diff --git a/apps/ca.c b/apps/ca.c

index 24883615ed6b..8a2b31579549 100644

--- a/apps/ca.c

+++ b/apps/ca.c

@@ -2367,7 +2367,7 @@ static char *make_revocation_str(REVINFO_TYPE rev_type, const char *rev_arg)

     case REV_CRL_REASON:

         for (i = 0; i < 8; i++) {

-            if (strcasecmp(rev_arg, crl_reasons[i]) == 0) {

+            if (OPENSSL_strcasecmp(rev_arg, crl_reasons[i]) == 0) {

                 reason = crl_reasons[i];

                 break;

             }

@@ -2584,7 +2584,7 @@ int unpack_revinfo(ASN1_TIME **prevtm, int *preason, ASN1_OBJECT **phold,

     }

     if (reason_str) {

         for (i = 0; i < NUM_REASONS; i++) {

-            if (strcasecmp(reason_str, crl_reasons[i]) == 0) {

+            if (OPENSSL_strcasecmp(reason_str, crl_reasons[i]) == 0) {

                 reason_code = i;

                 break;

             }

diff --git a/apps/cmp.c b/apps/cmp.c

index 9ea5cee4124d..5c6bcdad0a64 100644

--- a/apps/cmp.c

+++ b/apps/cmp.c

@@ -1745,7 +1745,7 @@ static int handle_opt_geninfo(OSSL_CMP_CTX *ctx)

     valptr[0] = '\0';

     valptr++;

-    if (strncasecmp(valptr, "int:", 4) != 0) {

+    if (OPENSSL_strncasecmp(valptr, "int:", 4) != 0) {

         CMP_err("missing 'int:' in -geninfo option");

         return 0;

     }

diff --git a/apps/ecparam.c b/apps/ecparam.c

index 12eed703de69..ecce36be71a2 100644

--- a/apps/ecparam.c

+++ b/apps/ecparam.c

@@ -229,7 +229,7 @@ int ecparam_main(int argc, char **argv)

                        point_format, 0);

         *p = OSSL_PARAM_construct_end();

-        if (strcasecmp(curve_name, "SM2") == 0)

+        if (OPENSSL_strcasecmp(curve_name, "SM2") == 0)

             gctx_params = EVP_PKEY_CTX_new_from_name(NULL, "sm2", NULL);

         else

             gctx_params = EVP_PKEY_CTX_new_from_name(NULL, "ec", NULL);

diff --git a/apps/lib/apps.c b/apps/lib/apps.c

index 30da6e8a8cb8..227da4982d14 100644

--- a/apps/lib/apps.c

+++ b/apps/lib/apps.c

@@ -688,8 +688,8 @@ int load_cert_certs(const char *uri,

     int ret = 0;

     char *pass_string;

-    if (exclude_http && (strncasecmp(uri, "http://", 7) == 0

-                         || strncasecmp(uri, "https://", 8) == 0)) {

+    if (exclude_http && (OPENSSL_strncasecmp(uri, "http://", 7) == 0

+                         || OPENSSL_strncasecmp(uri, "https://", 8) == 0)) {

         BIO_printf(bio_err, "error: HTTP retrieval not allowed for %s\n", desc);

         return ret;

     }

@@ -1182,20 +1182,20 @@ int set_name_ex(unsigned long *flags, const char *arg)

 int set_dateopt(unsigned long *dateopt, const char *arg)

 {

-    if (strcasecmp(arg, "rfc_822") == 0)

+    if (OPENSSL_strcasecmp(arg, "rfc_822") == 0)

         *dateopt = ASN1_DTFLGS_RFC822;

-    else if (strcasecmp(arg, "iso_8601") == 0)

+    else if (OPENSSL_strcasecmp(arg, "iso_8601") == 0)

         *dateopt = ASN1_DTFLGS_ISO8601;

     return 0;

 }

 int set_ext_copy(int *copy_type, const char *arg)

 {

-    if (strcasecmp(arg, "none") == 0)

+    if (OPENSSL_strcasecmp(arg, "none") == 0)

         *copy_type = EXT_COPY_NONE;

-    else if (strcasecmp(arg, "copy") == 0)

+    else if (OPENSSL_strcasecmp(arg, "copy") == 0)

         *copy_type = EXT_COPY_ADD;

-    else if (strcasecmp(arg, "copyall") == 0)

+    else if (OPENSSL_strcasecmp(arg, "copyall") == 0)

