crypto/evp/bio_b64.c - third_party/openssl - Git at Google

 /*
  * Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
  *
  * Licensed under the Apache License 2.0 (the "License").  You may not use
  * this file except in compliance with the License.  You can obtain a copy
  * in the file LICENSE in the source distribution or at
  * https://www.openssl.org/source/license.html
  */

 #include <stdio.h>
 #include <errno.h>
 #include "internal/cryptlib.h"
 #include <openssl/buffer.h>
 #include <openssl/evp.h>
 #include "internal/bio.h"

 static int b64_write(BIO *h, const char *buf, int num);
 static int b64_read(BIO *h, char *buf, int size);
 static int b64_puts(BIO *h, const char *str);
 static long b64_ctrl(BIO *h, int cmd, long arg1, void *arg2);
 static int b64_new(BIO *h);
 static int b64_free(BIO *data);
 static long b64_callback_ctrl(BIO *h, int cmd, BIO_info_cb *fp);
 #define B64_BLOCK_SIZE  1024
 #define B64_BLOCK_SIZE2 768
 #define B64_NONE        0
 #define B64_ENCODE      1
 #define B64_DECODE      2

 typedef struct b64_struct {
     /*
      * BIO *bio; moved to the BIO structure
      */
     int buf_len;
     int buf_off;
     int tmp_len;                /* used to find the start when decoding */
     int tmp_nl;                 /* If true, scan until '\n' */
     int encode;
     int start;                  /* have we started decoding yet? */
     int cont;                   /* <= 0 when finished */
     EVP_ENCODE_CTX *base64;
     char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
     char tmp[B64_BLOCK_SIZE];
 } BIO_B64_CTX;

 static const BIO_METHOD methods_b64 = {
     BIO_TYPE_BASE64,
     "base64 encoding",
     bwrite_conv,
     b64_write,
     bread_conv,
     b64_read,
     b64_puts,
     NULL,                       /* b64_gets, */
     b64_ctrl,
     b64_new,
     b64_free,
     b64_callback_ctrl,
 };


 const BIO_METHOD *BIO_f_base64(void)
 {
     return &methods_b64;
 }

 static int b64_new(BIO *bi)
 {
     BIO_B64_CTX *ctx;

     if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
         ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
         return 0;
     }

     ctx->cont = 1;
     ctx->start = 1;
     ctx->base64 = EVP_ENCODE_CTX_new();
     if (ctx->base64 == NULL) {
         OPENSSL_free(ctx);
         return 0;
     }

     BIO_set_data(bi, ctx);
     BIO_set_init(bi, 1);

     return 1;
 }

 static int b64_free(BIO *a)
 {
     BIO_B64_CTX *ctx;
     if (a == NULL)
         return 0;

     ctx = BIO_get_data(a);
     if (ctx == NULL)
         return 0;

     EVP_ENCODE_CTX_free(ctx->base64);
     OPENSSL_free(ctx);
     BIO_set_data(a, NULL);
     BIO_set_init(a, 0);

     return 1;
 }

 static int b64_read(BIO *b, char *out, int outl)
 {
     int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
     BIO_B64_CTX *ctx;
     unsigned char *p, *q;
     BIO *next;

     if (out == NULL)
         return 0;
     ctx = (BIO_B64_CTX *)BIO_get_data(b);

     next = BIO_next(b);
     if ((ctx == NULL) || (next == NULL))
         return 0;

     BIO_clear_retry_flags(b);

     if (ctx->encode != B64_DECODE) {
         ctx->encode = B64_DECODE;
         ctx->buf_len = 0;
         ctx->buf_off = 0;
         ctx->tmp_len = 0;
         EVP_DecodeInit(ctx->base64);
     }

     /* First check if there are bytes decoded/encoded */
     if (ctx->buf_len > 0) {
         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
         i = ctx->buf_len - ctx->buf_off;
         if (i > outl)
             i = outl;
         OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
         memcpy(out, &(ctx->buf[ctx->buf_off]), i);
         ret = i;
         out += i;
         outl -= i;
         ctx->buf_off += i;
         if (ctx->buf_len == ctx->buf_off) {
             ctx->buf_len = 0;
             ctx->buf_off = 0;
         }
     }

