Merge pull request trusteddomainproject#202 from futatuki/per-request-sign-algorithm

Author: futatuki

RELEASE_NOTES

@@ -13,6 +13,8 @@ release, and a summary of the changes in that release.
 	Make odkim.internal_ip() available to all Lua hooks.  Problem noted
 		by Iosif Fettich.
 	Make bind code DNSSEC-aware.  Patch from Jack Bates.
+	Extend KeyTable to specify signing algorithm.
+		Patch from Yasuhito Futatsuki.
 	Fix dkimf_db_nextpunct() so it doesn't incorrectly identify an encoded
 		hex digit as a value delimiter.
 	Fix issue #8: The password file critical section isn't big enough.

opendkim/opendkim-testkey.c

@@ -236,6 +236,8 @@ main(int argc, char **argv)
 	char domain[BUFRSZ];
 	char selector[BUFRSZ];
 	char keypath[MAXBUFRSZ];
+	char signalgstr[BUFRSZ];
+	dkim_alg_t signalg;
 
 	progname = (p = strrchr(argv[0], '/')) == NULL ? argv[0] : p + 1;
 
@@ -464,7 +466,7 @@ main(int argc, char **argv)
 		size_t keylen;
 		DKIMF_DB db;
 		char keyname[BUFRSZ + 1];
-		struct dkimf_db_data dbd[3];
+		struct dkimf_db_data dbd[4];
 
 		memset(dbd, '\0', sizeof dbd);
 
@@ -491,18 +493,22 @@ main(int argc, char **argv)
 			memset(domain, '\0', sizeof domain);
 			memset(selector, '\0', sizeof selector);
 			memset(keypath, '\0', sizeof keypath);
+			memset(signalgstr, '\0', sizeof signalgstr);
 
 			dbd[0].dbdata_buffer = domain;
 			dbd[0].dbdata_buflen = sizeof domain;
 			dbd[1].dbdata_buffer = selector;
 			dbd[1].dbdata_buflen = sizeof selector;
 			dbd[2].dbdata_buffer = keypath;
 			dbd[2].dbdata_buflen = sizeof keypath;
+			dbd[3].dbdata_buffer = signalgstr;
+			dbd[3].dbdata_buflen = sizeof signalgstr;
+			dbd[3].dbdata_flags = DKIMF_DB_DATA_OPTIONAL;
 
 			keylen = sizeof keyname;
 
 			status = dkimf_db_walk(db, c == 0, keyname, &keylen,
-			                       dbd, 3);
+			                       dbd, 4);
 			if (status == -1)
 			{
 				fprintf(stderr,
@@ -524,6 +530,27 @@ main(int argc, char **argv)
 				        progname, c, keyname);
 			}
 
+			if (signalgstr[0] != '\0')
+			{
+				signalg = (dkim_alg_t)dkim_name_to_code(dkim_table_algorithms,
+				                                        signalgstr);
+				if (signalg == -1)
+				{
+					fprintf(stderr,
+					        "%s: unknown sign algorithm "
+					        "'%s' for key '%s'\n",
+					        progname, signalgstr, keyname);
+					return 1;
+				}
+
+				if (verbose > 1)
+				{
+					fprintf(stderr,
+				        "%s: key '%s': sign algorithm is '%s'\n",
+				        progname, keyname, signalgstr);
+				}
+			}
+
 			if (keypath[0] == '/' ||
 			    strncmp(keypath, "./", 2) == 0 ||
 			    strncmp(keypath, "../", 3) == 0)
@@ -572,6 +599,9 @@ main(int argc, char **argv)
 				        progname, keyname);
 			}
 
+			/* To do: check consistency of the key and algorithm.
+			   It is needed to extend dkim_test_key() for it */
+
 			dnssec = DKIM_DNSSEC_UNKNOWN;
 
 			status = dkim_test_key(lib, selector, domain,

opendkim/opendkim.c

@@ -4919,10 +4919,12 @@ dkimf_add_signrequest(struct msgctx *dfc, DKIMF_DB keytable, char *keyname,
 	_Bool found = FALSE;
 	size_t keydatasz = 0;
 	struct signreq *new;
-	struct dkimf_db_data dbd[3];
+	struct dkimf_db_data dbd[4];
 	char keydata[MAXBUFRSZ + 1];
 	char domain[DKIM_MAXHOSTNAMELEN + 1];
 	char selector[BUFRSZ + 1];
+	char signalgstr[BUFRSZ + 1];
+	dkim_alg_t signalg = DKIM_SIGN_DEFAULT;
 	char err[BUFRSZ + 1];
 
 	assert(dfc != NULL);
@@ -4948,6 +4950,7 @@ dkimf_add_signrequest(struct msgctx *dfc, DKIMF_DB keytable, char *keyname,
 		memset(domain, '\0', sizeof domain);
 		memset(selector, '\0', sizeof selector);
 		memset(keydata, '\0', sizeof keydata);
+		memset(signalgstr, '\0', sizeof signalgstr);
 
 		dbd[0].dbdata_buffer = domain;
 		dbd[0].dbdata_buflen = sizeof domain - 1;
@@ -4958,9 +4961,12 @@ dkimf_add_signrequest(struct msgctx *dfc, DKIMF_DB keytable, char *keyname,
 		dbd[2].dbdata_buffer = keydata;
 		dbd[2].dbdata_buflen = sizeof keydata - 1;
 		dbd[2].dbdata_flags = DKIMF_DB_DATA_OPTIONAL;
+		dbd[3].dbdata_buffer = signalgstr;
+		dbd[3].dbdata_buflen = sizeof signalgstr - 1;
+		dbd[3].dbdata_flags = DKIMF_DB_DATA_OPTIONAL;
 