         *copy_type = EXT_COPY_ALL;

     else

         return 0;

@@ -1275,7 +1275,7 @@ static int set_table_opts(unsigned long *flags, const char *arg,

     }

     for (ptbl = in_tbl; ptbl->name; ptbl++) {

-        if (strcasecmp(arg, ptbl->name) == 0) {

+        if (OPENSSL_strcasecmp(arg, ptbl->name) == 0) {

             *flags &= ~ptbl->mask;

             if (c)

                 *flags |= ptbl->flag;

diff --git a/apps/lib/engine_loader.c b/apps/lib/engine_loader.c

index c093f31e1b39..42775a89f361 100644

--- a/apps/lib/engine_loader.c

+++ b/apps/lib/engine_loader.c

@@ -71,7 +71,7 @@ static OSSL_STORE_LOADER_CTX *engine_open(const OSSL_STORE_LOADER *loader,

     char *keyid = NULL;

     OSSL_STORE_LOADER_CTX *ctx = NULL;

-    if (strncasecmp(p, ENGINE_SCHEME_COLON, sizeof(ENGINE_SCHEME_COLON) - 1)

+    if (OPENSSL_strncasecmp(p, ENGINE_SCHEME_COLON, sizeof(ENGINE_SCHEME_COLON) - 1)

         != 0)

         return NULL;

     p += sizeof(ENGINE_SCHEME_COLON) - 1;

diff --git a/apps/lib/http_server.c b/apps/lib/http_server.c

index 03faac7707b7..df9575e2cd21 100644

--- a/apps/lib/http_server.c

+++ b/apps/lib/http_server.c

@@ -453,10 +453,11 @@ int http_server_get_asn1_req(const ASN1_ITEM *it, ASN1_VALUE **preq,

         }

         *line_end = '\0';

         /* https://tools.ietf.org/html/rfc7230#section-6.3 Persistence */

-        if (found_keep_alive != NULL && strcasecmp(key, "Connection") == 0) {

-            if (strcasecmp(value, "keep-alive") == 0)

+        if (found_keep_alive != NULL

+            && OPENSSL_strcasecmp(key, "Connection") == 0) {

+            if (OPENSSL_strcasecmp(value, "keep-alive") == 0)

                 *found_keep_alive = 1;

-            else if (strcasecmp(value, "close") == 0)

+            else if (OPENSSL_strcasecmp(value, "close") == 0)

                 *found_keep_alive = 0;

         }

     }

diff --git a/apps/lib/names.c b/apps/lib/names.c

index 5e2e7e147c7f..462703c6462b 100644

--- a/apps/lib/names.c

+++ b/apps/lib/names.c

@@ -11,14 +11,11 @@

 #include <openssl/bio.h>

 #include <openssl/safestack.h>

 #include "names.h"

-

-#ifdef _WIN32

-# define strcasecmp _stricmp

-#endif

+#include "openssl/crypto.h"

 int name_cmp(const char * const *a, const char * const *b)

 {

-    return strcasecmp(*a, *b);

+    return OPENSSL_strcasecmp(*a, *b);

 }

 void collect_names(const char *name, void *vdata)

diff --git a/apps/lib/vms_term_sock.c b/apps/lib/vms_term_sock.c

index 1b27699b9d49..4d9a69b29e03 100644

--- a/apps/lib/vms_term_sock.c

+++ b/apps/lib/vms_term_sock.c

@@ -132,7 +132,7 @@ int main (int argc, char *argv[], char *envp[])

         len;

     LogMessage ("Enter 'q' or 'Q' to quit ...");

-    while (strcasecmp (TermBuff, "Q")) {

+    while (OPENSSL_strcasecmp (TermBuff, "Q")) {

         /*

         ** Create the terminal socket

         */

diff --git a/apps/list.c b/apps/list.c

index 9732d6625a05..620ce0083134 100644

--- a/apps/list.c

+++ b/apps/list.c

@@ -71,7 +71,7 @@ static void legacy_cipher_fn(const EVP_CIPHER *c,

 {

     if (select_name != NULL

         && (c == NULL

-            || strcasecmp(select_name,  EVP_CIPHER_get0_name(c)) != 0))

+            || OPENSSL_strcasecmp(select_name,  EVP_CIPHER_get0_name(c)) != 0))

         return;

     if (c != NULL) {

         BIO_printf(arg, "  %s\n", EVP_CIPHER_get0_name(c));

