Add and use HAS_PREFIX() and CHECK_AND_SKIP_PREFIX() for checking if string has literal prefix

Reviewed-by: Paul Dale <pauli@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/15847)

8 files changed, 59 insertions, 74 deletions

diff --git a/apps/fipsinstall.c b/apps/fipsinstall.c
index d0efdf7643..8152f3956b 100644
--- a/apps/fipsinstall.c
+++ b/apps/fipsinstall.c
@@ -7,7 +7,7 @@
  * https://www.openssl.org/source/license.html
  */
 
-#include <string.h>
+#include "internal/cryptlib.h"
 #include <openssl/evp.h>
 #include <openssl/err.h>
 #include <openssl/provider.h>
@@ -368,9 +368,9 @@ opthelp:
         case OPT_MACOPT:
             if (!sk_OPENSSL_STRING_push(opts, opt_arg()))
                 goto opthelp;
-            if (strncmp(opt_arg(), "hexkey:", 7) == 0)
+            if (HAS_PREFIX(opt_arg(), "hexkey:"))
                 gotkey = 1;
-            else if (strncmp(opt_arg(), "digest:", 7) == 0)
+            else if (HAS_PREFIX(opt_arg(), "digest:"))
                 gotdigest = 1;
             break;
         case OPT_VERIFY:
diff --git a/apps/include/apps.h b/apps/include/apps.h
index 6018a83ca4..7d9b64a3c6 100644
--- a/apps/include/apps.h
+++ b/apps/include/apps.h
@@ -11,6 +11,7 @@
 # define OSSL_APPS_H
 
 # include "e_os.h" /* struct timeval for DTLS */
+# include "internal/cryptlib.h" /* for HAS_PREFIX */
 # include "internal/nelem.h"
 # include "internal/sockets.h" /* for openssl_fdset() */
 # include <assert.h>
diff --git a/apps/lib/apps.c b/apps/lib/apps.c
index 82eeaea249..2c4c292b94 100644
--- a/apps/lib/apps.c
+++ b/apps/lib/apps.c
@@ -260,21 +260,21 @@ static char *app_get_pass(const char *arg, int keepbio)
     int i;
 
     /* PASS_SOURCE_SIZE_MAX = max number of chars before ':' in below strings */
-    if (strncmp(arg, "pass:", 5) == 0)
-        return OPENSSL_strdup(arg + 5);
-    if (strncmp(arg, "env:", 4) == 0) {
-        tmp = getenv(arg + 4);
+    if (CHECK_AND_SKIP_PREFIX(arg, "pass:"))
+        return OPENSSL_strdup(arg);
+    if (CHECK_AND_SKIP_PREFIX(arg, "env:")) {
+        tmp = getenv(arg);
         if (tmp == NULL) {
-            BIO_printf(bio_err, "No environment variable %s\n", arg + 4);
+            BIO_printf(bio_err, "No environment variable %s\n", arg);
             return NULL;
         }
         return OPENSSL_strdup(tmp);
     }
     if (!keepbio || pwdbio == NULL) {
-        if (strncmp(arg, "file:", 5) == 0) {
-            pwdbio = BIO_new_file(arg + 5, "r");
+        if (CHECK_AND_SKIP_PREFIX(arg, "file:")) {
+            pwdbio = BIO_new_file(arg, "r");
             if (pwdbio == NULL) {
-                BIO_printf(bio_err, "Can't open file %s\n", arg + 5);
+                BIO_printf(bio_err, "Can't open file %s\n", arg);
                 return NULL;
             }
 #if !defined(_WIN32)
@@ -286,13 +286,13 @@ static char *app_get_pass(const char *arg, int keepbio)
              * on real Windows descriptors, such as those obtained
              * with CreateFile.
              */
-        } else if (strncmp(arg, "fd:", 3) == 0) {
+        } else if (CHECK_AND_SKIP_PREFIX(arg, "fd:")) {
             BIO *btmp;
-            i = atoi(arg + 3);
+            i = atoi(arg);
             if (i >= 0)
                 pwdbio = BIO_new_fd(i, BIO_NOCLOSE);
             if ((i < 0) || !pwdbio) {
-                BIO_printf(bio_err, "Can't access file descriptor %s\n", arg + 3);
+                BIO_printf(bio_err, "Can't access file descriptor %s\n", arg);
                 return NULL;
             }
             /*
@@ -450,10 +450,8 @@ CONF *app_load_config_modules(const char *configfile)
     return conf;
 }
 
