diff --git a/crypto/asn1/t_spki.c b/crypto/asn1/t_spki.c
index 51b56d0aa9f746bafbe3864c1a8c4cabf1ea98a0..64ee77eeecbafab4772aeebec4d85e60b5ab67df 100644
--- a/crypto/asn1/t_spki.c
+++ b/crypto/asn1/t_spki.c
@@ -38,7 +38,7 @@ int NETSCAPE_SPKI_print(BIO *out, NETSCAPE_SPKI *spki)
     }
     chal = spki->spkac->challenge;
     if (chal->length)
-        BIO_printf(out, "  Challenge String: %s\n", chal->data);
+        BIO_printf(out, "  Challenge String: %.*s\n", chal->length, chal->data);
     i = OBJ_obj2nid(spki->sig_algor.algorithm);
     BIO_printf(out, "  Signature Algorithm: %s",
                (i == NID_undef) ? "UNKNOWN" : OBJ_nid2ln(i));
diff --git a/crypto/ec/ec_asn1.c b/crypto/ec/ec_asn1.c
index 7b7c75ce84435ae5b9e03da66b33a5819ccf786e..e497a259095d4318032611bea520421114184f86 100644
--- a/crypto/ec/ec_asn1.c
+++ b/crypto/ec/ec_asn1.c
@@ -761,7 +761,10 @@ EC_GROUP *EC_GROUP_new_from_ecparameters(const ECPARAMETERS *params)
         ret->seed_len = params->curve->seed->length;
     }
 
-    if (!params->order || !params->base || !params->base->data) {
+    if (params->order == NULL
+            || params->base == NULL
+            || params->base->data == NULL
+            || params->base->length == 0) {
         ECerr(EC_F_EC_GROUP_NEW_FROM_ECPARAMETERS, EC_R_ASN1_ERROR);
         goto err;
     }
diff --git a/crypto/sm2/sm2_crypt.c b/crypto/sm2/sm2_crypt.c
index ef505f64412bdcd8d5cd95f423f3ee23d030a3e0..1188abfc6b5756c3bf86fee8ca9e66d22391fec2 100644
--- a/crypto/sm2/sm2_crypt.c
+++ b/crypto/sm2/sm2_crypt.c
@@ -61,29 +61,20 @@ static size_t ec_field_size(const EC_GROUP *group)
     return field_size;
 }
 
-int sm2_plaintext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
-                       size_t *pt_size)
+int sm2_plaintext_size(const unsigned char *ct, size_t ct_size, size_t *pt_size)
 {
-    const size_t field_size = ec_field_size(EC_KEY_get0_group(key));
-    const int md_size = EVP_MD_size(digest);
-    size_t overhead;
+    struct SM2_Ciphertext_st *sm2_ctext = NULL;
 
-    if (md_size < 0) {
-        SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_DIGEST);
-        return 0;
-    }
-    if (field_size == 0) {
-        SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_FIELD);
-        return 0;
-    }
+    sm2_ctext = d2i_SM2_Ciphertext(NULL, &ct, ct_size);
 
-    overhead = 10 + 2 * field_size + (size_t)md_size;
-    if (msg_len <= overhead) {
+    if (sm2_ctext == NULL) {
         SM2err(SM2_F_SM2_PLAINTEXT_SIZE, SM2_R_INVALID_ENCODING);
         return 0;
     }
 
-    *pt_size = msg_len - overhead;
+    *pt_size = sm2_ctext->C2->length;
+    SM2_Ciphertext_free(sm2_ctext);
+
     return 1;
 }
 
diff --git a/crypto/sm2/sm2_pmeth.c b/crypto/sm2/sm2_pmeth.c
index b42a14c32f265a76c4263a512426c8143d348d6c..27025fbf3a2c5af66140147a0b2c8f9b2427aad5 100644
--- a/crypto/sm2/sm2_pmeth.c
+++ b/crypto/sm2/sm2_pmeth.c
@@ -151,7 +151,7 @@ static int pkey_sm2_decrypt(EVP_PKEY_CTX *ctx,
     const EVP_MD *md = (dctx->md == NULL) ? EVP_sm3() : dctx->md;
 
