Implement base64 without openssl

common/base64.c

@@ -1,5 +1,5 @@
 /**
- * Copyright (C) 2017 Koichiro Iwao, all xrdp contributors
+ * Copyright (C) 2022 Matt Burt, all xrdp contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -26,57 +26,229 @@
 
 #include "string_calls.h"
 
-#include <openssl/bio.h>
+#include "base64.h"
-#include <openssl/evp.h>
 
-size_t
+/*
-base64_decoded_bytes(const char *src)
+ * Values for invalid and padding characters, used in the charmap
+ * for converting base64 to binary
+ *
+ * Thse value are specially chosen to make it easy to detect padding or
+ * invalid characters by or-ing together the values looked up in
+ * a base64 quantum */
+#define E_INVALID 0x40
+#define E_PAD 0x80
+
+/* Determine the character set on this platform */
+#if ('a' == 0x61 && 'z' == 0x7a ) && \
+    ('A' == 0x41 && 'Z' == 0x5a ) && \
+    ('0' == 0x30 && '9' == 0x39 )
+# define PLATFORM_IS_ASCII 1
+#else
+#   error "Unrecognised character set on this platform"
+#endif /* character set check */
+
+
+/*
+ * Define a table to map the base64 character values to bit values.
+ */
+#ifdef PLATFORM_IS_ASCII
+#define CHARMAP_BASE 0x28
+#define E_IV E_INVALID  /* For table alignment */
+const unsigned char charmap[] =
 {
-    size_t len;
+    /* 0x28 */ E_IV, E_IV, E_IV, 0x3e, E_IV, E_IV, E_IV, 0x3f,
-    size_t padding;
+    /* 0x30 */ 0x34, 0x35, 0x36, 0x37, 0x38, 0x39, 0x3a, 0x3b,
+    /* 0x38 */ 0x3c, 0x3d, E_IV, E_IV, E_IV, E_PAD, E_IV, E_IV,
+    /* 0x40 */ E_IV, 0x00, 0x01, 0x02, 0x03, 0x04, 0x05, 0x06,
+    /* 0x48 */ 0x07, 0x08, 0x09, 0x0a, 0x0b, 0x0c, 0x0d, 0x0e,
+    /* 0x50 */ 0x0f, 0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16,
+    /* 0x58 */ 0x17, 0x18, 0x19, E_IV, E_IV, E_IV, E_IV, E_IV,
+    /* 0x60 */ E_IV, 0x1a, 0x1b, 0x1c, 0x1d, 0x1e, 0x1f, 0x20,
+    /* 0x68 */ 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27, 0x28,
+    /* 0x70 */ 0x29, 0x2a, 0x2b, 0x2c, 0x2d, 0x2e, 0x2f, 0x30,
+    /* 0x78 */ 0x31, 0x32, 0x33
+};
+#undef E_IV
+#endif /* PLATFORM_IS_ASCII */
 
-    len = g_strlen(src);
-    padding = 0;
 
