2 * Copyright 1995-2016 The OpenSSL Project Authors. All Rights Reserved.
4 * Licensed under the OpenSSL license (the "License"). You may not use
5 * this file except in compliance with the License. You can obtain a copy
6 * in the file LICENSE in the source distribution or at
7 * https://www.openssl.org/source/license.html
12 #include "internal/cryptlib.h"
13 #include <openssl/buffer.h>
14 #include <openssl/evp.h>
15 #include "internal/bio.h"
17 static int b64_write(BIO *h, const char *buf, int num);
18 static int b64_read(BIO *h, char *buf, int size);
19 static int b64_puts(BIO *h, const char *str);
20 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
21 static int b64_new(BIO *h);
22 static int b64_free(BIO *data);
23 static long b64_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
24 #define B64_BLOCK_SIZE 1024
25 #define B64_BLOCK_SIZE2 768
30 typedef struct b64_struct {
32 * BIO *bio; moved to the BIO structure
36 int tmp_len; /* used to find the start when decoding */
37 int tmp_nl; /* If true, scan until '\n' */
39 int start; /* have we started decoding yet? */
40 int cont; /* <= 0 when finished */
41 EVP_ENCODE_CTX *base64;
42 char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
43 char tmp[B64_BLOCK_SIZE];
46 static const BIO_METHOD methods_b64 = {
49 /* TODO: Convert to new style write function */
52 /* TODO: Convert to new style read function */
64 const BIO_METHOD *BIO_f_base64(void)
69 static int b64_new(BIO *bi)
73 ctx = OPENSSL_zalloc(sizeof(*ctx));
79 ctx->base64 = EVP_ENCODE_CTX_new();
80 if (ctx->base64 == NULL) {
85 BIO_set_data(bi, ctx);
91 static int b64_free(BIO *a)
97 ctx = BIO_get_data(a);
101 EVP_ENCODE_CTX_free(ctx->base64);
103 BIO_set_data(a, NULL);
109 static int b64_read(BIO *b, char *out, int outl)
111 int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
113 unsigned char *p, *q;
118 ctx = (BIO_B64_CTX *)BIO_get_data(b);
121 if ((ctx == NULL) || (next == NULL))
124 BIO_clear_retry_flags(b);
126 if (ctx->encode != B64_DECODE) {
127 ctx->encode = B64_DECODE;
131 EVP_DecodeInit(ctx->base64);
134 /* First check if there are bytes decoded/encoded */
135 if (ctx->buf_len > 0) {
136 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
137 i = ctx->buf_len - ctx->buf_off;
140 OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
141 memcpy(out, &(ctx->buf[ctx->buf_off]), i);
146 if (ctx->buf_len == ctx->buf_off) {
153 * At this point, we have room of outl bytes and an empty buffer, so we
154 * should read in some more.
162 i = BIO_read(next, &(ctx->tmp[ctx->tmp_len]),
163 B64_BLOCK_SIZE - ctx->tmp_len);
168 /* Should we continue next time we are called? */
169 if (!BIO_should_retry(next)) {
171 /* If buffer empty break */
172 if (ctx->tmp_len == 0)
174 /* Fall through and process what we have */
178 /* else we retry and add more data to buffer */
186 * We need to scan, a line at a time until we have a valid line if we
189 if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
192 } else if (ctx->start) {
193 q = p = (unsigned char *)ctx->tmp;
195 for (j = 0; j < i; j++) {
200 * due to a previous very long line, we need to keep on
201 * scanning for a '\n' before we even start looking for
202 * base64 encoded stuff.