@@ -370,7 +370,7 @@ DEFINE_STACK_OF(EVP_RAND)

 static int rand_cmp(const EVP_RAND * const *a, const EVP_RAND * const *b)

 {

-    int ret = strcasecmp(EVP_RAND_get0_name(*a), EVP_RAND_get0_name(*b));

+    int ret = OPENSSL_strcasecmp(EVP_RAND_get0_name(*a), EVP_RAND_get0_name(*b));

     if (ret == 0)

         ret = strcmp(OSSL_PROVIDER_get0_name(EVP_RAND_get0_provider(*a)),

@@ -404,7 +404,7 @@ static void list_random_generators(void)

         const EVP_RAND *m = sk_EVP_RAND_value(rands, i);

         if (select_name != NULL

-            && strcasecmp(EVP_RAND_get0_name(m), select_name) != 0)

+            && OPENSSL_strcasecmp(EVP_RAND_get0_name(m), select_name) != 0)

             continue;

         BIO_printf(bio_out, "  %s", EVP_RAND_get0_name(m));

         BIO_printf(bio_out, " @ %s\n",

@@ -463,7 +463,7 @@ static void display_random(const char *name, EVP_RAND_CTX *drbg)

         if (gettables != NULL)

             for (; gettables->key != NULL; gettables++) {

                 /* State has been dealt with already, so ignore */

-                if (strcasecmp(gettables->key, OSSL_RAND_PARAM_STATE) == 0)

+                if (OPENSSL_strcasecmp(gettables->key, OSSL_RAND_PARAM_STATE) == 0)

                     continue;

                 /* Outside of verbose mode, we skip non-string values */

                 if (gettables->data_type != OSSL_PARAM_UTF8_STRING

diff --git a/apps/rehash.c b/apps/rehash.c

index fb6c08c420ca..e4a4e14fd497 100644

--- a/apps/rehash.c

+++ b/apps/rehash.c

@@ -214,7 +214,7 @@ static int handle_symlink(const char *filename, const char *fullpath)

         return -1;

     for (type = OSSL_NELEM(suffixes) - 1; type > 0; type--) {

         const char *suffix = suffixes[type];

-        if (strncasecmp(suffix, &filename[i], strlen(suffix)) == 0)

+        if (OPENSSL_strncasecmp(suffix, &filename[i], strlen(suffix)) == 0)

             break;

     }

     i += strlen(suffixes[type]);

@@ -249,7 +249,7 @@ static int do_file(const char *filename, const char *fullpath, enum Hash h)

     if ((ext = strrchr(filename, '.')) == NULL)

         goto end;

     for (i = 0; i < OSSL_NELEM(extensions); i++) {

-        if (strcasecmp(extensions[i], ext + 1) == 0)

+        if (OPENSSL_strcasecmp(extensions[i], ext + 1) == 0)

             break;

     }

     if (i >= OSSL_NELEM(extensions))

diff --git a/apps/s_server.c b/apps/s_server.c

index ccaec3124bf4..e93cfa1e2c7a 100644

--- a/apps/s_server.c

+++ b/apps/s_server.c

@@ -432,7 +432,7 @@ static int ssl_servername_cb(SSL *s, int *ad, void *arg)

         return SSL_TLSEXT_ERR_NOACK;

     if (servername != NULL) {

-        if (strcasecmp(servername, p->servername))

+        if (OPENSSL_strcasecmp(servername, p->servername))

             return p->extension_error;

         if (ctx2 != NULL) {

             BIO_printf(p->biodebug, "Switching server context.\n");

diff --git a/crypto/LPdir_unix.c b/crypto/LPdir_unix.c

index ddf68b576f88..fe9fc0dd43ba 100644

--- a/crypto/LPdir_unix.c

+++ b/crypto/LPdir_unix.c

@@ -141,7 +141,8 @@ const char *LP_find_file(LP_DIR_CTX **ctx, const char *directory)

             p--;

         if (p > (*ctx)->entry_name && p[-1] == ';')

             p[-1] = '\0';

-        if (strcasecmp((*ctx)->entry_name, (*ctx)->previous_entry_name) == 0)

+        if (OPENSSL_strcasecmp((*ctx)->entry_name,

+                               (*ctx)->previous_entry_name) == 0)

             goto again;