     if (out == NULL) {
-        if (!sm2_plaintext_size(ec, md, inlen, outlen))
+        if (!sm2_plaintext_size(in, inlen, outlen))
             return -1;
         else
             return 1;
diff --git a/crypto/x509v3/v3_alt.c b/crypto/x509v3/v3_alt.c
index 4dce0041012e44b755df4cb141cf85f348f35b85..6e5f9f8b0eac676c23e3c42aedc46dc55a1e62bb 100644
--- a/crypto/x509v3/v3_alt.c
+++ b/crypto/x509v3/v3_alt.c
@@ -9,6 +9,7 @@
 
 #include <stdio.h>
 #include "internal/cryptlib.h"
+#include "crypto/x509.h"
 #include <openssl/conf.h>
 #include <openssl/x509v3.h>
 #include "ext_dat.h"
@@ -99,17 +100,20 @@ STACK_OF(CONF_VALUE) *i2v_GENERAL_NAME(X509V3_EXT_METHOD *method,
         break;
 
     case GEN_EMAIL:
-        if (!X509V3_add_value_uchar("email", gen->d.ia5->data, &ret))
+        if (!x509v3_add_len_value_uchar("email", gen->d.ia5->data,
+                                        gen->d.ia5->length, &ret))
             return NULL;
         break;
 
     case GEN_DNS:
-        if (!X509V3_add_value_uchar("DNS", gen->d.ia5->data, &ret))
+        if (!x509v3_add_len_value_uchar("DNS", gen->d.ia5->data,
+                                        gen->d.ia5->length, &ret))
             return NULL;
         break;
 
     case GEN_URI:
-        if (!X509V3_add_value_uchar("URI", gen->d.ia5->data, &ret))
+        if (!x509v3_add_len_value_uchar("URI", gen->d.ia5->data,
+                                        gen->d.ia5->length, &ret))
             return NULL;
         break;
 
diff --git a/crypto/x509v3/v3_cpols.c b/crypto/x509v3/v3_cpols.c
index 1d12c899125c852eaef6000d4a921162cf3b2917..861e8455dd084c3c6a129e162913d4b757f7751f 100644
--- a/crypto/x509v3/v3_cpols.c
+++ b/crypto/x509v3/v3_cpols.c
@@ -422,7 +422,8 @@ static void print_qualifiers(BIO *out, STACK_OF(POLICYQUALINFO) *quals,
         qualinfo = sk_POLICYQUALINFO_value(quals, i);
         switch (OBJ_obj2nid(qualinfo->pqualid)) {
         case NID_id_qt_cps:
-            BIO_printf(out, "%*sCPS: %s\n", indent, "",
+            BIO_printf(out, "%*sCPS: %.*s\n", indent, "",
+                       qualinfo->d.cpsuri->length,
                        qualinfo->d.cpsuri->data);
             break;
 
@@ -447,7 +448,8 @@ static void print_notice(BIO *out, USERNOTICE *notice, int indent)
     if (notice->noticeref) {
         NOTICEREF *ref;
         ref = notice->noticeref;
-        BIO_printf(out, "%*sOrganization: %s\n", indent, "",
+        BIO_printf(out, "%*sOrganization: %.*s\n", indent, "",
+                   ref->organization->length,
                    ref->organization->data);
         BIO_printf(out, "%*sNumber%s: ", indent, "",
                    sk_ASN1_INTEGER_num(ref->noticenos) > 1 ? "s" : "");
@@ -470,7 +472,8 @@ static void print_notice(BIO *out, USERNOTICE *notice, int indent)
         BIO_puts(out, "\n");
     }
     if (notice->exptext)
-        BIO_printf(out, "%*sExplicit Text: %s\n", indent, "",
+        BIO_printf(out, "%*sExplicit Text: %.*s\n", indent, "",
+                   notice->exptext->length,
                    notice->exptext->data);
 }
 
diff --git a/crypto/x509v3/v3_ncons.c b/crypto/x509v3/v3_ncons.c
index 2a7b4f0992a81382e41c6e3d89833caf34b8d0d8..cb701c4d844bc1fb8a728b9d0fabd93aef45aba5 100644
--- a/crypto/x509v3/v3_ncons.c
+++ b/crypto/x509v3/v3_ncons.c
@@ -63,8 +63,31 @@ ASN1_SEQUENCE(NAME_CONSTRAINTS) = {
 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(GENERAL_SUBTREE)
 IMPLEMENT_ASN1_ALLOC_FUNCTIONS(NAME_CONSTRAINTS)
 
