diff options
Diffstat (limited to 'package/ead/src/tinysrp/tinysrp.c')
| -rw-r--r-- | package/ead/src/tinysrp/tinysrp.c | 235 |
1 files changed, 235 insertions, 0 deletions
diff --git a/package/ead/src/tinysrp/tinysrp.c b/package/ead/src/tinysrp/tinysrp.c new file mode 100644 index 0000000000..fc01055417 --- /dev/null +++ b/package/ead/src/tinysrp/tinysrp.c @@ -0,0 +1,235 @@ +/* This bit implements a simple API for using the SRP library over sockets. */ + +#include <stdio.h> +#include <string.h> +#include <stdlib.h> +#include <unistd.h> +#include <sys/types.h> +#include <sys/socket.h> +#include "t_defines.h" +#include "t_pwd.h" +#include "t_server.h" +#include "t_client.h" +#include "tinysrp.h" + +#ifndef MSG_WAITALL +#ifdef linux +#define MSG_WAITALL 0x100 /* somehow not defined on my box */ +#endif +#endif + +/* This is called by the client with a connected socket, username, and +passphrase. pass can be NULL in which case the user is queried. */ + +int tsrp_client_authenticate(int s, char *user, char *pass, TSRP_SESSION *tsrp) +{ + int i, index; + unsigned char username[MAXUSERLEN + 1], sbuf[MAXSALTLEN]; + unsigned char msgbuf[MAXPARAMLEN + 1], bbuf[MAXPARAMLEN]; + unsigned char passbuf[128], *skey; + struct t_client *tc; + struct t_preconf *tcp; /* @@@ should go away */ + struct t_num salt, *A, B; + + /* Send the username. */ + + i = strlen(user); + if (i > MAXUSERLEN) { + i = MAXUSERLEN; + } + msgbuf[0] = i; + memcpy(msgbuf + 1, user, i); + if (send(s, msgbuf, i + 1, 0) < 0) { + return 0; + } + memcpy(username, user, i); + username[i] = '\0'; + + /* Get the prime index and salt. */ + + i = recv(s, msgbuf, 2, MSG_WAITALL); + if (i <= 0) { + return 0; + } + index = msgbuf[0]; + if (index <= 0 || index > t_getprecount()) { + return 0; + } + tcp = t_getpreparam(index - 1); + salt.len = msgbuf[1]; + if (salt.len > MAXSALTLEN) { + return 0; + } + salt.data = sbuf; + i = recv(s, sbuf, salt.len, MSG_WAITALL); + if (i <= 0) { + return 0; + } + + /* @@@ t_clientopen() needs a variant that takes the index */ + + tc = t_clientopen(username, &tcp->modulus, &tcp->generator, &salt); + if (tc == NULL) { + return 0; + } + + /* Calculate A and send it to the server. */ + + A = t_clientgenexp(tc); + msgbuf[0] = A->len - 1; /* len is max 256 */ + memcpy(msgbuf + 1, A->data, A->len); + if (send(s, msgbuf, A->len + 1, 0) < 0) { + return 0; + } + + /* Ask the user for the passphrase. */ + + if (pass == NULL) { + t_getpass(passbuf, sizeof(passbuf), "Enter password:"); + pass = passbuf; + } + t_clientpasswd(tc, pass); + + /* Get B from the server. */ + + i = recv(s, msgbuf, 1, 0); + if (i <= 0) { + return 0; + } + B.len = msgbuf[0] + 1; + B.data = bbuf; + i = recv(s, bbuf, B.len, MSG_WAITALL); + if (i <= 0) { + return 0; + } + + /* Compute the session key. */ + + skey = t_clientgetkey(tc, &B); + if (skey == NULL) { + return 0; + } + + /* Send the response. */ + + if (send(s, t_clientresponse(tc), RESPONSE_LEN, 0) < 0) { + return 0; + } + + /* Get the server's response. */ + + i = recv(s, msgbuf, RESPONSE_LEN, MSG_WAITALL); + if (i <= 0) { + return 0; + } + if (t_clientverify(tc, msgbuf) != 0) { + return 0; + } + + /* All done. Now copy the key and clean up. */ + + if (tsrp) { + memcpy(tsrp->username, username, strlen(username) + 1); + memcpy(tsrp->key, skey, SESSION_KEY_LEN); + } + t_clientclose(tc); + + return 1; +} + +/* This is called by the server with a connected socket. */ + +int tsrp_server_authenticate(int s, TSRP_SESSION *tsrp) +{ + int i, j; + unsigned char username[MAXUSERLEN], *skey; + unsigned char msgbuf[MAXPARAMLEN + 1], abuf[MAXPARAMLEN]; + struct t_server *ts; + struct t_num A, *B; + + /* Get the username. */ + + i = recv(s, msgbuf, 1, 0); + if (i <= 0) { + return 0; + } + j = msgbuf[0]; + i = recv(s, username, j, MSG_WAITALL); + if (i <= 0) { + return 0; + } + username[j] = '\0'; + + ts = t_serveropen(username); + if (ts == NULL) { + return 0; + } + + /* Send the prime index and the salt. */ + + msgbuf[0] = ts->index; /* max 256 primes... */ + i = ts->s.len; + msgbuf[1] = i; + memcpy(msgbuf + 2, ts->s.data, i); + if (send(s, msgbuf, i + 2, 0) < 0) { + return 0; + } + + /* Calculate B while we're waiting. */ + + B = t_servergenexp(ts); + + /* Get A from the client. */ + + i = recv(s, msgbuf, 1, 0); + if (i <= 0) { + return 0; + } + A.len = msgbuf[0] + 1; + A.data = abuf; + i = recv(s, abuf, A.len, MSG_WAITALL); + if (i <= 0) { + return 0; + } + + /* Now send B. */ + + msgbuf[0] = B->len - 1; + memcpy(msgbuf + 1, B->data, B->len); + if (send(s, msgbuf, B->len + 1, 0) < 0) { + return 0; + } + + /* Calculate the session key while we're waiting. */ + + skey = t_servergetkey(ts, &A); + if (skey == NULL) { + return 0; + } + + /* Get the response from the client. */ + + i = recv(s, msgbuf, RESPONSE_LEN, MSG_WAITALL); + if (i <= 0) { + return 0; + } + if (t_serververify(ts, msgbuf) != 0) { + return 0; + } + + /* Client authenticated. Now authenticate ourselves to the client. */ + + if (send(s, t_serverresponse(ts), RESPONSE_LEN, 0) < 0) { + return 0; + } + + /* Copy the key and clean up. */ + + if (tsrp) { + memcpy(tsrp->username, username, strlen(username) + 1); + memcpy(tsrp->key, skey, SESSION_KEY_LEN); + } + t_serverclose(ts); + + return 1; +} |