RT3757: base64 encoding bugs

Rewrite EVP_DecodeUpdate.

In particular: reject extra trailing padding, and padding in the middle
of the content. Don't limit line length. Add tests.

Previously, the behaviour was ill-defined, and depended on the position
of the padding within the input.

In addition, this appears to fix a possible two-byte oob read.

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
Reviewed-by: Dr Stephen Henson <steve@openssl.org>

CHANGES

@@ -4,6 +4,12 @@
 
  Changes between 1.0.2 and 1.1.0  [xx XXX xxxx]
 
+  *) Rewrite EVP_DecodeUpdate (base64 decoding) to fix several bugs.
+     This changes the decoding behaviour for some invalid messages,
+     though the change is mostly in the more lenient direction, and
+     legacy behaviour is preserved as much as possible.
+     [Emilia Käsper]
+
   *) New testing framework
      The testing framework has been largely rewritten and is now using
      perl and the perl modules Test::Harness and an extended variant of

crypto/evp/encode.c

@@ -103,6 +103,7 @@ abcdefghijklmnopqrstuvwxyz0123456789+/";
 #define B64_WS                  0xE0
 #define B64_ERROR               0xFF
 #define B64_NOT_BASE64(a)       (((a)|0x13) == 0xF3)
+#define B64_BASE64(a)           !B64_NOT_BASE64(a)
 
 static const unsigned char data_ascii2bin[128] = {
     0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
@@ -218,8 +219,9 @@ int EVP_EncodeBlock(unsigned char *t, const unsigned char *f, int dlen)
 
 void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
 {
-    ctx->length = 30;
+    /* Only ctx->num is used during decoding. */
     ctx->num = 0;
+    ctx->length = 0;
     ctx->line_num = 0;
     ctx->expect_nl = 0;
 }
@@ -228,139 +230,123 @@ void EVP_DecodeInit(EVP_ENCODE_CTX *ctx)
  * -1 for error
  *  0 for last line
  *  1 for full line
+ *
+ * Note: even though EVP_DecodeUpdate attempts to detect and report end of
+ * content, the context doesn't currently remember it and will accept more data
+ * in the next call. Therefore, the caller is responsible for checking and
+ * rejecting a 0 return value in the middle of content.
+ *
+ * Note: even though EVP_DecodeUpdate has historically tried to detect end of
+ * content based on line length, this has never worked properly. Therefore,
+ * we now return 0 when one of the following is true:
+ *   - Padding or B64_EOF was detected and the last block is complete.
+ *   - Input has zero-length.
+ * -1 is returned if:
+ *   - Invalid characters are detected.
+ *   - There is extra trailing padding, or data after padding.
+ *   - B64_EOF is detected after an incomplete base64 block.
  */
 int EVP_DecodeUpdate(EVP_ENCODE_CTX *ctx, unsigned char *out, int *outl,
                      const unsigned char *in, int inl)
 {
-    int seof = -1, eof = 0, rv = -1, ret = 0, i, v, tmp, n, ln, exp_nl;
+    int seof = 0, eof = 0, rv = -1, ret = 0, i, v, tmp, n, decoded_len;
     unsigned char *d;
 
     n = ctx->num;
     d = ctx->enc_data;
-    ln = ctx->line_num;
-    exp_nl = ctx->expect_nl;
 
-    /* last line of input. */
+    if (n > 0 && d[n - 1] == '=') {
-    if ((inl == 0) || ((n == 0) && (conv_ascii2bin(in[0]) == B64_EOF))) {
+        eof++;
+        if (n > 1 && d[n - 2] == '=')
+            eof++;
+    }
+
+     /* Legacy behaviour: an empty input chunk signals end of input. */
+    if (inl == 0) {
         rv = 0;
         goto end;
     }
 
-    /* We parse the input data */
     for (i = 0; i < inl; i++) {
-        /* If the current line is > 80 characters, scream a lot */
-        if (ln >= 80) {
-            rv = -1;
-            goto end;
-        }
-
-        /* Get char and put it into the buffer */
         tmp = *(in++);
         v = conv_ascii2bin(tmp);
-        /* only save the good data :-) */
+        if (v == B64_ERROR) {
-        if (!B64_NOT_BASE64(v)) {
-            OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
-            d[n++] = tmp;
-            ln++;
-        } else if (v == B64_ERROR) {
             rv = -1;
             goto end;
         }
 