     }

 #endif

diff --git a/crypto/asn1/ameth_lib.c b/crypto/asn1/ameth_lib.c

index 031a6c936ad1..0de5785c2745 100644

--- a/crypto/asn1/ameth_lib.c

+++ b/crypto/asn1/ameth_lib.c

@@ -10,7 +10,6 @@

 /* We need to use some engine deprecated APIs */

 #define OPENSSL_SUPPRESS_DEPRECATED

-#include "e_os.h"               /* for strncasecmp */

 #include "internal/cryptlib.h"

 #include <stdio.h>

 #include <openssl/asn1t.h>

@@ -134,7 +133,7 @@ const EVP_PKEY_ASN1_METHOD *EVP_PKEY_asn1_find_str(ENGINE **pe,

         if (ameth->pkey_flags & ASN1_PKEY_ALIAS)

             continue;

         if ((int)strlen(ameth->pem_str) == len

-            && strncasecmp(ameth->pem_str, str, len) == 0)

+            && OPENSSL_strncasecmp(ameth->pem_str, str, len) == 0)

             return ameth;

     }

     return NULL;

diff --git a/crypto/asn1/asn1_gen.c b/crypto/asn1/asn1_gen.c

index ecff2be02e1f..59d42daf4a1c 100644

--- a/crypto/asn1/asn1_gen.c

+++ b/crypto/asn1/asn1_gen.c

@@ -10,7 +10,6 @@

 #include "internal/cryptlib.h"

 #include <openssl/asn1.h>

 #include <openssl/x509v3.h>

-#include "e_os.h" /* strncasecmp() */

 #define ASN1_GEN_FLAG           0x10000

 #define ASN1_GEN_FLAG_IMP       (ASN1_GEN_FLAG|1)

@@ -565,7 +564,8 @@ static int asn1_str2tag(const char *tagstr, int len)

     tntmp = tnst;

     for (i = 0; i < OSSL_NELEM(tnst); i++, tntmp++) {

-        if ((len == tntmp->len) && (strncasecmp(tntmp->strnam, tagstr, len) == 0))

+        if ((len == tntmp->len)

+            && (OPENSSL_strncasecmp(tntmp->strnam, tagstr, len) == 0))

             return tntmp->tag;

     }

diff --git a/crypto/conf/conf_def.c b/crypto/conf/conf_def.c

index c05c3c6b109d..6fe8427dc5e6 100644

--- a/crypto/conf/conf_def.c

+++ b/crypto/conf/conf_def.c

@@ -11,7 +11,7 @@

 #include <stdio.h>

 #include <string.h>

-#include "e_os.h" /* strcasecmp and struct stat */

+#include "e_os.h" /* struct stat */

 #ifdef __TANDEM

 # include <sys/types.h> /* needed for stat.h */

 # include <sys/stat.h> /* struct stat */

@@ -192,11 +192,11 @@ static int def_load(CONF *conf, const char *name, long *line)

 /* Parse a boolean value and fill in *flag. Return 0 on error. */

 static int parsebool(const char *pval, int *flag)

 {

-    if (strcasecmp(pval, "on") == 0

-            || strcasecmp(pval, "true") == 0) {

+    if (OPENSSL_strcasecmp(pval, "on") == 0

+            || OPENSSL_strcasecmp(pval, "true") == 0) {

         *flag = 1;

-    } else if (strcasecmp(pval, "off") == 0

-            || strcasecmp(pval, "false") == 0) {

+    } else if (OPENSSL_strcasecmp(pval, "off") == 0

+            || OPENSSL_strcasecmp(pval, "false") == 0) {

         *flag = 0;

     } else {

         ERR_raise(ERR_LIB_CONF, CONF_R_INVALID_PRAGMA);

@@ -839,8 +839,10 @@ static BIO *get_next_file(const char *path, OPENSSL_DIR_CTX **dirctx)

         namelen = strlen(filename);

-        if ((namelen > 5 && strcasecmp(filename + namelen - 5, ".conf") == 0)

-            || (namelen > 4 && strcasecmp(filename + namelen - 4, ".cnf") == 0)) {

+        if ((namelen > 5

+             && OPENSSL_strcasecmp(filename + namelen - 5, ".conf") == 0)

+             || (namelen > 4

+                 && OPENSSL_strcasecmp(filename + namelen - 4, ".cnf") == 0)) {

             size_t newlen;

             char *newpath;

             BIO *bio;

diff --git a/crypto/context.c b/crypto/context.c

index 3333af4c534e..4fef24cadd5a 100644

--- a/crypto/context.c

+++ b/crypto/context.c

@@ -14,6 +14,7 @@

 #include "internal/core.h"

