/src/openssl/crypto/evp/bio_b64.c

Source
/*
 * Copyright 1995-2025 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"
#include "crypto/evp.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;
    unsigned char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
    unsigned char tmp[B64_BLOCK_SIZE];
    unsigned char *encoded_buf;
    size_t encoded_buf_len;
} 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)
        return 0;

    ctx->cont = 1;
    ctx->start = 1;
    ctx->encoded_buf = NULL;
    ctx->encoded_buf_len = 0;
    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;

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

    return 1;
}

/*
 * Unless `BIO_FLAGS_BASE64_NO_NL` is set, this BIO ignores leading lines that
 * aren't exclusively composed of valid Base64 characters (followed by <CRLF>
 * or <LF>).  Once a valid Base64 line is found, `ctx->start` is set to 0 and
 * lines are processed until EOF or the first line that contains invalid Base64
 * characters.  In a nod to PEM, lines that start with a '-' (hyphen) are
 * treated as a soft EOF, rather than an error.
 */
static int b64_read(BIO *b, char *out, int outl)
{
    int ret = 0, i, ii, j, k, x, n, num, ret_code;
    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 buffered bytes already decoded */
    if (ctx->buf_len > 0) {
        if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        i = ctx->buf_len - ctx->buf_off;
        if (i > outl)
            i = outl;
        if (!ossl_assert(ctx->buf_off + i < (int)sizeof(ctx->buf))) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        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;
        }
    }

    /* Restore any non-retriable error condition (ctx->cont < 0) */
    ret_code = ctx->cont < 0 ? ctx->cont : 0;

    /*
     * At this point, we have room of outl bytes and an either an empty buffer,
     * or outl == 0, so we'll attempt to read in some more.
     */
    while (outl > 0) {
        int again = ctx->cont;

        if (again <= 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)) {
                /* Incomplete final Base64 chunk in the decoder is an error */
                if (ctx->tmp_len == 0) {
                    if (EVP_DecodeFinal(ctx->base64, NULL, &num) < 0)
                        ret_code = -1;
                    EVP_DecodeInit(ctx->base64);
                }
                ctx->cont = ret_code;
            }
            if (ctx->tmp_len == 0)
                break;
            /* Fall through and process what we have */
            i = 0;
            /* But don't loop to top-up even if the buffer is not full! */
            again = 0;
        }

        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) != 0) {
            ctx->tmp_len = 0;
        } else if (ctx->start) {
            q = p = 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, ctx->buf, &num, p, (int)(q - p));
                EVP_DecodeInit(ctx->base64);
                if (k <= 0 && num == 0) {
                    p = q;
                    continue;
                }

                ctx->start = 0;
                if (p != ctx->tmp) {
                    i -= (int)(p - ctx->tmp);
                    for (x = 0; x < i; x++)
                        ctx->tmp[x] = p[x];
                }
                break;
            }

            /* we fell off the end without starting */
            if (ctx->start) {
                /*
                 * Is this is one long chunk?, if so, keep on reading until a
                 * new line.
                 */
                if (p == ctx->tmp) {
                    /* Check buffer full */
                    if (i == B64_BLOCK_SIZE) {
                        ctx->tmp_nl = 1;
                        ctx->tmp_len = 0;
                    }
                } else if (p != q) {
                    /* Retain partial line at end of buffer */
                    n = (int)(q - p);
                    for (ii = 0; ii < n; ii++)
                        ctx->tmp[ii] = p[ii];
                    ctx->tmp_len = n;
                } else {
                    /* All we have is newline terminated non-start data */
                    ctx->tmp_len = 0;
                }
                /*
                 * Try to read more if possible, otherwise we can't make
                 * progress unless the underlying BIO is retriable and may
                 * produce more data next time we're called.
                 */
                if (again > 0)
                    continue;
                else
                    break;
            } else {
                ctx->tmp_len = 0;
            }
        } else if (i < B64_BLOCK_SIZE && again > 0) {
            /*
             * If buffer isn't full and we can retry then restart to read in
             * more data.
             */
            continue;
        }

        i = EVP_DecodeUpdate(ctx->base64, ctx->buf, &ctx->buf_len,
            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 = ctx->start ? 0 : i;
            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_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;
    int encoded_length;
    unsigned char *encoded;
    int n_bytes_enc;

