/* pk7_mime.c */ /* Written by Dr Stephen N Henson (steve@openssl.org) for the OpenSSL * project. */ /* ==================================================================== * Copyright (c) 1999-2005 The OpenSSL Project. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * * 3. All advertising materials mentioning features or use of this * software must display the following acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit. (http://www.OpenSSL.org/)" * * 4. The names "OpenSSL Toolkit" and "OpenSSL Project" must not be used to * endorse or promote products derived from this software without * prior written permission. For written permission, please contact * licensing@OpenSSL.org. * * 5. Products derived from this software may not be called "OpenSSL" * nor may "OpenSSL" appear in their names without prior written * permission of the OpenSSL Project. * * 6. Redistributions of any form whatsoever must retain the following * acknowledgment: * "This product includes software developed by the OpenSSL Project * for use in the OpenSSL Toolkit (http://www.OpenSSL.org/)" * * THIS SOFTWARE IS PROVIDED BY THE OpenSSL PROJECT ``AS IS'' AND ANY * EXPRESSED OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE OpenSSL PROJECT OR * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED * OF THE POSSIBILITY OF SUCH DAMAGE. * ==================================================================== * * This product includes cryptographic software written by Eric Young * (eay@cryptsoft.com). This product includes software written by Tim * Hudson (tjh@cryptsoft.com). * */ #include <stdio.h> #include <ctype.h> #include "cryptlib.h" #include <openssl/rand.h> #include <openssl/x509.h> /* MIME and related routines */ /* MIME format structures * Note that all are translated to lower case apart from * parameter values. Quotes are stripped off */ typedef struct { char *param_name; /* Param name e.g. "micalg" */ char *param_value; /* Param value e.g. "sha1" */ } MIME_PARAM; DECLARE_STACK_OF(MIME_PARAM) IMPLEMENT_STACK_OF(MIME_PARAM) typedef struct { char *name; /* Name of line e.g. "content-type" */ char *value; /* Value of line e.g. "text/plain" */ STACK_OF(MIME_PARAM) *params; /* Zero or more parameters */ } MIME_HEADER; DECLARE_STACK_OF(MIME_HEADER) IMPLEMENT_STACK_OF(MIME_HEADER) static int pkcs7_output_data(BIO *bio, BIO *data, PKCS7 *p7, int flags); static int B64_write_PKCS7(BIO *bio, PKCS7 *p7); static PKCS7 *B64_read_PKCS7(BIO *bio); static char * strip_ends(char *name); static char * strip_start(char *name); static char * strip_end(char *name); static MIME_HEADER *mime_hdr_new(char *name, char *value); static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value); static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio); static int mime_hdr_cmp(const MIME_HEADER * const *a, const MIME_HEADER * const *b); static int mime_param_cmp(const MIME_PARAM * const *a, const MIME_PARAM * const *b); static void mime_param_free(MIME_PARAM *param); static int mime_bound_check(char *line, int linelen, char *bound, int blen); static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret); static int strip_eol(char *linebuf, int *plen); static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name); static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name); static void mime_hdr_free(MIME_HEADER *hdr); #define MAX_SMLEN 1024 #define mime_debug(x) /* x */ /* Base 64 read and write of PKCS#7 structure */ static int B64_write_PKCS7(BIO *bio, PKCS7 *p7) { BIO *b64; if(!