210 k = EVP_DecodeUpdate(ctx->base64,
211 (unsigned char *)ctx->buf,
213 if ((k <= 0) && (num == 0) && (ctx->start))
214 EVP_DecodeInit(ctx->base64);
216 if (p != (unsigned char *)
218 i -= (p - (unsigned char *)
220 for (x = 0; x < i; x++)
223 EVP_DecodeInit(ctx->base64);
230 /* we fell off the end without starting */
231 if ((j == i) && (num == 0)) {
233 * Is this is one long chunk?, if so, keep on reading until a
236 if (p == (unsigned char *)&(ctx->tmp[0])) {
237 /* Check buffer full */
238 if (i == B64_BLOCK_SIZE) {
242 } else if (p != q) { /* finished on a '\n' */
244 for (ii = 0; ii < n; ii++)
245 ctx->tmp[ii] = p[ii];
248 /* else finished on a '\n' */
253 } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
255 * If buffer isn't full and we can retry then restart to read in
261 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
264 jj = i & ~3; /* process per 4 */
265 z = EVP_DecodeBlock((unsigned char *)ctx->buf,
266 (unsigned char *)ctx->tmp, jj);
268 if (ctx->tmp[jj - 1] == '=') {
270 if (ctx->tmp[jj - 2] == '=')
275 * z is now number of output bytes and jj is the number consumed
278 memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
279 ctx->tmp_len = i - jj;
287 i = EVP_DecodeUpdate(ctx->base64,
288 (unsigned char *)ctx->buf, &ctx->buf_len,
289 (unsigned char *)ctx->tmp, i);
299 if (ctx->buf_len <= outl)
304 memcpy(out, ctx->buf, i);
307 if (ctx->buf_off == ctx->buf_len) {
314 /* BIO_clear_retry_flags(b); */
315 BIO_copy_next_retry(b);
316 return ((ret == 0) ? ret_code : ret);
319 static int b64_write(BIO *b, const char *in, int inl)
327 ctx = (BIO_B64_CTX *)BIO_get_data(b);
329 if ((ctx == NULL) || (next == NULL))
332 BIO_clear_retry_flags(b);
334 if (ctx->encode != B64_ENCODE) {
335 ctx->encode = B64_ENCODE;
339 EVP_EncodeInit(ctx->base64);
342 OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
343 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
344 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
345 n = ctx->buf_len - ctx->buf_off;
347 i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
349 BIO_copy_next_retry(b);
352 OPENSSL_assert(i <= n);
354 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
355 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
358 /* at this point all pending data has been written */
362 if ((in == NULL) || (inl <= 0))
366 n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;
368 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
369 if (ctx->tmp_len > 0) {
370 OPENSSL_assert(ctx->tmp_len <= 3);
371 n = 3 - ctx->tmp_len;
373 * There's a theoretical possibility for this
377 memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
380 if (ctx->tmp_len < 3)
383 EVP_EncodeBlock((unsigned char *)ctx->buf,
384 (unsigned char *)ctx->tmp, ctx->tmp_len);
385 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
386 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
388 * Since we're now done using the temporary buffer, the
389 * length should be 0'd
394 memcpy(ctx->tmp, in, n);
401 EVP_EncodeBlock((unsigned char *)ctx->buf,
402 (const unsigned char *)in, n);
403 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
404 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
408 if (!EVP_EncodeUpdate(ctx->base64,
409 (unsigned char *)ctx->buf, &ctx->buf_len,
410 (unsigned char *)in, n))
411 return ((ret == 0) ? -1 : ret);
412 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
413 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
422 i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
424 BIO_copy_next_retry(b);
425 return ((ret == 0) ? i : ret);
427 OPENSSL_assert(i <= n);
430 OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
431 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
439 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
446 ctx = (BIO_B64_CTX *)BIO_get_data(b);
448 if ((ctx == NULL) || (next == NULL))
455 ctx->encode = B64_NONE;
456 ret = BIO_ctrl(next, cmd, num, ptr);
458 case BIO_CTRL_EOF: /* More to read */
462 ret = BIO_ctrl(next, cmd, num, ptr);
464 case BIO_CTRL_WPENDING: /* More to write in buffer */
465 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
466 ret = ctx->buf_len - ctx->buf_off;
467 if ((ret == 0) && (ctx->encode != B64_NONE)
468 && (EVP_ENCODE_CTX_num(ctx->base64) != 0))
471 ret = BIO_ctrl(next, cmd, num, ptr);
473 case BIO_CTRL_PENDING: /* More to read in buffer */
474 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
475 ret = ctx->buf_len - ctx->buf_off;
477 ret = BIO_ctrl(next, cmd, num, ptr);
480 /* do a final write */
482 while (ctx->buf_len != ctx->buf_off) {
483 i = b64_write(b, NULL, 0);
487 if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
488 if (ctx->tmp_len != 0) {
489 ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
490 (unsigned char *)ctx->tmp,
496 } else if (ctx->encode != B64_NONE
497 && EVP_ENCODE_CTX_num(ctx->base64) != 0) {
499 EVP_EncodeFinal(ctx->base64,
500 (unsigned char *)ctx->buf, &(ctx->buf_len));
501 /* push out the bytes */
504 /* Finally flush the underlying BIO */
505 ret = BIO_ctrl(next, cmd, num, ptr);
508 case BIO_C_DO_STATE_MACHINE:
509 BIO_clear_retry_flags(b);
510 ret = BIO_ctrl(next, cmd, num, ptr);
511 BIO_copy_next_retry(b);
520 ret = BIO_ctrl(next, cmd, num, ptr);
526 static long b64_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
529 BIO *next = BIO_next(b);
535 ret = BIO_callback_ctrl(next, cmd, fp);
541 static int b64_puts(BIO *b, const char *str)
543 return b64_write(b, str, strlen(str));