 #include "internal/bio.h"

 #include "internal/provider.h"

+#include "crypto/ctype.h"

 # include <sys/types.h>

 # include <sys/stat.h>

@@ -150,7 +151,8 @@ static CRYPTO_THREAD_LOCAL default_context_thread_local;

 {

 	 read_kernel_fips_flag();

     return CRYPTO_THREAD_init_local(&default_context_thread_local, NULL)

-        && context_init(&default_context_int);

+        && context_init(&default_context_int)

+        && ossl_init_casecmp();

 }

 void ossl_lib_ctx_default_deinit(void)

diff --git a/crypto/core_namemap.c b/crypto/core_namemap.c

index 55248affc663..7e11ab1c8845 100644

--- a/crypto/core_namemap.c

+++ b/crypto/core_namemap.c

@@ -7,7 +7,6 @@

  * https://www.openssl.org/source/license.html

  */

-#include "e_os.h"                /* strcasecmp */

 #include "internal/namemap.h"

 #include <openssl/lhash.h>

 #include "crypto/lhash.h"      /* ossl_lh_strcasehash */

@@ -49,7 +48,7 @@ static unsigned long namenum_hash(const NAMENUM_ENTRY *n)

 static int namenum_cmp(const NAMENUM_ENTRY *a, const NAMENUM_ENTRY *b)

 {

-    return strcasecmp(a->name, b->name);

+    return OPENSSL_strcasecmp(a->name, b->name);

 }

 static void namenum_free(NAMENUM_ENTRY *n)

diff --git a/crypto/ctype.c b/crypto/ctype.c

index 83c24a546f53..321306eb5f50 100644

--- a/crypto/ctype.c

+++ b/crypto/ctype.c

@@ -12,6 +12,19 @@

 #include "crypto/ctype.h"

 #include <openssl/ebcdic.h>

+#include <openssl/crypto.h>

+#include "internal/core.h"

+#include "internal/thread_once.h"

+

+#ifndef OPENSSL_SYS_WINDOWS

+#include <strings.h>

+#endif

+#include <locale.h>

+

+#ifdef OPENSSL_SYS_MACOSX

+#include <xlocale.h>

+#endif

+

 /*

  * Define the character classes for each character in the seven bit ASCII

  * character set.  This is independent of the host's character set, characters

@@ -278,3 +291,90 @@ int ossl_ascii_isdigit(const char inchar) {

         return 1;

     return 0;

 }

+

+/* str[n]casecmp_l is defined in POSIX 2008-01. Value is taken accordingly

+ * https://www.gnu.org/software/libc/manual/html_node/Feature-Test-Macros.html */

+

+#if (defined OPENSSL_SYS_WINDOWS) || (defined(_POSIX_C_SOURCE) && _POSIX_C_SOURCE >= 200809L)

+

+# if defined OPENSSL_SYS_WINDOWS

+# define locale_t _locale_t

+# define freelocale _free_locale

+# define strcasecmp_l _stricmp_l

+# define strncasecmp_l _strnicmp_l

+# endif

+

+# ifndef FIPS_MODULE

+static locale_t loc;

+

+static int locale_base_inited = 0;

+static CRYPTO_ONCE locale_base = CRYPTO_ONCE_STATIC_INIT;

+static CRYPTO_ONCE locale_base_deinit = CRYPTO_ONCE_STATIC_INIT;

+

+void *ossl_c_locale() {

+    return (void *)loc;

+}

+

+DEFINE_RUN_ONCE_STATIC(ossl_init_locale_base)

+{

+# ifdef OPENSSL_SYS_WINDOWS

+    loc = _create_locale(LC_COLLATE, "C");

+# else

+    loc = newlocale(LC_COLLATE_MASK, "C", (locale_t) 0);

+# endif

+    locale_base_inited = 1;

+    return (loc == (locale_t) 0) ? 0 : 1;

+}

+

+DEFINE_RUN_ONCE_STATIC(ossl_deinit_locale_base)

+{

+    if (locale_base_inited && loc) {

+        freelocale(loc);

+        loc = NULL;

+    }

+    return 1;

+}

+

+int ossl_init_casecmp()

+{

+   return RUN_ONCE(&locale_base, ossl_init_locale_base);

+}

+

+void ossl_deinit_casecmp() {

+    (void)RUN_ONCE(&locale_base_deinit, ossl_deinit_locale_base);

