Single pass processing to cleartext S/MIME signing.

CHANGES

@@ -4,6 +4,17 @@
 
  Changes between 0.9.7a and 0.9.8  [xx XXX xxxx]
 
+  *) Support for single pass processing for S/MIME signing. This now
+     means that S/MIME signing can be done from a pipe, in addition
+     cleartext signing (multipart/signed type) is effectively streaming
+     and the signed data does not need to be all held in memory.
+
+     This is done with a new flag PKCS7_PARTSIGN. When this flag is set
+     PKCS7_sign() only initializes the PKCS7 structure and the actual signing
+     is done after the data is output (and digests calculated) in
+     SMIME_write_PKCS7().
+     [Steve Henson]
+
   *) Add full support for -rpath/-R, both in shared libraries and
      applications, at least on the platforms where it's known how
      to do it.

apps/smime.c

 /* smime.c */
 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+ * project.
  */
 /* ====================================================================
- * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2003 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
@@ -478,8 +478,14 @@ int MAIN(int argc, char **argv)
 	if(operation == SMIME_ENCRYPT) {
 		p7 = PKCS7_encrypt(encerts, in, cipher, flags);
 	} else if(operation == SMIME_SIGN) {
+		/* If detached data and SMIME output enable partial
+		 * signing.
+		 */
+		if ((flags & PKCS7_DETACHED) && (outformat == FORMAT_SMIME))
+			flags |= PKCS7_PARTSIGN;
 		p7 = PKCS7_sign(signer, key, other, in, flags);
-		if (BIO_reset(in) != 0 && (flags & PKCS7_DETACHED)) {
+		/* Don't need to rewind for partial signing */
+		if (!(flags & PKCS7_PARTSIGN) && (BIO_reset(in) != 0)) {
 		  BIO_printf(bio_err, "Can't rewind input file\n");
 		  goto end;
 		}

crypto/pkcs7/pk7_mime.c

 /* pk7_mime.c */
 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+ * project.
  */
 /* ====================================================================
- * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2003 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
@@ -86,6 +86,7 @@ STACK_OF(MIME_PARAM) *params;		/* Zero or more parameters */
 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);
@@ -150,7 +151,6 @@ static PKCS7 *B64_read_PKCS7(BIO *bio)
 
 int SMIME_write_PKCS7(BIO *bio, PKCS7 *p7, BIO *data, int flags)
 {
-	char linebuf[MAX_SMLEN];
 	char bound[33], c;
 	int i;
 	if((flags & PKCS7_DETACHED) && data) {
@@ -171,9 +171,9 @@ int SMIME_write_PKCS7(BIO *bio, PKCS7 *p7, BIO *data, int flags)
 		BIO_printf(bio, "This is an S/MIME signed message\n\n");
 		/* Now write out the first part */
 		BIO_printf(bio, "------%s\r\n", bound);
-		if(flags & PKCS7_TEXT) BIO_printf(bio, "Content-Type: text/plain\n\n");
-		while((i = BIO_read(data, linebuf, MAX_SMLEN)) > 0) 
-						BIO_write(bio, linebuf, i);
+
+		pkcs7_output_data(bio, data, p7, flags);
+
 		BIO_printf(bio, "\n------%s\n", bound);
 
 		/* Headers for signature */
@@ -195,6 +195,47 @@ int SMIME_write_PKCS7(BIO *bio, PKCS7 *p7, BIO *data, int flags)
 	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_PARTSIGN))
+		{
+		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 from output BIO */
+
+	while (1)
+		{
+		tmpbio = BIO_pop(p7bio);
+		if (tmpbio == out)
+			break;
+		BIO_free(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
@@ -314,7 +355,8 @@ int SMIME_crlf_copy(BIO *in, BIO *out, int flags)
 						BIO_write(out, linebuf, len);
 		return 1;
 	}
-	if(flags & PKCS7_TEXT) BIO_printf(out, "Content-Type: text/plain\r\n\r\n");
+	if(flags & PKCS7_TEXT)
+		BIO_printf(out, "Content-Type: text/plain\r\n\r\n");
 	while ((len = BIO_gets(in, linebuf, MAX_SMLEN)) > 0) {
 		eol = 0;
 		while(iscrlf(linebuf[len - 1])) {

crypto/pkcs7/pk7_smime.c

 /* pk7_smime.c */
 /* Written by Dr Stephen N Henson (shenson@bigfoot.com) for the OpenSSL
- * project 1999.
+ * project.
  */
 /* ====================================================================
- * Copyright (c) 1999 The OpenSSL Project.  All rights reserved.
+ * Copyright (c) 1999-2003 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
@@ -97,14 +97,6 @@ PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
 			PKCS7_add_certificate(p7, sk_X509_value(certs, i));
 	}
 
-	if(!(p7bio = PKCS7_dataInit(p7, NULL))) {
-		PKCS7err(PKCS7_F_PKCS7_SIGN,ERR_R_MALLOC_FAILURE);
-		return NULL;
-	}
-
-
-	SMIME_crlf_copy(data, p7bio, flags);
-
 	if(!(flags & PKCS7_NOATTR)) {
 		PKCS7_add_signed_attribute(si, NID_pkcs9_contentType,
 				V_ASN1_OBJECT, OBJ_nid2obj(NID_pkcs7_data));
@@ -133,6 +125,16 @@ PKCS7 *PKCS7_sign(X509 *signcert, EVP_PKEY *pkey, STACK_OF(X509) *certs,
 		}
 	}
 
+	if (flags & PKCS7_PARTSIGN)
+		return p7;
+
+	if (!(p7bio = PKCS7_dataInit(p7, NULL))) {
+		PKCS7err(PKCS7_F_PKCS7_SIGN,ERR_R_MALLOC_FAILURE);
+		return NULL;
+	}
+
+	SMIME_crlf_copy(data, p7bio, flags);
+
 	if(flags & PKCS7_DETACHED)PKCS7_set_detached(p7, 1);
 
         if (!PKCS7_dataFinal(p7,p7bio)) {

crypto/pkcs7/pkcs7.h

@@ -260,6 +260,7 @@ DECLARE_PKCS12_STACK_OF(PKCS7)
 #define PKCS7_BINARY		0x80
 #define PKCS7_NOATTR		0x100
 #define	PKCS7_NOSMIMECAP	0x200
+#define	PKCS7_PARTSIGN		0x400
 
 /* Flags: for compatibility with older code */