(b64 = BIO_new(BIO_f_base64()))) { PKCS7err(PKCS7_F_B64_WRITE_PKCS7,ERR_R_MALLOC_FAILURE); return 0; } bio = BIO_push(b64, bio); i2d_PKCS7_bio(bio, p7); (void)BIO_flush(bio); bio = BIO_pop(bio); BIO_free(b64); return 1; } static PKCS7 *B64_read_PKCS7(BIO *bio) { BIO *b64; PKCS7 *p7; if(!(b64 = BIO_new(BIO_f_base64()))) { PKCS7err(PKCS7_F_B64_READ_PKCS7,ERR_R_MALLOC_FAILURE); return 0; } bio = BIO_push(b64, bio); if(!(p7 = d2i_PKCS7_bio(bio, NULL))) PKCS7err(PKCS7_F_B64_READ_PKCS7,PKCS7_R_DECODE_ERROR); (void)BIO_flush(bio); bio = BIO_pop(bio); BIO_free(b64); return p7; } /* SMIME sender */ int SMIME_write_PKCS7(BIO *bio, PKCS7 *p7, BIO *data, int flags) { char bound[33], c; int i; char *mime_prefix, *mime_eol, *msg_type=NULL; if (flags & PKCS7_NOOLDMIMETYPE) mime_prefix = "application/pkcs7-"; else mime_prefix = "application/x-pkcs7-"; if (flags & PKCS7_CRLFEOL) mime_eol = "\r\n"; else mime_eol = "\n"; if((flags & PKCS7_DETACHED) && data) { /* We want multipart/signed */ /* Generate a random boundary */ RAND_pseudo_bytes((unsigned char *)bound, 32); for(i = 0; i < 32; i++) { c = bound[i] & 0xf; if(c < 10) c += '0'; else c += 'A' - 10; bound[i] = c; } bound[32] = 0; BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol); BIO_printf(bio, "Content-Type: multipart/signed;"); BIO_printf(bio, " protocol=\"%ssignature\";", mime_prefix); BIO_printf(bio, " micalg=sha1; boundary=\"----%s\"%s%s", bound, mime_eol, mime_eol); BIO_printf(bio, "This is an S/MIME signed message%s%s", mime_eol, mime_eol); /* Now write out the first part */ BIO_printf(bio, "------%s%s", bound, mime_eol); pkcs7_output_data(bio, data, p7, flags); BIO_printf(bio, "%s------%s%s", mime_eol, bound, mime_eol); /* Headers for signature */ BIO_printf(bio, "Content-Type: %ssignature;", mime_prefix); BIO_printf(bio, " name=\"smime.p7s\"%s", mime_eol); BIO_printf(bio, "Content-Transfer-Encoding: base64%s", mime_eol); BIO_printf(bio, "Content-Disposition: attachment;"); BIO_printf(bio, " filename=\"smime.p7s\"%s%s", mime_eol, mime_eol); B64_write_PKCS7(bio, p7); BIO_printf(bio,"%s------%s--%s%s", mime_eol, bound, mime_eol, mime_eol); return 1; } /* Determine smime-type header */ if (PKCS7_type_is_enveloped(p7)) msg_type = "enveloped-data"; else if (PKCS7_type_is_signed(p7)) { /* If we have any signers it is signed-data othewise * certs-only. */ STACK_OF(PKCS7_SIGNER_INFO) *sinfos; sinfos = PKCS7_get_signer_info(p7); if (sk_PKCS7_SIGNER_INFO_num(sinfos) > 0) msg_type = "signed-data"; else msg_type = "certs-only"; } /* MIME headers */ BIO_printf(bio, "MIME-Version: 1.0%s", mime_eol); BIO_printf(bio, "Content-Disposition: attachment;"); BIO_printf(bio, " filename=\"smime.p7m\"%s", mime_eol); BIO_printf(bio, "Content-Type: %smime;", mime_prefix); if (msg_type) BIO_printf(bio, " smime-type=%s;", msg_type); BIO_printf(bio, " name=\"smime.p7m\"%s", mime_eol); BIO_printf(bio, "Content-Transfer-Encoding: base64%s%s", mime_eol, mime_eol); B64_write_PKCS7(bio, p7); BIO_printf(bio, "%s", mime_eol); return 1; } /* Handle output of PKCS#7 data */ static int pkcs7_output_data(BIO *out, BIO *data, PKCS7 *p7, int flags) { BIO *tmpbio, *p7bio; if (!