michael@0: 
michael@0: /* This Source Code Form is subject to the terms of the Mozilla Public
michael@0:  * License, v. 2.0. If a copy of the MPL was not distributed with this
michael@0:  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
michael@0: 
michael@0: #ifdef FREEBL_NO_DEPEND
michael@0: #include "stubs.h"
michael@0: #endif
michael@0: 
michael@0: #include "shsign.h"
michael@0: #include "prlink.h"
michael@0: #include "prio.h"
michael@0: #include "blapi.h"
michael@0: #include "seccomon.h"
michael@0: #include "stdio.h"
michael@0: #include "prmem.h"
michael@0: #include "hasht.h"
michael@0: #include "pqg.h"
michael@0: 
michael@0: /*
michael@0:  * Most modern version of Linux support a speed optimization scheme where an
michael@0:  * application called prelink modifies programs and shared libraries to quickly
michael@0:  * load if they fit into an already designed address space. In short, prelink
michael@0:  * scans the list of programs and libraries on your system, assigns them a
michael@0:  * predefined space in the the address space, then provides the fixups to the
michael@0:  * library.
michael@0: 
michael@0:  * The modification of the shared library is correctly detected by the freebl
michael@0:  * FIPS checksum scheme where we check a signed hash of the library against the
michael@0:  * library itself.
michael@0:  * 
michael@0:  * The prelink command itself can reverse the process of modification and
michael@0:  * output the prestine shared library as it was before prelink made it's
michael@0:  * changes. If FREEBL_USE_PRELINK is set Freebl uses prelink to output the
michael@0:  * original copy of the shared library before prelink modified it.
michael@0:  */
michael@0: #ifdef FREEBL_USE_PRELINK
michael@0: #ifndef FREELB_PRELINK_COMMAND
michael@0: #define FREEBL_PRELINK_COMMAND "/usr/sbin/prelink -u -o -"
michael@0: #endif
michael@0: #include "private/pprio.h"
michael@0: 
michael@0: #include <stdlib.h>
michael@0: #include <unistd.h>
michael@0: #include <fcntl.h>
michael@0: #include <sys/wait.h>
michael@0: #include <sys/stat.h>
michael@0: 
michael@0: /*
michael@0:  * This function returns an NSPR PRFileDesc * which the caller can read to
michael@0:  * obtain the prestine value of the shared library, before any OS related
michael@0:  * changes to it (usually address fixups). 
michael@0:  *
michael@0:  * If prelink is installed, this
michael@0:  * file descriptor is a pipe connecting the output of 
michael@0:  *            /usr/sbin/prelink -u -o - {Library}
michael@0:  * and *pid returns the process id of the prelink child.
michael@0:  *
michael@0:  * If prelink is not installed, it returns a normal readonly handle to the
michael@0:  * library itself and *pid is set to '0'.
michael@0:  */
michael@0: PRFileDesc *
michael@0: bl_OpenUnPrelink(const char *shName, int *pid)
michael@0: {
michael@0:     char *command= strdup(FREEBL_PRELINK_COMMAND);
michael@0:     char *argString = NULL;
michael@0:     char  **argv = NULL;
michael@0:     char *shNameArg = NULL;
michael@0:     char *cp;
michael@0:     pid_t child;
michael@0:     int argc = 0, argNext = 0;
michael@0:     struct stat statBuf;
michael@0:     int pipefd[2] = {-1,-1};
michael@0:     int ret;
michael@0: 
michael@0:     *pid = 0;
michael@0: 
michael@0:     /* make sure the prelink command exists first. If not, fall back to
michael@0:      * just reading the file */
michael@0:     for (cp = command; *cp ; cp++) {
michael@0: 	if (*cp == ' ') {
michael@0: 	    *cp++ = 0;
michael@0: 	    argString = cp;
michael@0: 	    break;
michael@0:         }
michael@0:     }
michael@0:     memset (&statBuf, 0, sizeof(statBuf));
michael@0:     /* stat the file, follow the link */
michael@0:     ret = stat(command, &statBuf);
michael@0:     if (ret < 0) {
michael@0: 	free(command);
michael@0: 	return PR_Open(shName, PR_RDONLY, 0);
michael@0:     }
michael@0:     /* file exits, make sure it's an executable */
michael@0:     if (!S_ISREG(statBuf.st_mode) || 
michael@0: 			((statBuf.st_mode & (S_IXUSR|S_IXGRP|S_IXOTH)) == 0)) {
