From 3562e78743202e43aec8727005182a2558117eca Mon Sep 17 00:00:00 2001 From: marha Date: Sun, 28 Jun 2009 22:07:26 +0000 Subject: Checked in the following released items: xkeyboard-config-1.4.tar.gz ttf-bitstream-vera-1.10.tar.gz font-alias-1.0.1.tar.gz font-sun-misc-1.0.0.tar.gz font-sun-misc-1.0.0.tar.gz font-sony-misc-1.0.0.tar.gz font-schumacher-misc-1.0.0.tar.gz font-mutt-misc-1.0.0.tar.gz font-misc-misc-1.0.0.tar.gz font-misc-meltho-1.0.0.tar.gz font-micro-misc-1.0.0.tar.gz font-jis-misc-1.0.0.tar.gz font-isas-misc-1.0.0.tar.gz font-dec-misc-1.0.0.tar.gz font-daewoo-misc-1.0.0.tar.gz font-cursor-misc-1.0.0.tar.gz font-arabic-misc-1.0.0.tar.gz font-winitzki-cyrillic-1.0.0.tar.gz font-misc-cyrillic-1.0.0.tar.gz font-cronyx-cyrillic-1.0.0.tar.gz font-screen-cyrillic-1.0.1.tar.gz font-xfree86-type1-1.0.1.tar.gz font-adobe-utopia-type1-1.0.1.tar.gz font-ibm-type1-1.0.0.tar.gz font-bitstream-type1-1.0.0.tar.gz font-bitstream-speedo-1.0.0.tar.gz font-bh-ttf-1.0.0.tar.gz font-bh-type1-1.0.0.tar.gz font-bitstream-100dpi-1.0.0.tar.gz font-bh-lucidatypewriter-100dpi-1.0.0.tar.gz font-bh-100dpi-1.0.0.tar.gz font-adobe-utopia-100dpi-1.0.1.tar.gz font-adobe-100dpi-1.0.0.tar.gz font-util-1.0.1.tar.gz font-bitstream-75dpi-1.0.0.tar.gz font-bh-lucidatypewriter-75dpi-1.0.0.tar.gz font-adobe-utopia-75dpi-1.0.1.tar.gz font-bh-75dpi-1.0.0.tar.gz bdftopcf-1.0.1.tar.gz font-adobe-75dpi-1.0.0.tar.gz mkfontscale-1.0.6.tar.gz openssl-0.9.8k.tar.gz bigreqsproto-1.0.2.tar.gz xtrans-1.2.2.tar.gz resourceproto-1.0.2.tar.gz inputproto-1.4.4.tar.gz compositeproto-0.4.tar.gz damageproto-1.1.0.tar.gz zlib-1.2.3.tar.gz xkbcomp-1.0.5.tar.gz freetype-2.3.9.tar.gz pthreads-w32-2-8-0-release.tar.gz pixman-0.12.0.tar.gz kbproto-1.0.3.tar.gz evieext-1.0.2.tar.gz fixesproto-4.0.tar.gz recordproto-1.13.2.tar.gz randrproto-1.2.2.tar.gz scrnsaverproto-1.1.0.tar.gz renderproto-0.9.3.tar.gz xcmiscproto-1.1.2.tar.gz fontsproto-2.0.2.tar.gz xextproto-7.0.3.tar.gz xproto-7.0.14.tar.gz libXdmcp-1.0.2.tar.gz libxkbfile-1.0.5.tar.gz libfontenc-1.0.4.tar.gz libXfont-1.3.4.tar.gz libX11-1.1.5.tar.gz libXau-1.0.4.tar.gz libxcb-1.1.tar.gz xorg-server-1.5.3.tar.gz --- openssl/doc/crypto/BIO_f_md.pod | 138 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 138 insertions(+) create mode 100644 openssl/doc/crypto/BIO_f_md.pod (limited to 'openssl/doc/crypto/BIO_f_md.pod') diff --git a/openssl/doc/crypto/BIO_f_md.pod b/openssl/doc/crypto/BIO_f_md.pod new file mode 100644 index 000000000..0d24083e6 --- /dev/null +++ b/openssl/doc/crypto/BIO_f_md.pod @@ -0,0 +1,138 @@ +=pod + +=head1 NAME + +BIO_f_md, BIO_set_md, BIO_get_md, BIO_get_md_ctx - message digest BIO filter + +=head1 SYNOPSIS + + #include + #include + + BIO_METHOD * BIO_f_md(void); + int BIO_set_md(BIO *b,EVP_MD *md); + int BIO_get_md(BIO *b,EVP_MD **mdp); + int BIO_get_md_ctx(BIO *b,EVP_MD_CTX **mdcp); + +=head1 DESCRIPTION + +BIO_f_md() returns the message digest BIO method. This is a filter +BIO that digests any data passed through it, it is a BIO wrapper +for the digest routines EVP_DigestInit(), EVP_DigestUpdate() +and EVP_DigestFinal(). + +Any data written or read through a digest BIO using BIO_read() and +BIO_write() is digested. + +BIO_gets(), if its B parameter is large enough finishes the +digest calculation and returns the digest value. BIO_puts() is +not supported. + +BIO_reset() reinitialises