-        /*
-         * have we seen a '=' which is 'definitly' the last input line.  seof
-         * will point to the character that holds it. and eof will hold how
-         * many characters to chop off.
-         */
         if (tmp == '=') {
-            if (seof == -1)
-                seof = n;
             eof++;
+        } else if (eof > 0 && B64_BASE64(v)) {
+            /* More data after padding. */
+            rv = -1;
+            goto end;
         }
 
-        if (v == B64_CR) {
+        if (eof > 2) {
-            ln = 0;
+            rv = -1;
-            if (exp_nl)
+            goto end;
-                continue;
         }
 
-        /* eoln */
+        if (v == B64_EOF) {
-        if (v == B64_EOLN) {
+            seof = 1;
-            ln = 0;
+            goto tail;
-            if (exp_nl) {
-                exp_nl = 0;
-                continue;
-            }
-        }
-        exp_nl = 0;
-
-        /*
-         * If we are at the end of input and it looks like a line, process
-         * it.
-         */
-        if (((i + 1) == inl) && (((n & 3) == 0) || eof)) {
-            v = B64_EOF;
-            /*
-             * In case things were given us in really small records (so two
-             * '=' were given in separate updates), eof may contain the
-             * incorrect number of ending bytes to skip, so let's redo the
-             * count
-             */
-            eof = 0;
-            if (d[n - 1] == '=')
-                eof++;
-            if (d[n - 2] == '=')
-                eof++;
-            /* There will never be more than two '=' */
         }
 
-        if ((v == B64_EOF && (n & 3) == 0) || (n >= 64)) {
+        /* Only save valid base64 characters. */
-            /*
+        if (B64_BASE64(v)) {
-             * This is needed to work correctly on 64 byte input lines.  We
+            if (n >= 64) {
-             * process the line and then need to accept the '\n'
+                /*
-             */
+                 * We increment n once per loop, and empty the buffer as soon as
-            if ((v != B64_EOF) && (n >= 64))
+                 * we reach 64 characters, so this can only happen if someone's
-                exp_nl = 1;
+                 * manually messed with the ctx. Refuse to write any more data.
-            if (n > 0) {
+                 */
-                v = EVP_DecodeBlock(out, d, n);
+                rv = -1;
-                n = 0;
-                if (v < 0) {
-                    rv = 0;
-                    goto end;
-                }
-                if (eof > v) {
-                    rv = -1;
-                    goto end;
-                }
-                ret += (v - eof);
-            } else {
-                eof = 1;
-                v = 0;
-            }
-
-            /*
-             * This is the case where we have had a short but valid input
-             * line
-             */
-            if ((v < ctx->length) && eof) {
-                rv = 0;
-                goto end;
-            } else
-                ctx->length = v;
-
-            if (seof >= 0) {
-                rv = 0;
                 goto end;
             }
-            out += v;
+            OPENSSL_assert(n < (int)sizeof(ctx->enc_data));
+            d[n++] = tmp;
+        }
+
+        if (n == 64) {
+            decoded_len = EVP_DecodeBlock(out, d, n);
+            n = 0;
+            if (decoded_len < 0 || eof > decoded_len) {
+                rv = -1;
+                goto end;
+            }
+            ret += decoded_len - eof;
+            out += decoded_len - eof;
         }
     }
-    rv = 1;
+
- end:
+    /*
+     * Legacy behaviour: if the current line is a full base64-block (i.e., has
+     * 0 mod 4 base64 characters), it is processed immediately. We keep this
+     * behaviour as applications may not be calling EVP_DecodeFinal properly.
+     */
+tail:
+    if (n > 0) {
+        if ((n & 3) == 0) {
+        decoded_len = EVP_DecodeBlock(out, d, n);
+        n = 0;
+        if (decoded_len < 0 || eof > decoded_len) {
+            rv = -1;
+            goto end;
+        }
+        ret += (decoded_len - eof);
+        } else if (seof) {
+            /* EOF in the middle of a base64 block. */
+            rv = -1;
+            goto end;
+        }
+    }
+
+    rv = seof || (n == 0 && eof) ? 0 : 1;
+end:
+    /* Legacy behaviour. This should probably rather be zeroed on error. */
     *outl = ret;
     ctx->num = n;
-    ctx->line_num = ln;
-    ctx->expect_nl = exp_nl;
     return (rv);
 }
 

