WIP: Bug 1804091 NSS needs to move off of DSA for integrity checks. r=nss-reviewers,jschanck

When we first added integrity checks to NSS for FIPS compliance, the only signature method allowed was DSA. NIST will be sunsetting DSA in 2023, so we need to update our integrity checks again. Since the time we added these checks, NIST has started accepting HMAC as a valid signature algorithm for integrity checks. HMAC is easier, faster and requires smaller .chk files and openssl and gnutls has been using hmac now for years for this purpose.

Since we need to move off of DSA anyway it's time to move to HMAC.

This patch does this move. shlibsign now produces HMAC_256 by default. It moves the version number up because even though nss includes a type field, previous versions of NSS did not look at the type field when checking integrity. Bumping the version number will cause previous versions of NSS to fail early if presented with a newly generated integrity check file (even though it should fail later anyway). shlibsign now has the ability to generate 'legacy' check files so it can be used to generate check files for older versions of NSS.

NSS can still accept older check files unless NSS_STRICT_INTEGRITY is set at compile time. This means tools which may be using old shlibsign to resign nss shared libraries will continue to work. At some point we can remove all DSA support (maybe after one enterprise release cycle).

While completing this work, we also complete some integrity code cleanup. There are lots of magic numbers defining where things fall in the integrity check header. These are now moved to a structure and defined in the shsign.h header. Both shlibsign and shvfy have been updated to use this header.

New test cases are not needed since fips.sh adequately tests our integrity code (both normal case and against mangled libraries which should fail). Though the lowhash test was updated to catch a particular issue we can run into when we use the LOWHASH code. On RHEL-7, we use the NSSLOWHASH_ interface in freebl in libc, which needs to run independently of nspr and nssutil. This requirement puts a pretty heavy burned on freebl to be self-contained when used for NSSLOWHASH_, including running integrity checks. The previous test program linked with nssutil and nspr (just like all of the rest of the nss tests) and weren't detecting issues when unimplemented stub functions where called. This patch includes fixing those lowhash tests and also implementing the stubs needed by the current integrity check code.


cmd/lowhashtest/Makefile
remove linking lowhashtest with all the libraries except freebl.

cmd/lowhashtest/lowhashtest.c
remove any dependency NSPR or NSSUTIL in the code.

cmd/lowhashtest/manifest.mn
remove spurious requires statements.

cmd/shlibsign/shlibsign.c
add hmac code.
   add ability to select the hash type from the command line.
separate signature processing into their own functions for DSA and HMAC
General cleanups.
    Use PR_ARRAY_SIZE rather then a custom define.
    move error printing outside utility functions (so we don't have to pass around filenames everywhere)
    Use NSSSignChkHeader instead of a Buf with magic offsets for the Check file Header.
Add ability to make old style .chk files for old versions of NSS.
    Add option to revert to DSA
    Add option to use old version numbers: only valid if DSA is set.

lib/freebl/Makefile
    All NSS_STRICT_INTEGRITY to be set at build time. Setting NSS_STRICT_INTEGRITY only accepts hmac256, hmac384, hmac512. If it's not set, NSS will accept older .chk file formats (like DSA-2).

lib/freebl/nsslowhash.c
    lowhashtest files expect to set NSS_FIPS to force fips mode when testing the lowhash interface, but NSS_FIPS was not being looked at in the nsslow_GetFIPSEnabled. NOTE: setting NSS_FIPS to true will force FIPS mode if the system isn't already in FIPS mode. Setting it to FALSE will not turn it off if the system is already in FIPS mode.

lib/freebl/shsign.h
Update version.
Add new defines for HMAC
add new Header structure to remove magic offsets into a raw buffer in the code.

lib/freebl/shvfy.c
Add HMAC processing.
Turn off DSA processing if NSS_STRICT_INTEGERITY is set.
Refactor the signature processing.

