diff options
Diffstat (limited to 'security/nss/lib/freebl/shvfy.c')
| -rw-r--r-- | security/nss/lib/freebl/shvfy.c | 534 |
1 files changed, 534 insertions, 0 deletions
diff --git a/security/nss/lib/freebl/shvfy.c b/security/nss/lib/freebl/shvfy.c new file mode 100644 index 000000000..af4a34fb0 --- /dev/null +++ b/security/nss/lib/freebl/shvfy.c @@ -0,0 +1,534 @@ + +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifdef FREEBL_NO_DEPEND +#include "stubs.h" +#endif + +#include "shsign.h" +#include "prlink.h" +#include "prio.h" +#include "blapi.h" +#include "seccomon.h" +#include "stdio.h" +#include "prmem.h" +#include "hasht.h" +#include "pqg.h" +#include "blapii.h" + +/* + * Most modern version of Linux support a speed optimization scheme where an + * application called prelink modifies programs and shared libraries to quickly + * load if they fit into an already designed address space. In short, prelink + * scans the list of programs and libraries on your system, assigns them a + * predefined space in the the address space, then provides the fixups to the + * library. + + * The modification of the shared library is correctly detected by the freebl + * FIPS checksum scheme where we check a signed hash of the library against the + * library itself. + * + * The prelink command itself can reverse the process of modification and + * output the prestine shared library as it was before prelink made it's + * changes. If FREEBL_USE_PRELINK is set Freebl uses prelink to output the + * original copy of the shared library before prelink modified it. + */ +#ifdef FREEBL_USE_PRELINK +#ifndef FREELB_PRELINK_COMMAND +#define FREEBL_PRELINK_COMMAND "/usr/sbin/prelink -u -o -" +#endif +#include "private/pprio.h" + +#include <stdlib.h> +#include <unistd.h> +#include <fcntl.h> +#include <sys/wait.h> +#include <sys/stat.h> + +/* + * This function returns an NSPR PRFileDesc * which the caller can read to + * obtain the prestine value of the shared library, before any OS related + * changes to it (usually address fixups). + * + * If prelink is installed, this + * file descriptor is a pipe connecting the output of + * /usr/sbin/prelink -u -o - {Library} + * and *pid returns the process id of the prelink child. + * + * If prelink is not installed, it returns a normal readonly handle to the + * library itself and *pid is set to '0'. + */ +PRFileDesc * +bl_OpenUnPrelink(const char *shName, int *pid) +{ + char *command = strdup(FREEBL_PRELINK_COMMAND); + char *argString = NULL; + char **argv = NULL; + char *shNameArg = NULL; + char *cp; + pid_t child; + int argc = 0, argNext = 0; + struct stat statBuf; + int pipefd[2] = { -1, -1 }; + int ret; + + *pid = 0; + + /* make sure the prelink command exists first. If not, fall back to + * just reading the file */ + for (cp = command; *cp; cp++) { + if (*cp == ' ') { + *cp++ = 0; + argString = cp; + break; + } + } + memset(&statBuf, 0, sizeof(statBuf)); + /* stat the file, follow the link */ + ret = stat(command, &statBuf); + if (ret < 0) { + free(command); + return PR_Open(shName, PR_RDONLY, 0); + } + /* file exits, make sure it's an executable */ + if (!S_ISREG(statBuf.st_mode) || + ((statBuf.st_mode & (S_IXUSR | S_IXGRP | S_IXOTH)) == 0)) { + free(command); + return PR_Open(shName, PR_RDONLY, 0); + } + + /* OK, the