(flags & PKCS7_STREAM)) { SMIME_crlf_copy(data, out, flags); return 1; } /* Partial sign operation */ /* Initialize sign operation */ p7bio = PKCS7_dataInit(p7, out); /* Copy data across, computing digests etc */ SMIME_crlf_copy(data, p7bio, flags); /* Must be detached */ PKCS7_set_detached(p7, 1); /* Finalize signatures */ PKCS7_dataFinal(p7, p7bio); /* Now remove any digests prepended to the BIO */ while (p7bio != out) { tmpbio = BIO_pop(p7bio); BIO_free(p7bio); p7bio = tmpbio; } return 1; } /* SMIME reader: handle multipart/signed and opaque signing. * in multipart case the content is placed in a memory BIO * pointed to by "bcont". In opaque this is set to NULL */ PKCS7 *SMIME_read_PKCS7(BIO *bio, BIO **bcont) { BIO *p7in; STACK_OF(MIME_HEADER) *headers = NULL; STACK_OF(BIO) *parts = NULL; MIME_HEADER *hdr; MIME_PARAM *prm; PKCS7 *p7; int ret; if(bcont) *bcont = NULL; if (!(headers = mime_parse_hdr(bio))) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7,PKCS7_R_MIME_PARSE_ERROR); return NULL; } if(!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { sk_MIME_HEADER_pop_free(headers, mime_hdr_free); PKCS7err(PKCS7_F_SMIME_READ_PKCS7, PKCS7_R_NO_CONTENT_TYPE); return NULL; } /* Handle multipart/signed */ if(!strcmp(hdr->value, "multipart/signed")) { /* Split into two parts */ prm = mime_param_find(hdr, "boundary"); if(!prm || !prm->param_value) { sk_MIME_HEADER_pop_free(headers, mime_hdr_free); PKCS7err(PKCS7_F_SMIME_READ_PKCS7, PKCS7_R_NO_MULTIPART_BOUNDARY); return NULL; } ret = multi_split(bio, prm->param_value, &parts); sk_MIME_HEADER_pop_free(headers, mime_hdr_free); if(!ret || (sk_BIO_num(parts) != 2) ) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7, PKCS7_R_NO_MULTIPART_BODY_FAILURE); sk_BIO_pop_free(parts, BIO_vfree); return NULL; } /* Parse the signature piece */ p7in = sk_BIO_value(parts, 1); if (!(headers = mime_parse_hdr(p7in))) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7,PKCS7_R_MIME_SIG_PARSE_ERROR); sk_BIO_pop_free(parts, BIO_vfree); return NULL; } /* Get content type */ if(!(hdr = mime_hdr_find(headers, "content-type")) || !hdr->value) { sk_MIME_HEADER_pop_free(headers, mime_hdr_free); PKCS7err(PKCS7_F_SMIME_READ_PKCS7, PKCS7_R_NO_SIG_CONTENT_TYPE); return NULL; } if(strcmp(hdr->value, "application/x-pkcs7-signature") && strcmp(hdr->value, "application/pkcs7-signature")) { sk_MIME_HEADER_pop_free(headers, mime_hdr_free); PKCS7err(PKCS7_F_SMIME_READ_PKCS7,PKCS7_R_SIG_INVALID_MIME_TYPE); ERR_add_error_data(2, "type: ", hdr->value); sk_BIO_pop_free(parts, BIO_vfree); return NULL; } sk_MIME_HEADER_pop_free(headers, mime_hdr_free); /* Read in PKCS#7 */ if(!(p7 = B64_read_PKCS7(p7in))) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7,PKCS7_R_PKCS7_SIG_PARSE_ERROR); sk_BIO_pop_free(parts, BIO_vfree); return NULL; } if(bcont) { *bcont = sk_BIO_value(parts, 0); BIO_free(p7in); sk_BIO_free(parts); } else sk_BIO_pop_free(parts, BIO_vfree); return p7; } /* OK, if not multipart/signed try opaque signature */ if (strcmp (hdr->value, "application/x-pkcs7-mime") && strcmp (hdr->value, "application/pkcs7-mime")) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7,PKCS7_R_INVALID_MIME_TYPE); ERR_add_error_data(2, "type: ", hdr->value); sk_MIME_HEADER_pop_free(headers, mime_hdr_free); return NULL; } sk_MIME_HEADER_pop_free(headers, mime_hdr_free); if(!