[Backport 2.28] Fix incorrect dispatch to USAGE in example programs, which causes uninitialized memory to be used

ChangeLog.d/fix-example-programs-no-args.txt

@@ -0,0 +1,4 @@
+Bugfix
+   * Fix behavior of certain sample programs which could, when run with no
+     arguments, access uninitialized memory in some cases. Fixes #6700 (which
+     was found by TrustInSoft Analyzer during REDOCS'22) and #1120.

programs/hash/generic_sum.c

@@ -173,7 +173,7 @@ int main(int argc, char *argv[])
 
     mbedtls_md_init(&md_ctx);
 
-    if (argc == 1) {
+    if (argc < 2) {
         const int *list;
 
         mbedtls_printf("print mode:  generic_sum <mbedtls_md> <file> <file> ...\n");

programs/pkey/dh_genprime.c

@@ -75,7 +75,7 @@ int main(int argc, char **argv)
     mbedtls_ctr_drbg_init(&ctr_drbg);
     mbedtls_entropy_init(&entropy);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/pkey/gen_key.c

@@ -204,7 +204,7 @@ int main(int argc, char *argv[])
     mbedtls_ctr_drbg_init(&ctr_drbg);
     memset(buf, 0, sizeof(buf));
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
 #if defined(MBEDTLS_ECP_C)

programs/pkey/key_app.c

@@ -95,7 +95,7 @@ int main(int argc, char *argv[])
     mbedtls_mpi_init(&D); mbedtls_mpi_init(&E); mbedtls_mpi_init(&DP);
     mbedtls_mpi_init(&DQ); mbedtls_mpi_init(&QP);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto cleanup;

programs/pkey/key_app_writer.c

@@ -209,7 +209,7 @@ int main(int argc, char *argv[])
     mbedtls_mpi_init(&D); mbedtls_mpi_init(&E); mbedtls_mpi_init(&DP);
     mbedtls_mpi_init(&DQ); mbedtls_mpi_init(&QP);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/ssl/ssl_client2.c

@@ -767,7 +767,7 @@ int main(int argc, char *argv[])
     mbedtls_test_enable_insecure_external_rng();
 #endif  /* MBEDTLS_PSA_CRYPTO_EXTERNAL_RNG */
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         if (ret == 0) {
             ret = 1;

programs/ssl/ssl_mail_client.c

@@ -367,7 +367,7 @@ int main(int argc, char *argv[])
     mbedtls_pk_init(&pkey);
     mbedtls_ctr_drbg_init(&ctr_drbg);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
 

programs/ssl/ssl_server2.c

@@ -1449,7 +1449,7 @@ int main(int argc, char *argv[])
     signal(SIGINT, term_handler);
 #endif
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         if (ret == 0) {
             ret = 1;

programs/test/query_compile_time_config.c

@@ -38,7 +38,7 @@
 
 int main(int argc, char *argv[])
 {
-    if (argc != 2) {
+    if (argc < 2 || strcmp(argv[1], "-h") == 0) {
         mbedtls_printf(USAGE, argv[0]);
         return MBEDTLS_EXIT_FAILURE;
     }

programs/util/pem2der.c

@@ -193,7 +193,7 @@ int main(int argc, char *argv[])
     memset(buf, 0, sizeof(buf));
     memset(der_buffer, 0, sizeof(der_buffer));
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/x509/cert_app.c

@@ -165,7 +165,7 @@ int main(int argc, char *argv[])
     memset(&cacrl, 0, sizeof(mbedtls_x509_crl));
 #endif
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/x509/cert_req.c

@@ -163,7 +163,7 @@ int main(int argc, char *argv[])
     mbedtls_ctr_drbg_init(&ctr_drbg);
     memset(buf, 0, sizeof(buf));
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/x509/cert_write.c

@@ -241,7 +241,7 @@ int main(int argc, char *argv[])
     mbedtls_x509_crt_init(&issuer_crt);
     memset(buf, 0, 1024);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/x509/crl_app.c

@@ -72,7 +72,7 @@ int main(int argc, char *argv[])
      */
     mbedtls_x509_crl_init(&crl);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;

programs/x509/req_app.c

@@ -72,7 +72,7 @@ int main(int argc, char *argv[])
      */
     mbedtls_x509_csr_init(&csr);
 
-    if (argc == 0) {
+    if (argc < 2) {
 usage:
         mbedtls_printf(USAGE);
         goto exit;