prelink command exists and looks correct, use it */ + /* build the arglist while we can still malloc */ + /* count the args if any */ + if (argString && *argString) { + /* argString may have leading spaces, strip them off*/ + for (cp = argString; *cp && *cp == ' '; cp++) + ; + argString = cp; + if (*cp) { + /* there is at least one arg.. */ + argc = 1; + } + + /* count the rest: Note there is no provision for escaped + * spaces here */ + for (cp = argString; *cp; cp++) { + if (*cp == ' ') { + while (*cp && *cp == ' ') + cp++; + if (*cp) + argc++; + } + } + } + + /* add the additional args: argv[0] (command), shName, NULL*/ + argc += 3; + argv = PORT_NewArray(char *, argc); + if (argv == NULL) { + goto loser; + } + + /* fill in the arglist */ + argv[argNext++] = command; + if (argString && *argString) { + argv[argNext++] = argString; + for (cp = argString; *cp; cp++) { + if (*cp == ' ') { + *cp++ = 0; + while (*cp && *cp == ' ') + cp++; + if (*cp) + argv[argNext++] = cp; + } + } + } + /* exec doesn't advertise taking const char **argv, do the paranoid + * copy */ + shNameArg = strdup(shName); + if (shNameArg == NULL) { + goto loser; + } + argv[argNext++] = shNameArg; + argv[argNext++] = 0; + + ret = pipe(pipefd); + if (ret < 0) { + goto loser; + } + + /* use vfork() so we don't trigger the pthread_at_fork() handlers */ + child = vfork(); + if (child < 0) + goto loser; + if (child == 0) { + /* set up the file descriptors */ + /* if we need to support BSD, this will need to be an open of + * /dev/null and dup2(nullFD, 0)*/ + close(0); + /* associate pipefd[1] with stdout */ + if (pipefd[1] != 1) + dup2(pipefd[1], 1); + close(2); + close(pipefd[0]); + /* should probably close the other file descriptors? */ + + execv(command, argv); + /* avoid at_exit() handlers */ + _exit(1); /* shouldn't reach here except on an error */ + } + close(pipefd[1]); + pipefd[1] = -1; + + /* this is safe because either vfork() as full fork() semantics, and thus + * already has it's own address space, or because vfork() has paused + * the parent util the exec or exit */ + free(command); + free(shNameArg); + PORT_Free(argv); + + *pid = child; + + return PR_ImportPipe(pipefd[0]); + +loser: + if (pipefd[0] != -1) { + close(pipefd[0]); + } + if (pipefd[1] != -1) { + close(pipefd[1]); + } + free(command); + free(shNameArg); + PORT_Free(argv); + + return NULL; +} + +/* + * bl_CloseUnPrelink - + * + * This closes the file descripter and reaps and children openned and crated by + * b;_OpenUnprelink. It's primary difference between it and just close is + * that it calls wait on the pid if one is supplied, preventing zombie children + * from hanging around. + */ +void +bl_CloseUnPrelink(PRFileDesc *file, int pid) +{ + /* close the file descriptor */ + PR_Close(file); + /* reap the child */ + if (pid) { + waitpid(pid, NULL, 0); + } +} +#endif + +/* #define DEBUG_SHVERIFY 1 */ + +static char * +mkCheckFileName(const char *libName) +{ + int ln_len = PORT_Strlen(libName); + char *output = PORT_Alloc(ln_len + sizeof(SGN_SUFFIX)); + int index = ln_len + 1 - sizeof("." SHLIB_SUFFIX); + + if ((index > 0) && + (PORT_Strncmp(&libName[index], + "." SHLIB_SUFFIX, sizeof("." SHLIB_SUFFIX)) == 0)) { + ln_len = index; + } + PORT_Memcpy(output, libName, ln_len); + PORT_Memcpy(&output[ln_len], SGN_SUFFIX, sizeof(SGN_SUFFIX)); + return