+
+#define IA5_OFFSET_LEN(ia5base, offset) \
+    ((ia5base)->length - ((unsigned char *)(offset) - (ia5base)->data))
+
+/* Like memchr but for ASN1_IA5STRING. Additionally you can specify the
+ * starting point to search from
+ */
+# define ia5memchr(str, start, c) memchr(start, c, IA5_OFFSET_LEN(str, start))
+
+/* Like memrrchr but for ASN1_IA5STRING */
+static char *ia5memrchr(ASN1_IA5STRING *str, int c)
+{
+    int i;
+
+    for (i = str->length; i > 0 && str->data[i - 1] != c; i--);
+
+    if (i == 0)
+        return NULL;
+
+    return (char *)&str->data[i - 1];
+}
+
 /*
- * We cannot use strncasecmp here because that applies locale specific rules.
+ * We cannot use strncasecmp here because that applies locale specific rules. It
+ * also doesn't work with ASN1_STRINGs that may have embedded NUL characters.
  * For example in Turkish 'I' is not the uppercase character for 'i'. We need to
  * do a simple ASCII case comparison ignoring the locale (that is why we use
  * numeric constants below).
@@ -89,20 +112,12 @@ static int ia5ncasecmp(const char *s1, const char *s2, size_t n)
 
             /* c1 > c2 */
             return 1;
-        } else if (*s1 == 0) {
-            /* If we get here we know that *s2 == 0 too */
-            return 0;
         }
     }
 
     return 0;
 }
 
-static int ia5casecmp(const char *s1, const char *s2)
-{
-    return ia5ncasecmp(s1, s2, SIZE_MAX);
-}
-
 static void *v2i_NAME_CONSTRAINTS(const X509V3_EXT_METHOD *method,
                                   X509V3_CTX *ctx, STACK_OF(CONF_VALUE) *nval)
 {
@@ -337,7 +352,7 @@ static int cn2dnsid(ASN1_STRING *cn, unsigned char **dnsid, size_t *idlen)
         --utf8_length;
 
     /* Reject *embedded* NULs */
-    if ((size_t)utf8_length != strlen((char *)utf8_value)) {
+    if (memchr(utf8_value, 0, utf8_length) != NULL) {
         OPENSSL_free(utf8_value);
         return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
     }
@@ -536,9 +551,14 @@ static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
 {
     char *baseptr = (char *)base->data;
     char *dnsptr = (char *)dns->data;
+
     /* Empty matches everything */
-    if (!*baseptr)
+    if (base->length == 0)
         return X509_V_OK;
+
+    if (dns->length < base->length)
+        return X509_V_ERR_PERMITTED_VIOLATION;
+
     /*
      * Otherwise can add zero or more components on the left so compare RHS
      * and if dns is longer and expect '.' as preceding character.
@@ -549,7 +569,7 @@ static int nc_dns(ASN1_IA5STRING *dns, ASN1_IA5STRING *base)
             return X509_V_ERR_PERMITTED_VIOLATION;
     }
 
-    if (ia5casecmp(baseptr, dnsptr))
+    if (ia5ncasecmp(baseptr, dnsptr, base->length))
         return X509_V_ERR_PERMITTED_VIOLATION;
 
     return X509_V_OK;
@@ -560,16 +580,17 @@ static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
 {
     const char *baseptr = (char *)base->data;
     const char *emlptr = (char *)eml->data;
+    const char *baseat = ia5memrchr(base, '@');
+    const char *emlat = ia5memrchr(eml, '@');
+    size_t basehostlen, emlhostlen;
 