test/evp_test.c

@@ -124,12 +124,58 @@ static int parse_line(char **pkw, char **pval, char *linebuf)
     return 1;
 }
 
+/*
+ * Unescape some escape sequences in string literals.
+ * Return the result in a newly allocated buffer.
+ * Currently only supports '\n'.
+ * If the input length is 0, returns a valid 1-byte buffer, but sets
+ * the length to 0.
+ */
+static unsigned char* unescape(const char *input, size_t input_len,
+                               size_t *out_len)
+{
+    unsigned char *ret, *p;
+    size_t i;
+    if (input_len == 0) {
+        *out_len = 0;
+        return OPENSSL_zalloc(1);
+    }
+
+    /* Escaping is non-expanding; over-allocate original size for simplicity. */
+    ret = p = OPENSSL_malloc(input_len);
+    if (ret == NULL)
+        return NULL;
+
+    for (i = 0; i < input_len; i++) {
+        if (input[i] == '\\') {
+            if (i == input_len - 1 || input[i+1] != 'n')
+                goto err;
+            *p++ = '\n';
+            i++;
+        } else {
+            *p++ = input[i];
+        }
+    }
+
+    *out_len = p - ret;
+    return ret;
+
+ err:
+    OPENSSL_free(ret);
+    return NULL;
+}
+
 /* For a hex string "value" convert to a binary allocated buffer */
 static int test_bin(const char *value, unsigned char **buf, size_t *buflen)
 {
     long len;
     if (!*value) {
-        /* Don't return NULL for zero length buffer */
+        /*
+         * Don't return NULL for zero length buffer.
+         * This is needed for some tests with empty keys: HMAC_Init_ex() expects
+         * a non-NULL key buffer even if the key length is 0, in order to detect
+         * key reset.
+         */
         *buf = OPENSSL_malloc(1);
         if (!*buf)
             return 0;
@@ -145,19 +191,12 @@ static int test_bin(const char *value, unsigned char **buf, size_t *buflen)
         if (value[vlen - 1] != '"')
             return 0;
         vlen--;
-        if (vlen == 0) {
+        *buf = unescape(value, vlen, buflen);
-            *buf = OPENSSL_malloc(1);
+        if (*buf == NULL)
-            if (*buf == NULL)
+            return 0;
-                return 0;
-            **buf = 0;
-        } else {
-            *buf = BUF_memdup(value, vlen);
-            if (*buf == NULL)
-                return 0;
-        }
-        *buflen = vlen;
         return 1;
     }
+
     *buf = string_to_hex(value, &len);
     if (!*buf) {
         fprintf(stderr, "Value=%s\n", value);
@@ -217,9 +256,10 @@ struct evp_test {
     /* Number of tests skipped */
     int nskip;
     /* If output mismatch expected and got value */
-    unsigned char *out_got;
+    unsigned char *out_received;
+    size_t out_received_len;
     unsigned char *out_expected;
-    size_t out_len;
+    size_t out_expected_len;
     /* test specific data */
     void *data;
     /* Current test should be skipped */
@@ -252,6 +292,7 @@ static const struct evp_test_method psign_test_method, pverify_test_method;
 static const struct evp_test_method pdecrypt_test_method;
 static const struct evp_test_method pverify_recover_test_method;
 static const struct evp_test_method pbe_test_method;
+static const struct evp_test_method encode_test_method;
 
 static const struct evp_test_method *evp_test_list[] = {
     &digest_test_method,
@@ -262,6 +303,7 @@ static const struct evp_test_method *evp_test_list[] = {
     &pdecrypt_test_method,
     &pverify_recover_test_method,
     &pbe_test_method,
+    &encode_test_method,
     NULL
 };
 