-#define IS_HTTP(uri) ((uri) != NULL \
-        && strncmp(uri, OSSL_HTTP_PREFIX, strlen(OSSL_HTTP_PREFIX)) == 0)
-#define IS_HTTPS(uri) ((uri) != NULL \
-        && strncmp(uri, OSSL_HTTPS_PREFIX, strlen(OSSL_HTTPS_PREFIX)) == 0)
+#define IS_HTTP(uri) ((uri) != NULL  && HAS_PREFIX(uri, OSSL_HTTP_PREFIX))
+#define IS_HTTPS(uri) ((uri) != NULL && HAS_PREFIX(uri, OSSL_HTTPS_PREFIX))
 
 X509 *load_cert_pass(const char *uri, int format, int maybe_stdin,
                      const char *pass, const char *desc)
diff --git a/apps/lib/http_server.c b/apps/lib/http_server.c
index 03faac7707..8f654660b4 100644
--- a/apps/lib/http_server.c
+++ b/apps/lib/http_server.c
@@ -17,7 +17,6 @@
 # define _POSIX_C_SOURCE 2
 #endif
 
-#include <string.h>
 #include <ctype.h>
 #include "http_server.h"
 #include "internal/sockets.h"
@@ -37,6 +36,7 @@ static int verbosity = LOG_INFO;
 #define HTTP_VERSION_PATT "1." /* allow 1.x */
 #define HTTP_PREFIX_VERSION HTTP_PREFIX""HTTP_VERSION_PATT
 #define HTTP_1_0 HTTP_PREFIX_VERSION"0" /* "HTTP/1.0" */
+#define HTTP_VERSION_STR " "HTTP_PREFIX_VERSION
 
 #ifdef HTTP_DAEMON
 
@@ -336,15 +336,12 @@ int http_server_get_asn1_req(const ASN1_ITEM *it, ASN1_VALUE **preq,
         *end = '\0';
     log_message(prog, LOG_INFO, "Received request, 1st line: %s", reqbuf);
 
-    meth = reqbuf;
-    url = meth + 3;
-    if ((accept_get && strncmp(meth, "GET ", 4) == 0)
-            || (url++, strncmp(meth, "POST ", 5) == 0)) {
-        static const char http_version_str[] = " "HTTP_PREFIX_VERSION;
-        static const size_t http_version_str_len = sizeof(http_version_str) - 1;
+    url = meth = reqbuf;
+    if ((accept_get && CHECK_AND_SKIP_PREFIX(url, "GET "))
+            || CHECK_AND_SKIP_PREFIX(url, "POST ")) {
 
         /* Expecting (GET|POST) {sp} /URL {sp} HTTP/1.x */
-        *(url++) = '\0';
+        url[-1] = '\0';
         while (*url == ' ')
             url++;
         if (*url != '/') {
@@ -360,7 +357,7 @@ int http_server_get_asn1_req(const ASN1_ITEM *it, ASN1_VALUE **preq,
         for (end = url; *end != '\0'; end++)
             if (*end == ' ')
                 break;
-        if (strncmp(end, http_version_str, http_version_str_len) != 0) {
+        if (!HAS_PREFIX(end, HTTP_VERSION_STR)) {
             log_message(prog, LOG_WARNING,
                         "Invalid %s -- bad HTTP/version string: %s",
                         meth, end + 1);
@@ -370,7 +367,7 @@ int http_server_get_asn1_req(const ASN1_ITEM *it, ASN1_VALUE **preq,
         *end = '\0';
         /* above HTTP 1.0, connection persistence is the default */
         if (found_keep_alive != NULL)
-            *found_keep_alive = end[http_version_str_len] > '0';
+            *found_keep_alive = end[sizeof(HTTP_VERSION_STR) - 1] > '0';
 