(p7 = B64_read_PKCS7(bio))) { PKCS7err(PKCS7_F_SMIME_READ_PKCS7, PKCS7_R_PKCS7_PARSE_ERROR); return NULL; } return p7; } /* Split a multipart/XXX message body into component parts: result is * canonical parts in a STACK of bios */ static int multi_split(BIO *bio, char *bound, STACK_OF(BIO) **ret) { char linebuf[MAX_SMLEN]; int len, blen; int eol = 0, next_eol = 0; BIO *bpart = NULL; STACK_OF(BIO) *parts; char state, part, first; blen = strlen(bound); part = 0; state = 0; first = 1; parts = sk_BIO_new_null(); *ret = parts; while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { state = mime_bound_check(linebuf, len, bound, blen); if(state == 1) { first = 1; part++; } else if(state == 2) { sk_BIO_push(parts, bpart); return 1; } else if(part) { /* Strip CR+LF from linebuf */ next_eol = strip_eol(linebuf, &len); if(first) { first = 0; if(bpart) sk_BIO_push(parts, bpart); bpart = BIO_new(BIO_s_mem()); BIO_set_mem_eof_return(bpart, 0); } else if (eol) BIO_write(bpart, "\r\n", 2); eol = next_eol; if (len) BIO_write(bpart, linebuf, len); } } return 0; } /* This is the big one: parse MIME header lines up to message body */ #define MIME_INVALID 0 #define MIME_START 1 #define MIME_TYPE 2 #define MIME_NAME 3 #define MIME_VALUE 4 #define MIME_QUOTE 5 #define MIME_COMMENT 6 static STACK_OF(MIME_HEADER) *mime_parse_hdr(BIO *bio) { char *p, *q, c; char *ntmp; char linebuf[MAX_SMLEN]; MIME_HEADER *mhdr = NULL; STACK_OF(MIME_HEADER) *headers; int len, state, save_state = 0; headers = sk_MIME_HEADER_new(mime_hdr_cmp); while ((len = BIO_gets(bio, linebuf, MAX_SMLEN)) > 0) { /* If whitespace at line start then continuation line */ if(mhdr && isspace((unsigned char)linebuf[0])) state = MIME_NAME; else state = MIME_START; ntmp = NULL; /* Go through all characters */ for(p = linebuf, q = linebuf; (c = *p) && (c!='\r') && (c!='\n'); p++) { /* State machine to handle MIME headers * if this looks horrible that's because it *is* */ switch(state) { case MIME_START: if(c == ':') { state = MIME_TYPE; *p = 0; ntmp = strip_ends(q); q = p + 1; } break; case MIME_TYPE: if(c == ';') { mime_debug("Found End Value\n"); *p = 0; mhdr = mime_hdr_new(ntmp, strip_ends(q)); sk_MIME_HEADER_push(headers, mhdr); ntmp = NULL; q = p + 1; state = MIME_NAME; } else if(c == '(') { save_state = state; state = MIME_COMMENT; } break; case MIME_COMMENT: if(c == ')') { state = save_state; } break; case MIME_NAME: if(c == '=') { state = MIME_VALUE; *p = 0; ntmp = strip_ends(q); q = p + 1; } break ; case MIME_VALUE: if(c == ';') { state = MIME_NAME; *p = 0; mime_hdr_addparam(mhdr, ntmp, strip_ends(q)); ntmp = NULL; q = p + 1; } else if (c == '"') { mime_debug("Found Quote\n"); state = MIME_QUOTE; } else if(c == '(') { save_state = state; state = MIME_COMMENT; } break; case MIME_QUOTE: if(c == '"') { mime_debug("Found Match Quote\n"); state = MIME_VALUE; } break; } } if(state == MIME_TYPE) { mhdr = mime_hdr_new(ntmp, strip_ends(q)); sk_MIME_HEADER_push(headers, mhdr); } else if(state == MIME_VALUE) mime_hdr_addparam(mhdr, ntmp, strip_ends(q)); if(p == linebuf) break; /* Blank line means end of headers */ } return headers; } static char *strip_ends(char *name) { return strip_end(strip_start(name)); } /* Strip a parameter of whitespace from start of param */ static char *strip_start(char *name) { char *p, c; /* Look for first non white space or quote */ for(p = name; (c = *p) ;p++) { if(c == '"') { /* Next char is start of string if non null */ if(p[1]) return p + 1; /* Else null string */ return NULL; } if(!isspace((unsigned char)c)) return p; } return NULL; } /* As above but strip from end of string : maybe should handle brackets? */ static char *strip_end(char *name) { char *p, c; if(!name) return NULL; /* Look for first non white space or quote */ for(p = name + strlen(name) - 1; p >= name ;p--) { c = *p; if(c == '"') { if(p - 1 == name) return NULL; *p = 0; return name; } if(isspace((unsigned char)c)) *p = 0; else return name; } return NULL; } static MIME_HEADER *mime_hdr_new(char *name, char *value) { MIME_HEADER *mhdr; char *tmpname, *tmpval, *p; int c; if(name) { if(!