    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);
        if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
            evp_encode_ctx_set_flags(ctx->base64, EVP_ENCODE_CTX_NO_NEWLINES);
    }
    if (!ossl_assert(ctx->buf_off < (int)sizeof(ctx->buf))) {
        ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
        return -1;
    }
    if (!ossl_assert(ctx->buf_len <= (int)sizeof(ctx->buf))) {
        ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
        return -1;
    }
    if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
        ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
        return -1;
    }
    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;
        }
        ctx->buf_off += i;
        if (!ossl_assert(ctx->buf_off <= (int)sizeof(ctx->buf))) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        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;

    encoded_length = EVP_ENCODE_LENGTH(inl);

    if (ctx->encoded_buf == NULL || (size_t)encoded_length > ctx->encoded_buf_len) {
        OPENSSL_free(ctx->encoded_buf);
        ctx->encoded_buf = OPENSSL_malloc(encoded_length);
        if (ctx->encoded_buf == NULL) {
            ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
            return -1;
        }
        ctx->encoded_buf_len = encoded_length;
    }

    encoded = ctx->encoded_buf;

    if (encoded == NULL) {
        ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
        return -1;
    }
    n_bytes_enc = 0;
    if (!EVP_EncodeUpdate(ctx->base64, encoded, &n_bytes_enc,
            (unsigned char *)in, inl)) {
        return -1;
    }
    ret += inl;
    i = BIO_write(next, encoded, n_bytes_enc);
    if (i <= 0)
        BIO_copy_next_retry(b);
    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 there is no ctx or no next BIO, BIO_read() returns 0, which means EOF.
     * BIO_eof() should return 1 in this case.
     */
    if (ctx == NULL || next == NULL)
        return cmd == BIO_CTRL_EOF;

    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 */
        if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        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 */
        if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
            ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
            return -1;
        }
        ret = ctx->buf_len - ctx->buf_off;
        if (ret <= 0)
            ret = BIO_ctrl(next, cmd, num, ptr);
        break;
    case BIO_CTRL_FLUSH:
        if (ctx->encode == B64_ENCODE) {
            /* do a final write */
        again:
            while (ctx->buf_len != ctx->buf_off) {
                i = b64_write(b, NULL, 0);
                if (i < 0)
                    return i;
            }
            if (EVP_ENCODE_CTX_num(ctx->base64) != 0) {
                ctx->buf_off = 0;
                EVP_EncodeFinal(ctx->base64, ctx->buf, &(ctx->buf_len));
                /* push out the bytes */
                goto again;
            }
        }
        /* Finally flush the underlying BIO */
        BIO_clear_retry_flags(b);
        ret = BIO_ctrl(next, cmd, num, ptr);
        BIO_copy_next_retry(b);
        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)
{
    size_t len = strlen(str);