+}

+# endif

+

+int OPENSSL_strcasecmp(const char *s1, const char *s2)

+{

+    return strcasecmp_l(s1, s2, (locale_t)ossl_c_locale());

+}

+

+int OPENSSL_strncasecmp(const char *s1, const char *s2, size_t n)

+{

+    return strncasecmp_l(s1, s2, n, (locale_t)ossl_c_locale());

+}

+#else

+# ifndef FIPS_MODULE

+void *ossl_c_locale() {

+    return NULL;

+}

+# endif

+

+int ossl_init_casecmp() {

+    return 1;

+}

+

+void ossl_deinit_casecmp() {

+}

+

+int OPENSSL_strcasecmp(const char *s1, const char *s2)

+{

+    return strcasecmp(s1, s2);

+}

+

+int OPENSSL_strncasecmp(const char *s1, const char *s2, size_t n)

+{

+    return strncasecmp(s1, s2, n);

+}

+#endif

diff --git a/crypto/dh/dh_group_params.c b/crypto/dh/dh_group_params.c

index c71f4053da6c..7608cbae5a28 100644

--- a/crypto/dh/dh_group_params.c

+++ b/crypto/dh/dh_group_params.c

@@ -23,7 +23,6 @@

 #include <openssl/objects.h>

 #include "internal/nelem.h"

 #include "crypto/dh.h"

-#include "e_os.h" /* strcasecmp */

 static DH *dh_param_init(OSSL_LIB_CTX *libctx, const DH_NAMED_GROUP *group)

 {

diff --git a/crypto/ec/ec_backend.c b/crypto/ec/ec_backend.c

index 381da71f33a8..0d84a3332296 100644

--- a/crypto/ec/ec_backend.c

+++ b/crypto/ec/ec_backend.c

@@ -54,7 +54,7 @@ int ossl_ec_encoding_name2id(const char *name)

         return OPENSSL_EC_NAMED_CURVE;

     for (i = 0, sz = OSSL_NELEM(encoding_nameid_map); i < sz; i++) {

-        if (strcasecmp(name, encoding_nameid_map[i].ptr) == 0)

+        if (OPENSSL_strcasecmp(name, encoding_nameid_map[i].ptr) == 0)

             return encoding_nameid_map[i].id;

     }

     return -1;

@@ -91,7 +91,7 @@ static int ec_check_group_type_name2id(const char *name)

         return 0;

     for (i = 0, sz = OSSL_NELEM(check_group_type_nameid_map); i < sz; i++) {

-        if (strcasecmp(name, check_group_type_nameid_map[i].ptr) == 0)

+        if (OPENSSL_strcasecmp(name, check_group_type_nameid_map[i].ptr) == 0)

             return check_group_type_nameid_map[i].id;

     }

     return -1;

@@ -136,7 +136,7 @@ int ossl_ec_pt_format_name2id(const char *name)

         return (int)POINT_CONVERSION_UNCOMPRESSED;

     for (i = 0, sz = OSSL_NELEM(format_nameid_map); i < sz; i++) {

-        if (strcasecmp(name, format_nameid_map[i].ptr) == 0)

+        if (OPENSSL_strcasecmp(name, format_nameid_map[i].ptr) == 0)

             return format_nameid_map[i].id;

     }

     return -1;

diff --git a/crypto/ec/ec_lib.c b/crypto/ec/ec_lib.c

index 2ee8284eaff3..ecd53fee008a 100644

--- a/crypto/ec/ec_lib.c

+++ b/crypto/ec/ec_lib.c

@@ -22,7 +22,6 @@

 #include "crypto/ec.h"

 #include "internal/nelem.h"

 #include "ec_local.h"

-#include "e_os.h" /* strcasecmp */

 /* functions for EC_GROUP objects */

@@ -1581,9 +1580,10 @@ EC_GROUP *EC_GROUP_new_from_params(const OSSL_PARAM params[],

         ERR_raise(ERR_LIB_EC, EC_R_INVALID_FIELD);

         goto err;

     }

-    if (strcasecmp(ptmp->data, SN_X9_62_prime_field) == 0) {

+    if (OPENSSL_strcasecmp(ptmp->data, SN_X9_62_prime_field) == 0) {

         is_prime_field = 1;

-    } else if (strcasecmp(ptmp->data, SN_X9_62_characteristic_two_field) == 0) {