(tmpname = BUF_strdup(name))) return NULL; for(p = tmpname ; *p; p++) { c = *p; if(isupper(c)) { c = tolower(c); *p = c; } } } else tmpname = NULL; if(value) { if(!(tmpval = BUF_strdup(value))) return NULL; for(p = tmpval ; *p; p++) { c = *p; if(isupper(c)) { c = tolower(c); *p = c; } } } else tmpval = NULL; mhdr = (MIME_HEADER *) OPENSSL_malloc(sizeof(MIME_HEADER)); if(!mhdr) return NULL; mhdr->name = tmpname; mhdr->value = tmpval; if(!(mhdr->params = sk_MIME_PARAM_new(mime_param_cmp))) return NULL; return mhdr; } static int mime_hdr_addparam(MIME_HEADER *mhdr, char *name, char *value) { char *tmpname, *tmpval, *p; int c; MIME_PARAM *mparam; if(name) { tmpname = BUF_strdup(name); if(!tmpname) return 0; for(p = tmpname ; *p; p++) { c = *p; if(isupper(c)) { c = tolower(c); *p = c; } } } else tmpname = NULL; if(value) { tmpval = BUF_strdup(value); if(!tmpval) return 0; } else tmpval = NULL; /* Parameter values are case sensitive so leave as is */ mparam = (MIME_PARAM *) OPENSSL_malloc(sizeof(MIME_PARAM)); if(!mparam) return 0; mparam->param_name = tmpname; mparam->param_value = tmpval; sk_MIME_PARAM_push(mhdr->params, mparam); return 1; } static int mime_hdr_cmp(const MIME_HEADER * const *a, const MIME_HEADER * const *b) { return(strcmp((*a)->name, (*b)->name)); } static int mime_param_cmp(const MIME_PARAM * const *a, const MIME_PARAM * const *b) { return(strcmp((*a)->param_name, (*b)->param_name)); } /* Find a header with a given name (if possible) */ static MIME_HEADER *mime_hdr_find(STACK_OF(MIME_HEADER) *hdrs, char *name) { MIME_HEADER htmp; int idx; htmp.name = name; idx = sk_MIME_HEADER_find(hdrs, &htmp); if(idx < 0) return NULL; return sk_MIME_HEADER_value(hdrs, idx); } static MIME_PARAM *mime_param_find(MIME_HEADER *hdr, char *name) { MIME_PARAM param; int idx; param.param_name = name; idx = sk_MIME_PARAM_find(hdr->params, ¶m); if(idx < 0) return NULL; return sk_MIME_PARAM_value(hdr->params, idx); } static void mime_hdr_free(MIME_HEADER *hdr) { if(hdr->name) OPENSSL_free(hdr->name); if(hdr->value) OPENSSL_free(hdr->value); if(hdr->params) sk_MIME_PARAM_pop_free(hdr->params, mime_param_free); OPENSSL_free(hdr); } static void mime_param_free(MIME_PARAM *param) { if(param->param_name) OPENSSL_free(param->param_name); if(param->param_value) OPENSSL_free(param->param_value); OPENSSL_free(param); } /* Check for a multipart boundary. Returns: * 0 : no boundary * 1 : part boundary * 2 : final boundary */ static int mime_bound_check(char *line, int linelen, char *bound, int blen) { if(linelen == -1) linelen = strlen(line); if(blen == -1) blen = strlen(bound); /* Quickly eliminate if line length too short */ if(blen + 2 > linelen) return 0; /* Check for part boundary */ if(!strncmp(line, "--", 2) && !strncmp(line + 2, bound, blen)) { if(!strncmp(line + blen + 2, "--", 2)) return 2; else return 1; } return 0; } static int strip_eol(char *linebuf, int *plen) { int len = *plen; char *p, c; int is_eol = 0; p = linebuf + len - 1; for (p = linebuf + len - 1; len > 0; len--, p--) { c = *p; if (c == '\n') is_eol = 1; else if (c != '\r') break; } *plen = len; return is_eol; }