lib/freebl/stubs.c
Add SECITEM_ItemsAreEqual for HMAC shvfy
Add implementations for SECITEM_ItemsAreEqual, SECITEM_ZfreeItem, and PR_GetEnvSecure. The first is new. The second solves and existing bug which is only seen on RHEL7, and the last is needed for the fix to nsslowhash.c above.
PR_GetEnvSecure() calls secure_getenv if _USE_GNU is set, otherwise it falls back to the normal getenv. This should be safe since it's only used in LOWHASH to get the NSS_FIPS environment variable, which only has the effect of making LOWHASH run in fips mode when it otherwise wouldn't.

lib/freebl/stubs.c
Add SECITEM_ItemsAreEqual for HMAC shvfy

tests/lowhash/lowhash.sh
Make the test executable so it can be run on it's own.

Differential Revision: https://phabricator.services.mozilla.com/D164137

6 files changed, 328 insertions, 180 deletions

diff --git a/lib/freebl/Makefile b/lib/freebl/Makefile
index 228549ede..a15db872f 100644
--- a/lib/freebl/Makefile
+++ b/lib/freebl/Makefile
@@ -101,6 +101,9 @@ endif
 ifdef NSS_NO_INIT_SUPPORT
     DEFINES += -DNSS_NO_INIT_SUPPORT
 endif
+ifdef NSS_STRICT_INTEGRITY
+    DEFINES += -DNSS_STRICT_INTEGRITY_
+endif
 
 ifdef FREEBL_PRELINK_COMMAND
 	DEFINES +=-DFREEBL_PRELINK_COMMAND=\"$(FREEBL_PRELINK_COMMAND)\"
diff --git a/lib/freebl/nsslowhash.c b/lib/freebl/nsslowhash.c
index 22f97810f..e950e0865 100644
--- a/lib/freebl/nsslowhash.c
+++ b/lib/freebl/nsslowhash.c
@@ -6,6 +6,7 @@
 #include "stubs.h"
 #endif
 #include "prtypes.h"
+#include "prenv.h"
 #include "secerr.h"
 #include "blapi.h"
 #include "hasht.h"
@@ -30,6 +31,12 @@ nsslow_GetFIPSEnabled(void)
     FILE *f;
     char d;
     size_t size;
+    const char *env;
+
+    env = PR_GetEnvSecure("NSS_FIPS");
+    if (env && (*env == 'y' || *env == 'f' || *env == '1' || *env == 't')) {
+        return 1;
+    }
 
     f = fopen("/proc/sys/crypto/fips_enabled", "r");
     if (!f)
diff --git a/lib/freebl/shsign.h b/lib/freebl/shsign.h
index 590c0e6b3..d1a595a39 100644
--- a/lib/freebl/shsign.h
+++ b/lib/freebl/shsign.h
@@ -8,7 +8,19 @@
 #define SGN_SUFFIX ".chk"
 #define NSS_SIGN_CHK_MAGIC1 0xf1
 #define NSS_SIGN_CHK_MAGIC2 0xc5
-#define NSS_SIGN_CHK_MAJOR_VERSION 0x01
-#define NSS_SIGN_CHK_MINOR_VERSION 0x02
+/* new hmac based signatures */
+#define NSS_SIGN_CHK_MAJOR_VERSION 0x02
+#define NSS_SIGN_CHK_MINOR_VERSION 0x01
+#define NSS_SIGN_CHK_TYPE_FLAGS 0xff000000
+#define NSS_SIGN_CHK_FLAG_HMAC 0x80000000
 
+typedef struct NSSSignChkHeaderStr NSSSignChkHeader;
+struct NSSSignChkHeaderStr {
+    unsigned char magic1;
+    unsigned char magic2;
+    unsigned char majorVersion;
+    unsigned char minorVersion;
+    unsigned char offset[4];
+    unsigned char type[4];
+};
 #endif /* _SHSIGN_H_ */
diff --git a/lib/freebl/shvfy.c b/lib/freebl/shvfy.c
index 0428bf6c0..e713f64b0 100644
--- a/lib/freebl/shvfy.c
+++ b/lib/freebl/shvfy.c
@@ -19,6 +19,7 @@
 #include "pqg.h"
 #include "blapii.h"
 #include "secitem.h"
+#include "pkcs11t.h"
 