         /*-
          * Skip "GET / HTTP..." requests often used by load-balancers.
diff --git a/apps/openssl.c b/apps/openssl.c
index e20661277e..f347d64417 100644
--- a/apps/openssl.c
+++ b/apps/openssl.c
@@ -8,8 +8,8 @@
  */
 
 #include <stdio.h>
-#include <string.h>
 #include <stdlib.h>
+#include "internal/cryptlib.h"
 #include <openssl/bio.h>
 #include <openssl/crypto.h>
 #include <openssl/trace.h>
@@ -417,12 +417,12 @@ static int do_cmd(LHASH_OF(FUNCTION) *prog, int argc, char *argv[])
             warn_deprecated(fp);
         return fp->func(argc, argv);
     }
-    if ((strncmp(argv[0], "no-", 3)) == 0) {
+    f.name = argv[0];
+    if (CHECK_AND_SKIP_PREFIX(f.name, "no-")) {
         /*
          * User is asking if foo is unsupported, by trying to "run" the
          * no-foo command.  Strange.
          */
-        f.name = argv[0] + 3;
         if (lh_FUNCTION_retrieve(prog, &f) == NULL) {
             BIO_printf(bio_out, "%s\n", argv[0]);
             return 0;
diff --git a/apps/s_client.c b/apps/s_client.c
index 46cecb9a82..d40f7c948f 100644
--- a/apps/s_client.c
+++ b/apps/s_client.c
@@ -2530,7 +2530,7 @@ int s_client_main(int argc, char **argv)
                  */
                 if (mbuf_len > 1 && mbuf[0] == '"') {
                     make_uppercase(mbuf);
-                    if (strncmp(mbuf, "\"STARTTLS\"", 10) == 0)
+                    if (HAS_PREFIX(mbuf, "\"STARTTLS\""))
                         foundit = 1;
                 }
             } while (mbuf_len > 1 && mbuf[0] == '"');
@@ -2558,7 +2558,7 @@ int s_client_main(int argc, char **argv)
              */
             strncpy(sbuf, mbuf, 2);
             make_uppercase(sbuf);
-            if (strncmp(sbuf, "OK", 2) != 0) {
+            if (!HAS_PREFIX(sbuf, "OK")) {
                 BIO_printf(bio_err, "STARTTLS not supported: %s", mbuf);
                 goto shut;
             }
diff --git a/apps/s_server.c b/apps/s_server.c
index 27c7db80a7..13d59faf14 100644
--- a/apps/s_server.c
+++ b/apps/s_server.c
@@ -2985,7 +2985,7 @@ static void print_connection_info(SSL *con)
 
 static int www_body(int s, int stype, int prot, unsigned char *context)
 {
-    char *buf = NULL;
+    char *buf = NULL, *p;
     int ret = 1;
     int i, j, k, dot;
     SSL *con;
@@ -3001,7 +3001,7 @@ static int www_body(int s, int stype, int prot, unsigned char *context)
     /* Set width for a select call if needed */
     width = s + 1;
 
-    buf = app_malloc(bufsize, "server www buffer");
+    p = buf = app_malloc(bufsize, "server www buffer");
     io = BIO_new(BIO_f_buffer());
     ssl_bio = BIO_new(BIO_f_ssl());
     if ((io == NULL) || (ssl_bio == NULL))
@@ -3093,15 +3093,14 @@ static int www_body(int s, int stype, int prot, unsigned char *context)
         }
 
