diff options
Diffstat (limited to 'src/challenge.c')
| -rw-r--r-- | src/challenge.c | 51 |
1 files changed, 35 insertions, 16 deletions
diff --git a/src/challenge.c b/src/challenge.c index f269313..f0b02ad 100644 --- a/src/challenge.c +++ b/src/challenge.c @@ -46,6 +46,7 @@ #include <stdlib.h> #include <string.h> #include <sys/time.h> +#include <assert.h> #include "challenge.h" #include "options.h" @@ -55,48 +56,66 @@ /* generate_challenge: Generates a random challenge, incorporating the current * local timestamp to avoid replay attacks. */ -challenge_t* generate_challenge(void) { +challenge_t *generate_challenge(void) { struct timeval tt; challenge_t *c; int i; c = (challenge_t *) calloc(1, sizeof(challenge_t)); + assert(c != NULL); gettimeofday(&tt, 0); - c->sec = tt.tv_sec; - c->usec_rnd = tt.tv_usec + pt_random(); + c->plain.sec = tt.tv_sec; + c->plain.usec_rnd = tt.tv_usec + pt_random(); for (i=0;i<6;i++) - c->random[i] = pt_random(); + c->plain.random[i] = pt_random(); return c; } -/* generate_response: Generates a response to the given challenge. The response +/* generate_response_md5: Generates a response to the given challenge. The response * is generated by combining the concatenating the challenge data with the * md5 digest of the password, and then calculating the MD5 digest of the * entire buffer. The result is stored in the passed-in challenge, overwriting * the challenge data. */ -void generate_response(challenge_t *challenge) { - md5_byte_t buf[sizeof(challenge_t)+kMD5_digest_size]; +void generate_response_md5(challenge_plain_t *plain, challenge_digest_t *digest) { + md5_byte_t buf[sizeof(*plain) + kMD5_digest_size]; md5_state_t state; - memcpy(buf, challenge, sizeof(challenge_t)); - memcpy(&buf[sizeof(challenge_t)], opts.password_digest, kMD5_digest_size); - memset(challenge, 0, sizeof(challenge_t)); + digest->hash_type = HT_MD5; + memcpy(buf, plain, sizeof(*plain)); + memcpy(&buf[sizeof(*plain)], opts.md5_password_digest, kMD5_digest_size); + memset(plain, 0, sizeof(*plain)); + md5_init(&state); - md5_append(&state, buf, sizeof(challenge_t)+kMD5_digest_size); - md5_finish(&state, (md5_byte_t*)challenge); + md5_append(&state, buf, sizeof(*plain) + kMD5_digest_size); + md5_finish(&state, (md5_byte_t *) &digest->md5[0]); } -/* validate_challenge: Checks whether a given response matches the expected +/* validate_challenge_md5: Checks whether a given response matches the expected * response, returning 1 if validation succeeded, and 0 otherwise. Note that * overwriting the local challenge with the challenge result is not a problem, * as the data will not be used again anyway (authentication either succeeds, * or the connection is closed down). */ -int validate_challenge(challenge_t *local, challenge_t *remote) { - generate_response(local); - if (memcmp(local, remote, sizeof(challenge_t)) == 0) +int validate_challenge_md5(challenge_t *local, challenge_digest_t *remote) { + generate_response_md5(&local->plain, &local->digest); + if (remote->hash_type == HT_MD5 && + memcmp(&local->digest.md5[0], &remote->md5[0], sizeof(local->digest.md5)) == 0) + { return 1; + } return 0; } + +#ifdef ENABLE_SHA512 +void generate_response_sha512(challenge_t *challenge) +{ + /* TODO: Implement me! */ +} + +int validate_challenge_sha512(challenge_t *local, challenge_t *remote) +{ + /* TODO: Implement me! */ +} +#endif /* ENABLE_SHA512 */ |