 #ifndef NSS_FIPS_DISABLED
 
@@ -321,228 +322,315 @@ BLAPI_SHVerifyFile(const char *shName)
     return blapi_SHVerifyFile(shName, PR_FALSE);
 }
 
+#ifndef NSS_STRICT_INTEGRITY
+/* This allows checks with old shlibsign .chk files. If NSS_STRICT_INTEGRITY
+ * is set, we don't accept DSA */
 static PRBool
-blapi_SHVerifyFile(const char *shName, PRBool self)
+blapi_SHVerifyDSACheck(PRFileDesc *shFD, const SECHashObject *hashObj,
+                       DSAPublicKey *key, const SECItem *signature)
 {
-    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;
-    (void)count; /* Suppress unused var warning (Bug 1738028) */
-#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];
+    int bytesRead;
     unsigned char hashBuf[HASH_LENGTH_MAX];
+    unsigned char buf[4096];
+    SECStatus rv;
 
-    PORT_Memset(&key, 0, sizeof(key));
+    hash.type = siBuffer;
     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)) {
+    /* hash our library file */
+    hashcx = hashObj->create();
+    if (hashcx == NULL) {
         return PR_FALSE;
     }
+    hashObj->begin(hashcx);
 
-    if (!shName) {
-        goto loser;
+    while ((bytesRead = PR_Read(shFD, buf, sizeof(buf))) > 0) {
+        hashObj->update(hashcx, buf, bytesRead);
     }
+    hashObj->end(hashcx, hash.data, &hash.len, hash.len);
+    hashObj->destroy(hashcx, PR_TRUE);
 
-    /* figure out the name of our check file */
-    checkName = mkCheckFileName(shName);
-    if (!checkName) {
-        goto loser;
-    }
+    /* verify the hash against the check file */
+    rv = DSA_VerifyDigest(key, signature, &hash);
+    PORT_Memset(hashBuf, 0, sizeof hashBuf);
+    return (rv == SECSuccess) ? PR_TRUE : PR_FALSE;
+}
+#endif
 
-    /* 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;
+#ifdef NSS_STRICT_INTEGRITY
+/* don't allow MD2, MD5, SHA1 or SHA224 as your integrity hash */
+static PRBool
+blapi_HashAllowed(SECHashObject *hashObj)
+{
+    switch (hashObj->type) {
+        case HASH_AlgSHA256:
+        case HASH_AlgSHA384:
+        case HASH_AlgSHA512:
+            return PR_TRUE;
+        default:
+            break;
     }
+    return PR_FALSE;
+}
+#endif
 
-    /* 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;
-    }
+static PRBool
+blapi_SHVerifyHMACCheck(PRFileDesc *shFD, const SECHashObject *hashObj,
+                        const SECItem *key, const SECItem *signature)
+{
+    HMACContext *hmaccx = NULL;
+    SECItem hash;
+    int bytesRead;
+    unsigned char hashBuf[HASH_LENGTH_MAX];
+    unsigned char buf[4096];
+    SECStatus rv;
+    PRBool result = PR_FALSE;
+
+#ifdef NSS_STRICT_INTEGRITY
+    if (!blapi_HashAllowed(hashObj)) {
+        return PR_FALSE;
 #endif
 
-    /* seek past any future header extensions */
-    offset = decodeInt(&buf[4]);
-    if (PR_Seek(checkFD, offset, PR_SEEK_SET) < 0) {
-        goto loser;
-    }
+        hash.type = siBuffer;
+        hash.data = hashBuf;
+        hash.len = hashObj->length;
 
-    /* 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;
-    }
+        /* create an hmac for the library file */
+        hmaccx = HMAC_Create(hashObj, key->data, key->len, PR_TRUE);
+        if (hmaccx == NULL) {
+            return PR_FALSE;
+        }
+        HMAC_Begin(hmaccx);
+
+        while ((bytesRead = PR_Read(shFD, buf, sizeof(buf))) > 0) {
+            HMAC_Update(hmaccx, buf, bytesRead);
+        }
+        rv = HMAC_Finish(hmaccx, hash.data, &hash.len, hash.len);
 