     /*
      * At this point, we have room of outl bytes and an empty buffer, so we
      * should read in some more.
      */

     ret_code = 0;
     while (outl > 0) {
         if (ctx->cont <= 0)
             break;

         i = BIO_read(next, &(ctx->tmp[ctx->tmp_len]),
                      B64_BLOCK_SIZE - ctx->tmp_len);

         if (i <= 0) {
             ret_code = i;

             /* Should we continue next time we are called? */
             if (!BIO_should_retry(next)) {
                 ctx->cont = i;
                 /* If buffer empty break */
                 if (ctx->tmp_len == 0)
                     break;
                 /* Fall through and process what we have */
                 else
                     i = 0;
             }
             /* else we retry and add more data to buffer */
             else
                 break;
         }
         i += ctx->tmp_len;
         ctx->tmp_len = i;

         /*
          * We need to scan, a line at a time until we have a valid line if we
          * are starting.
          */
         if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
             /* ctx->start=1; */
             ctx->tmp_len = 0;
         } else if (ctx->start) {
             q = p = (unsigned char *)ctx->tmp;
             num = 0;
             for (j = 0; j < i; j++) {
                 if (*(q++) != '\n')
                     continue;

                 /*
                  * due to a previous very long line, we need to keep on
                  * scanning for a '\n' before we even start looking for
                  * base64 encoded stuff.
                  */
                 if (ctx->tmp_nl) {
                     p = q;
                     ctx->tmp_nl = 0;
                     continue;
                 }

                 k = EVP_DecodeUpdate(ctx->base64,
                                      (unsigned char *)ctx->buf,
                                      &num, p, q - p);
                 if ((k <= 0) && (num == 0) && (ctx->start))
                     EVP_DecodeInit(ctx->base64);
                 else {
                     if (p != (unsigned char *)
                         &(ctx->tmp[0])) {
                         i -= (p - (unsigned char *)
                               &(ctx->tmp[0]));
                         for (x = 0; x < i; x++)
                             ctx->tmp[x] = p[x];
                     }
                     EVP_DecodeInit(ctx->base64);
                     ctx->start = 0;
                     break;
                 }
                 p = q;
             }

             /* we fell off the end without starting */
             if ((j == i) && (num == 0)) {
                 /*
                  * Is this is one long chunk?, if so, keep on reading until a
                  * new line.
                  */
                 if (p == (unsigned char *)&(ctx->tmp[0])) {
                     /* Check buffer full */
                     if (i == B64_BLOCK_SIZE) {
                         ctx->tmp_nl = 1;
                         ctx->tmp_len = 0;
                     }
                 } else if (p != q) { /* finished on a '\n' */
                     n = q - p;
                     for (ii = 0; ii < n; ii++)
                         ctx->tmp[ii] = p[ii];
                     ctx->tmp_len = n;
                 }
                 /* else finished on a '\n' */
                 continue;
             } else {
                 ctx->tmp_len = 0;
             }
         } else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
             /*
              * If buffer isn't full and we can retry then restart to read in
              * more data.
              */
             continue;
         }

         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
             int z, jj;

             jj = i & ~3;        /* process per 4 */
             z = EVP_DecodeBlock((unsigned char *)ctx->buf,
                                 (unsigned char *)ctx->tmp, jj);
             if (jj > 2) {
                 if (ctx->tmp[jj - 1] == '=') {
                     z--;
                     if (ctx->tmp[jj - 2] == '=')
                         z--;
                 }
             }
             /*
              * z is now number of output bytes and jj is the number consumed
              */
             if (jj != i) {
                 memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
                 ctx->tmp_len = i - jj;
             }
             ctx->buf_len = 0;
             if (z > 0) {
                 ctx->buf_len = z;
             }
             i = z;
         } else {
             i = EVP_DecodeUpdate(ctx->base64,
                                  (unsigned char *)ctx->buf, &ctx->buf_len,
                                  (unsigned char *)ctx->tmp, i);
             ctx->tmp_len = 0;
         }
         /*
          * If eof or an error was signalled, then the condition
          * 'ctx->cont <= 0' will prevent b64_read() from reading
          * more data on subsequent calls. This assignment was
          * deleted accidentally in commit 5562cfaca4f3.
          */
         ctx->cont = i;

         ctx->buf_off = 0;
         if (i < 0) {
             ret_code = 0;
             ctx->buf_len = 0;
             break;
         }