+    } else if (OPENSSL_strcasecmp(ptmp->data,

+                                  SN_X9_62_characteristic_two_field) == 0) {

         is_prime_field = 0;

     } else {

         /* Invalid field */

diff --git a/crypto/encode_decode/decoder_lib.c b/crypto/encode_decode/decoder_lib.c

index 10a38b6f82a7..de6d3def3101 100644

--- a/crypto/encode_decode/decoder_lib.c

+++ b/crypto/encode_decode/decoder_lib.c

@@ -789,7 +789,7 @@ static int decoder_process(const OSSL_PARAM params[], void *arg)

          */

         trace_data_structure = data_structure;

         if (data_type != NULL && data_structure != NULL

-            && strcasecmp(data_structure, "type-specific") == 0)

+            && OPENSSL_strcasecmp(data_structure, "type-specific") == 0)

             data_structure = NULL;

         OSSL_TRACE_BEGIN(DECODER) {

@@ -850,7 +850,7 @@ static int decoder_process(const OSSL_PARAM params[], void *arg)

          * that's the case, we do this extra check.

          */

         if (decoder == NULL && ctx->start_input_type != NULL

-            && strcasecmp(ctx->start_input_type, new_input_type) != 0) {

+            && OPENSSL_strcasecmp(ctx->start_input_type, new_input_type) != 0) {

             OSSL_TRACE_BEGIN(DECODER) {

                 BIO_printf(trc_out,

                            "(ctx %p) %s [%u] the start input type '%s' doesn't match the input type of the considered decoder, skipping...\n",

@@ -896,7 +896,8 @@ static int decoder_process(const OSSL_PARAM params[], void *arg)

          */

         if (data_structure != NULL

             && (new_input_structure == NULL

-                || strcasecmp(data_structure, new_input_structure) != 0)) {

+                || OPENSSL_strcasecmp(data_structure,

+                                      new_input_structure) != 0)) {

             OSSL_TRACE_BEGIN(DECODER) {

                 BIO_printf(trc_out,

                            "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure of the considered decoder, skipping...\n",

@@ -915,7 +916,8 @@ static int decoder_process(const OSSL_PARAM params[], void *arg)

             && ctx->input_structure != NULL

             && new_input_structure != NULL) {

             data->flag_input_structure_checked = 1;

-            if (strcasecmp(new_input_structure, ctx->input_structure) != 0) {

+            if (OPENSSL_strcasecmp(new_input_structure,

+                                   ctx->input_structure) != 0) {

                 OSSL_TRACE_BEGIN(DECODER) {

                     BIO_printf(trc_out,

                                "(ctx %p) %s [%u] the previous decoder's data structure doesn't match the input structure given by the user, skipping...\n",

diff --git a/crypto/encode_decode/decoder_pkey.c b/crypto/encode_decode/decoder_pkey.c

index 475117a463af..833061d873ed 100644

--- a/crypto/encode_decode/decoder_pkey.c

+++ b/crypto/encode_decode/decoder_pkey.c

@@ -18,7 +18,6 @@

 #include "crypto/evp.h"

 #include "crypto/decoder.h"

 #include "encoder_local.h"

-#include "e_os.h"                /* strcasecmp on Windows */

 int OSSL_DECODER_CTX_set_passphrase(OSSL_DECODER_CTX *ctx,

                                     const unsigned char *kstr,

diff --git a/crypto/encode_decode/encoder_lib.c b/crypto/encode_decode/encoder_lib.c

index cfd9275172f5..2a83af825c2d 100644

--- a/crypto/encode_decode/encoder_lib.c

+++ b/crypto/encode_decode/encoder_lib.c

@@ -7,7 +7,6 @@

  * https://www.openssl.org/source/license.html

  */

-#include "e_os.h"                /* strcasecmp on Windows */

 #include <openssl/core_names.h>

 #include <openssl/bio.h>

 #include <openssl/encoder.h>

@@ -453,8 +452,8 @@ static int encoder_process(struct encoder_process_data_st *data)

          */

         if (top) {

             if (data->ctx->output_type != NULL

-                && strcasecmp(current_output_type,

-                              data->ctx->output_type) != 0) {

+                && OPENSSL_strcasecmp(current_output_type,

+                                      data->ctx->output_type) != 0) {

                 OSSL_TRACE_BEGIN(ENCODER) {

                     BIO_printf(trc_out,

                                "[%d]    Skipping because current encoder output type (%s) != desired output type (%s)\n",