michael@0: 	free(command);
michael@0: 	return PR_Open(shName, PR_RDONLY, 0);
michael@0:     }
michael@0: 
michael@0:     /* OK, the prelink command exists and looks correct, use it */
michael@0:     /* build the arglist while we can still malloc */
michael@0:     /* count the args if any */
michael@0:     if (argString && *argString) {
michael@0: 	/* argString may have leading spaces, strip them off*/
michael@0: 	for (cp = argString; *cp && *cp == ' '; cp++);
michael@0: 	argString = cp;
michael@0: 	if (*cp) {
michael@0: 	    /* there is at least one arg.. */
michael@0: 	    argc = 1;
michael@0: 	}
michael@0: 
michael@0:         /* count the rest: Note there is no provision for escaped
michael@0:          * spaces here */
michael@0: 	for (cp = argString; *cp ; cp++) {
michael@0: 	    if (*cp == ' ') {
michael@0: 		while (*cp && *cp == ' ') cp++;
michael@0: 		if (*cp) argc++;
michael@0: 	    }
michael@0: 	}
michael@0:     }
michael@0: 
michael@0:     /* add the additional args: argv[0] (command), shName, NULL*/
michael@0:     argc += 3;
michael@0:     argv = PORT_NewArray(char *, argc);
michael@0:     if (argv == NULL) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* fill in the arglist */
michael@0:     argv[argNext++] = command;
michael@0:     if (argString && *argString) {
michael@0: 	argv[argNext++] = argString;
michael@0: 	for (cp = argString; *cp; cp++) {
michael@0: 	    if (*cp == ' ') {
michael@0: 		*cp++ = 0;
michael@0: 		while (*cp && *cp == ' ') cp++;
michael@0: 		if (*cp) argv[argNext++] = cp;
michael@0: 	    }
michael@0: 	}
michael@0:     }
michael@0:     /* exec doesn't advertise taking const char **argv, do the paranoid
michael@0:      * copy */
michael@0:     shNameArg = strdup(shName);
michael@0:     if (shNameArg == NULL) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     argv[argNext++] = shNameArg;
michael@0:     argv[argNext++] = 0;
michael@0:     
michael@0:     ret = pipe(pipefd);
michael@0:     if (ret < 0) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* use vfork() so we don't trigger the pthread_at_fork() handlers */
michael@0:     child = vfork();
michael@0:     if (child < 0) goto loser;
michael@0:     if (child == 0) {
michael@0: 	/* set up the file descriptors */
michael@0: 	/* if we need to support BSD, this will need to be an open of 
michael@0: 	 * /dev/null and dup2(nullFD, 0)*/
michael@0: 	close(0);
michael@0: 	/* associate pipefd[1] with stdout */
michael@0: 	if (pipefd[1] != 1) dup2(pipefd[1], 1);
michael@0: 	close(2);
michael@0: 	close(pipefd[0]);
michael@0: 	/* should probably close the other file descriptors? */
michael@0: 
michael@0: 
michael@0: 	execv(command, argv);
michael@0: 	/* avoid at_exit() handlers */
michael@0: 	_exit(1); /* shouldn't reach here except on an error */
michael@0:     }
michael@0:     close(pipefd[1]);
michael@0:     pipefd[1] = -1;
michael@0: 
michael@0:     /* this is safe because either vfork() as full fork() semantics, and thus
michael@0:      * already has it's own address space, or because vfork() has paused
michael@0:      * the parent util the exec or exit */
michael@0:     free(command);
michael@0:     free(shNameArg);
michael@0:     PORT_Free(argv);
michael@0: 
michael@0:     *pid = child;
michael@0: 
michael@0:     return PR_ImportPipe(pipefd[0]);
michael@0: 
michael@0: loser:
michael@0:     if (pipefd[0] != -1) {
michael@0: 	close(pipefd[0]);
michael@0:     }
michael@0:     if (pipefd[1] != -1) {
michael@0: 	close(pipefd[1]);
michael@0:     }
michael@0:     free(command);
michael@0:     free(shNameArg);
michael@0:     PORT_Free(argv);
michael@0: 
michael@0:     return NULL;
michael@0: }
michael@0: 
michael@0: /*
michael@0:  * bl_CloseUnPrelink -
michael@0:  *
michael@0:  * This closes the file descripter and reaps and children openned and crated by
michael@0:  * b;_OpenUnprelink. It's primary difference between it and just close is
michael@0:  * that it calls wait on the pid if one is supplied, preventing zombie children
michael@0:  * from hanging around.