-    if (src[len - 1] == '=')
+/**
+ * Lookup a value in the charmap
+ *
+ * @param x - byte to lookup. Only referenced once so can safely have
+ *            side effects.
+ * @param dest - destination to assign result to.
+ */
+#define CM_LOOKUP(x,dest) \
+    { \
+        unsigned int t = (unsigned int)(x) - CHARMAP_BASE;\
+        dest = (t < sizeof(charmap)) ? charmap[t] : E_INVALID; \
+    }
+
+/*****************************************************************************/
+
+int
+base64_decode(const char *src, char *dst, size_t dst_len, size_t *actual_len)
+{
+    *actual_len = 0;
+    size_t src_len;
+    size_t src_i = 0;
+    size_t dst_i = 0;
+    unsigned int a;  /* Four characters of base64 quantum */
+    unsigned int b;
+    unsigned int c;
+    unsigned int d;
+    unsigned int v;
+
+#define OUTPUT_CHAR(x) \
+    { \
+        if (dst_i < dst_len) \
+        { \
+            dst[dst_i] = (x);\
+        } \
+        ++dst_i; \
+    }
+
+    src_len = g_strlen(src);
+
+    while (src_i < src_len)
     {
-        padding++;
+        if ((src_len - src_i) >= 4)
-
-        if (src[len - 2] == '=')
         {
-            padding++;
+            /* Usual case  - full quantum */
+            CM_LOOKUP(src[src_i++], a);
+            CM_LOOKUP(src[src_i++], b);
+            CM_LOOKUP(src[src_i++], c);
+            CM_LOOKUP(src[src_i++], d);
+        }
+        else
+        {
+            /* Add padding on the end to make up the full quantum */
+            CM_LOOKUP(src[src_i++], a);
+            b = E_PAD;
+            c = E_PAD;
+            d = E_PAD;
+            if ((src_len - src_i) > 0)
+            {
+                CM_LOOKUP(src[src_i++], b);
+            }
+            if ((src_len - src_i) > 0)
+            {
+                CM_LOOKUP(src[src_i++], c);
+            }
+        }
+
+        /*
+         * Bitwise-or the translated quantum values together, so that
+         * any invalid or padding characters can be detected with a
+         * single test */
+        v = a | b | c | d;
+
+        if ((v & E_INVALID) != 0)
+        {
+            return -1;  /* At least one invalid character */
+        }
+
+        if ((v & E_PAD) == 0)
+        {
+            /* No padding - a full quantum */
+            v = (a << 18) | (b << 12) | (c << 6) | d;
+            OUTPUT_CHAR(v >> 16);
+            OUTPUT_CHAR((v >> 8) & 0xff);
+            OUTPUT_CHAR(v & 0xff);
+        }
+        else if (((a | b | c) & E_PAD) == 0)
+        {
+            /* No padding in the first 3 chars, so the padding must
+             * be at the end */
+            v = (a << 10) | (b << 4) | (c >> 2);
+            OUTPUT_CHAR(v >> 8);
+            OUTPUT_CHAR(v & 0xff);
+        }
+        else if (((a | b) & E_PAD) == 0 && c == d)
+        {
+            /* No padding in first two chars, so if the last two chars are
+             * equal, they must both be padding */
+            v = (a << 2) | (b >> 4);
+            OUTPUT_CHAR(v);
+        }
+        else
+        {
+            /* Illegal padding */
+            return -1;
         }
     }
 
-    return len * 3 / 4 - padding;
+    *actual_len = dst_i;
+    return 0;
+
+#undef OUTPUT_CHAR
 }
 
 /*****************************************************************************/
-char *
+size_t
-base64_decode(char *dst, const char *src, size_t len)
+base64_encode(const char *src, size_t src_len, char *dst, size_t dst_len)
 {
-    BIO *b64;
+    char *p = dst;
-    BIO *bio;
+    size_t src_i = 0;
-    char *b64str;
+    size_t max_src_len;
-    size_t estimated_decoded_bytes;
+    unsigned int v;
-    size_t decoded_bytes;
+    static const char *b64chr =
+        "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+        "abcdefghijklmnopqrstuvwxyz"
+        "0123456789+/=";
 
-    b64str = g_strdup(src);
+    /* Each three octets of the source results in four bytes at the output,
-    estimated_decoded_bytes = base64_decoded_bytes(b64str);
+     * plus we need a terminator. So we can work out the maximum number of
-    dst[estimated_decoded_bytes] = '\0';
+     * source octets we can process */
-
+    if (dst_len == 0)
-    b64 = BIO_new(BIO_f_base64());
-    bio = BIO_new_mem_buf(b64str, len);
-    bio = BIO_push(b64, bio);
-    BIO_set_flags(bio, BIO_FLAGS_BASE64_NO_NL);
-    decoded_bytes = BIO_read(bio, dst, len);
-    BIO_free_all(bio);
-
-    /* if input is corrupt, return empty string */
-    if (estimated_decoded_bytes != decoded_bytes)
     {
-        g_strncpy(dst, "", sizeof(""));
+        max_src_len = 0;
+    }
+    else
+    {
+        max_src_len = (dst_len - 1) / 4 * 3;
     }
 
