X-Git-Url: http://www.average.org/gitweb/?p=pam_pcsc_cr.git;a=blobdiff_plain;f=authobj.c;h=b402094df224cd13651227c15e47bb9184976343;hp=2b774abccae724298d35666d94d9fd83ebbf1f7b;hb=b4ed664ffb6e3f3764fa2b2f4b05437df43d7f19;hpb=1fb61b04544488148032c06475042aec167d6097

diff --git a/authobj.c b/authobj.c
index 2b774ab..b402094 100644
--- a/authobj.c
+++ b/authobj.c
@@ -1,104 +1,273 @@
+/*
+Copyright (c) 2013 Eugene Crosser
+
+This software is provided 'as-is', without any express or implied
+warranty. In no event will the authors be held liable for any damages
+arising from the use of this software.
+
+Permission is granted to anyone to use this software for any purpose,
+including commercial applications, and to alter it and redistribute it
+freely, subject to the following restrictions:
+
+    1. The origin of this software must not be misrepresented; you must
+    not claim that you wrote the original software. If you use this
+    software in a product, an acknowledgment in the product documentation
+    would be appreciated but is not required.
+
+    2. Altered source versions must be plainly marked as such, and must
+    not be misrepresented as being the original software.
+
+    3. This notice may not be removed or altered from any source
+    distribution.
+*/
+
 #ifdef HAVE_CONFIG_H
 # include "config.h"
 #endif
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 #include <alloca.h>
 #include "serial.h"
 #include "crypto.h"
 #include "authobj.h"
 
-int make_challenge(const char *id, const char *pass, const char *nonce,
-		unsigned char *challenge, int *challengesize)
+static struct _auth_chunk
+make_challenge(const char *uid, const char *pass, const char *nonce)
 {
+	struct _auth_chunk ho = {0};
+	unsigned long rc;
 	serializer_t srl;
+	int datasize = strlen(uid) + strlen(pass) + strlen(nonce) +
+			4 * sizeof(short);
+	unsigned char *data = alloca(datasize);
+	int hashsize = sizeof(ho.data);
+
+	serial_init(&srl, data, datasize);
+	if (serial_put(&srl, uid, strlen(uid)) != strlen(uid)) {
+		ho.err = "challenge: serialization of uid failed";
+	} else if (serial_put(&srl, pass, strlen(pass)) != strlen(pass)) {
+		ho.err = "challenge: serialization of pass failed";
+	} else if (serial_put(&srl, nonce, strlen(nonce)) != strlen(nonce)) {
+		ho.err = "challenge: serialization of nonce failed";
+	} else if (serial_put(&srl, NULL, 0) != 0) {
+		ho.err = "challenge: serialization of terminator failed";
+	}
+	if (!ho.err) {
+		if ((rc = hash(data, serial_size(&srl), &ho.data, &hashsize))) {
+			ho.err = crypto_errstr(rc);
+		} else if (hashsize != sizeof(ho.data)) {
+			ho.err = "challenge: hash size is wrong";
+		}
+	}
+	memset(data, 0, datasize);
+	return ho;
+}
+
+static struct _auth_chunk
+new_key(const unsigned char *challenge, const int challengesize,
+	const unsigned char *secret, const int secsize)
+{
+	struct _auth_chunk ho = {0};
+	unsigned long rc;
+	int keysize = sizeof(ho.data);
+
+	if ((rc = hmac(secret, secsize, challenge, challengesize,
+			&ho.data, &keysize))) {
+		ho.err = crypto_errstr(rc);
+	} else if (keysize != sizeof(ho.data)) {
+		ho.err = "make_key: hash size is wrong";
+	}
+	return ho;
+}
+
+static struct _auth_chunk
+make_key(const char *userid, const char *password, const char *nonce,
+	const unsigned char *secret, const int secsize,
+	struct _auth_chunk (*fetch_key)(const unsigned char *chal,
+					const int csize))
+{
+	struct _auth_chunk ho_chal, ho_key = {0};
 
-	serial_init(&srl, challenge, *challengesize);
-	if (serial_put(&srl, id, strlen(id)) != strlen(id))
-		return aoe_serial;
-	if (serial_put(&srl, pass, strlen(pass)) != strlen(pass))
-		return aoe_serial;
-	if (serial_put(&srl, nonce, strlen(nonce)) != strlen(nonce))
-		return aoe_serial;
-	if (serial_put(&srl, NULL, 0) != 0)
-		return aoe_serial;
-	*challengesize = serial_size(&srl);
-	return 0;
+	if (!userid || !password || !nonce) {
+		ho_key.err = "make_key: missing uid, pass or nonce";
+		return ho_key;
+	}
+	ho_chal = make_challenge(userid, password, nonce);
+	if (ho_chal.err) {
+		ho_key.err = ho_chal.err;
+		return ho_key;
+	}
+	if (secret && secsize) {
+		ho_key = new_key(ho_chal.data, sizeof(ho_chal.data),
+				secret, secsize);
+	} else if (fetch_key) {
+		ho_key = (*fetch_key)(ho_chal.data, sizeof(ho_chal.data));
+	} else {
+		ho_key.err = "make_key: neither secret nor fetch_key present";
+	}
+	memset(&ho_chal, 0, sizeof(ho_chal));
+	return ho_key;
 }
 