michael@0:  */
michael@0: void
michael@0: bl_CloseUnPrelink( PRFileDesc *file, int pid)
michael@0: {
michael@0:     /* close the file descriptor */
michael@0:     PR_Close(file);
michael@0:     /* reap the child */
michael@0:     if (pid) {
michael@0: 	waitpid(pid, NULL, 0);
michael@0:     }
michael@0: }
michael@0: #endif
michael@0: 
michael@0: /* #define DEBUG_SHVERIFY 1 */
michael@0: 
michael@0: static char *
michael@0: mkCheckFileName(const char *libName)
michael@0: {
michael@0:     int ln_len = PORT_Strlen(libName);
michael@0:     char *output = PORT_Alloc(ln_len+sizeof(SGN_SUFFIX));
michael@0:     int index = ln_len + 1 - sizeof("."SHLIB_SUFFIX);
michael@0: 
michael@0:     if ((index > 0) &&
michael@0:         (PORT_Strncmp(&libName[index],
michael@0:                         "."SHLIB_SUFFIX,sizeof("."SHLIB_SUFFIX)) == 0)) {
michael@0:         ln_len = index;
michael@0:     }
michael@0:     PORT_Memcpy(output,libName,ln_len);
michael@0:     PORT_Memcpy(&output[ln_len],SGN_SUFFIX,sizeof(SGN_SUFFIX));
michael@0:     return output;
michael@0: }
michael@0: 
michael@0: static int
michael@0: decodeInt(unsigned char *buf)
michael@0: {
michael@0:     return (buf[3]) | (buf[2] << 8) | (buf[1] << 16) | (buf[0] << 24);
michael@0: }
michael@0: 
michael@0: static SECStatus
michael@0: readItem(PRFileDesc *fd, SECItem *item)
michael@0: {
michael@0:     unsigned char buf[4];
michael@0:     int bytesRead;
michael@0: 
michael@0: 
michael@0:     bytesRead = PR_Read(fd, buf, 4);
michael@0:     if (bytesRead != 4) {
michael@0: 	return SECFailure;
michael@0:     }
michael@0:     item->len = decodeInt(buf);
michael@0: 
michael@0:     item->data = PORT_Alloc(item->len);
michael@0:     if (item->data == NULL) {
michael@0: 	item->len = 0;
michael@0: 	return SECFailure;
michael@0:     }
michael@0:     bytesRead = PR_Read(fd, item->data, item->len);
michael@0:     if (bytesRead != item->len) {
michael@0: 	PORT_Free(item->data);
michael@0: 	item->data = NULL;
michael@0: 	item->len = 0;
michael@0: 	return SECFailure;
michael@0:     }
michael@0:     return SECSuccess;
michael@0: }
michael@0: 
michael@0: PRBool
michael@0: BLAPI_SHVerify(const char *name, PRFuncPtr addr)
michael@0: {
michael@0:     PRBool result = PR_FALSE; /* if anything goes wrong,
michael@0: 			       * the signature does not verify */
michael@0:     /* find our shared library name */
michael@0:     char *shName = PR_GetLibraryFilePathname(name, addr);
michael@0:     if (!shName) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     result = BLAPI_SHVerifyFile(shName);
michael@0: 
michael@0: loser:
michael@0:     if (shName != NULL) {
michael@0: 	PR_Free(shName);
michael@0:     }
michael@0: 
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: PRBool
michael@0: BLAPI_SHVerifyFile(const char *shName)
michael@0: {
michael@0:     char *checkName = NULL;
michael@0:     PRFileDesc *checkFD = NULL;
michael@0:     PRFileDesc *shFD = NULL;
michael@0:     void  *hashcx = NULL;
michael@0:     const SECHashObject *hashObj = NULL;
michael@0:     SECItem signature = { 0, NULL, 0 };
michael@0:     SECItem hash;
michael@0:     int bytesRead, offset;
michael@0:     SECStatus rv;
michael@0:     DSAPublicKey key;
michael@0:     int count;
michael@0: #ifdef FREEBL_USE_PRELINK
michael@0:     int pid = 0;
michael@0: #endif
michael@0: 
michael@0:     PRBool result = PR_FALSE; /* if anything goes wrong,