         /* else we have data */
-        if (((www == 1) && (strncmp("GET ", buf, 4) == 0)) ||
-            ((www == 2) && (strncmp("GET /stats ", buf, 11) == 0))) {
-            char *p;
+        if ((www == 1 && HAS_PREFIX(buf, "GET "))
+             || (www == 2 && HAS_PREFIX(buf, "GET /stats "))) {
             X509 *peer = NULL;
             STACK_OF(SSL_CIPHER) *sk;
             static const char *space = "                          ";
 
-            if (www == 1 && strncmp("GET /reneg", buf, 10) == 0) {
-                if (strncmp("GET /renegcert", buf, 14) == 0)
+            if (www == 1 && HAS_PREFIX(buf, "GET /reneg")) {
+                if (HAS_PREFIX(buf, "GET /renegcert"))
                     SSL_set_verify(con,
                                    SSL_VERIFY_PEER | SSL_VERIFY_CLIENT_ONCE,
                                    NULL);
@@ -3142,6 +3141,7 @@ static int www_body(int s, int stype, int prot, unsigned char *context)
             BIO_puts(io, "\n");
             for (i = 0; i < local_argc; i++) {
                 const char *myp;
+
                 for (myp = local_argv[i]; *myp; myp++)
                     switch (*myp) {
                     case '<':
@@ -3221,16 +3221,12 @@ static int www_body(int s, int stype, int prot, unsigned char *context)
             }
             BIO_puts(io, "</pre></BODY></HTML>\r\n\r\n");
             break;
-        } else if ((www == 2 || www == 3)
-                   && (strncmp("GET /", buf, 5) == 0)) {
+        } else if ((www == 2 || www == 3) && HAS_PREFIX(p, "GET /")) {
             BIO *file;
-            char *p, *e;
+            char *e;
             static const char *text =
                 "HTTP/1.0 200 ok\r\nContent-type: text/plain\r\n\r\n";
 
-            /* skip the '/' */
-            p = &(buf[5]);
-
             dot = 1;
             for (e = p; *e != '\0'; e++) {
                 if (e[0] == ' ')
@@ -3523,7 +3519,7 @@ static int rev_body(int s, int stype, int prot, unsigned char *context)
                 p--;
                 i--;
             }
-            if (!s_ign_eof && (i == 5) && (strncmp(buf, "CLOSE", 5) == 0)) {
+            if (!s_ign_eof && i == 5 && HAS_PREFIX(buf, "CLOSE")) {
                 ret = 1;
                 BIO_printf(bio_err, "CONNECTION CLOSED\n");
                 goto end;
diff --git a/apps/speed.c b/apps/speed.c
index ada559228d..0ee7347f5b 100644
--- a/apps/speed.c
+++ b/apps/speed.c
@@ -1638,8 +1638,8 @@ int speed_main(int argc, char **argv)
         if (strcmp(algo, "openssl") == 0) /* just for compatibility */
             continue;
 #endif
-        if (strncmp(algo, "rsa", 3) == 0) {
-            if (algo[3] == '\0') {
+        if (HAS_PREFIX(algo, "rsa")) {
+            if (algo[sizeof("rsa") - 1] == '\0') {
                 memset(rsa_doit, 1, sizeof(rsa_doit));
                 continue;
             }
@@ -1649,8 +1649,8 @@ int speed_main(int argc, char **argv)
             }
         }
 #ifndef OPENSSL_NO_DH
-        if (strncmp(algo, "ffdh", 4) == 0) {
-            if (algo[4] == '\0') {
+        if (HAS_PREFIX(algo, "ffdh")) {
+            if (algo[sizeof("ffdh") - 1] == '\0') {
                 memset(ffdh_doit, 1, sizeof(ffdh_doit));
                 continue;
             }
@@ -1660,8 +1660,8 @@ int speed_main(int argc, char **argv)
             }
         }
 #endif
-        if (strncmp(algo, "dsa", 3) == 0) {
-            if (algo[3] == '\0') {
+        if (HAS_PREFIX(algo, "dsa")) {
+            if (algo[sizeof("dsa") - 1] == '\0') {
                 memset(dsa_doit, 1, sizeof(dsa_doit));
                 continue;
             }
@@ -1678,8 +1678,8 @@ int speed_main(int argc, char **argv)
             doit[D_CBC_128_CML] = doit[D_CBC_192_CML] = doit[D_CBC_256_CML] = 1;
             continue;
         }
-        if (strncmp(algo, "ecdsa", 5) == 0) {
-            if (algo[5] == '\0') {
+        if (HAS_PREFIX(algo, "ecdsa")) {
+            if (algo[sizeof("ecdsa") - 1] == '\0') {
                 memset(ecdsa_doit, 1, sizeof(ecdsa_doit));
                 continue;
             }
@@ -1688,8 +1688,8 @@ int speed_main(int argc, char **argv)
                 continue;
             }
         }
-        if (strncmp(algo, "ecdh", 4) == 0) {
-            if (algo[4] == '\0') {
+        if (HAS_PREFIX(algo, "ecdh")) {
+            if (algo[sizeof("ecdh") - 1] == '\0') {
                 memset(ecdh_doit, 1, sizeof(ecdh_doit));
                 continue;
             }
@@ -3458,20 +3458,19 @@ static int do_multi(int multi, int size_num)
                 continue;
             }
             printf("Got: %s from %d\n", buf, n);
-            if (strncmp(buf, "+F:", 3) == 0) {
+            p = buf;
+            if (CHECK_AND_SKIP_PREFIX(p, "+F:")) {
                 int alg;
                 int j;
 