    if (len > INT_MAX)
        return -1;
    return b64_write(b, str, (int)len);
}

Coverage Report

Created: 2026-03-09 06:55

Line	Count	Source
1		/*
2		* Copyright 1995-2025 The OpenSSL Project Authors. All Rights Reserved.
3		*
4		* Licensed under the Apache License 2.0 (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
8		*/
9
10		#include <stdio.h>
11		#include <errno.h>
12		#include "internal/cryptlib.h"
13		#include <openssl/buffer.h>
14		#include <openssl/evp.h>
15		#include "internal/bio.h"
16		#include "crypto/evp.h"
17
18		static int b64_write(BIO h, const char buf, int num);
19		static int b64_read(BIO h, char buf, int size);
20		static int b64_puts(BIO h, const char str);
21		static long b64_ctrl(BIO h, int cmd, long arg1, void arg2);
22		static int b64_new(BIO *h);
23		static int b64_free(BIO *data);
24		static long b64_callback_ctrl(BIO h, int cmd, BIO_info_cb fp);
25	0	#define B64_BLOCK_SIZE 1024
26		#define B64_BLOCK_SIZE2 768
27	0	#define B64_NONE 0
28	0	#define B64_ENCODE 1
29	0	#define B64_DECODE 2
30
31		typedef struct b64_struct {
32		/*
33		* BIO *bio; moved to the BIO structure
34		*/
35		int buf_len;
36		int buf_off;
37		int tmp_len; /* used to find the start when decoding */
38		int tmp_nl; /* If true, scan until '\n' */
39		int encode;
40		int start; /* have we started decoding yet? */
41		int cont; /* <= 0 when finished */
42		EVP_ENCODE_CTX *base64;
43		unsigned char buf[EVP_ENCODE_LENGTH(B64_BLOCK_SIZE) + 10];
44		unsigned char tmp[B64_BLOCK_SIZE];
45		unsigned char *encoded_buf;
46		size_t encoded_buf_len;
47		} BIO_B64_CTX;
48
49		static const BIO_METHOD methods_b64 = {
50		BIO_TYPE_BASE64,
51		"base64 encoding",
52		bwrite_conv,
53		b64_write,
54		bread_conv,
55		b64_read,
56		b64_puts,
57		NULL, /* b64_gets, */
58		b64_ctrl,
59		b64_new,
60		b64_free,
61		b64_callback_ctrl,
62		};
63
64		const BIO_METHOD *BIO_f_base64(void)
65	0	{
66	0	return &methods_b64;
67	0	}
68
69		static int b64_new(BIO *bi)
70	0	{
71	0	BIO_B64_CTX *ctx;
72
73	0	if ((ctx = OPENSSL_zalloc(sizeof(*ctx))) == NULL)
74	0	return 0;
75
76	0	ctx->cont = 1;
77	0	ctx->start = 1;
78	0	ctx->encoded_buf = NULL;
79	0	ctx->encoded_buf_len = 0;
80	0	ctx->base64 = EVP_ENCODE_CTX_new();
81	0	if (ctx->base64 == NULL) {
82	0	OPENSSL_free(ctx);
83	0	return 0;
84	0	}
85
86	0	BIO_set_data(bi, ctx);
87	0	BIO_set_init(bi, 1);
88
89	0	return 1;
90	0	}
91
92		static int b64_free(BIO *a)
93	0	{
94	0	BIO_B64_CTX *ctx;
95
96	0	if (a == NULL)
97	0	return 0;
98
99	0	ctx = BIO_get_data(a);
100	0	if (ctx == NULL)
101	0	return 0;
102
103	0	OPENSSL_free(ctx->encoded_buf);
104	0	ctx->encoded_buf = NULL;
105	0	ctx->encoded_buf_len = 0;
106	0	EVP_ENCODE_CTX_free(ctx->base64);
107	0	OPENSSL_free(ctx);
108	0	BIO_set_data(a, NULL);
109	0	BIO_set_init(a, 0);
110
111	0	return 1;
112	0	}
113
114		/*
115		* Unless `BIO_FLAGS_BASE64_NO_NL` is set, this BIO ignores leading lines that
116		* aren't exclusively composed of valid Base64 characters (followed by <CRLF>
117		* or <LF>). Once a valid Base64 line is found, `ctx->start` is set to 0 and
118		* lines are processed until EOF or the first line that contains invalid Base64
119		* characters. In a nod to PEM, lines that start with a '-' (hyphen) are
120		* treated as a soft EOF, rather than an error.
121		*/
122		static int b64_read(BIO b, char out, int outl)
123	0	{
124	0	int ret = 0, i, ii, j, k, x, n, num, ret_code;
125	0	BIO_B64_CTX *ctx;
126	0	unsigned char p, q;
127	0	BIO *next;
128
129	0	if (out == NULL)
130	0	return 0;
131	0	ctx = (BIO_B64_CTX *)BIO_get_data(b);
132