-    const char *baseat = strchr(baseptr, '@');
-    const char *emlat = strchr(emlptr, '@');
     if (!emlat)
         return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
     /* Special case: initial '.' is RHS match */
-    if (!baseat && (*baseptr == '.')) {
+    if (!baseat && base->length > 0 && (*baseptr == '.')) {
         if (eml->length > base->length) {
             emlptr += eml->length - base->length;
-            if (ia5casecmp(baseptr, emlptr) == 0)
+            if (ia5ncasecmp(baseptr, emlptr, base->length) == 0)
                 return X509_V_OK;
         }
         return X509_V_ERR_PERMITTED_VIOLATION;
@@ -589,8 +610,10 @@ static int nc_email(ASN1_IA5STRING *eml, ASN1_IA5STRING *base)
         baseptr = baseat + 1;
     }
     emlptr = emlat + 1;
+    basehostlen = IA5_OFFSET_LEN(base, baseptr);
+    emlhostlen = IA5_OFFSET_LEN(eml, emlptr);
     /* Just have hostname left to match: case insensitive */
-    if (ia5casecmp(baseptr, emlptr))
+    if (basehostlen != emlhostlen || ia5ncasecmp(baseptr, emlptr, emlhostlen))
         return X509_V_ERR_PERMITTED_VIOLATION;
 
     return X509_V_OK;
@@ -601,10 +624,14 @@ static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
 {
     const char *baseptr = (char *)base->data;
     const char *hostptr = (char *)uri->data;
-    const char *p = strchr(hostptr, ':');
+    const char *p = ia5memchr(uri, (char *)uri->data, ':');
     int hostlen;
+
     /* Check for foo:// and skip past it */
-    if (!p || (p[1] != '/') || (p[2] != '/'))
+    if (p == NULL
+            || IA5_OFFSET_LEN(uri, p) < 3
+            || p[1] != '/'
+            || p[2] != '/')
         return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
     hostptr = p + 3;
 
@@ -612,13 +639,13 @@ static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
 
     /* Look for a port indicator as end of hostname first */
 
-    p = strchr(hostptr, ':');
+    p = ia5memchr(uri, hostptr, ':');
     /* Otherwise look for trailing slash */
-    if (!p)
-        p = strchr(hostptr, '/');
+    if (p == NULL)
+        p = ia5memchr(uri, hostptr, '/');
 
-    if (!p)
-        hostlen = strlen(hostptr);
+    if (p == NULL)
+        hostlen = IA5_OFFSET_LEN(uri, hostptr);
     else
         hostlen = p - hostptr;
 
@@ -626,7 +653,7 @@ static int nc_uri(ASN1_IA5STRING *uri, ASN1_IA5STRING *base)
         return X509_V_ERR_UNSUPPORTED_NAME_SYNTAX;
 
     /* Special case: initial '.' is RHS match */
-    if (*baseptr == '.') {
+    if (base->length > 0 && *baseptr == '.') {
         if (hostlen > base->length) {
             p = hostptr + hostlen - base->length;
             if (ia5ncasecmp(p, baseptr, base->length) == 0)
diff --git a/crypto/x509v3/v3_pci.c b/crypto/x509v3/v3_pci.c
index 3d124fa6d95d617eeebabcc7c395fd09ab0f86bc..98b6ef25e28092a1b99776b58eb4b8eaad8fc1ec 100644
--- a/crypto/x509v3/v3_pci.c
+++ b/crypto/x509v3/v3_pci.c
@@ -77,7 +77,8 @@ static int i2r_pci(X509V3_EXT_METHOD *method, PROXY_CERT_INFO_EXTENSION *pci,
     i2a_ASN1_OBJECT(out, pci->proxyPolicy->policyLanguage);
     BIO_puts(out, "\n");
     if (pci->proxyPolicy->policy && pci->proxyPolicy->policy->data)
-        BIO_printf(out, "%*sPolicy Text: %s\n", indent, "",
+        BIO_printf(out, "%*sPolicy Text: %.*s\n", indent, "",
+                   pci->proxyPolicy->policy->length,
                    pci->proxyPolicy->policy->data);
     return 1;
 }
diff --git a/crypto/x509v3/v3_utl.c b/crypto/x509v3/v3_utl.c
index 7281a7b917a8cc127ef019cd8339ffb5eb6e1e51..513dc68b0809dbd6c522fd75514a37d7c022f8a6 100644
--- a/crypto/x509v3/v3_utl.c
+++ b/crypto/x509v3/v3_utl.c
@@ -12,6 +12,7 @@
 #include "e_os.h"
 #include "internal/cryptlib.h"
 #include <stdio.h>
+#include <string.h>
 #include "crypto/ctype.h"
 #include <openssl/conf.h>
 #include <openssl/crypto.h>
@@ -34,17 +35,26 @@ static int ipv6_hex(unsigned char *out, const char *in, int inlen);
 