-                p = buf + 3;
                 alg = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
                 for (j = 0; j < size_num; ++j)
                     results[alg][j] += atof(sstrsep(&p, sep));
-            } else if (strncmp(buf, "+F2:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F2:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
 
@@ -3480,11 +3479,10 @@ static int do_multi(int multi, int size_num)
 
                 d = atof(sstrsep(&p, sep));
                 rsa_results[k][1] += d;
-            } else if (strncmp(buf, "+F3:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F3:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
 
@@ -3493,11 +3491,10 @@ static int do_multi(int multi, int size_num)
 
                 d = atof(sstrsep(&p, sep));
                 dsa_results[k][1] += d;
-            } else if (strncmp(buf, "+F4:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F4:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
 
@@ -3506,21 +3503,19 @@ static int do_multi(int multi, int size_num)
 
                 d = atof(sstrsep(&p, sep));
                 ecdsa_results[k][1] += d;
-            } else if (strncmp(buf, "+F5:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F5:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
 
                 d = atof(sstrsep(&p, sep));
                 ecdh_results[k][0] += d;
-            } else if (strncmp(buf, "+F6:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F6:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
                 sstrsep(&p, sep);
@@ -3531,11 +3526,10 @@ static int do_multi(int multi, int size_num)
                 d = atof(sstrsep(&p, sep));
                 eddsa_results[k][1] += d;
 # ifndef OPENSSL_NO_SM2
-            } else if (strncmp(buf, "+F7:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F7:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
                 sstrsep(&p, sep);
@@ -3547,18 +3541,17 @@ static int do_multi(int multi, int size_num)
                 sm2_results[k][1] += d;
 # endif /* OPENSSL_NO_SM2 */
 # ifndef OPENSSL_NO_DH
-            } else if (strncmp(buf, "+F8:", 4) == 0) {
+            } else if (CHECK_AND_SKIP_PREFIX(p, "+F8:")) {
                 int k;
                 double d;
 
-                p = buf + 4;
                 k = atoi(sstrsep(&p, sep));
                 sstrsep(&p, sep);
 
                 d = atof(sstrsep(&p, sep));
                 ffdh_results[k][0] += d;
 # endif /* OPENSSL_NO_DH */
-            } else if (strncmp(buf, "+H:", 3) == 0) {
+            } else if (HAS_PREFIX(buf, "+H:")) {
                 ;
             } else {
                 BIO_printf(bio_err, "Unknown type '%s' from child %d\n", buf,