@@ -290,17 +332,21 @@ static void free_expected(struct evp_test *t)
     OPENSSL_free(t->expected_err);
     t->expected_err = NULL;
     OPENSSL_free(t->out_expected);
-    OPENSSL_free(t->out_got);
+    OPENSSL_free(t->out_received);
     t->out_expected = NULL;
-    t->out_got = NULL;
+    t->out_received = NULL;
+    t->out_expected_len = 0;
+    t->out_received_len = 0;
+    /* Literals. */
+    t->err = NULL;
 }
 
 static void print_expected(struct evp_test *t)
 {
-    if (t->out_expected == NULL)
+    if (t->out_expected == NULL && t->out_received == NULL)
         return;
-    hex_print("Expected:", t->out_expected, t->out_len);
+    hex_print("Expected:", t->out_expected, t->out_expected_len);
-    hex_print("Got:     ", t->out_got, t->out_len);
+    hex_print("Got:     ", t->out_received, t->out_received_len);
     free_expected(t);
 }
 
@@ -496,21 +542,37 @@ static int process_test(struct evp_test *t, char *buf, int verbose)
     return 1;
 }
 
-static int check_output(struct evp_test *t, const unsigned char *expected,
+static int check_var_length_output(struct evp_test *t,
-                        const unsigned char *got, size_t len)
+                                   const unsigned char *expected,
+                                   size_t expected_len,
+                                   const unsigned char *received,
+                                   size_t received_len)
 {
-    if (!memcmp(expected, got, len))
+    if (expected_len == received_len &&
+        memcmp(expected, received, expected_len) == 0) {
         return 0;
-    t->out_expected = BUF_memdup(expected, len);
+    }
-    t->out_got = BUF_memdup(got, len);
+
-    t->out_len = len;
+    /* The result printing code expects a non-NULL buffer. */
-    if (t->out_expected == NULL || t->out_got == NULL) {
+    t->out_expected = BUF_memdup(expected, expected_len ? expected_len : 1);
+    t->out_expected_len = expected_len;
+    t->out_received = BUF_memdup(received, received_len ? received_len : 1);
+    t->out_received_len = received_len;
+    if (t->out_expected == NULL || t->out_received == NULL) {
         fprintf(stderr, "Memory allocation error!\n");
         exit(1);
     }
     return 1;
 }
 
+static int check_output(struct evp_test *t,
+                        const unsigned char *expected,
+                        const unsigned char *received,
+                        size_t len)
+{
+    return check_var_length_output(t, expected, len, received, len);
+}
+
 int main(int argc, char **argv)
 {
     FILE *in = NULL;
@@ -528,17 +590,7 @@ int main(int argc, char **argv)
     OpenSSL_add_all_algorithms();
 