         if (ctx->buf_len <= outl)
             i = ctx->buf_len;
         else
             i = outl;

         memcpy(out, ctx->buf, i);
         ret += i;
         ctx->buf_off = i;
         if (ctx->buf_off == ctx->buf_len) {
             ctx->buf_len = 0;
             ctx->buf_off = 0;
         }
         outl -= i;
         out += i;
     }
     /* BIO_clear_retry_flags(b); */
     BIO_copy_next_retry(b);
     return ((ret == 0) ? ret_code : ret);
 }

 static int b64_write(BIO *b, const char *in, int inl)
 {
     int ret = 0;
     int n;
     int i;
     BIO_B64_CTX *ctx;
     BIO *next;

     ctx = (BIO_B64_CTX *)BIO_get_data(b);
     next = BIO_next(b);
     if ((ctx == NULL) || (next == NULL))
         return 0;

     BIO_clear_retry_flags(b);

     if (ctx->encode != B64_ENCODE) {
         ctx->encode = B64_ENCODE;
         ctx->buf_len = 0;
         ctx->buf_off = 0;
         ctx->tmp_len = 0;
         EVP_EncodeInit(ctx->base64);
     }

     OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
     OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
     OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
     n = ctx->buf_len - ctx->buf_off;
     while (n > 0) {
         i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
         if (i <= 0) {
             BIO_copy_next_retry(b);
             return i;
         }
         OPENSSL_assert(i <= n);
         ctx->buf_off += i;
         OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
         n -= i;
     }
     /* at this point all pending data has been written */
     ctx->buf_off = 0;
     ctx->buf_len = 0;

     if ((in == NULL) || (inl <= 0))
         return 0;

     while (inl > 0) {
         n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;

         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
             if (ctx->tmp_len > 0) {
                 OPENSSL_assert(ctx->tmp_len <= 3);
                 n = 3 - ctx->tmp_len;
                 /*
                  * There's a theoretical possibility for this
                  */
                 if (n > inl)
                     n = inl;
                 memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
                 ctx->tmp_len += n;
                 ret += n;
                 if (ctx->tmp_len < 3)
                     break;
                 ctx->buf_len =
                     EVP_EncodeBlock((unsigned char *)ctx->buf,
                                     (unsigned char *)ctx->tmp, ctx->tmp_len);
                 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
                 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
                 /*
                  * Since we're now done using the temporary buffer, the
                  * length should be 0'd
                  */
                 ctx->tmp_len = 0;
             } else {
                 if (n < 3) {
                     memcpy(ctx->tmp, in, n);
                     ctx->tmp_len = n;
                     ret += n;
                     break;
                 }
                 n -= n % 3;
                 ctx->buf_len =
                     EVP_EncodeBlock((unsigned char *)ctx->buf,
                                     (const unsigned char *)in, n);
                 OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
                 OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
                 ret += n;
             }
         } else {
             if (!EVP_EncodeUpdate(ctx->base64,
                                  (unsigned char *)ctx->buf, &ctx->buf_len,
                                  (unsigned char *)in, n))
                 return ((ret == 0) ? -1 : ret);
             OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
             OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
             ret += n;
         }
         inl -= n;
         in += n;

         ctx->buf_off = 0;
         n = ctx->buf_len;
         while (n > 0) {
             i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
             if (i <= 0) {
                 BIO_copy_next_retry(b);
                 return ((ret == 0) ? i : ret);
             }
             OPENSSL_assert(i <= n);
             n -= i;
             ctx->buf_off += i;
             OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
             OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
         }
         ctx->buf_len = 0;
         ctx->buf_off = 0;
     }
     return ret;
 }

 static long b64_ctrl(BIO *b, int cmd, long num, void *ptr)
 {
     BIO_B64_CTX *ctx;
     long ret = 1;
     int i;
     BIO *next;

     ctx = (BIO_B64_CTX *)BIO_get_data(b);
     next = BIO_next(b);
     if ((ctx == NULL) || (next == NULL))
         return 0;