-int make_authobj(const char *id, const char *pass, const char *nonce,
+static struct _auth_obj
+make_authobj(const char *userid, const char *password, const char *nonce,
 		const unsigned char *secret, const int secsize,
-		const unsigned char *payload, const int paysize,
-		unsigned char *buffer, int *bufsize)
+		const unsigned char *payload, const int paylsize)
 {
+	struct _auth_obj ao = {0};
+	unsigned long rc;
 	unsigned char *data;
 	int datasize;
 	unsigned char datahash[HASHSIZE];
 	int datahashsize = HASHSIZE;
-	unsigned char *challenge;
-	int challengesize;
-	unsigned char key[HASHSIZE];
-	int keysize = HASHSIZE;
 	serializer_t srl;
 
-	datasize = ((secsize + paysize + HASHSIZE * 4 * sizeof(short) - 1) /
+	datasize = ((secsize + paylsize + HASHSIZE + 4 * sizeof(short) - 1) /
 			CBLKSIZE + 1) * CBLKSIZE;
 	data = alloca(datasize);
 	serial_init(&srl, data, datasize);
-	if (serial_put(&srl, secret, secsize) != secsize) return aoe_serial;
-	if (serial_put(&srl, payload, paysize) != paysize) return aoe_serial;
-	if (hash(data, serial_size(&srl), datahash, &datahashsize))
-		return aoe_size;
-	if (serial_put(&srl, datahash, datahashsize) != datahashsize)
-		return aoe_serial;
-	if (serial_put(&srl, NULL, 0) != 0) return aoe_serial;
-	datasize = ((serial_size(&srl) -1) / CBLKSIZE + 1) * CBLKSIZE;
-
-	challengesize = ((strlen(id) + strlen(pass) + strlen(nonce) +
-			4 * sizeof(short) - 1) / CBLKSIZE + 1) * CBLKSIZE;
-	challenge = alloca(challengesize);
-	if (make_challenge(id, pass, nonce, challenge, &challengesize))
-		return aoe_serial;
-
-	if (hmac(secret, secsize, challenge, challengesize,
-		key, &keysize)) return aoe_crypt;
-
-	if (*bufsize < datasize) return aoe_size;
-	if (encrypt(key, CBLKSIZE, data, buffer, datasize)) return aoe_crypt;
-	*bufsize = datasize;
-
-	return 0;
+	if (serial_put(&srl, secret, secsize) != secsize) {
+		ao.err = "authobj: serialization of secret failed";
+	} else if (serial_put(&srl, payload, paylsize) != paylsize) {
+		ao.err = "authobj: serialization of payload failed";
+	} else if ((rc = hash(data, serial_size(&srl),
+				datahash, &datahashsize))) {
+		ao.err = crypto_errstr(rc);
+	} else if (serial_put(&srl, datahash, datahashsize) != datahashsize) {
+		ao.err = "authobj: serialization of hash failed";
+	} else if (serial_put(&srl, NULL, 0) != 0) {
+		ao.err = "authobj: serialization of terminator failed";
+	} else {
+		unsigned long lrc;
+		int osize = ((serial_size(&srl) -1) / CBLKSIZE + 1) * CBLKSIZE;
+		struct _auth_chunk ho_key;
+
+		ho_key = make_key(userid, password, nonce,
+					secret, secsize, NULL);
+		if (ho_key.err) {
+			ao.err = ho_key.err;
+		} else if ((ao.buffer = malloc(osize + paylsize)) == NULL) {
+			ao.err = "make authobj: malloc failed";
+		} else if ((lrc = encrypt(ho_key.data, CBLKSIZE, data,
+					ao.buffer, osize))) {
+			ao.err = crypto_errstr(lrc);
+		} else {
+			ao.data = ao.buffer;
+			ao.datasize = osize;
+			if (payload && paylsize) {
+				/* payload passthrough */
+				ao.payload = ao.data + osize;
+				memcpy(ao.payload, payload, paylsize);
+				ao.paylsize = paylsize;
+			}
+		}
+		memset(&ho_key, 0, sizeof(ho_key));
+	}
+	memset(data, 0, datasize);
+	return ao;
 }
 