-    /* done with the check file */
-    PR_Close(checkFD);
-    checkFD = NULL;
+        HMAC_Destroy(hmaccx, PR_TRUE);
 
-    hashObj = HASH_GetRawHashObject(PQG_GetHashType(&key.params));
-    if (hashObj == NULL) {
-        goto loser;
+        /* verify the hmac against the check file */
+        if (rv == SECSuccess) {
+            result = SECITEM_ItemsAreEqual(signature, &hash);
+        }
+        PORT_Memset(hashBuf, 0, sizeof hashBuf);
+        return result;
     }
 
+    static PRBool
+    blapi_SHVerifyFile(const char *shName, PRBool self)
+    {
+        char *checkName = NULL;
+        PRFileDesc *checkFD = NULL;
+        PRFileDesc *shFD = NULL;
+        const SECHashObject *hashObj = NULL;
+        SECItem signature = { 0, NULL, 0 };
+        int bytesRead, offset, type;
+        SECStatus rv;
+        SECItem hmacKey = { 0, NULL, 0 };
+#ifdef FREEBL_USE_PRELINK
+        int pid = 0;
+#endif
+        PRBool result = PR_FALSE; /* if anything goes wrong,
+                   * the signature does not verify */
+        NSSSignChkHeader header;
+#ifndef NSS_STRICT_INTEGRITY
+        DSAPublicKey key;
+
+        PORT_Memset(&key, 0, sizeof(key));
+#endif
+
+        /* 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, &header, sizeof(header));
+        if (bytesRead != sizeof(header)) {
+            goto loser;
+        }
+        if ((header.magic1 != NSS_SIGN_CHK_MAGIC1) ||
+            (header.magic2 != NSS_SIGN_CHK_MAGIC2)) {
+            goto loser;
+        }
+        /* we've bumped the version number so that newly signed .check
+     * files will fail nicely on old version of nss */
+        if (header.majorVersion > NSS_SIGN_CHK_MAJOR_VERSION) {
+            goto loser;
+        }
+        if (header.minorVersion < NSS_SIGN_CHK_MINOR_VERSION) {
+            goto loser;
+        }
+        type = decodeInt(header.type);
+
+        /* seek past any future header extensions */
+        offset = decodeInt(header.offset);
+        if (PR_Seek(checkFD, offset, PR_SEEK_SET) < 0) {
+            goto loser;
+        }
+
+        switch (type) {
+            case CKK_DSA:
+#ifdef NSS_STRICT_INTEGRITY
+                goto loser;
+#else
+            /* accept old dsa check files if NSS_STRICT_INTEGRITY is not set*/
+            /* 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 signature */
+            rv = readItem(checkFD, &signature);
+            if (rv != SECSuccess) {
+                goto loser;
+            }
+            hashObj = HASH_GetRawHashObject(PQG_GetHashType(&key.params));
+            break;
+#endif
+            default:
+                if ((type & NSS_SIGN_CHK_TYPE_FLAGS) != NSS_SIGN_CHK_FLAG_HMAC) {
+                    goto loser;
+                }
+                /* read the HMAC Key */
+                rv = readItem(checkFD, &hmacKey);
+                if (rv != SECSuccess) {
+                    goto loser;
+                }
+                /* read the siganture */
+                rv = readItem(checkFD, &signature);
+                if (rv != SECSuccess) {
+                    goto loser;
+                }
+                hashObj = HASH_GetRawHashObject(type & ~NSS_SIGN_CHK_TYPE_FLAGS);
+        }
+
+        /* done with the check file */
+        PR_Close(checkFD);
+        checkFD = NULL;
+
+        if (hashObj == NULL) {
+            goto loser;
+        }
+
 /* open our library file */
 #ifdef FREEBL_USE_PRELINK
-    shFD = bl_OpenUnPrelink(shName, &pid);
+        shFD = bl_OpenUnPrelink(shName, &pid);
 #else
     shFD = PR_Open(shName, PR_RDONLY, 0);
 #endif
-    if (shFD == NULL) {
+        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());
+            fprintf(stderr, "Failed to open the library file %s: (%d, %d)\n",
+                    shName, (int)PR_GetError(), (int)PR_GetOSError());
 #endif /* DEBUG_SHVERIFY */
-        goto loser;
-    }
+            goto loser;
+        }
 