     switch (cmd) {
     case BIO_CTRL_RESET:
         ctx->cont = 1;
         ctx->start = 1;
         ctx->encode = B64_NONE;
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_EOF:         /* More to read */
         if (ctx->cont <= 0)
             ret = 1;
         else
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_WPENDING:    /* More to write in buffer */
         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
         ret = ctx->buf_len - ctx->buf_off;
         if ((ret == 0) && (ctx->encode != B64_NONE)
             && (EVP_ENCODE_CTX_num(ctx->base64) != 0))
             ret = 1;
         else if (ret <= 0)
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_PENDING:     /* More to read in buffer */
         OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
         ret = ctx->buf_len - ctx->buf_off;
         if (ret <= 0)
             ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     case BIO_CTRL_FLUSH:
         /* do a final write */
  again:
         while (ctx->buf_len != ctx->buf_off) {
             i = b64_write(b, NULL, 0);
             if (i < 0)
                 return i;
         }
         if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
             if (ctx->tmp_len != 0) {
                 ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
                                                (unsigned char *)ctx->tmp,
                                                ctx->tmp_len);
                 ctx->buf_off = 0;
                 ctx->tmp_len = 0;
                 goto again;
             }
         } else if (ctx->encode != B64_NONE
                    && EVP_ENCODE_CTX_num(ctx->base64) != 0) {
             ctx->buf_off = 0;
             EVP_EncodeFinal(ctx->base64,
                             (unsigned char *)ctx->buf, &(ctx->buf_len));
             /* push out the bytes */
             goto again;
         }
         /* Finally flush the underlying BIO */
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;

     case BIO_C_DO_STATE_MACHINE:
         BIO_clear_retry_flags(b);
         ret = BIO_ctrl(next, cmd, num, ptr);
         BIO_copy_next_retry(b);
         break;

     case BIO_CTRL_DUP:
         break;
     case BIO_CTRL_INFO:
     case BIO_CTRL_GET:
     case BIO_CTRL_SET:
     default:
         ret = BIO_ctrl(next, cmd, num, ptr);
         break;
     }
     return ret;
 }

 static long b64_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp)
 {
     BIO *next = BIO_next(b);

     if (next == NULL)
         return 0;

     return BIO_callback_ctrl(next, cmd, fp);
 }

 static int b64_puts(BIO *b, const char *str)
 {
     return b64_write(b, str, strlen(str));
 }
	/*
	* Copyright 1995-2021 The OpenSSL Project Authors. All Rights Reserved.
	*
	* Licensed under the Apache License 2.0 (the "License"). You may not use
	* this file except in compliance with the License. You can obtain a copy
	* in the file LICENSE in the source distribution or at
	* https://www.openssl.org/source/license.html
	*/

	#include <stdio.h>
	#include <errno.h>
	#include "internal/cryptlib.h"
	#include <openssl/buffer.h>
	#include <openssl/evp.h>
	#include "internal/bio.h"

	static int b64_write(BIO h, const char buf, int num);
	static int b64_read(BIO h, char buf, int size);
	static int b64_puts(BIO h, const char str);
	static long b64_ctrl(BIO h, int cmd, long arg1, void arg2);
	static int b64_new(BIO *h);
	static int b64_free(BIO *data);
	static long b64_callback_ctrl(BIO h, int cmd, BIO_info_cb fp);
	#define B64_BLOCK_SIZE 1024
	#define B64_BLOCK_SIZE2 768
	#define B64_NONE 0
	#define B64_ENCODE 1
	#define B64_DECODE 2

	typedef struct b64_struct {
	/*
	* BIO *bio; moved to the BIO structure
	*/
	int buf_len;
	int buf_off;
	int tmp_len; /* used to find the start when decoding */
	int tmp_nl; /* If true, scan until '\n' */
	int encode;
	int start; /* have we started decoding yet? */
	int cont; /* <= 0 when finished */
	EVP_ENCODE_CTX *base64;
	char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
	char tmp[B64_BLOCK_SIZE];
	} BIO_B64_CTX;

	static const BIO_METHOD methods_b64 = {
	BIO_TYPE_BASE64,
	"base64 encoding",
	bwrite_conv,
	b64_write,
	bread_conv,
	b64_read,
	b64_puts,
	NULL, /* b64_gets, */
	b64_ctrl,
	b64_new,
	b64_free,
	b64_callback_ctrl,
	};


	const BIO_METHOD *BIO_f_base64(void)
	{
	return &methods_b64;
	}

	static int b64_new(BIO *bi)
	{
	BIO_B64_CTX *ctx;