a digest BIO. + +BIO_set_md() sets the message digest of BIO B to B: this +must be called to initialize a digest BIO before any data is +passed through it. It is a BIO_ctrl() macro. + +BIO_get_md() places the a pointer to the digest BIOs digest method +in B, it is a BIO_ctrl() macro. + +BIO_get_md_ctx() returns the digest BIOs context into B. + +=head1 NOTES + +The context returned by BIO_get_md_ctx() can be used in calls +to EVP_DigestFinal() and also the signature routines EVP_SignFinal() +and EVP_VerifyFinal(). + +The context returned by BIO_get_md_ctx() is an internal context +structure. Changes made to this context will affect the digest +BIO itself and the context pointer will become invalid when the digest +BIO is freed. + +After the digest has been retrieved from a digest BIO it must be +reinitialized by calling BIO_reset(), or BIO_set_md() before any more +data is passed through it. + +If an application needs to call BIO_gets() or BIO_puts() through +a chain containing digest BIOs then this can be done by prepending +a buffering BIO. + +=head1 RETURN VALUES + +BIO_f_md() returns the digest BIO method. + +BIO_set_md(), BIO_get_md() and BIO_md_ctx() return 1 for success and +0 for failure. + +=head1 EXAMPLES + +The following example creates a BIO chain containing an SHA1 and MD5 +digest BIO and passes the string "Hello World" through it. Error +checking has been omitted for clarity. + + BIO *bio, *mdtmp; + char message[] = "Hello World"; + bio = BIO_new(BIO_s_null()); + mdtmp = BIO_new(BIO_f_md()); + BIO_set_md(mdtmp, EVP_sha1()); + /* For BIO_push() we want to append the sink BIO and keep a note of + * the start of the chain. + */ + bio = BIO_push(mdtmp, bio); + mdtmp = BIO_new(BIO_f_md()); + BIO_set_md(mdtmp, EVP_md5()); + bio = BIO_push(mdtmp, bio); + /* Note: mdtmp can now be discarded */ + BIO_write(bio, message, strlen(message)); + +The next example digests data by reading through a chain instead: + + BIO *bio, *mdtmp; + char buf[1024]; + int rdlen; + bio = BIO_new_file(file, "rb"); + mdtmp = BIO_new(BIO_f_md()); + BIO_set_md(mdtmp, EVP_sha1()); + bio = BIO_push(mdtmp, bio); + mdtmp = BIO_new(BIO_f_md()); + BIO_set_md(mdtmp, EVP_md5()); + bio = BIO_push(mdtmp, bio); + do { + rdlen = BIO_read(bio, buf, sizeof(buf)); + /* Might want to do something with the data here */ + } while(rdlen > 0); + +This next example retrieves the message digests from a BIO chain and +outputs them. This could be used with the examples above. + + BIO *mdtmp; + unsigned char mdbuf[EVP_MAX_MD_SIZE]; + int mdlen; + int i; + mdtmp = bio; /* Assume bio has previously been set up */ + do { + EVP_MD *md; + mdtmp = BIO_find_type(mdtmp, BIO_TYPE_MD); + if(!mdtmp) break; + BIO_get_md(mdtmp, &md); + printf("%s digest", OBJ_nid2sn(EVP_MD_type(md))); + mdlen = BIO_gets(mdtmp, mdbuf, EVP_MAX_MD_SIZE); + for(i = 0; i < mdlen; i++) printf(":%02X", mdbuf[i]); + printf("\n"); + mdtmp = BIO_next(mdtmp); + } while(mdtmp); + + BIO_free_all(bio); + +=head1 BUGS + +The lack of support for BIO_puts() and the non standard behaviour of +BIO_gets() could be regarded as anomalous. It could be argued that BIO_gets() +and BIO_puts() should be passed to the next BIO in the chain and digest +the data passed through and that digests should be retrieved using a +separate BIO_ctrl() call. + +=head1 SEE ALSO + +TBA -- cgit v1.2.3