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strlcpy fixups on sycophant code
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C how does it work?

Fixed up my bad use of strlcpy that was causing segfaults.

Spent ages debugging a crazy error, where if I don't use the ident char
(the one set to 't' in eap_server.c) it gets set to the location of the
state file, which then breaks everything. Debugging got me nowhere, and
I suspect it's a crazy compiler optimisation breaking my poor C. Any
tips?
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@singe
singe committed Aug 16, 2018
1 parent 4f55700 commit 287b56a
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Showing 2 changed files with 28 additions and 23 deletions.
5 changes: 3 additions & 2 deletions src/eap_server/eap_server.c
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Original file line number Diff line number Diff line change
Expand Up @@ -180,7 +180,7 @@ int eap_user_get(struct eap_sm *sm, const u8 *identity, size_t identity_len,
if (mana.conf->enable_sycophant && os_strcmp("NOT_SET",mana.conf->sycophant_dir) != 0) {
char sup_state[2] = "*";
FILE* sycophantState;
char* sycophantStateFile;
char sycophantStateFile[sizeof(mana.conf->sycophant_dir)+16];
os_strlcpy(sycophantStateFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
strcat(sycophantStateFile,"SYCOPHANT_STATE");
sycophantState = fopen(sycophantStateFile,"rb");
Expand All @@ -190,7 +190,7 @@ int eap_user_get(struct eap_sm *sm, const u8 *identity, size_t identity_len,
}
if (os_strcmp(sup_state,"I") == 0) {
FILE* sycophantID;
char* sycophantIDFile;
char sycophantIDFile[sizeof(mana.conf->sycophant_dir)+15];
os_strlcpy(sycophantIDFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
if (phase2)
strcat(sycophantIDFile,"SYCOPHANT_P2ID");
Expand All @@ -209,6 +209,7 @@ int eap_user_get(struct eap_sm *sm, const u8 *identity, size_t identity_len,
wpa_printf(MSG_INFO, "MANA EAP Identity Phase %d: %.*s", phase2, (int)identity_len, identity);
if (phase2) {
char ident = 't'; // This must match the entry in the hostapd.eap_user RADIUS config file
wpa_printf(MSG_DEBUG, "MANA EAP Identiy Phase %d: Setting identity to %c", phase2, ident);
identity = (const u8 *)&ident;
identity_len = 1;
}
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46 changes: 25 additions & 21 deletions src/eap_server/eap_server_mschapv2.c
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Original file line number Diff line number Diff line change
Expand Up @@ -127,31 +127,35 @@ static struct wpabuf * eap_mschapv2_build_challenge(
WPA_PUT_BE16(ms->ms_length, ms_len);

//MANA SYCOPHANT START
if (mana.conf->enable_sycophant) {
if (mana.conf->enable_sycophant && os_strcmp("NOT_SET",mana.conf->sycophant_dir) != 0) {
char sup_state[2] = "*";
FILE* sycophantState;
char* sycophantStateFile;
char sycophantStateFile[sizeof(mana.conf->sycophant_dir)+16];
os_strlcpy(sycophantStateFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
strcat(sycophantStateFile,"SYCOPHANT_STATE");
sycophantState = fopen(sycophantStateFile,"rb");
wpa_printf(MSG_DEBUG, "SYCOPHANT: Checking Sycophant State File.");

while (os_strcmp(sup_state,"C") != 0) {
sycophantState = fopen(sycophantStateFile,"rb");
if (sycophantState == NULL) {
wpa_printf (MSG_ERROR,"SYCOPHANT: Unable to open state file %s, not relaying",sycophantStateFile);
break;
} else {
fread(sup_state,1,1,sycophantState);
fclose(sycophantState);
if (strcmp(sup_state,"Z") == 0) {
wpa_printf(MSG_DEBUG, "SYCOPHANT: State file is Z bailing!");
fclose(sycophantState);
break;
}
fclose(sycophantState);
usleep(10000); //Prevent thrashing
}
}