     memset(&t, 0, sizeof(t));
-    t.meth = NULL;
-    t.public = NULL;
-    t.private = NULL;
-    t.err = NULL;
-    t.line = 0;
     t.start_line = -1;
-    t.errors = 0;
-    t.ntests = 0;
-    t.out_expected = NULL;
-    t.out_got = NULL;
-    t.out_len = 0;
     in = fopen(argv[1], "r");
     t.in = in;
     while (fgets(buf, sizeof(buf), in)) {
@@ -1473,3 +1525,132 @@ static const struct evp_test_method pbe_test_method = {
     pbe_test_parse,
     pbe_test_run
 };
+
+/* Base64 tests */
+
+typedef enum {
+    BASE64_CANONICAL_ENCODING = 0,
+    BASE64_VALID_ENCODING = 1,
+    BASE64_INVALID_ENCODING = 2
+} base64_encoding_type;
+
+struct encode_data {
+    /* Input to encoding */
+    unsigned char *input;
+    size_t input_len;
+    /* Expected output */
+    unsigned char *output;
+    size_t output_len;
+    base64_encoding_type encoding;
+};
+
+static int encode_test_init(struct evp_test *t, const char *encoding)
+{
+    struct encode_data *edata = OPENSSL_zalloc(sizeof(*edata));
+
+    if (strcmp(encoding, "canonical") == 0) {
+        edata->encoding = BASE64_CANONICAL_ENCODING;
+    } else if (strcmp(encoding, "valid") == 0) {
+        edata->encoding = BASE64_VALID_ENCODING;
+    } else if (strcmp(encoding, "invalid") == 0) {
+        edata->encoding = BASE64_INVALID_ENCODING;
+        t->expected_err = BUF_strdup("DECODE_ERROR");
+        if (t->expected_err == NULL)
+            return 0;
+    } else {
+        fprintf(stderr, "Bad encoding: %s. Should be one of "
+                "{canonical, valid, invalid}\n", encoding);
+        return 0;
+    }
+    t->data = edata;
+    return 1;
+}
+
+static void encode_test_cleanup(struct evp_test *t)
+{
+    struct encode_data *edata = t->data;
+    test_free(edata->input);
+    test_free(edata->output);
+    memset(edata, 0, sizeof(*edata));
+}
+
+static int encode_test_parse(struct evp_test *t,
+                             const char *keyword, const char *value)
+{
+    struct encode_data *edata = t->data;
+    if (strcmp(keyword, "Input") == 0)
+        return test_bin(value, &edata->input, &edata->input_len);
+    if (strcmp(keyword, "Output") == 0)
+        return test_bin(value, &edata->output, &edata->output_len);
+    return 0;
+}
+
+static int encode_test_run(struct evp_test *t)
+{
+    struct encode_data *edata = t->data;
+    unsigned char *encode_out = NULL, *decode_out = NULL;
+    int output_len, chunk_len;
+    const char *err = "INTERNAL_ERROR";
+    EVP_ENCODE_CTX decode_ctx;
+
+    if (edata->encoding == BASE64_CANONICAL_ENCODING) {
+        EVP_ENCODE_CTX encode_ctx;
+        encode_out = OPENSSL_malloc(EVP_ENCODE_LENGTH(edata->input_len));
+        if (encode_out == NULL)
+            goto err;
+
+        EVP_EncodeInit(&encode_ctx);
+        EVP_EncodeUpdate(&encode_ctx, encode_out, &chunk_len,
+                         edata->input, edata->input_len);
+        output_len = chunk_len;
+
+        EVP_EncodeFinal(&encode_ctx, encode_out + chunk_len, &chunk_len);
+        output_len += chunk_len;
+
+        if (check_var_length_output(t, edata->output, edata->output_len,
+                                    encode_out, output_len)) {
+            err = "BAD_ENCODING";
+            goto err;
+        }
+    }
+
+    decode_out = OPENSSL_malloc(EVP_DECODE_LENGTH(edata->output_len));
+    if (decode_out == NULL)
+        goto err;
+
+    EVP_DecodeInit(&decode_ctx);
+    if (EVP_DecodeUpdate(&decode_ctx, decode_out, &chunk_len, edata->output,
+                         edata->output_len) < 0) {
+        err = "DECODE_ERROR";
+        goto err;
+    }
+    output_len = chunk_len;
+
+    if (EVP_DecodeFinal(&decode_ctx, decode_out + chunk_len, &chunk_len) != 1) {
+        err = "DECODE_ERROR";
+        goto err;
+    }
+    output_len += chunk_len;
+
+    if (edata->encoding != BASE64_INVALID_ENCODING &&
+        check_var_length_output(t, edata->input, edata->input_len,
+                                decode_out, output_len)) {
+        err = "BAD_DECODING";
+        goto err;
+    }
+
+    err = NULL;
+ err:
+    t->err = err;
+    OPENSSL_free(encode_out);
+    OPENSSL_free(decode_out);
+    return 1;
+}
+
+static const struct evp_test_method encode_test_method = {
+    "Encoding",
+    encode_test_init,
+    encode_test_cleanup,
+    encode_test_parse,
+    encode_test_run,
+};

