1 /* 2 * Copyright 2018-2021 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 <string.h> 12 #include <errno.h> 13 #include "bio_local.h" 14 15 static int prefix_write(BIO *b, const char *out, size_t outl, 16 size_t *numwritten); 17 static int prefix_read(BIO *b, char *buf, size_t size, size_t *numread); 18 static int prefix_puts(BIO *b, const char *str); 19 static int prefix_gets(BIO *b, char *str, int size); 20 static long prefix_ctrl(BIO *b, int cmd, long arg1, void *arg2); 21 static int prefix_create(BIO *b); 22 static int prefix_destroy(BIO *b); 23 static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp); 24 25 static const BIO_METHOD prefix_meth = { 26 BIO_TYPE_BUFFER, 27 "prefix", 28 prefix_write, 29 NULL, 30 prefix_read, 31 NULL, 32 prefix_puts, 33 prefix_gets, 34 prefix_ctrl, 35 prefix_create, 36 prefix_destroy, 37 prefix_callback_ctrl, 38 }; 39 40 const BIO_METHOD *BIO_f_prefix(void) 41 { 42 return &prefix_meth; 43 } 44 45 typedef struct prefix_ctx_st { 46 char *prefix; /* Text prefix, given by user */ 47 unsigned int indent; /* Indentation amount, given by user */ 48 49 int linestart; /* flag to indicate we're at the line start */ 50 } PREFIX_CTX; 51 52 static int prefix_create(BIO *b) 53 { 54 PREFIX_CTX *ctx = OPENSSL_zalloc(sizeof(*ctx)); 55 56 if (ctx == NULL) 57 return 0; 58 59 ctx->prefix = NULL; 60 ctx->indent = 0; 61 ctx->linestart = 1; 62 BIO_set_data(b, ctx); 63 BIO_set_init(b, 1); 64 return 1; 65 } 66 67 static int prefix_destroy(BIO *b) 68 { 69 PREFIX_CTX *ctx = BIO_get_data(b); 70 71 OPENSSL_free(ctx->prefix); 72 OPENSSL_free(ctx); 73 return 1; 74 } 75 76 static int prefix_read(BIO *b, char *in, size_t size, size_t *numread) 77 { 78 return BIO_read_ex(BIO_next(b), in, size, numread); 79 } 80 81 static int prefix_write(BIO *b, const char *out, size_t outl, 82 size_t *numwritten) 83 { 84 PREFIX_CTX *ctx = BIO_get_data(b); 85 86 if (ctx == NULL) 87 return 0; 88 89 /* 90 * If no prefix is set or if it's empty, and no indentation amount is set, 91 * we've got nothing to do here 92 */ 93 if ((ctx->prefix == NULL || *ctx->prefix == '\0') 94 && ctx->indent == 0) { 95 /* 96 * We do note if what comes next will be a new line, though, so we're 97 * prepared to handle prefix and indentation the next time around. 98 */ 99 if (outl > 0) 100 ctx->linestart = (out[outl-1] == '\n'); 101 return BIO_write_ex(BIO_next(b), out, outl, numwritten); 102 } 103 104 *numwritten = 0; 105 106 while (outl > 0) { 107 size_t i; 108 char c; 109 110 /* 111 * If we know that we're at the start of the line, output prefix and 112 * indentation. 113 */ 114 if (ctx->linestart) { 115 size_t dontcare; 116 117 if (ctx->prefix != NULL 118 && !BIO_write_ex(BIO_next(b), ctx->prefix, strlen(ctx->prefix), 119 &dontcare)) 120 return 0; 121 BIO_printf(BIO_next(b), "%*s", ctx->indent, ""); 122 ctx->linestart = 0; 123 } 124 125 /* Now, go look for the next LF, or the end of the string */ 126 for (i = 0, c = '\0'; i < outl && (c = out[i]) != '\n'; i++) 127 continue; 128 if (c == '\n') 129 i++; 130 131 /* Output what we found so far */ 132 while (i > 0) { 133 size_t num = 0; 134 135 if (!BIO_write_ex(BIO_next(b), out, i, &num)) 136 return 0; 137 out += num; 138 outl -= num; 139 *numwritten += num; 140 i -= num; 141 } 142 143 /* If we found a LF, what follows is a new line, so take note */ 144 if (c == '\n') 145 ctx->linestart = 1; 146 } 147 148 return 1; 149 } 150 151 static long prefix_ctrl(BIO *b, int cmd, long num, void *ptr) 152 { 153 long ret = 0; 154 PREFIX_CTX *ctx; 155 156 if (b == NULL || (ctx = BIO_get_data(b)) == NULL) 157 return -1; 158 159 switch (cmd) { 160 case BIO_CTRL_SET_PREFIX: 161 OPENSSL_free(ctx->prefix); 162 if (ptr == NULL) { 163 ctx->prefix = NULL; 164 ret = 1; 165 } else { 166 ctx->prefix = OPENSSL_strdup((const char *)ptr); 167 ret = ctx->prefix != NULL; 168 } 169 break; 170 case BIO_CTRL_SET_INDENT: 171 if (num >= 0) { 172 ctx->indent = (unsigned int)num; 173 ret = 1; 174 } 175 break; 176 case BIO_CTRL_GET_INDENT: 177 ret = (long)ctx->indent; 178 break; 179 default: 180 /* Commands that we intercept before passing them along */ 181 switch (cmd) { 182 case BIO_C_FILE_SEEK: 183 case BIO_CTRL_RESET: 184 ctx->linestart = 1; 185 break; 186 } 187 if (BIO_next(b) != NULL) 188 ret = BIO_ctrl(BIO_next(b), cmd, num, ptr); 189 break; 190 } 191 return ret; 192 } 193 194 static long prefix_callback_ctrl(BIO *b, int cmd, BIO_info_cb *fp) 195 { 196 return BIO_callback_ctrl(BIO_next(b), cmd, fp); 197 } 198 199 static int prefix_gets(BIO *b, char *buf, int size) 200 { 201 return BIO_gets(BIO_next(b), buf, size); 202 } 203 204 static int prefix_puts(BIO *b, const char *str) 205 { 206 return BIO_write(b, str, strlen(str)); 207 } 208