-    return dst;
+    if (src_len > max_src_len)
+    {
+        src_len = max_src_len;
+    }
+
+    while (src_i < src_len)
+    {
+        switch (src_len - src_i)
+        {
+            case 1:
+                v = (unsigned int)(unsigned char)src[src_i++] << 4;
+                *p++ = b64chr[v >> 6];
+                *p++ = b64chr[v & 0x3f];
+                *p++ = b64chr[64];
+                *p++ = b64chr[64];
+                break;
+
+            case 2:
+                v = (unsigned int)(unsigned char)src[src_i++] << 10;
+                v |= (unsigned int)(unsigned char)src[src_i++] << 2;
+                *p++ = b64chr[v >> 12];
+                *p++ = b64chr[(v >> 6) & 0x3f];
+                *p++ = b64chr[v & 0x3f];
+                *p++ = b64chr[64];
+                break;
+
+            default:
+                v = (unsigned int)(unsigned char)src[src_i++] << 16;
+                v |= (unsigned int)(unsigned char)src[src_i++] << 8;
+                v |= (unsigned int)(unsigned char)src[src_i++];
+                *p++ = b64chr[v >> 18];
+                *p++ = b64chr[(v >> 12) & 0x3f];
+                *p++ = b64chr[(v >> 6) & 0x3f];
+                *p++ = b64chr[v & 0x3f];
+                break;
+        }
+    }
+
+    *p = '\0';
+
+    return src_len;
 }

common/base64.h

@@ -1,5 +1,5 @@
 /**
- * Copyright (C) 2017 Koichiro Iwao, all xrdp contributors
+ * Copyright (C) 2021 Koichiro Iwao, all xrdp contributors
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
@@ -17,16 +17,66 @@
 /**
  * @file    common/base64.h
  * @brief   Base64 encoder / decoder
+ *
+ * Base-64 is described in RFC4648. The following notes apply to this
+ * implementation:-
+ * - The only supported characters are [A-Za-z0-9+/=]. At present,
+ *   embedded linefeeds and URL encodings are not supported.
+ *
  */
 
-#if !defined(SSL_CALLS_H)
+#if !defined(BASE64_CALLS_H)
-#define SSL_CALLS_H
+#define BASE64_CALLS_H
 
 #include "arch.h"
 
-size_t
+/*
-base64_decoded_bytes(const char *src);
+ * Decodes a base64 string
-char *
+ *
-base64_decode(char *dst, const char *src, size_t len);
+ * @param src Pointer to null-terminated source
+ * @param dst Pointer to output buffer
+ * @param dst_len Length of above. No more than this is written to the
+ *                output buffer
+ * @param actual_len Pointer to value to receive actual length of decoded data
+ * @return 0 for success, 1 for an invalid input string
+ *
+ * The following notes apply to this implementation:-
+ * - Embedded padding is supported, provided it only occurs at the end
+ *   of a quantum as described in RFC4648(4). This allows concatenated
+ *   encodings to be fed into the decoder.
+ * - Padding of the last quantum is assumed if not provided.
+ * - Excess padding of the last quantum is ignored.
+ *
+ * Only dst_len bytes at most are written to the output. The length
+ * returned in actual_len however represents how much buffer is needed for
+ * a correct result. This may be more than dst_len, and enables the caller
+ * to detect a potential buffer overflow
+ */
+int
+base64_decode(const char *src, char *dst, size_t dst_len, size_t *actual_len);
 
-#endif
+/*
+ * Encodes a buffer as base64
+ *
+ * @param src Pointer to source
+ * @param src_len Length of above.
+ * @param dst Pointer to output buffer for null-terminated string
+ * @param dst_len Length of above. No more than this is written to the
+ *                output buffer
+ * @return Number of source characters processed
+ *
+ * The following notes apply to this implementation:-
+ * - Padding of the last quantum is always written if the number of
+ *   source bytes is not divisible by 3.
+ *
+ * The number of source characters processed is always returned. If
+ * the destination buffer is too small for all the output plus a
+ * terminator, the returned value from this procedure will be less than
+ * src_len. In this case no padding characters will have been written,
+ * and the remaining characters can be converted with more calls to
+ * this procedure.
+ */
+size_t
+base64_encode(const char *src, size_t src_len, char *dst, size_t dst_len);
+
+#endif /* BASE64_CALLS_H */

tests/common/Makefile.am

@@ -6,6 +6,8 @@ AM_CPPFLAGS = \
 LOG_DRIVER = env AM_TAP_AWK='$(AWK)' $(SHELL) \
                   $(top_srcdir)/tap-driver.sh
 