michael@0: 			       * the signature does not verify */
michael@0:     unsigned char buf[4096];
michael@0:     unsigned char hashBuf[HASH_LENGTH_MAX];
michael@0: 
michael@0:     PORT_Memset(&key,0,sizeof(key));
michael@0:     hash.data = hashBuf;
michael@0:     hash.len = sizeof(hashBuf);
michael@0: 
michael@0:     if (!shName) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* figure out the name of our check file */
michael@0:     checkName = mkCheckFileName(shName);
michael@0:     if (!checkName) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* open the check File */
michael@0:     checkFD = PR_Open(checkName, PR_RDONLY, 0);
michael@0:     if (checkFD == NULL) {
michael@0: #ifdef DEBUG_SHVERIFY
michael@0:         fprintf(stderr, "Failed to open the check file %s: (%d, %d)\n",
michael@0:                 checkName, (int)PR_GetError(), (int)PR_GetOSError());
michael@0: #endif /* DEBUG_SHVERIFY */
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* read and Verify the headerthe header */
michael@0:     bytesRead = PR_Read(checkFD, buf, 12);
michael@0:     if (bytesRead != 12) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     if ((buf[0] != NSS_SIGN_CHK_MAGIC1) || (buf[1] != NSS_SIGN_CHK_MAGIC2)) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     if ((buf[2] != NSS_SIGN_CHK_MAJOR_VERSION) || 
michael@0: 				(buf[3] < NSS_SIGN_CHK_MINOR_VERSION)) {
michael@0: 	goto loser;
michael@0:     }
michael@0: #ifdef notdef
michael@0:     if (decodeInt(&buf[8]) != CKK_DSA) {
michael@0: 	goto loser;
michael@0:     }
michael@0: #endif
michael@0: 
michael@0:     /* seek past any future header extensions */
michael@0:     offset = decodeInt(&buf[4]);
michael@0:     PR_Seek(checkFD, offset, PR_SEEK_SET);
michael@0: 
michael@0:     /* read the key */
michael@0:     rv = readItem(checkFD,&key.params.prime);
michael@0:     if (rv != SECSuccess) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     rv = readItem(checkFD,&key.params.subPrime);
michael@0:     if (rv != SECSuccess) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     rv = readItem(checkFD,&key.params.base);
michael@0:     if (rv != SECSuccess) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     rv = readItem(checkFD,&key.publicValue);
michael@0:     if (rv != SECSuccess) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     /* read the siganture */
michael@0:     rv = readItem(checkFD,&signature);
michael@0:     if (rv != SECSuccess) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* done with the check file */
michael@0:     PR_Close(checkFD);
michael@0:     checkFD = NULL;
michael@0: 
michael@0:     hashObj = HASH_GetRawHashObject(PQG_GetHashType(&key.params));
michael@0:     if (hashObj == NULL) {
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* open our library file */
michael@0: #ifdef FREEBL_USE_PRELINK
michael@0:     shFD = bl_OpenUnPrelink(shName,&pid);
michael@0: #else
michael@0:     shFD = PR_Open(shName, PR_RDONLY, 0);
michael@0: #endif
michael@0:     if (shFD == NULL) {
michael@0: #ifdef DEBUG_SHVERIFY
michael@0:         fprintf(stderr, "Failed to open the library file %s: (%d, %d)\n",
michael@0:                 shName, (int)PR_GetError(), (int)PR_GetOSError());
michael@0: #endif /* DEBUG_SHVERIFY */
michael@0: 	goto loser;
michael@0:     }
michael@0: 
michael@0:     /* hash our library file with SHA1 */
michael@0:     hashcx = hashObj->create();