output; +} + +static int +decodeInt(unsigned char *buf) +{ + return (buf[3]) | (buf[2] << 8) | (buf[1] << 16) | (buf[0] << 24); +} + +static SECStatus +readItem(PRFileDesc *fd, SECItem *item) +{ + unsigned char buf[4]; + int bytesRead; + + bytesRead = PR_Read(fd, buf, 4); + if (bytesRead != 4) { + return SECFailure; + } + item->len = decodeInt(buf); + + item->data = PORT_Alloc(item->len); + if (item->data == NULL) { + item->len = 0; + return SECFailure; + } + bytesRead = PR_Read(fd, item->data, item->len); + if (bytesRead != item->len) { + PORT_Free(item->data); + item->data = NULL; + item->len = 0; + return SECFailure; + } + return SECSuccess; +} + +static PRBool blapi_SHVerifyFile(const char *shName, PRBool self); + +static PRBool +blapi_SHVerify(const char *name, PRFuncPtr addr, PRBool self) +{ + PRBool result = PR_FALSE; /* if anything goes wrong, + * the signature does not verify */ + /* find our shared library name */ + char *shName = PR_GetLibraryFilePathname(name, addr); + if (!shName) { + goto loser; + } + result = blapi_SHVerifyFile(shName, self); + +loser: + if (shName != NULL) { + PR_Free(shName); + } + + return result; +} + +PRBool +BLAPI_SHVerify(const char *name, PRFuncPtr addr) +{ + return blapi_SHVerify(name, addr, PR_FALSE); +} + +PRBool +BLAPI_SHVerifyFile(const char *shName) +{ + return blapi_SHVerifyFile(shName, PR_FALSE); +} + +static PRBool +blapi_SHVerifyFile(const char *shName, PRBool self) +{ + char *checkName = NULL; + PRFileDesc *checkFD = NULL; + PRFileDesc *shFD = NULL; + void *hashcx = NULL; + const SECHashObject *hashObj = NULL; + SECItem signature = { 0, NULL, 0 }; + SECItem hash; + int bytesRead, offset; + SECStatus rv; + DSAPublicKey key; + int count; +#ifdef FREEBL_USE_PRELINK + int pid = 0; +#endif + + PRBool result = PR_FALSE; /* if anything goes wrong, + * the signature does not verify */ + unsigned char buf[4096]; + unsigned char hashBuf[HASH_LENGTH_MAX]; + + PORT_Memset(&key, 0, sizeof(key)); + hash.data = hashBuf; + hash.len = sizeof(hashBuf); + + /* If our integrity check was never ran or failed, fail any other + * integrity checks to prevent any token going into FIPS mode. */ + if (!self && (BL_FIPSEntryOK(PR_FALSE) != SECSuccess)) { + return PR_FALSE; + } + + if (!shName) { + goto loser; + } + + /* figure out the name of our check file */ + checkName = mkCheckFileName(shName); + if (!checkName) { + goto loser; + } + + /* open the check File */ + checkFD = PR_Open(checkName, PR_RDONLY, 0); + if (checkFD == NULL) { +#ifdef DEBUG_SHVERIFY + fprintf(stderr, "Failed to open the check file %s: (%d, %d)\n", + checkName, (int)PR_GetError(), (int)PR_GetOSError()); +#endif /* DEBUG_SHVERIFY */ + goto loser; + } + + /* read and Verify the headerthe header */ + bytesRead = PR_Read(checkFD, buf, 12); + if (bytesRead != 12) { + goto loser; + } + if ((buf[0] != NSS_SIGN_CHK_MAGIC1) || (buf[1] != NSS_SIGN_CHK_MAGIC2)) { + goto loser; + } + if ((buf[2] != NSS_SIGN_CHK_MAJOR_VERSION) || + (buf[3] < NSS_SIGN_CHK_MINOR_VERSION)) { + goto loser; + } +#ifdef notdef + if (decodeInt(&buf[8]) != CKK_DSA) { + goto loser; + } +#endif + + /* seek past any future header extensions */ + offset = decodeInt(&buf[4]); + if (PR_Seek(checkFD, offset, PR_SEEK_SET) < 0) { + goto loser; + } + + /* read