+PACKAGE_STRING = "libcommon"
+
 TESTS = test_common
 check_PROGRAMS = test_common
 
@@ -14,7 +16,8 @@ test_common_SOURCES = \
     test_common_main.c \
     test_string_calls.c \
     test_os_calls.c \
-    test_ssl_calls.c
+    test_ssl_calls.c \
+    test_base64.c
 
 test_common_CFLAGS = \
     @CHECK_CFLAGS@ \

tests/common/test_base64.c

@@ -0,0 +1,400 @@
+
+#if defined(HAVE_CONFIG_H)
+#include "config_ac.h"
+#endif
+
+#include "os_calls.h"
+#include "string_calls.h"
+#include "base64.h"
+
+#include "test_common.h"
+/*
+* These are the example test strings in RFC4648(10)
+*/
+static const char *rfc4648_ex1_text = "";
+static const char *rfc4648_ex1_b64 = "";
+static const char *rfc4648_ex2_text = "f";
+static const char *rfc4648_ex2_b64 = "Zg==";
+static const char *rfc4648_ex3_text = "fo";
+static const char *rfc4648_ex3_b64 = "Zm8=";
+static const char *rfc4648_ex4_text = "foo";
+static const char *rfc4648_ex4_b64 = "Zm9v";
+static const char *rfc4648_ex5_text = "foob";
+static const char *rfc4648_ex5_b64 = "Zm9vYg==";
+static const char *rfc4648_ex6_text = "fooba";
+static const char *rfc4648_ex6_b64 = "Zm9vYmE=";
+static const char *rfc4648_ex7_text = "foobar";
+static const char *rfc4648_ex7_b64 = "Zm9vYmFy";
+
+/* Every single valid base64 character, except padding */
+static const char *all_b64 =
+    "ABCDEFGHIJKL"
+    "MNOPQRSTUVWX"
+    "YZabcdefghij"
+    "klmnopqrstuv"
+    "wxyz01234567"
+    "89+/";
+
+/* What we should get as binary if we decode this */
+static const char all_b64_decoded[] =
+{
+    '\x00', '\x10', '\x83', '\x10', '\x51', '\x87', '\x20', '\x92', '\x8b',
+    '\x30', '\xd3', '\x8f', '\x41', '\x14', '\x93', '\x51', '\x55', '\x97',
+    '\x61', '\x96', '\x9b', '\x71', '\xd7', '\x9f', '\x82', '\x18', '\xa3',
+    '\x92', '\x59', '\xa7', '\xa2', '\x9a', '\xab', '\xb2', '\xdb', '\xaf',
+    '\xc3', '\x1c', '\xb3', '\xd3', '\x5d', '\xb7', '\xe3', '\x9e', '\xbb',
+    '\xf3', '\xdf', '\xbf'
+};
+
+static void
+test_rfc4648_to_b64(const char *plaintext, size_t len, const char *b64)
+{
+    char buff[256];
+    size_t result;
+
+    result = base64_encode(plaintext, len, buff, sizeof(buff));
+    ck_assert_int_eq(result, len);
+    ck_assert_str_eq(buff, b64);
+
+}
+
+/* Text-only encoder wrapper */
+static void
+test_rfc4648_to_b64_text(const char *plaintext, const char *b64)
+{
+    test_rfc4648_to_b64(plaintext, g_strlen(plaintext), b64);
+}
+
+/* Text-only decoder wrapper for valid base64 */
+static void
+test_rfc4648_from_b64_text(const char *b64, const char *text)
+{
+    char buff[256];
+    size_t actual_len;
+    int result;
+
+    result = base64_decode(b64, buff, sizeof(buff), &actual_len);
+    ck_assert_int_eq(result, 0);
+    ck_assert_int_lt(actual_len, sizeof(buff));
+    buff[actual_len] = '\0';
+    ck_assert_str_eq(buff, text);
+}
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex1_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex1_text, rfc4648_ex1_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex1_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex1_b64, rfc4648_ex1_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex2_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex2_text, rfc4648_ex2_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex2_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex2_b64, rfc4648_ex2_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex3_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex3_text, rfc4648_ex3_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex3_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex3_b64, rfc4648_ex3_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex4_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex4_text, rfc4648_ex4_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex4_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex4_b64, rfc4648_ex4_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex5_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex5_text, rfc4648_ex5_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex5_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex5_b64, rfc4648_ex5_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex6_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex6_text, rfc4648_ex6_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex6_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex6_b64, rfc4648_ex6_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex7_to)
+{
+    test_rfc4648_to_b64_text(rfc4648_ex7_text, rfc4648_ex7_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_rfc4648_ex7_from)
+{
+    test_rfc4648_from_b64_text(rfc4648_ex7_b64, rfc4648_ex7_text);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_all_valid_from)
+{
+    char buff[256];
+    size_t actual_len;
+    int result;
+    char *str_result;
+    char *str_expected;
+
+    result = base64_decode(all_b64, buff, sizeof(buff), &actual_len);
+    ck_assert_int_eq(result, 0);
+    ck_assert_int_eq(actual_len, sizeof(all_b64_decoded));
+    str_result = bin_to_hex(buff, actual_len);
+    str_expected = bin_to_hex(all_b64_decoded, sizeof(all_b64_decoded));
+    ck_assert_str_eq(str_result, str_expected);
+    free(str_result);
+    free(str_expected);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_all_valid_to)
+{
+    char buff[256];
+    size_t result;
+
+    result = base64_encode(all_b64_decoded, sizeof(all_b64_decoded),
+                           buff, sizeof(buff));
+    ck_assert_int_eq(result, sizeof(all_b64_decoded));
+    ck_assert_str_eq(buff, all_b64);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_all_invalid)
+{
+    char buff[256];
+    size_t actual_len;
+    char valid[256] = {0};
+    char encoded[5] = { "T0sh" }; /* Decodes to 'OK!' */
+    int result;
+
+    /* Make a note of all the valid b64 characters */
+    unsigned int i = 0;
+    unsigned char c;
+    while ((c = all_b64[i]) != '\0')
+    {
+        valid[c] = 1;
+        ++i;
+    }
+
+    /* Check the decoder's working on a simple string...*/
+    result = base64_decode(encoded, buff, sizeof(buff), &actual_len);
+    ck_assert_int_eq(result, 0);
+    ck_assert_int_eq(actual_len, 3);
+    buff[actual_len] = '\0';
+    ck_assert_str_eq(buff, "OK!");
+
+    /* Now replace the 1st character with all invalid characters in turn,
+     * and check they're rejected */
+    for (i = 0 ; i < 256; ++i)
+    {
+        if (i != '\0' && !valid[i]) /* Don't try the string terminator char! */
+        {
+            encoded[0] = i;
+            result = base64_decode(encoded, buff, sizeof(buff), &actual_len);
+            if (result == 0)
+            {
+                ck_abort_msg("Character 0x%02x was not rejected", i);
+            }
+        }
+    }
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_small_buffer_encode)
+{
+    char buff[10 * 4 + 1]; /* Enough space for 10 quanta */
+
+    size_t result;
+
+    result = base64_encode(all_b64_decoded, sizeof(all_b64_decoded),
+                           buff, sizeof(buff));
+    /* Should have read 10 lots of 24 bits from the input */
+    ck_assert_int_eq(result, 10 * 3);
+    ck_assert_str_eq(buff, "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmn");
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_small_buffer_decode)
+{
+    char buff[10]; /* Enough space for 10 chars */
+
+    size_t actual_len;
+    int result;
+    char *str_result;
+    char *str_expected;
+