	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL) {
	ERR_raise(ERR_LIB_EVP, ERR_R_MALLOC_FAILURE);
	return 0;
	}

	ctx->cont = 1;
	ctx->start = 1;
	ctx->base64 = EVP_ENCODE_CTX_new();
	if (ctx->base64 == NULL) {
	OPENSSL_free(ctx);
	return 0;
	}

	BIO_set_data(bi, ctx);
	BIO_set_init(bi, 1);

	return 1;
	}

	static int b64_free(BIO *a)
	{
	BIO_B64_CTX *ctx;
	if (a == NULL)
	return 0;

	ctx = BIO_get_data(a);
	if (ctx == NULL)
	return 0;

	EVP_ENCODE_CTX_free(ctx->base64);
	OPENSSL_free(ctx);
	BIO_set_data(a, NULL);
	BIO_set_init(a, 0);

	return 1;
	}

	static int b64_read(BIO b, char out, int outl)
	{
	int ret = 0, i, ii, j, k, x, n, num, ret_code = 0;
	BIO_B64_CTX *ctx;
	unsigned char p, q;
	BIO *next;

	if (out == NULL)
	return 0;
	ctx = (BIO_B64_CTX *)BIO_get_data(b);

	next = BIO_next(b);
	if ((ctx == NULL) \|\| (next == NULL))
	return 0;

	BIO_clear_retry_flags(b);

	if (ctx->encode != B64_DECODE) {
	ctx->encode = B64_DECODE;
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	ctx->tmp_len = 0;
	EVP_DecodeInit(ctx->base64);
	}

	/* First check if there are bytes decoded/encoded */
	if (ctx->buf_len > 0) {
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	i = ctx->buf_len - ctx->buf_off;
	if (i > outl)
	i = outl;
	OPENSSL_assert(ctx->buf_off + i < (int)sizeof(ctx->buf));
	memcpy(out, &(ctx->buf[ctx->buf_off]), i);
	ret = i;
	out += i;
	outl -= i;
	ctx->buf_off += i;
	if (ctx->buf_len == ctx->buf_off) {
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	}
	}

	/*
	* At this point, we have room of outl bytes and an empty buffer, so we
	* should read in some more.
	*/

	ret_code = 0;
	while (outl > 0) {
	if (ctx->cont <= 0)
	break;

	i = BIO_read(next, &(ctx->tmp[ctx->tmp_len]),
	B64_BLOCK_SIZE - ctx->tmp_len);

	if (i <= 0) {
	ret_code = i;

	/* Should we continue next time we are called? */
	if (!BIO_should_retry(next)) {
	ctx->cont = i;
	/* If buffer empty break */
	if (ctx->tmp_len == 0)
	break;
	/* Fall through and process what we have */
	else
	i = 0;
	}
	/* else we retry and add more data to buffer */
	else
	break;
	}
	i += ctx->tmp_len;
	ctx->tmp_len = i;

	/*
	* We need to scan, a line at a time until we have a valid line if we
	* are starting.
	*/
	if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)) {
	/* ctx->start=1; */
	ctx->tmp_len = 0;
	} else if (ctx->start) {
	q = p = (unsigned char *)ctx->tmp;
	num = 0;
	for (j = 0; j < i; j++) {
	if (*(q++) != '\n')
	continue;

	/*
	* due to a previous very long line, we need to keep on
	* scanning for a '\n' before we even start looking for
	* base64 encoded stuff.
	*/
	if (ctx->tmp_nl) {
	p = q;
	ctx->tmp_nl = 0;
	continue;
	}

	k = EVP_DecodeUpdate(ctx->base64,
	(unsigned char *)ctx->buf,
	&num, p, q - p);
	if ((k <= 0) && (num == 0) && (ctx->start))
	EVP_DecodeInit(ctx->base64);
	else {
	if (p != (unsigned char *)
	&(ctx->tmp[0])) {
	i -= (p - (unsigned char *)
	&(ctx->tmp[0]));
	for (x = 0; x < i; x++)
	ctx->tmp[x] = p[x];
	}
	EVP_DecodeInit(ctx->base64);
	ctx->start = 0;
	break;
	}
	p = q;
	}