the key */ + rv = readItem(checkFD, &key.params.prime); + if (rv != SECSuccess) { + goto loser; + } + rv = readItem(checkFD, &key.params.subPrime); + if (rv != SECSuccess) { + goto loser; + } + rv = readItem(checkFD, &key.params.base); + if (rv != SECSuccess) { + goto loser; + } + rv = readItem(checkFD, &key.publicValue); + if (rv != SECSuccess) { + goto loser; + } + /* read the siganture */ + rv = readItem(checkFD, &signature); + if (rv != SECSuccess) { + goto loser; + } + + /* done with the check file */ + PR_Close(checkFD); + checkFD = NULL; + + hashObj = HASH_GetRawHashObject(PQG_GetHashType(&key.params)); + if (hashObj == NULL) { + goto loser; + } + +/* open our library file */ +#ifdef FREEBL_USE_PRELINK + shFD = bl_OpenUnPrelink(shName, &pid); +#else + shFD = PR_Open(shName, PR_RDONLY, 0); +#endif + if (shFD == NULL) { +#ifdef DEBUG_SHVERIFY + fprintf(stderr, "Failed to open the library file %s: (%d, %d)\n", + shName, (int)PR_GetError(), (int)PR_GetOSError()); +#endif /* DEBUG_SHVERIFY */ + goto loser; + } + + /* hash our library file with SHA1 */ + hashcx = hashObj->create(); + if (hashcx == NULL) { + goto loser; + } + hashObj->begin(hashcx); + + count = 0; + while ((bytesRead = PR_Read(shFD, buf, sizeof(buf))) > 0) { + hashObj->update(hashcx, buf, bytesRead); + count += bytesRead; + } +#ifdef FREEBL_USE_PRELINK + bl_CloseUnPrelink(shFD, pid); +#else + PR_Close(shFD); +#endif + shFD = NULL; + + hashObj->end(hashcx, hash.data, &hash.len, hash.len); + + /* verify the hash against the check file */ + if (DSA_VerifyDigest(&key, &signature, &hash) == SECSuccess) { + result = PR_TRUE; + } +#ifdef DEBUG_SHVERIFY + { + int i, j; + fprintf(stderr, "File %s: %d bytes\n", shName, count); + fprintf(stderr, " hash: %d bytes\n", hash.len); +#define STEP 10 + for (i = 0; i < hash.len; i += STEP) { + fprintf(stderr, " "); + for (j = 0; j < STEP && (i + j) < hash.len; j++) { + fprintf(stderr, " %02x", hash.data[i + j]); + } + fprintf(stderr, "\n"); + } + fprintf(stderr, " signature: %d bytes\n", signature.len); + for (i = 0; i < signature.len; i += STEP) { + fprintf(stderr, " "); + for (j = 0; j < STEP && (i + j) < signature.len; j++) { + fprintf(stderr, " %02x", signature.data[i + j]); + } + fprintf(stderr, "\n"); + } + fprintf(stderr, "Verified : %s\n", result ? "TRUE" : "FALSE"); + } +#endif /* DEBUG_SHVERIFY */ + +loser: + if (checkName != NULL) { + PORT_Free(checkName); + } + if (checkFD != NULL) { + PR_Close(checkFD); + } + if (shFD != NULL) { + PR_Close(shFD); + } + if (hashcx != NULL) { + if (hashObj) { + hashObj->destroy(hashcx, PR_TRUE); + } + } + if (signature.data != NULL) { + PORT_Free(signature.data); + } + if (key.params.prime.data != NULL) { + PORT_Free(key.params.prime.data); + } + if (key.params.subPrime.data != NULL) { + PORT_Free(key.params.subPrime.data); + } + if (key.params.base.data != NULL) { + PORT_Free(key.params.base.data); + } + if (key.publicValue.data != NULL) { + PORT_Free(key.publicValue.data); + } + + return result; +} + +PRBool +BLAPI_VerifySelf(const char *name) +{ + if (name == NULL) { + /* + * If name is NULL, freebl is statically linked into softoken. + * softoken will call BLAPI_SHVerify next to verify itself. + */ + return PR_TRUE; + } + return blapi_SHVerify(name, (PRFuncPtr)decodeInt, PR_TRUE); +} |