]> www.average.org Git - pam_pcsc_cr.git/blobdiff - authobj.c
wip single-function authobj
[pam_pcsc_cr.git] / authobj.c
index f06de57f4542191ad040178570fa2903be90cfd2..f8d577d8d66eb43efbcf89409c620791ceca0ca9 100644 (file)
--- a/authobj.c
+++ b/authobj.c
 #include "serial.h"
 #include "crypto.h"
 #include "authobj.h"
+#include "pcsc_cr.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;
+}
 
-       if (serial_init(&srl, challenge, *challengesize)) return -1;
-       if (serial_put(&srl, id, strlen(id)) != strlen(id)) return -1;
-       if (serial_put(&srl, pass, strlen(pass)) != strlen(pass)) return -1;
-       if (serial_put(&srl, nonce, strlen(nonce)) != strlen(nonce)) return -1;
-       if (serial_put(&srl, NULL, 0) != 0) return -1;
-       *challengesize = ((serial_size(&srl) -1) / CBLKSIZE + 1) * CBLKSIZE;
-       return 0;
+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;
 }
 
-int make_authobj(const char *id, const char *pass, const char *nonce,
+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};
+
+       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;
+}
+
+static struct _auth_obj
+make_authobj(char *userid, char *password, 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);
-       if (serial_init(&srl, data, datasize)) return -1;
-       if (serial_put(&srl, secret, secsize) != secsize) return -1;
-       if (serial_put(&srl, payload, paysize) != paysize) return -1;
-       if (hash(data, serial_size(&srl), datahash, &datahashsize))
-               return -1;
-       if (serial_put(&srl, datahash, datahashsize) != datahashsize)
-               return -1;
-       if (serial_put(&srl, NULL, 0) != 0) return -1;
-       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 -1;
-
-       if (hmac(secret, secsize, challenge, challengesize,
-               key, &keysize)) return -1;
-#if 0
-       int i;
-       for (i = 0; i < keysize; i++) printf(", 0x%02x", key[i]);
-       printf("\n");
-#endif
+       serial_init(&srl, data, datasize);
+       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;
+}
+
+static struct _auth_obj
+parse_authobj(char *userid, char *password, 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))
+{
+       unsigned long rc;
+       struct _auth_obj ao = {0};
+       struct _auth_chunk ho_key;
 
-       if (*bufsize < datasize) return -1;
-       *bufsize = datasize;
-       if (encrypt(key, CBLKSIZE, data, buffer, datasize)) return -1;
+       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;
 
-       return 0;
+               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;
 }
 
-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)
+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))
 {
-       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 -1;
-       if (serial_init(&srl, data, datasize)) return -1;
-       tsize = *secsize;
-       if ((*secsize = serial_get(&srl, secret, tsize)) > tsize) return -1;
-       tsize = *paysize;
-       if ((*paysize = serial_get(&srl, payload, tsize)) > tsize) return -1;
-       if (hash(data, serial_size(&srl), myhash, &myhashsize))
-               return -1;
-       if ((theirhashsize = serial_get(&srl, theirhash, theirhashsize)) != HASHSIZE)
-               return -1;
-       if ((myhashsize != theirhashsize) ||
-                               memcmp(myhash, theirhash, myhashsize))
-               return -1;
-       return 0;
+       unsigned char *wsecret;
+       int wsecsize;
+       unsigned char *wpayload;
+       int wpaylsize;
+       struct _auth_obj old_ao;
+       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;
 }