 /* Add a CONF_VALUE name value pair to stack */
 
-int X509V3_add_value(const char *name, const char *value,
-                     STACK_OF(CONF_VALUE) **extlist)
+static int x509v3_add_len_value(const char *name, const char *value,
+                                size_t vallen, STACK_OF(CONF_VALUE) **extlist)
 {
     CONF_VALUE *vtmp = NULL;
     char *tname = NULL, *tvalue = NULL;
     int sk_allocated = (*extlist == NULL);
 
-    if (name && (tname = OPENSSL_strdup(name)) == NULL)
-        goto err;
-    if (value && (tvalue = OPENSSL_strdup(value)) == NULL)
+    if (name != NULL && (tname = OPENSSL_strdup(name)) == NULL)
         goto err;
+    if (value != NULL && vallen > 0) {
+        /*
+         * We tolerate a single trailing NUL character, but otherwise no
+         * embedded NULs
+         */
+        if (memchr(value, 0, vallen - 1) != NULL)
+            goto err;
+        tvalue = OPENSSL_strndup(value, vallen);
+        if (tvalue == NULL)
+            goto err;
+    }
     if ((vtmp = OPENSSL_malloc(sizeof(*vtmp))) == NULL)
         goto err;
     if (sk_allocated && (*extlist = sk_CONF_VALUE_new_null()) == NULL)
@@ -67,10 +77,26 @@ int X509V3_add_value(const char *name, const char *value,
     return 0;
 }
 
+int X509V3_add_value(const char *name, const char *value,
+                     STACK_OF(CONF_VALUE) **extlist)
+{
+    return x509v3_add_len_value(name, value,
+                                value != NULL ? strlen((const char *)value) : 0,
+                                extlist);
+}
+
 int X509V3_add_value_uchar(const char *name, const unsigned char *value,
                            STACK_OF(CONF_VALUE) **extlist)
 {
-    return X509V3_add_value(name, (const char *)value, extlist);
+    return x509v3_add_len_value(name, (const char *)value,
+                                value != NULL ? strlen((const char *)value) : 0,
+                                extlist);
+}
+
+int x509v3_add_len_value_uchar(const char *name, const unsigned char *value,
+                               size_t vallen, STACK_OF(CONF_VALUE) **extlist)
+{
+    return x509v3_add_len_value(name, (const char *)value, vallen, extlist);
 }
 
 /* Free function for STACK_OF(CONF_VALUE) */
@@ -502,18 +528,26 @@ static int append_ia5(STACK_OF(OPENSSL_STRING) **sk, const ASN1_IA5STRING *email
     /* First some sanity checks */
     if (email->type != V_ASN1_IA5STRING)
         return 1;
-    if (!email->data || !email->length)
+    if (email->data == NULL || email->length == 0)
+        return 1;
+    if (memchr(email->data, 0, email->length) != NULL)
         return 1;
     if (*sk == NULL)
         *sk = sk_OPENSSL_STRING_new(sk_strcmp);
     if (*sk == NULL)
         return 0;
+
+    emtmp = OPENSSL_strndup((char *)email->data, email->length);
+    if (emtmp == NULL)
+        return 0;
+
     /* Don't add duplicates */
-    if (sk_OPENSSL_STRING_find(*sk, (char *)email->data) != -1)
+    if (sk_OPENSSL_STRING_find(*sk, emtmp) != -1) {
+        OPENSSL_free(emtmp);
         return 1;
-    emtmp = OPENSSL_strdup((char *)email->data);
-    if (emtmp == NULL || !sk_OPENSSL_STRING_push(*sk, emtmp)) {
-        OPENSSL_free(emtmp);    /* free on push failure */
+    }
+    if (!sk_OPENSSL_STRING_push(*sk, emtmp)) {
+        OPENSSL_free(emtmp); /* free on push failure */
         X509_email_free(*sk);
         *sk = NULL;
         return 0;
diff --git a/include/crypto/sm2.h b/include/crypto/sm2.h
index 76ee80baff19237e6f9eadd1088492418b9556f1..50851a83cea224c48d61f602ed3acfb28c901554 100644
--- a/include/crypto/sm2.h
+++ b/include/crypto/sm2.h
@@ -60,8 +60,7 @@ int sm2_verify(const unsigned char *dgst, int dgstlen,
 int sm2_ciphertext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
                         size_t *ct_size);
 