133	0	next = BIO_next(b);
134	0	if (ctx == NULL \|\| next == NULL)
135	0	return 0;
136
137	0	BIO_clear_retry_flags(b);
138
139	0	if (ctx->encode != B64_DECODE) {
140	0	ctx->encode = B64_DECODE;
141	0	ctx->buf_len = 0;
142	0	ctx->buf_off = 0;
143	0	ctx->tmp_len = 0;
144	0	EVP_DecodeInit(ctx->base64);
145	0	}
146
147		/* First check if there are buffered bytes already decoded */
148	0	if (ctx->buf_len > 0) {
149	0	if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
150	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
151	0	return -1;
152	0	}
153	0	i = ctx->buf_len - ctx->buf_off;
154	0	if (i > outl)
155	0	i = outl;
156	0	if (!ossl_assert(ctx->buf_off + i < (int)sizeof(ctx->buf))) {
157	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
158	0	return -1;
159	0	}
160	0	memcpy(out, &(ctx->buf[ctx->buf_off]), i);
161	0	ret = i;
162	0	out += i;
163	0	outl -= i;
164	0	ctx->buf_off += i;
165	0	if (ctx->buf_len == ctx->buf_off) {
166	0	ctx->buf_len = 0;
167	0	ctx->buf_off = 0;
168	0	}
169	0	}
170
171		/* Restore any non-retriable error condition (ctx->cont < 0) */
172	0	ret_code = ctx->cont < 0 ? ctx->cont : 0;
173
174		/*
175		* At this point, we have room of outl bytes and an either an empty buffer,
176		* or outl == 0, so we'll attempt to read in some more.
177		*/
178	0	while (outl > 0) {
179	0	int again = ctx->cont;
180
181	0	if (again <= 0)
182	0	break;
183
184	0	i = BIO_read(next, &(ctx->tmp[ctx->tmp_len]),
185	0	B64_BLOCK_SIZE - ctx->tmp_len);
186
187	0	if (i <= 0) {
188	0	ret_code = i;
189
190		/* Should we continue next time we are called? */
191	0	if (!BIO_should_retry(next)) {
192		/* Incomplete final Base64 chunk in the decoder is an error */
193	0	if (ctx->tmp_len == 0) {
194	0	if (EVP_DecodeFinal(ctx->base64, NULL, &num) < 0)
195	0	ret_code = -1;
196	0	EVP_DecodeInit(ctx->base64);
197	0	}
198	0	ctx->cont = ret_code;
199	0	}
200	0	if (ctx->tmp_len == 0)
201	0	break;
202		/* Fall through and process what we have */
203	0	i = 0;
204		/* But don't loop to top-up even if the buffer is not full! */
205	0	again = 0;
206	0	}
207
208	0	i += ctx->tmp_len;
209	0	ctx->tmp_len = i;
210
211		/*
212		* We need to scan, a line at a time until we have a valid line if we
213		* are starting.
214		*/
215	0	if (ctx->start && (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL) != 0) {
216	0	ctx->tmp_len = 0;
217	0	} else if (ctx->start) {
218	0	q = p = ctx->tmp;
219	0	num = 0;
220	0	for (j = 0; j < i; j++) {
221	0	if (*(q++) != '\n')
222	0	continue;
223
224		/*
225		* due to a previous very long line, we need to keep on
226		* scanning for a '\n' before we even start looking for
227		* base64 encoded stuff.
228		*/
229	0	if (ctx->tmp_nl) {
230	0	p = q;
231	0	ctx->tmp_nl = 0;
232	0	continue;
233	0	}
234
235	0	k = EVP_DecodeUpdate(ctx->base64, ctx->buf, &num, p, (int)(q - p));
236	0	EVP_DecodeInit(ctx->base64);
237	0	if (k <= 0 && num == 0) {
238	0	p = q;
239	0	continue;
240	0	}
241
242	0	ctx->start = 0;
243	0	if (p != ctx->tmp) {
244	0	i -= (int)(p - ctx->tmp);
245	0	for (x = 0; x < i; x++)
246	0	ctx->tmp[x] = p[x];
247	0	}
248	0	break;
249	0	}
250
251		/* we fell off the end without starting */
252	0	if (ctx->start) {
253		/*
254		* Is this is one long chunk?, if so, keep on reading until a
255		* new line.
256		*/
257	0	if (p == ctx->tmp) {
258		/* Check buffer full */
259	0	if (i == B64_BLOCK_SIZE) {
260	0	ctx->tmp_nl = 1;
261	0	ctx->tmp_len = 0;
262	0	}
263	0	} else if (p != q) {
264		/* Retain partial line at end of buffer */
265	0	n = (int)(q - p);
266	0	for (ii = 0; ii < n; ii++)
267	0	ctx->tmp[ii] = p[ii];
268	0	ctx->tmp_len = n;
269	0	} else {
270		/* All we have is newline terminated non-start data */
271	0	ctx->tmp_len = 0;
272	0	}
273		/*
274		* Try to read more if possible, otherwise we can't make
275		* progress unless the underlying BIO is retriable and may
276		* produce more data next time we're called.
277		*/
278	0	if (again > 0)
279	0	continue;
280	0	else
281	0	break;
282	0	} else {
283	0	ctx->tmp_len = 0;
284	0	}
285	0	} else if (i < B64_BLOCK_SIZE && again > 0) {
286		/*
287		* If buffer isn't full and we can retry then restart to read in
288		* more data.
289		*/
290	0	continue;
291	0	}
292
293	0	i = EVP_DecodeUpdate(ctx->base64, ctx->buf, &ctx->buf_len,
294	0	ctx->tmp, i);
295	0	ctx->tmp_len = 0;
296		/*
297		* If eof or an error was signalled, then the condition
298		* 'ctx->cont <= 0' will prevent b64_read() from reading
299		* more data on subsequent calls. This assignment was
300		* deleted accidentally in commit 5562cfaca4f3.
301		*/
302	0	ctx->cont = i;
303
304	0	ctx->buf_off = 0;
305	0	if (i < 0) {
306	0	ret_code = ctx->start ? 0 : i;
307	0	ctx->buf_len = 0;
308	0	break;
309	0	}
310
311	0	if (ctx->buf_len <= outl)
312	0	i = ctx->buf_len;
313	0	else
314	0	i = outl;
315
316	0	memcpy(out, ctx->buf, i);
317	0	ret += i;
318	0	ctx->buf_off = i;
319	0	if (ctx->buf_off == ctx->buf_len) {
320	0	ctx->buf_len = 0;
321	0	ctx->buf_off = 0;
322	0	}
323	0	outl -= i;
324	0	out += i;
325	0	}
326	0	BIO_copy_next_retry(b);
327	0	return ret == 0 ? ret_code : ret;
328	0	}
329
330		static int b64_write(BIO b, const char in, int inl)
331	0	{
332	0	int ret = 0;
333	0	int n;
334	0	int i;
335	0	BIO_B64_CTX *ctx;
336	0	BIO *next;
337	0	int encoded_length;
338	0	unsigned char *encoded;
339	0	int n_bytes_enc;
340
341	0	ctx = (BIO_B64_CTX *)BIO_get_data(b);
342	0	next = BIO_next(b);
343	0	if (ctx == NULL \|\| next == NULL)
344	0	return 0;
345
346	0	BIO_clear_retry_flags(b);
347
348	0	if (ctx->encode != B64_ENCODE) {
349	0	ctx->encode = B64_ENCODE;
350	0	ctx->buf_len = 0;
351	0	ctx->buf_off = 0;
352	0	ctx->tmp_len = 0;
353	0	EVP_EncodeInit(ctx->base64);
354	0	if (BIO_get_flags(b) & BIO_FLAGS_BASE64_NO_NL)
355	0	evp_encode_ctx_set_flags(ctx->base64, EVP_ENCODE_CTX_NO_NEWLINES);
356	0	}
357	0	if (!ossl_assert(ctx->buf_off < (int)sizeof(ctx->buf))) {
358	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
359	0	return -1;
360	0	}
361	0	if (!ossl_assert(ctx->buf_len <= (int)sizeof(ctx->buf))) {
362	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
363	0	return -1;
364	0	}
365	0	if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
366	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
367	0	return -1;
368	0	}
369	0	n = ctx->buf_len - ctx->buf_off;
370	0	while (n > 0) {
371	0	i = BIO_write(next, &(ctx->buf[ctx->buf_off]), n);
372	0	if (i <= 0) {
373	0	BIO_copy_next_retry(b);
374	0	return i;
375	0	}
376	0	ctx->buf_off += i;
377	0	if (!ossl_assert(ctx->buf_off <= (int)sizeof(ctx->buf))) {
378	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
379	0	return -1;
380	0	}
381	0	if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
382	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
383	0	return -1;
384	0	}
385	0	n -= i;
386	0	}
387		/* at this point all pending data has been written */
388	0	ctx->buf_off = 0;
389	0	ctx->buf_len = 0;
390
391	0	if (in == NULL \|\| inl <= 0)
392	0	return 0;
393
394	0	encoded_length = EVP_ENCODE_LENGTH(inl);
395
396	0	if (ctx->encoded_buf == NULL \|\| (size_t)encoded_length > ctx->encoded_buf_len) {
397	0	OPENSSL_free(ctx->encoded_buf);