+    result = base64_decode(all_b64, buff, sizeof(buff), &actual_len);
+    ck_assert_int_eq(result, 0);
+    ck_assert_int_eq(actual_len, sizeof(all_b64_decoded));
+    str_result = bin_to_hex(buff, sizeof(buff));
+    str_expected = bin_to_hex(all_b64_decoded, sizeof(buff));
+    ck_assert_str_eq(str_result, str_expected);
+    free(str_result);
+    free(str_expected);
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_add_pad_one)
+{
+    /* Check that a missing trailing '=' is added when decoding */
+    test_rfc4648_from_b64_text("Zm8", "fo"); /* RFC4648 example 3 */
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_add_pad_two)
+{
+    /* Check that two missing trailing '=' chars are added when decoding */
+    test_rfc4648_from_b64_text("Zg", "f"); /* RFC4648 example 2 */
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_bad_pad)
+{
+    char buff[16];
+    size_t actual_len;
+
+    /* Check all bad quanta with padding chars */
+    static const char *bad_pad[] =
+    {
+        "=AAA",
+        "A=AA",
+        "AA=A",
+        "==AA",
+        "=A=A",
+        "=AA=",
+        "A==A",
+        "A=A=",
+        "===A",
+        "A===",
+        NULL
+    };
+    const char **p;
+
+    for (p = bad_pad ; *p != NULL ; ++p)
+    {
+        int result = base64_decode(*p, buff, sizeof(buff), &actual_len);
+        if (result == 0)
+        {
+            ck_abort_msg("Padding '%s' was not rejected", *p);
+        }
+    }
+}
+END_TEST
+
+/******************************************************************************/
+START_TEST(test_b64_concat_pad)
+{
+    const char *src =
+        "VGVzdA=="  /* Test */
+        "IA=="      /* <space> */
+        "Y29uY2F0ZW5hdGVk" /* concatenated */
+        "IA=="      /* <space> */
+        "cGFkZGluZw=="; /*padding */
+    const char *expected = "Test concatenated padding";
+    char buff[64];
+    size_t actual_len;
+    int result;
+
+    result = base64_decode(src, buff, sizeof(buff), &actual_len);
+    ck_assert_int_eq(result, 0);
+    ck_assert_int_eq(actual_len, g_strlen(expected));
+    buff[actual_len] = '\0';
+    ck_assert_str_eq(buff, expected);
+}
+END_TEST
+
+/******************************************************************************/
+Suite *
+make_suite_test_base64(void)
+{
+    Suite *s;
+    TCase *tc_b64;
+
+    s = suite_create("base64");
+
+    tc_b64 = tcase_create("base64");
+    suite_add_tcase(s, tc_b64);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex1_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex1_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex2_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex2_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex3_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex3_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex4_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex4_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex5_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex5_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex6_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex6_from);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex7_to);
+    tcase_add_test(tc_b64, test_b64_rfc4648_ex7_from);
+    tcase_add_test(tc_b64, test_b64_all_valid_from);
+    tcase_add_test(tc_b64, test_b64_all_valid_to);
+    tcase_add_test(tc_b64, test_b64_all_invalid);
+    tcase_add_test(tc_b64, test_b64_small_buffer_encode);
+    tcase_add_test(tc_b64, test_b64_small_buffer_decode);
+    tcase_add_test(tc_b64, test_b64_add_pad_one);
+    tcase_add_test(tc_b64, test_b64_add_pad_two);
+    tcase_add_test(tc_b64, test_b64_bad_pad);
+    tcase_add_test(tc_b64, test_b64_concat_pad);
+
+    return s;
+}