-    /* hash our library file with SHA1 */
-    hashcx = hashObj->create();
-    if (hashcx == NULL) {
-        goto loser;
-    }
-    hashObj->begin(hashcx);
+        switch (type) {
+            case CKK_DSA:
+#ifndef NSS_STRICT_INTEGRITY
+                result = blapi_SHVerifyDSACheck(shFD, hashObj, &key, &signature);
+#endif
+                break;
+            default:
+                if ((type & NSS_SIGN_CHK_TYPE_FLAGS) != NSS_SIGN_CHK_FLAG_HMAC) {
+                    break;
+                }
+                result = blapi_SHVerifyHMACCheck(shFD, hashObj, &hmacKey, &signature);
+                break;
+        }
 
-    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);
+        bl_CloseUnPrelink(shFD, pid);
 #else
     PR_Close(shFD);
 #endif
-    shFD = NULL;
-
-    hashObj->end(hashcx, hash.data, &hash.len, hash.len);
+        shFD = NULL;
 
-    /* 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");
+    loser:
+        PORT_Memset(&header, 0, sizeof header);
+        if (checkName != NULL) {
+            PORT_Free(checkName);
         }
-        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");
+        if (checkFD != NULL) {
+            PR_Close(checkFD);
         }
-        fprintf(stderr, "Verified : %s\n", result ? "TRUE" : "FALSE");
-    }
-#endif /* DEBUG_SHVERIFY */
-
-loser:
-    PORT_Memset(buf, 0, sizeof buf);
-    PORT_Memset(hashBuf, 0, sizeof hashBuf);
-    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 (shFD != NULL) {
+            PR_Close(shFD);
         }
-    }
-    if (signature.data != NULL) {
-        SECITEM_ZfreeItem(&signature, PR_FALSE);
-    }
-    if (key.params.prime.data != NULL) {
-        SECITEM_ZfreeItem(&key.params.prime, PR_FALSE);
-    }
-    if (key.params.subPrime.data != NULL) {
-        SECITEM_ZfreeItem(&key.params.subPrime, PR_FALSE);
-    }
-    if (key.params.base.data != NULL) {
-        SECITEM_ZfreeItem(&key.params.base, PR_FALSE);
-    }
-    if (key.publicValue.data != NULL) {
-        SECITEM_ZfreeItem(&key.publicValue, PR_FALSE);
+        if (hmacKey.data != NULL) {
+            SECITEM_ZfreeItem(&hmacKey, PR_FALSE);
+        }
+        if (signature.data != NULL) {
+            SECITEM_ZfreeItem(&signature, PR_FALSE);
+        }
+#ifndef NSS_STRICT_INTEGRITY
+        if (key.params.prime.data != NULL) {
+            SECITEM_ZfreeItem(&key.params.prime, PR_FALSE);
+        }
+        if (key.params.subPrime.data != NULL) {
+            SECITEM_ZfreeItem(&key.params.subPrime, PR_FALSE);
+        }
+        if (key.params.base.data != NULL) {
+            SECITEM_ZfreeItem(&key.params.base, PR_FALSE);
+        }
+        if (key.publicValue.data != NULL) {
+            SECITEM_ZfreeItem(&key.publicValue, PR_FALSE);
+        }
+#endif
+        return result;
     }
 
-    return result;
-}
-
-PRBool
-BLAPI_VerifySelf(const char *name)
-{
-    if (name == NULL) {
-        /*
+    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 PR_TRUE;
+        }
+        return blapi_SHVerify(name, (PRFuncPtr)decodeInt, PR_TRUE);
     }
-    return blapi_SHVerify(name, (PRFuncPtr)decodeInt, PR_TRUE);
-}
 