michael@0:     if (hashcx == NULL) {
michael@0: 	goto loser;
michael@0:     }
michael@0:     hashObj->begin(hashcx);
michael@0: 
michael@0:     count = 0;
michael@0:     while ((bytesRead = PR_Read(shFD, buf, sizeof(buf))) > 0) {
michael@0: 	hashObj->update(hashcx, buf, bytesRead);
michael@0: 	count += bytesRead;
michael@0:     }
michael@0: #ifdef FREEBL_USE_PRELINK
michael@0:     bl_CloseUnPrelink(shFD, pid);
michael@0: #else
michael@0:     PR_Close(shFD);
michael@0: #endif
michael@0:     shFD = NULL;
michael@0: 
michael@0:     hashObj->end(hashcx, hash.data, &hash.len, hash.len);
michael@0: 
michael@0: 
michael@0:     /* verify the hash against the check file */
michael@0:     if (DSA_VerifyDigest(&key, &signature, &hash) == SECSuccess) {
michael@0: 	result = PR_TRUE;
michael@0:     }
michael@0: #ifdef DEBUG_SHVERIFY
michael@0:   {
michael@0:         int i,j;
michael@0:         fprintf(stderr,"File %s: %d bytes\n",shName, count);
michael@0:         fprintf(stderr,"  hash: %d bytes\n", hash.len);
michael@0: #define STEP 10
michael@0:         for (i=0; i < hash.len; i += STEP) {
michael@0:            fprintf(stderr,"   ");
michael@0:            for (j=0; j < STEP && (i+j) < hash.len; j++) {
michael@0:                 fprintf(stderr," %02x", hash.data[i+j]);
michael@0:            }
michael@0:            fprintf(stderr,"\n");
michael@0:         }
michael@0:         fprintf(stderr,"  signature: %d bytes\n", signature.len);
michael@0:         for (i=0; i < signature.len; i += STEP) {
michael@0:            fprintf(stderr,"   ");
michael@0:            for (j=0; j < STEP && (i+j) < signature.len; j++) {
michael@0:                 fprintf(stderr," %02x", signature.data[i+j]);
michael@0:            }
michael@0:            fprintf(stderr,"\n");
michael@0:         }
michael@0: 	fprintf(stderr,"Verified : %s\n",result?"TRUE": "FALSE");
michael@0:     }
michael@0: #endif /* DEBUG_SHVERIFY */
michael@0: 
michael@0: 
michael@0: loser:
michael@0:     if (checkName != NULL) {
michael@0: 	PORT_Free(checkName);
michael@0:     }
michael@0:     if (checkFD != NULL) {
michael@0: 	PR_Close(checkFD);
michael@0:     }
michael@0:     if (shFD != NULL) {
michael@0: 	PR_Close(shFD);
michael@0:     }
michael@0:     if (hashcx != NULL) {
michael@0: 	if (hashObj) {
michael@0: 	    hashObj->destroy(hashcx,PR_TRUE);
michael@0: 	}
michael@0:     }
michael@0:     if (signature.data != NULL) {
michael@0: 	PORT_Free(signature.data);
michael@0:     }
michael@0:     if (key.params.prime.data != NULL) {
michael@0: 	PORT_Free(key.params.prime.data);
michael@0:     }
michael@0:     if (key.params.subPrime.data != NULL) {
michael@0: 	PORT_Free(key.params.subPrime.data);
michael@0:     }
michael@0:     if (key.params.base.data != NULL) {
michael@0: 	PORT_Free(key.params.base.data);
michael@0:     }
michael@0:     if (key.publicValue.data != NULL) {
michael@0: 	PORT_Free(key.publicValue.data);
michael@0:     }
michael@0: 
michael@0:     return result;
michael@0: }
michael@0: 
michael@0: PRBool
michael@0: BLAPI_VerifySelf(const char *name)
michael@0: {
michael@0:     if (name == NULL) {
michael@0: 	/*
michael@0: 	 * If name is NULL, freebl is statically linked into softoken.
michael@0: 	 * softoken will call BLAPI_SHVerify next to verify itself.
michael@0: 	 */
michael@0: 	return PR_TRUE;
michael@0:     }
michael@0:     return BLAPI_SHVerify(name, (PRFuncPtr) decodeInt);
michael@0: }