tests/common/test_common.h

@@ -4,8 +4,12 @@
 
 #include <check.h>
 
+char *
+bin_to_hex(const char *input, int length);
+
 Suite *make_suite_test_string(void);
 Suite *make_suite_test_os_calls(void);
 Suite *make_suite_test_ssl_calls(void);
+Suite *make_suite_test_base64(void);
 
 #endif /* TEST_COMMON_H */

tests/common/test_common_main.c

@@ -10,6 +10,36 @@
 
 #include "test_common.h"
 
+/**
+ * Converts a binary buffer to a hexadecimal representation
+ *
+ * Result must be free'd after use
+ */
+char *
+bin_to_hex(const char *input, int length)
+{
+    int i;
+    char *result = (char *)malloc(length * 2 + 1);
+    if (result != NULL)
+    {
+        char *p = result;
+        const char *hexdigit = "0123456789abcdef";
+        for (i = 0 ; i < length ; ++i)
+        {
+            int c = input[i];
+            if (c < 0)
+            {
+                c += 256;
+            }
+            *p++ = hexdigit[ c / 16];
+            *p++ = hexdigit[ c % 16];
+        }
+        *p = '\0';
+    }
+
+    return result;
+}
+
 int main (void)
 {
     int number_failed;
@@ -18,6 +48,7 @@ int main (void)
     sr = srunner_create (make_suite_test_string());
     srunner_add_suite(sr, make_suite_test_os_calls());
     srunner_add_suite(sr, make_suite_test_ssl_calls());
+    srunner_add_suite(sr, make_suite_test_base64());
     //   srunner_add_suite(sr, make_list_suite());
 
     srunner_set_tap(sr, "-");

tests/common/test_ssl_calls.c

@@ -9,32 +9,6 @@
 
 #include "test_common.h"
 
-static
-char *bin_to_hex(const char *input, int length)
-{
-    int i;
-    char *result = (char *)g_malloc(length * 2 + 1, 0);
-    if (result != NULL)
-    {
-        char *p = result;
-        const char *hexdigit = "0123456789abcdef";
-        for (i = 0 ; i < length ; ++i)
-        {
-            int c = input[i];
-            if (c < 0)
-            {
-                c += 256;
-            }
-            *p++ = hexdigit[ c / 16];
-            *p++ = hexdigit[ c % 16];
-        }
-        *p = '\0';
-    }
-
-    return result;
-}
-
-
 START_TEST(test_rc4_enc_ok)
 {
     const char *key = "16_byte_key-----";

xrdp/xrdp_login_wnd.c

@@ -346,6 +346,7 @@ xrdp_wm_show_edits(struct xrdp_wm *self, struct xrdp_bitmap *combo)
     struct xrdp_cfg_globals *globals;
     char resultIP[256];
     char *plain; /* base64 decoded string */
+    size_t plain_length; /* length of decoded base64 string */
     size_t base64_length; /* length of base64 string */
 
     globals = &self->xrdp_config->cfg_globals;
@@ -379,8 +380,9 @@ xrdp_wm_show_edits(struct xrdp_wm *self, struct xrdp_bitmap *combo)
             {
                 base64_length = g_strlen(value + BASE64PREFIX_LEN);
                 plain = (char *)g_malloc(base64_length, 0);
-                base64_decode(plain, value + BASE64PREFIX_LEN, base64_length);
+                base64_decode(value + BASE64PREFIX_LEN,
-                g_strncpy(value, plain, g_strlen(plain));
+                              plain, base64_length, &plain_length);
+                g_strncpy(value, plain, plain_length);
                 g_free(plain);
             }
             else if (g_strncmp(ASK, value, ASK_LEN) == 0)
@@ -421,7 +423,9 @@ xrdp_wm_show_edits(struct xrdp_wm *self, struct xrdp_bitmap *combo)
                 {
                     base64_length = g_strlen(value + ASK_LEN + BASE64PREFIX_LEN);
                     plain = (char *)g_malloc(base64_length, 0);
-                    base64_decode(plain, value + ASK_LEN + BASE64PREFIX_LEN, base64_length);
+                    base64_decode(value + ASK_LEN + BASE64PREFIX_LEN,
+                                  plain, base64_length, &plain_length);
+                    plain[plain_length] = '\0';
                     g_strncpy(b->caption1, plain, 255);
                     g_free(plain);
                 }