@@ -482,8 +481,8 @@ static int encoder_process(struct encoder_process_data_st *data)

          */

         if (data->ctx->output_structure != NULL

             && current_output_structure != NULL) {

-            if (strcasecmp(data->ctx->output_structure,

-                           current_output_structure) != 0) {

+            if (OPENSSL_strcasecmp(data->ctx->output_structure,

+                                   current_output_structure) != 0) {

                 OSSL_TRACE_BEGIN(ENCODER) {

                     BIO_printf(trc_out,

                                "[%d]    Skipping because current encoder output structure (%s) != ctx output structure (%s)\n",

diff --git a/crypto/encode_decode/encoder_pkey.c b/crypto/encode_decode/encoder_pkey.c

index c37edf966d7e..3a24317cf4d6 100644

--- a/crypto/encode_decode/encoder_pkey.c

+++ b/crypto/encode_decode/encoder_pkey.c

@@ -7,7 +7,6 @@

  * https://www.openssl.org/source/license.html

  */

-#include "e_os.h"                /* strcasecmp on Windows */

 #include <openssl/err.h>

 #include <openssl/ui.h>

 #include <openssl/params.h>

diff --git a/crypto/engine/tb_asnmth.c b/crypto/engine/tb_asnmth.c

index e3a5c82e9957..09d0ed9d3aae 100644

--- a/crypto/engine/tb_asnmth.c

+++ b/crypto/engine/tb_asnmth.c

@@ -152,7 +152,7 @@ const EVP_PKEY_ASN1_METHOD *ENGINE_get_pkey_asn1_meth_str(ENGINE *e,

         e->pkey_asn1_meths(e, &ameth, NULL, nids[i]);

         if (ameth != NULL

             && ((int)strlen(ameth->pem_str) == len)

-            && strncasecmp(ameth->pem_str, str, len) == 0)

+            && OPENSSL_strncasecmp(ameth->pem_str, str, len) == 0)

             return ameth;

     }

     return NULL;

@@ -177,7 +177,7 @@ static void look_str_cb(int nid, STACK_OF(ENGINE) *sk, ENGINE *def, void *arg)

         e->pkey_asn1_meths(e, &ameth, NULL, nid);

         if (ameth != NULL

                 && ((int)strlen(ameth->pem_str) == lk->len)

-                && strncasecmp(ameth->pem_str, lk->str, lk->len) == 0) {

+                && OPENSSL_strncasecmp(ameth->pem_str, lk->str, lk->len) == 0) {

             lk->e = e;

             lk->ameth = ameth;

             return;

diff --git a/crypto/evp/ctrl_params_translate.c b/crypto/evp/ctrl_params_translate.c

index 961ca116b32f..0aa1c23beec7 100644

--- a/crypto/evp/ctrl_params_translate.c

+++ b/crypto/evp/ctrl_params_translate.c

@@ -37,8 +37,6 @@

 #include "crypto/dh.h"

 #include "crypto/ec.h"

-#include "e_os.h"                /* strcasecmp() for Windows */

-

 struct translation_ctx_st;       /* Forwarding */

 struct translation_st;           /* Forwarding */

@@ -905,7 +903,7 @@ static int fix_kdf_type(enum state state,

         /* Convert KDF type strings to numbers */

         for (; kdf_type_map->kdf_type_str != NULL; kdf_type_map++)

-            if (strcasecmp(ctx->p2, kdf_type_map->kdf_type_str) == 0) {

+            if (OPENSSL_strcasecmp(ctx->p2, kdf_type_map->kdf_type_str) == 0) {

                 ctx->p1 = kdf_type_map->kdf_type_num;

                 ret = 1;

                 break;

@@ -2469,10 +2467,11 @@ lookup_translation(struct translation_st *tmpl,

              * cmd name in the template.

              */

             if (item->ctrl_str != NULL

-                && strcasecmp(tmpl->ctrl_str, item->ctrl_str) == 0)

+                && OPENSSL_strcasecmp(tmpl->ctrl_str, item->ctrl_str) == 0)

                 ctrl_str = tmpl->ctrl_str;

             else if (item->ctrl_hexstr != NULL

-                     && strcasecmp(tmpl->ctrl_hexstr, item->ctrl_hexstr) == 0)

+                     && OPENSSL_strcasecmp(tmpl->ctrl_hexstr,

+                                           item->ctrl_hexstr) == 0)