekp, + (void**)&ske->seskey, (size_t *)&ske->seskeylen); + if (err) + log_fatal ("encrypt_seskey failed: %s\n", gpg_strerror (err)); /* Save the session key for later. */ session_key = sesdek; diff --git a/g10/main.h b/g10/main.h index 393a1b09e..509126c65 100644 --- a/g10/main.h +++ b/g10/main.h @@ -232,7 +232,8 @@ void display_online_help( const char *keyword ); /*-- encode.c --*/ int setup_symkey (STRING2KEY **symkey_s2k,DEK **symkey_dek); -void encrypt_seskey (DEK *dek, DEK **seskey, byte *enckey); +gpg_error_t encrypt_seskey (DEK *dek, DEK **r_seskey, + void **r_enckey, size_t *r_enckeylen); int use_aead (pk_list_t pk_list, int algo); int use_mdc (pk_list_t pk_list,int algo); int encrypt_symmetric (const char *filename ); |