 		if (dkimf_db_get(keytable, keyname, strlen(keyname),
-		                 dbd, 3, &found) != 0)
+		                 dbd, 4, &found) != 0)
 		{
 			memset(err, '\0', sizeof err);
 			(void) dkimf_db_strerror(keytable, err, sizeof err);
@@ -5064,6 +5070,24 @@ dkimf_add_signrequest(struct msgctx *dfc, DKIMF_DB keytable, char *keyname,
  			if (curconf->conf_safekeys)
 				return 2;
 		}
+
+		if (dbd[3].dbdata_buflen > 0 && signalgstr[0] != '\0')
+		{
+			signalg = (dkim_alg_t)dkim_name_to_code(dkim_table_algorithms,
+			                                        signalgstr);
+			if (signalg == -1)
+			{
+				if (dolog)
+				{
+					syslog(LOG_ERR,
+					       "KeyTable entry for '%s' corrupt:"
+					       " invalid sign algorithm %s",
+					       keyname, signalgstr);
+				}
+
+				return 2;
+			}
+		}
 	}
 
 	new = malloc(sizeof *new);
@@ -5076,6 +5100,7 @@ dkimf_add_signrequest(struct msgctx *dfc, DKIMF_DB keytable, char *keyname,
 	new->srq_selector = NULL;
 	new->srq_keydata = NULL;
 	new->srq_signlen = signlen;
+	new->srq_signalg = signalg;
 	if (signer != NULL && signer[0] != '\0')
 		new->srq_signer = (u_char *) strdup(signer);
 	else
@@ -8312,11 +8337,12 @@ dkimf_config_load(struct config *data, struct dkimf_config *conf,
 		{
 			_Bool first = TRUE;
 			_Bool found;
-			struct dkimf_db_data dbd[3];
+			struct dkimf_db_data dbd[4];
 			char keyname[BUFRSZ + 1];
 			char domain[BUFRSZ + 1];
 			char selector[BUFRSZ + 1];
 			char keydata[BUFRSZ + 1];
+			char signalgstr[BUFRSZ + 1];
 			char signer[BUFRSZ + 1];
 
 			dbd[0].dbdata_flags = 0;
@@ -8344,10 +8370,13 @@ dkimf_config_load(struct config *data, struct dkimf_config *conf,
 				dbd[2].dbdata_buffer = keydata;
 				dbd[2].dbdata_buflen = sizeof keydata - 1;
 				dbd[2].dbdata_flags = DKIMF_DB_DATA_BINARY;
+				dbd[3].dbdata_buffer = signalgstr;
+				dbd[3].dbdata_buflen = sizeof signalgstr - 1;
+				dbd[3].dbdata_flags = DKIMF_DB_DATA_OPTIONAL;
 
 				if (dkimf_db_get(conf->conf_keytabledb,	
 				                 keyname, strlen(keyname),
-				                 dbd, 3, &found) != 0 ||
+				                 dbd, 4, &found) != 0 ||
 				    !found ||
 				    dbd[0].dbdata_buflen == 0 ||
 				    dbd[1].dbdata_buflen == 0 ||
@@ -12604,6 +12633,7 @@ mlfi_eoh(SMFICTX *ctx)
 
 		for (sr = dfc->mctx_srhead; sr != NULL; sr = sr->srq_next)
 		{
+			dkim_alg_t signalg;
 #ifdef _FFR_CONDITIONAL
 			if (sr->srq_dkim != NULL)
 				continue;
@@ -12630,13 +12660,15 @@ mlfi_eoh(SMFICTX *ctx)
 				selector = conf->conf_selector;
 			}
 
+			signalg = (sr->srq_signalg == DKIM_SIGN_DEFAULT)?
+			          dfc->mctx_signalg:sr->srq_signalg;
 			sr->srq_dkim = dkim_sign(conf->conf_libopendkim,
 			                         dfc->mctx_jobid,
 			                         NULL, keydata, selector,
 			                         sdomain,
 			                         dfc->mctx_hdrcanon,
 			                         dfc->mctx_bodycanon,
-			                         dfc->mctx_signalg,
+			                         signalg,
 			                         signlen, &status);
 
 			if (sr->srq_dkim == NULL || status != DKIM_STAT_OK)

opendkim/opendkim.conf.5.in

@@ -349,15 +349,22 @@ If present, overrides any
 setting in the configuration file.  The data set named here maps each key
 name to three values: (a) the name of the domain to use in the signature's
 "d=" value; (b) the name of the selector to use in the signature's "s=" value;
-and (c) either a private key or a path to a file containing a private key.
+and (c) either a private key or a path to a file containing a private key;
+(d) (optional) signing algorithm to use with this key.
 If the first value consists solely of a percent sign ("%") character,
 it will be replaced by the apparent domain of the sender when generating
 a signature.
 If the third value starts with a slash ("/") character, or "./" or "../",
 then it is presumed to refer to a file from which the private key should
 be read, otherwise it is itself a PEM-encoded private key or a base64-encoded
 DER private key; a "%" in the third value in this case will be replaced by
-the apparent domain name of the sender.  The
+the apparent domain name of the sender.  The fourth field should be one
+of supported siginig algorithms (see
+.I SignatureAlgorithm
+below).
+If it is omited, the algorithm specified in
+.I SignatureAlgorithm
+is used for the key.
 .I SigningTable
 (see below) is used to select records from this table to be used to add
 signatures based on the message sender.

opendkim/opendkim.h

@@ -120,6 +120,7 @@ struct signreq
 	u_char *		srq_domain;
 	u_char *		srq_selector;
 	u_char *		srq_signer;
+	dkim_alg_t		srq_signalg;
 	DKIM *			srq_dkim;
 	struct signreq *	srq_next;
 };