	/* we fell off the end without starting */
	if ((j == i) && (num == 0)) {
	/*
	* Is this is one long chunk?, if so, keep on reading until a
	* new line.
	*/
	if (p == (unsigned char *)&(ctx->tmp[0])) {
	/* Check buffer full */
	if (i == B64_BLOCK_SIZE) {
	ctx->tmp_nl = 1;
	ctx->tmp_len = 0;
	}
	} else if (p != q) { /* finished on a '\n' */
	n = q - p;
	for (ii = 0; ii < n; ii++)
	ctx->tmp[ii] = p[ii];
	ctx->tmp_len = n;
	}
	/* else finished on a '\n' */
	continue;
	} else {
	ctx->tmp_len = 0;
	}
	} else if ((i < B64_BLOCK_SIZE) && (ctx->cont > 0)) {
	/*
	* If buffer isn't full and we can retry then restart to read in
	* more data.
	*/
	continue;
	}

	if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
	int z, jj;

	jj = i & ~3; /* process per 4 */
	z = EVP_DecodeBlock((unsigned char *)ctx->buf,
	(unsigned char *)ctx->tmp, jj);
	if (jj > 2) {
	if (ctx->tmp[jj - 1] == '=') {
	z--;
	if (ctx->tmp[jj - 2] == '=')
	z--;
	}
	}
	/*
	* z is now number of output bytes and jj is the number consumed
	*/
	if (jj != i) {
	memmove(ctx->tmp, &ctx->tmp[jj], i - jj);
	ctx->tmp_len = i - jj;
	}
	ctx->buf_len = 0;
	if (z > 0) {
	ctx->buf_len = z;
	}
	i = z;
	} else {
	i = EVP_DecodeUpdate(ctx->base64,
	(unsigned char *)ctx->buf, &ctx->buf_len,
	(unsigned char *)ctx->tmp, i);
	ctx->tmp_len = 0;
	}
	/*
	* If eof or an error was signalled, then the condition
	* 'ctx->cont <= 0' will prevent b64_read() from reading
	* more data on subsequent calls. This assignment was
	* deleted accidentally in commit 5562cfaca4f3.
	*/
	ctx->cont = i;

	ctx->buf_off = 0;
	if (i < 0) {
	ret_code = 0;
	ctx->buf_len = 0;
	break;
	}

	if (ctx->buf_len <= outl)
	i = ctx->buf_len;
	else
	i = outl;

	memcpy(out, ctx->buf, i);
	ret += i;
	ctx->buf_off = i;
	if (ctx->buf_off == ctx->buf_len) {
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	}
	outl -= i;
	out += i;
	}
	/* BIO_clear_retry_flags(b); */
	BIO_copy_next_retry(b);
	return ((ret == 0) ? ret_code : ret);
	}

	static int b64_write(BIO b, const char in, int inl)
	{
	int ret = 0;
	int n;
	int i;
	BIO_B64_CTX *ctx;
	BIO *next;

	ctx = (BIO_B64_CTX *)BIO_get_data(b);
	next = BIO_next(b);
	if ((ctx == NULL) \|\| (next == NULL))
	return 0;

	BIO_clear_retry_flags(b);

	if (ctx->encode != B64_ENCODE) {
	ctx->encode = B64_ENCODE;
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	ctx->tmp_len = 0;
	EVP_EncodeInit(ctx->base64);
	}

	OPENSSL_assert(ctx->buf_off < (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	n = ctx->buf_len - ctx->buf_off;
	while (n > 0) {
	i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
	if (i <= 0) {
	BIO_copy_next_retry(b);
	return i;
	}
	OPENSSL_assert(i <= n);
	ctx->buf_off += i;
	OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	n -= i;
	}
	/* at this point all pending data has been written */
	ctx->buf_off = 0;
	ctx->buf_len = 0;

	if ((in == NULL) \|\| (inl <= 0))
	return 0;

	while (inl > 0) {
	n = (inl > B64_BLOCK_SIZE) ? B64_BLOCK_SIZE : inl;