 #else /* NSS_FIPS_DISABLED */
 
diff --git a/lib/freebl/stubs.c b/lib/freebl/stubs.c
index 122e5b251..82b5b2e78 100644
--- a/lib/freebl/stubs.c
+++ b/lib/freebl/stubs.c
@@ -170,6 +170,7 @@ STUB_DECLARE(char *, PR_GetEnvSecure, (const char *));
 
 STUB_DECLARE(SECItem *, SECITEM_AllocItem_Util, (PLArenaPool * arena, SECItem *item, unsigned int len));
 STUB_DECLARE(SECComparison, SECITEM_CompareItem_Util, (const SECItem *a, const SECItem *b));
+STUB_DECLARE(PRBool, SECITEM_ItemsAreEqual_Util, (const SECItem *a, const SECItem *b));
 STUB_DECLARE(SECStatus, SECITEM_CopyItem_Util, (PLArenaPool * arena, SECItem *to, const SECItem *from));
 STUB_DECLARE(void, SECITEM_FreeItem_Util, (SECItem * zap, PRBool freeit));
 STUB_DECLARE(void, SECITEM_ZfreeItem_Util, (SECItem * zap, PRBool freeit));
@@ -573,8 +574,11 @@ extern char *
 PR_GetEnvSecure_stub(const char *var)
 {
     STUB_SAFE_CALL1(PR_GetEnvSecure, var);
-    abort();
-    return NULL;
+#ifdef __USE_GNU
+    return secure_getenv(var);
+#else
+    return getenv(var);
+#endif
 }
 
 extern void
@@ -622,6 +626,30 @@ SECITEM_CompareItem_stub(const SECItem *a, const SECItem *b)
     return SECEqual;
 }
 
+extern PRBool
+SECITEM_ItemsAreEqual_stub(const SECItem *a, const SECItem *b)
+{
+    STUB_SAFE_CALL2(SECITEM_ItemsAreEqual_Util, a, b);
+    /* two nulls are equal */
+    if (!a && !b) {
+        return PR_TRUE;
+    }
+    /* only one NULL is not equal */
+    if (!a || !b) {
+        return PR_FALSE;
+    }
+    /* we know both secitems have been set, now make sure the lengths
+     * are equal */
+    if (a->len != b->len) {
+        return PR_FALSE;
+    }
+    /* lengths are equal, safe to verify the data */
+    if (PORT_Memcmp(a->data, b->data, b->len) != 0) {
+        return PR_FALSE;
+    }
+    return PR_TRUE;
+}
+
 extern SECStatus
 SECITEM_CopyItem_stub(PLArenaPool *arena, SECItem *to, const SECItem *from)
 {
@@ -646,7 +674,16 @@ extern void
 SECITEM_ZfreeItem_stub(SECItem *zap, PRBool freeit)
 {
     STUB_SAFE_CALL2(SECITEM_ZfreeItem_Util, zap, freeit);
-    abort();
+    if (zap) {
+        if (zap->data) {
+            PORT_Memset(zap->data, 0, zap->len);
+            PORT_Free_stub(zap->data);
+        }
+        PORT_Memset(zap, 0, sizeof(SECItem));
+        if (freeit) {
+            PORT_Free_stub(zap);
+        }
+    }
 }
 
 extern int
diff --git a/lib/freebl/stubs.h b/lib/freebl/stubs.h
index e63cf7a5d..e6d9ed03a 100644
--- a/lib/freebl/stubs.h
+++ b/lib/freebl/stubs.h
@@ -35,6 +35,7 @@
 
 #define SECITEM_AllocItem SECITEM_AllocItem_stub
 #define SECITEM_CompareItem SECITEM_CompareItem_stub
+#define SECITEM_ItemsAreEqual SECITEM_ItemsAreEqual_stub
 #define SECITEM_CopyItem SECITEM_CopyItem_stub
 #define SECITEM_FreeItem SECITEM_FreeItem_stub
 #define SECITEM_ZfreeItem SECITEM_ZfreeItem_stub