test/evptests.txt

@@ -2624,3 +2624,176 @@ Salt = 7361006c74
 iter = 4096
 MD = sha512
 Key = 9d9e9c4cd21fe4be24d5b8244c759665
+
+# Base64 tests
+
+Encoding = canonical
+Input = ""
+Output = ""
+
+Encoding = canonical
+Input = "h"
+Output = "aA==\n"
+
+Encoding = canonical
+Input = "hello"
+Output = "aGVsbG8=\n"
+
+Encoding = canonical
+Input = "hello world!"
+Output = "aGVsbG8gd29ybGQh\n"
+
+Encoding = canonical
+Input = 00010203040506070809a0b0c0d0e0f000
+Output = "AAECAwQFBgcICaCwwNDg8AA=\n"
+
+# Missing padding
+Encoding = invalid
+Output = "aGVsbG8"
+
+Encoding = invalid
+Output = "aGVsbG8\n"
+
+# Tolerate missing newline
+Encoding = valid
+Input = "hello"
+Output = "aGVsbG8="
+
+# Don't tolerate extra trailing '='
+Encoding = invalid
+Input = "hello"
+Output = "aGVsbG8==\n"
+
+Encoding = invalid
+Output = "aGVsbG8===\n"
+
+# Don't tolerate data after '='
+Encoding = invalid
+Output = "aGV=sbG8=\n"
+
+# Newlines are ignored
+Encoding = valid
+Input = "hello"
+Output = "aGV\nsbG8=\n"
+
+Encoding = canonical
+Input = "hello"
+Output = 614756736247383d0a
+
+# Invalid characters
+Encoding = invalid
+Output = 614756736247383d0a00
+
+Encoding = invalid
+Output = 61475600736247383d0a
+
+Encoding = invalid
+Output = 61475601736247383d0a
+
+Encoding = canonical
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE9wZW5TU0wK\n"
+
+Encoding = valid
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE9wZW5TU0wK"
+
+# Truncate 1-3 chars
+Encoding = invalid
+Output = "T3BlblNTTE9wZW5TU0w"
+
+Encoding = invalid
+Output = "T3BlblNTTE9wZW5TU0"
+
+Encoding = invalid
+Output = "T3BlblNTTE9wZW5TU"
+
+Encoding = invalid
+Output = "T3BlblNTTE9wZW5TU0wK===="
+
+Encoding = invalid
+Output = "T3BlblNTTE9wZW5TU0wK============================================\n"
+
+Encoding = invalid
+Output = "YQ==YQ==YQ==\n"
+
+Encoding = invalid
+Output = "A"
+
+Encoding = invalid
+Output = "A\n"
+
+Encoding = invalid
+Output = "A="
+
+Encoding = invalid
+Output = "A==\n"
+
+Encoding = invalid
+Output = "A===\n"
+
+Encoding = invalid
+Output = "A====\n"
+
+Encoding = valid
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE9wZW5TU0wK\n\n"
+
+Encoding = valid
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE\n9wZW5TU0wK"
+
+# CVE 2015-0292
+Encoding = invalid
+Output = "ZW5jb2RlIG1lCg==================================================================\n"
+
+Encoding = canonical
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA==\n"
+
+Encoding = valid
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA\n==\n"
+
+Encoding = valid
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA=\n=\n"
+
+Encoding = invalid
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA====\n"
+
+# Multiline output without padding
+Encoding = canonical
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4\neHh4eHh4eHh4eHh4\n"
+
+# Multiline output with padding
+Encoding = canonical
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4\neHh4eHh4eHh4eHh4eHh4eA==\n"
+
+# Multiline output with line break in the middle of a b64 block is accepted
+Encoding = valid
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh\n4eHh4eHh4eHh4eHh4eHh4eA==\n"
+
+# Long lines are accepted
+Encoding = valid
+Input = "xxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxxx"
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA==\n"
+
+# Multiline input with data after '='.
+Encoding = invalid
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eA==\neHh4eHh4eHh4eHh4eHh4eHh4\n"
+
+Encoding = invalid
+Output = "eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4eHh4\neA==eHh4eHh4eHh4eHh4eHh4\n"
+
+# B64_EOF ('-') terminates input and trailing bytes are ignored
+Encoding = valid
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE9wZW5TU0wK\n-abcd"
+
+Encoding = valid
+Input = "OpenSSLOpenSSL\n"
+Output = "T3BlblNTTE9wZW5TU0wK-abcd"