if (strcmp(sup_state,"C") == 0) {
wpa_printf(MSG_DEBUG, "SYCOPHANT: State file says we have a challenge.");
FILE* challengeIn;
char* challengeInFile;
char challengeInFile[sizeof(mana.conf->sycophant_dir)+10];
os_strlcpy(challengeInFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
strcat(challengeInFile,"CHALLENGE");
challengeIn = fopen(challengeInFile, "rb");
Expand All @@ -168,11 +172,10 @@ static struct wpabuf * eap_mschapv2_build_challenge(
fclose(challengeIn);
// Blank file
challengeIn = fopen(challengeInFile, "wb");
fclose(challengeIn);
} else {
fclose(challengeIn);
usleep(1000); // Prevent thrashing
}
fclose(challengeIn);
}
// TODO: find replace for all these random youtube vids
// https://www.youtube.com/watch?v=QUNJ5TRRYqg
Expand Down Expand Up @@ -357,24 +360,26 @@ static void eap_mschapv2_process_response(struct eap_sm *sm,
pos = (u8 *) (resp + 1);

//MANA SYCOPHANT START
if (mana.conf->enable_sycophant) {
if (mana.conf->enable_sycophant && os_strcmp("NOT_SET",mana.conf->sycophant_dir) != 0) {
char sup_state[2] = "*";
FILE* sycophantState;
char* sycophantStateFile;
char sycophantStateFile[sizeof(mana.conf->sycophant_dir)+16];
os_strlcpy(sycophantStateFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
strcat(sycophantStateFile,"SYCOPHANT_STATE");
sycophantState = fopen(sycophantStateFile,"rb");

if (sycophantState != NULL) {
wpa_printf(MSG_DEBUG, "SYCOPHANT: Checking state file.");
fread(sup_state,1,1,sycophantState);
fclose(sycophantState);
} else {
wpa_printf (MSG_ERROR,"SYCOPHANT: Unable to open state file %s, not relaying",sycophantStateFile);
}

if (strcmp(sup_state,"C") == 0) {
wpa_printf(MSG_DEBUG, "SYCOPHANT: State file at Challenge, write the Response.");
FILE* responseOut;
char* responseOutFile;
char responseOutFile[sizeof(mana.conf->sycophant_dir)+9];
os_strlcpy(responseOutFile,mana.conf->sycophant_dir,sizeof(mana.conf->sycophant_dir));
strcat(responseOutFile,"RESPONSE");
responseOut = fopen(responseOutFile, "wb");
Expand All @@ -384,20 +389,19 @@ static void eap_mschapv2_process_response(struct eap_sm *sm,
fwrite(respData->buf,respData->used,1,responseOut);
wpa_hexdump(MSG_DEBUG, "SYCOPHANT: Response to be sent to supplicant", respData->buf, respData->used);
fclose(responseOut);
// Inform of our readyness
sycophantState = fopen(sycophantStateFile,"wb");
if (sycophantState != NULL) {
sup_state[0] = 'R';
fwrite(sup_state,1,1,sycophantState);
fclose(sycophantState);
wpa_printf(MSG_INFO,"SYCOPHANT: MSCHAPv2 Response handed off to supplicant.");
} else {
wpa_printf (MSG_ERROR,"SYCOPHANT: Unable to open state file %s",sycophantStateFile);
}
}
}

// Inform of our readyness
sycophantState = fopen(sycophantStateFile,"wb");

if (sycophantState != NULL) {
sup_state[0] = 'R';
fwrite(sup_state,1,1,sycophantState);
fclose(sycophantState);
wpa_printf(MSG_INFO,"SYCOPHANT: MSCHAPv2 Response handed off to supplicant.");
} else {
wpa_printf (MSG_ERROR,"SYCOPHANT: Unable to open state file %s",sycophantStateFile);
}
}
//MANA SYCOPHANT END

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