[DRAFT] Add EVP_read_pw_string

crypto/CMakeLists.txt

@@ -452,6 +452,7 @@ add_library(
   pem/pem_info.c
   pem/pem_lib.c
   pem/pem_oth.c
+  pem/pem_passwd.c
   pem/pem_pk8.c
   pem/pem_pkey.c
   pem/pem_x509.c

crypto/fipsmodule/evp/evp.c

@@ -69,6 +69,7 @@
 #include <openssl/thread.h>
 
 #include "../../evp_extra/internal.h"
+#include "../../pem/internal.h"
 #include "../../internal.h"
 #include "internal.h"
 
@@ -156,6 +157,64 @@ int EVP_PKEY_cmp(const EVP_PKEY *a, const EVP_PKEY *b) {
   return -2;
 }
 
+static const char* prompt_string = "Enter PEM pass phrase:";
+
+char *EVP_get_pw_prompt(void) {
+    return (char*)prompt_string;
+}
+
+int EVP_read_pw_string(char *buf, int length, const char *prompt, int verify) {
+  return EVP_read_pw_string_min(buf, 0, length, prompt, verify);
+}
+
+int EVP_read_pw_string_min(char *buf, int min_length, int length,
+                           const char *prompt, int verify) {
+  int ret = -1;
+  char verify_buf[1024];
+
+  if (prompt == NULL) {
+    prompt = EVP_get_pw_prompt();
+  }
+
+  if (!openssl_console_open()) {
+    return ret;
+  }
+
+  // Write initial password prompt
+  if (!openssl_console_write(prompt)) {
+    return ret;
+  }
+
+  // Read password with echo disabled, returns 1 on success, 0 on error, -2 on interrupt
+  ret = openssl_console_read(buf, min_length, length, 0);
+  if (ret != 0) {
+    OPENSSL_cleanse(buf, sizeof(buf));
+    OPENSSL_PUT_ERROR(PEM, PEM_R_PROBLEMS_GETTING_PASSWORD);
+    return ret;
+  }
+
+  if (verify) {
+    openssl_console_write("Verifying - ");
+    openssl_console_write(prompt);
+
+    ret = openssl_console_read(verify_buf, min_length, sizeof(verify_buf), 0);
+
+    if (ret == 0) {
+      if (strcmp(buf, verify_buf) != 0) {
+        openssl_console_write("Verify failure\n");
+        ret = -1;
+      }
+    } else {
+      OPENSSL_PUT_ERROR(PEM, PEM_R_PROBLEMS_GETTING_PASSWORD);
+    }
+  }
+
+  openssl_console_close();
+
+  OPENSSL_cleanse(verify_buf, sizeof(verify_buf));
+  return ret;
+}
+
 int EVP_PKEY_copy_parameters(EVP_PKEY *to, const EVP_PKEY *from) {
   SET_DIT_AUTO_RESET;
   if (to->type == EVP_PKEY_NONE) {

crypto/pem/internal.h

@@ -1,5 +1,10 @@
 #include <openssl/pem.h>
 
+#define MIN_LENGTH 4
+
+#if defined(__cplusplus)
+extern "C" {
+#endif
 
 // PEM utility functions
 // PEM_proc_type appends a Proc-Type header to |buf|, determined by |type|.
@@ -9,3 +14,14 @@ void PEM_proc_type(char buf[PEM_BUFSIZE], int type);
 // and a single parameter, specified by hex-encoding |len| bytes from |str|.
 void PEM_dek_info(char buf[PEM_BUFSIZE], const char *type, size_t len,
                   char *str);
+
+// Console Management Functions
+OPENSSL_EXPORT int openssl_console_open(void);
+OPENSSL_EXPORT int openssl_console_close(void);
+OPENSSL_EXPORT int openssl_console_write(const char *str);
+OPENSSL_EXPORT int openssl_console_read(char *buf, int minsize, int maxsize, int echo);
+
+
+#if defined(__cplusplus)
+}  // extern C
+#endif

crypto/pem/pem_lib.c

@@ -75,8 +75,6 @@
 #include "../fipsmodule/evp/internal.h"
 
 
-#define MIN_LENGTH 4
-
 static int load_iv(char **fromp, unsigned char *to, size_t num);
 static int check_pem(const char *nm, const char *name);
 
@@ -785,13 +783,37 @@ int PEM_read_bio(BIO *bp, char **name, char **header, unsigned char **data,
 }
 
 int PEM_def_callback(char *buf, int size, int rwflag, void *userdata) {
-  if (!buf || !userdata || size < 0) {
+  if (!buf || size < 0) {
     return 0;
   }
-  size_t len = strlen((char *)userdata);
-  if (len >= (size_t)size) {
+
+  if (userdata) {
+    size_t len =  strlen((char *)userdata);
+    if (len >= (size_t)size) {
+      return 0;
+    }
+    OPENSSL_strlcpy(buf, userdata, (size_t)size);
+    return (int)len;
+  }
+
+  const char *prompt = EVP_get_pw_prompt();
+  if (prompt == NULL) {
+    prompt = "Enter PEM pass phrase:";
+  }
+
+  /*
+     * rwflag == 0 means decryption
+     * rwflag == 1 means encryption
+     *
+     * We assume that for encryption, we want a minimum length, while for
+     * decryption, we cannot know any minimum length, so we assume zero.
+     */
+  int min_len = rwflag ? MIN_LENGTH : 0;
+
+  int ret = EVP_read_pw_string_min(buf, min_len, size, prompt, rwflag);
+  if (ret != 0 || size > INT_MAX) {
     return 0;
   }
-  OPENSSL_strlcpy(buf, userdata, (size_t)size);
-  return (int)len;
+
+  return (int)OPENSSL_strnlen(buf, size);
 }