	if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
	if (ctx->tmp_len > 0) {
	OPENSSL_assert(ctx->tmp_len <= 3);
	n = 3 - ctx->tmp_len;
	/*
	* There's a theoretical possibility for this
	*/
	if (n > inl)
	n = inl;
	memcpy(&(ctx->tmp[ctx->tmp_len]), in, n);
	ctx->tmp_len += n;
	ret += n;
	if (ctx->tmp_len < 3)
	break;
	ctx->buf_len =
	EVP_EncodeBlock((unsigned char *)ctx->buf,
	(unsigned char *)ctx->tmp, ctx->tmp_len);
	OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	/*
	* Since we're now done using the temporary buffer, the
	* length should be 0'd
	*/
	ctx->tmp_len = 0;
	} else {
	if (n < 3) {
	memcpy(ctx->tmp, in, n);
	ctx->tmp_len = n;
	ret += n;
	break;
	}
	n -= n % 3;
	ctx->buf_len =
	EVP_EncodeBlock((unsigned char *)ctx->buf,
	(const unsigned char *)in, n);
	OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	ret += n;
	}
	} else {
	if (!EVP_EncodeUpdate(ctx->base64,
	(unsigned char *)ctx->buf, &ctx->buf_len,
	(unsigned char *)in, n))
	return ((ret == 0) ? -1 : ret);
	OPENSSL_assert(ctx->buf_len <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	ret += n;
	}
	inl -= n;
	in += n;

	ctx->buf_off = 0;
	n = ctx->buf_len;
	while (n > 0) {
	i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
	if (i <= 0) {
	BIO_copy_next_retry(b);
	return ((ret == 0) ? i : ret);
	}
	OPENSSL_assert(i <= n);
	n -= i;
	ctx->buf_off += i;
	OPENSSL_assert(ctx->buf_off <= (int)sizeof(ctx->buf));
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	}
	ctx->buf_len = 0;
	ctx->buf_off = 0;
	}
	return ret;
	}

	static long b64_ctrl(BIO b, int cmd, long num, void ptr)
	{
	BIO_B64_CTX *ctx;
	long ret = 1;
	int i;
	BIO *next;

	ctx = (BIO_B64_CTX *)BIO_get_data(b);
	next = BIO_next(b);
	if ((ctx == NULL) \|\| (next == NULL))
	return 0;

	switch (cmd) {
	case BIO_CTRL_RESET:
	ctx->cont = 1;
	ctx->start = 1;
	ctx->encode = B64_NONE;
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_EOF: /* More to read */
	if (ctx->cont <= 0)
	ret = 1;
	else
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_WPENDING: /* More to write in buffer */
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	ret = ctx->buf_len - ctx->buf_off;
	if ((ret == 0) && (ctx->encode != B64_NONE)
	&& (EVP_ENCODE_CTX_num(ctx->base64) != 0))
	ret = 1;
	else if (ret <= 0)
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_PENDING: /* More to read in buffer */
	OPENSSL_assert(ctx->buf_len >= ctx->buf_off);
	ret = ctx->buf_len - ctx->buf_off;
	if (ret <= 0)
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	case BIO_CTRL_FLUSH:
	/* do a final write */
	again:
	while (ctx->buf_len != ctx->buf_off) {
	i = b64_write(b, NULL, 0);
	if (i < 0)
	return i;
	}
	if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) {
	if (ctx->tmp_len != 0) {
	ctx->buf_len = EVP_EncodeBlock((unsigned char *)ctx->buf,
	(unsigned char *)ctx->tmp,
	ctx->tmp_len);
	ctx->buf_off = 0;
	ctx->tmp_len = 0;
	goto again;
	}
	} else if (ctx->encode != B64_NONE
	&& EVP_ENCODE_CTX_num(ctx->base64) != 0) {
	ctx->buf_off = 0;
	EVP_EncodeFinal(ctx->base64,
	(unsigned char *)ctx->buf, &(ctx->buf_len));
	/* push out the bytes */
	goto again;
	}
	/* Finally flush the underlying BIO */
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;

	case BIO_C_DO_STATE_MACHINE:
	BIO_clear_retry_flags(b);
	ret = BIO_ctrl(next, cmd, num, ptr);
	BIO_copy_next_retry(b);
	break;

	case BIO_CTRL_DUP:
	break;
	case BIO_CTRL_INFO:
	case BIO_CTRL_GET:
	case BIO_CTRL_SET:
	default:
	ret = BIO_ctrl(next, cmd, num, ptr);
	break;
	}
	return ret;
	}

	static long b64_callback_ctrl(BIO b, int cmd, BIO_info_cb fp)
	{
	BIO *next = BIO_next(b);

	if (next == NULL)
	return 0;

	return BIO_callback_ctrl(next, cmd, fp);
	}

	static int b64_puts(BIO b, const char str)
	{
	return b64_write(b, str, strlen(str));
	}