-int sm2_plaintext_size(const EC_KEY *key, const EVP_MD *digest, size_t msg_len,
-                       size_t *pt_size);
+int sm2_plaintext_size(const unsigned char *ct, size_t ct_size, size_t *pt_size);
 
 int sm2_encrypt(const EC_KEY *key,
                 const EVP_MD *digest,
diff --git a/include/crypto/x509.h b/include/crypto/x509.h
index b53c2b03c39ec4625f0439a8c2e61c51edcca724..7ffb8abfe71b4cd1ed5780fd843c3013d2108f0a 100644
--- a/include/crypto/x509.h
+++ b/include/crypto/x509.h
@@ -8,6 +8,8 @@
  */
 
 #include "internal/refcount.h"
+#include <openssl/x509.h>
+#include <openssl/conf.h>
 
 /* Internal X509 structures and functions: not for application use */
 
@@ -284,3 +286,6 @@ int a2i_ipadd(unsigned char *ipout, const char *ipasc);
 int x509_set1_time(ASN1_TIME **ptm, const ASN1_TIME *tm);
 
 void x509_init_sig_info(X509 *x);
+
+int x509v3_add_len_value_uchar(const char *name, const unsigned char *value,
+                               size_t vallen, STACK_OF(CONF_VALUE) **extlist);
diff --git a/test/sm2_internal_test.c b/test/sm2_internal_test.c
index 2bb73947ff3bd6e89458b624915fd78f016c407f..41827bb82fcb710e176ad57e6fd9dadab5602066 100644
--- a/test/sm2_internal_test.c
+++ b/test/sm2_internal_test.c
@@ -185,7 +185,7 @@ static int test_sm2_crypt(const EC_GROUP *group,
     if (!TEST_mem_eq(ctext, ctext_len, expected, ctext_len))
         goto done;
 
-    if (!TEST_true(sm2_plaintext_size(key, digest, ctext_len, &ptext_len))
+    if (!TEST_true(sm2_plaintext_size(ctext, ctext_len, &ptext_len))
             || !TEST_int_eq(ptext_len, msg_len))
         goto done;
 
diff --git a/test/x509_time_test.c b/test/x509_time_test.c
index b6fd38a5c587a40eb29634f81cb30433d9d05735..d0993d9c0416ece2937e6f7ea6d1495c38a73872 100644
--- a/test/x509_time_test.c
+++ b/test/x509_time_test.c
@@ -330,10 +330,12 @@ static int test_x509_time(int idx)
 
     /* if t is not NULL but expected_string is NULL, it is an 'OK' case too */
     if (t != NULL && x509_format_tests[idx].expected_string) {
-        if (!TEST_str_eq((const char *)t->data,
-                    x509_format_tests[idx].expected_string)) {
-            TEST_info("test_x509_time(%d) failed: expected_string %s, got %s\n",
-                    idx, x509_format_tests[idx].expected_string, t->data);
+        if (!TEST_mem_eq((const char *)t->data, t->length,
+                    x509_format_tests[idx].expected_string,
+                    strlen(x509_format_tests[idx].expected_string))) {
+            TEST_info("test_x509_time(%d) failed: expected_string %s, got %.*s\n",
+                    idx, x509_format_tests[idx].expected_string, t->length,
+                    t->data);
             goto out;
         }
     }