-int parse_authobj(const unsigned char *key, const int keysize,
-		const unsigned char *buffer, const int bufsize,
-		unsigned char *secret, int *secsize,
-		unsigned char *payload, int *paysize)
+static struct _auth_obj
+parse_authobj(const char *userid, const char *password, const char *nonce,
+		const unsigned char *secret, const int secsize,
+		const unsigned char *ablob, const int blobsize,
+		struct _auth_chunk (*fetch_key)(const unsigned char *chal,
+						const int csize))
 {
-	int datasize = bufsize;
-	unsigned char *data = alloca(datasize);
-	serializer_t srl;
-	int tsize;
-	unsigned char myhash[HASHSIZE];
-	int myhashsize = HASHSIZE;
-	unsigned char theirhash[HASHSIZE];
-	int theirhashsize = HASHSIZE;
-
-	if (decrypt(key, CBLKSIZE, buffer, data, datasize))
-		return aoe_crypt;
-	serial_init(&srl, data, datasize);
-	tsize = *secsize;
-	*secsize = serial_get(&srl, secret, tsize);
-	if (*secsize > tsize || *secsize <= 0) return aoe_serial;
-	tsize = *paysize;
-	*paysize = serial_get(&srl, payload, tsize);
-	if (*paysize > tsize || *paysize <= 0) return aoe_serial;
-	if (hash(data, serial_size(&srl), myhash, &myhashsize))
-		return aoe_crypt;
-	theirhashsize = serial_get(&srl, theirhash, theirhashsize);
-	if (theirhashsize != HASHSIZE) return aoe_data;
-	if ((myhashsize != theirhashsize) ||
-	    memcmp(myhash, theirhash, myhashsize))
-		return aoe_data;
-	return 0;
+	unsigned long rc;
+	struct _auth_obj ao = {0};
+	struct _auth_chunk ho_key;
+
+	ho_key = make_key(userid, password, nonce, secret, secsize, fetch_key);
+	if (ho_key.err) {
+		ao.err = ho_key.err;
+	} else if ((ao.buffer = malloc(blobsize)) == NULL) {
+		ao.err = "parse authobj: malloc failed";
+	} else if ((rc = decrypt(ho_key.data, CBLKSIZE,
+				ablob, ao.buffer, blobsize))) {
+		ao.err = crypto_errstr(rc);
+	} else {
+		serializer_t srl;
+		unsigned char myhash[HASHSIZE];
+		int myhsize = HASHSIZE;
+		unsigned char *theirhash;
+		int theirhsize;
+		unsigned long rc;
+
+		serial_init(&srl, ao.buffer, blobsize);
+		if (serial_get(&srl, (void**)&ao.data, &ao.datasize)) {
+			ao.err = "mismatch: impossible secret";
+		} else if (serial_get(&srl, (void**)&ao.payload, &ao.paylsize)) {
+			ao.err = "mismatch: impossible payload";
+		} else if ((rc = hash(ao.buffer, serial_size(&srl),
+					myhash, &myhsize))) {
+			ao.err = crypto_errstr(rc);
+		} else if (serial_get(&srl, (void**)&theirhash, &theirhsize)) {
+			ao.err = "mismatch: impossible hash";
+		} else if (theirhsize != HASHSIZE) {
+			ao.err = "mismatch: hash is of wrong size";
+		} else if ((myhsize != theirhsize) ||
+		    		memcmp(myhash, theirhash, myhsize)) {
+			ao.err = "mismatch: different hash";
+		}
+	}
+	memset(&ho_key, 0, sizeof(ho_key));
+	return ao;
+}
+
+struct _auth_obj authobj(const char *userid, const char *password,
+		const char *oldnonce, const char *newnonce,
+		const unsigned char *secret, const int secsize,
+		const unsigned char *payload, const int paylsize,
+		const unsigned char *ablob, const int blobsize,
+		struct _auth_chunk (*fetch_key)(const unsigned char *chal,
+						const int csize))
+{
+	const unsigned char *wsecret;
+	int wsecsize;
+	const unsigned char *wpayload;
+	int wpaylsize;
+	struct _auth_obj old_ao = {0};
+	struct _auth_obj new_ao = {0};
+
+	if (!secret || !secsize || !payload) {
+		old_ao = parse_authobj(userid, password, oldnonce,
+					secret, secsize,
+					ablob, blobsize, fetch_key);
+		if (old_ao.err) {
+			new_ao.err = old_ao.err;
+			if (old_ao.buffer) free(old_ao.buffer);
+			return new_ao;
+		} else {
+			if (secret && secsize) {
+				wsecret = secret;
+				wsecsize = secsize;
+			} else {
+				wsecret = old_ao.data;
+				wsecsize = old_ao.datasize;
+			}
+			if (payload) {
+				wpayload = payload;
+				wpaylsize = paylsize;
+			} else {
+				wpayload = old_ao.payload;
+				wpaylsize = old_ao.paylsize;
+			}
+		}
+	} else {
+		wsecret = secret;
+		wsecsize = secsize;
+		wpayload = payload;
+		wpaylsize = paylsize;
+	}
+
+
+	new_ao = make_authobj(userid, password, newnonce,
+				wsecret, wsecsize, wpayload, wpaylsize);
+
+	if (old_ao.data) memset(old_ao.data, 0, old_ao.datasize);
+	if (old_ao.payload) memset(old_ao.payload, 0, old_ao.paylsize);
+	if (old_ao.buffer) free(old_ao.buffer);
+	return new_ao;
 }