398	0	ctx->encoded_buf = OPENSSL_malloc(encoded_length);
399	0	if (ctx->encoded_buf == NULL) {
400	0	ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
401	0	return -1;
402	0	}
403	0	ctx->encoded_buf_len = encoded_length;
404	0	}
405
406	0	encoded = ctx->encoded_buf;
407
408	0	if (encoded == NULL) {
409	0	ERR_raise(ERR_LIB_BIO, ERR_R_MALLOC_FAILURE);
410	0	return -1;
411	0	}
412	0	n_bytes_enc = 0;
413	0	if (!EVP_EncodeUpdate(ctx->base64, encoded, &n_bytes_enc,
414	0	(unsigned char *)in, inl)) {
415	0	return -1;
416	0	}
417	0	ret += inl;
418	0	i = BIO_write(next, encoded, n_bytes_enc);
419	0	if (i <= 0)
420	0	BIO_copy_next_retry(b);
421	0	return ret;
422	0	}
423
424		static long b64_ctrl(BIO b, int cmd, long num, void ptr)
425	0	{
426	0	BIO_B64_CTX *ctx;
427	0	long ret = 1;
428	0	int i;
429	0	BIO *next;
430
431	0	ctx = (BIO_B64_CTX *)BIO_get_data(b);
432	0	next = BIO_next(b);
433		/*
434		* If there is no ctx or no next BIO, BIO_read() returns 0, which means EOF.
435		* BIO_eof() should return 1 in this case.
436		*/
437	0	if (ctx == NULL \|\| next == NULL)
438	0	return cmd == BIO_CTRL_EOF;
439
440	0	switch (cmd) {
441	0	case BIO_CTRL_RESET:
442	0	ctx->cont = 1;
443	0	ctx->start = 1;
444	0	ctx->encode = B64_NONE;
445	0	ret = BIO_ctrl(next, cmd, num, ptr);
446	0	break;
447	0	case BIO_CTRL_EOF: /* More to read */
448	0	if (ctx->cont <= 0)
449	0	ret = 1;
450	0	else
451	0	ret = BIO_ctrl(next, cmd, num, ptr);
452	0	break;
453	0	case BIO_CTRL_WPENDING: /* More to write in buffer */
454	0	if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
455	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
456	0	return -1;
457	0	}
458	0	ret = ctx->buf_len - ctx->buf_off;
459	0	if (ret == 0 && ctx->encode != B64_NONE
460	0	&& EVP_ENCODE_CTX_num(ctx->base64) != 0)
461	0	ret = 1;
462	0	else if (ret <= 0)
463	0	ret = BIO_ctrl(next, cmd, num, ptr);
464	0	break;
465	0	case BIO_CTRL_PENDING: /* More to read in buffer */
466	0	if (!ossl_assert(ctx->buf_len >= ctx->buf_off)) {
467	0	ERR_raise(ERR_LIB_BIO, ERR_R_INTERNAL_ERROR);
468	0	return -1;
469	0	}
470	0	ret = ctx->buf_len - ctx->buf_off;
471	0	if (ret <= 0)
472	0	ret = BIO_ctrl(next, cmd, num, ptr);
473	0	break;
474	0	case BIO_CTRL_FLUSH:
475	0	if (ctx->encode == B64_ENCODE) {
476		/* do a final write */
477	0	again:
478	0	while (ctx->buf_len != ctx->buf_off) {
479	0	i = b64_write(b, NULL, 0);
480	0	if (i < 0)
481	0	return i;
482	0	}
483	0	if (EVP_ENCODE_CTX_num(ctx->base64) != 0) {
484	0	ctx->buf_off = 0;
485	0	EVP_EncodeFinal(ctx->base64, ctx->buf, &(ctx->buf_len));
486		/* push out the bytes */
487	0	goto again;
488	0	}
489	0	}
490		/* Finally flush the underlying BIO */
491	0	BIO_clear_retry_flags(b);
492	0	ret = BIO_ctrl(next, cmd, num, ptr);
493	0	BIO_copy_next_retry(b);
494	0	break;
495
496	0	case BIO_C_DO_STATE_MACHINE:
497	0	BIO_clear_retry_flags(b);
498	0	ret = BIO_ctrl(next, cmd, num, ptr);
499	0	BIO_copy_next_retry(b);
500	0	break;
501
502	0	case BIO_CTRL_DUP:
503	0	break;
504	0	case BIO_CTRL_INFO:
505	0	case BIO_CTRL_GET:
506	0	case BIO_CTRL_SET:
507	0	default:
508	0	ret = BIO_ctrl(next, cmd, num, ptr);
509	0	break;
510	0	}
511	0	return ret;
512	0	}
513
514		static long b64_callback_ctrl(BIO b, int cmd, BIO_info_cb fp)
515	0	{
516	0	BIO *next = BIO_next(b);
517
518	0	if (next == NULL)
519	0	return 0;
520
521	0	return BIO_callback_ctrl(next, cmd, fp);
522	0	}
523
524		static int b64_puts(BIO b, const char str)
525	0	{
526	0	size_t len = strlen(str);
527
528	0	if (len > INT_MAX)
529	0	return -1;
530	0	return b64_write(b, str, (int)len);
531	0	}