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Diffstat (limited to 'secure/lib/libcrypto/man/EVP_DigestInit.3')
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diff --git a/secure/lib/libcrypto/man/EVP_DigestInit.3 b/secure/lib/libcrypto/man/EVP_DigestInit.3 new file mode 100644 index 0000000..4096ca2 --- /dev/null +++ b/secure/lib/libcrypto/man/EVP_DigestInit.3 @@ -0,0 +1,417 @@ +.\" Automatically generated by Pod::Man 2.28 (Pod::Simple 3.28) +.\" +.\" Standard preamble: +.\" ======================================================================== +.de Sp \" Vertical space (when we can't use .PP) +.if t .sp .5v +.if n .sp +.. +.de Vb \" Begin verbatim text +.ft CW +.nf +.ne \\$1 +.. +.de Ve \" End verbatim text +.ft R +.fi +.. +.\" Set up some character translations and predefined strings. \*(-- will +.\" give an unbreakable dash, \*(PI will give pi, \*(L" will give a left +.\" double quote, and \*(R" will give a right double quote. \*(C+ will +.\" give a nicer C++. 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No user-serviceable parts. +. \" fudge factors for nroff and troff +.if n \{\ +. ds #H 0 +. ds #V .8m +. ds #F .3m +. ds #[ \f1 +. ds #] \fP +.\} +.if t \{\ +. ds #H ((1u-(\\\\n(.fu%2u))*.13m) +. ds #V .6m +. ds #F 0 +. ds #[ \& +. ds #] \& +.\} +. \" simple accents for nroff and troff +.if n \{\ +. ds ' \& +. ds ` \& +. ds ^ \& +. ds , \& +. ds ~ ~ +. ds / +.\} +.if t \{\ +. ds ' \\k:\h'-(\\n(.wu*8/10-\*(#H)'\'\h"|\\n:u" +. ds ` \\k:\h'-(\\n(.wu*8/10-\*(#H)'\`\h'|\\n:u' +. ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'^\h'|\\n:u' +. ds , \\k:\h'-(\\n(.wu*8/10)',\h'|\\n:u' +. ds ~ \\k:\h'-(\\n(.wu-\*(#H-.1m)'~\h'|\\n:u' +. ds / \\k:\h'-(\\n(.wu*8/10-\*(#H)'\z\(sl\h'|\\n:u' +.\} +. \" troff and (daisy-wheel) nroff accents +.ds : \\k:\h'-(\\n(.wu*8/10-\*(#H+.1m+\*(#F)'\v'-\*(#V'\z.\h'.2m+\*(#F'.\h'|\\n:u'\v'\*(#V' +.ds 8 \h'\*(#H'\(*b\h'-\*(#H' +.ds o \\k:\h'-(\\n(.wu+\w'\(de'u-\*(#H)/2u'\v'-.3n'\*(#[\z\(de\v'.3n'\h'|\\n:u'\*(#] +.ds d- \h'\*(#H'\(pd\h'-\w'~'u'\v'-.25m'\f2\(hy\fP\v'.25m'\h'-\*(#H' +.ds D- D\\k:\h'-\w'D'u'\v'-.11m'\z\(hy\v'.11m'\h'|\\n:u' +.ds th \*(#[\v'.3m'\s+1I\s-1\v'-.3m'\h'-(\w'I'u*2/3)'\s-1o\s+1\*(#] +.ds Th \*(#[\s+2I\s-2\h'-\w'I'u*3/5'\v'-.3m'o\v'.3m'\*(#] +.ds ae a\h'-(\w'a'u*4/10)'e +.ds Ae A\h'-(\w'A'u*4/10)'E +. \" corrections for vroff +.if v .ds ~ \\k:\h'-(\\n(.wu*9/10-\*(#H)'\s-2\u~\d\s+2\h'|\\n:u' +.if v .ds ^ \\k:\h'-(\\n(.wu*10/11-\*(#H)'\v'-.4m'^\v'.4m'\h'|\\n:u' +. \" for low resolution devices (crt and lpr) +.if \n(.H>23 .if \n(.V>19 \ +\{\ +. ds : e +. ds 8 ss +. ds o a +. ds d- d\h'-1'\(ga +. ds D- D\h'-1'\(hy +. ds th \o'bp' +. ds Th \o'LP' +. ds ae ae +. ds Ae AE +.\} +.rm #[ #] #H #V #F C +.\" ======================================================================== +.\" +.IX Title "EVP_DigestInit 3" +.TH EVP_DigestInit 3 "2015-12-03" "1.0.2e" "OpenSSL" +.\" For nroff, turn off justification. Always turn off hyphenation; it makes +.\" way too many mistakes in technical documents. +.if n .ad l +.nh +.SH "NAME" +EVP_MD_CTX_init, EVP_MD_CTX_create, EVP_DigestInit_ex, EVP_DigestUpdate, +EVP_DigestFinal_ex, EVP_MD_CTX_cleanup, EVP_MD_CTX_destroy, EVP_MAX_MD_SIZE, +EVP_MD_CTX_copy_ex, EVP_DigestInit, EVP_DigestFinal, EVP_MD_CTX_copy, EVP_MD_type, +EVP_MD_pkey_type, EVP_MD_size, EVP_MD_block_size, EVP_MD_CTX_md, EVP_MD_CTX_size, +EVP_MD_CTX_block_size, EVP_MD_CTX_type, EVP_md_null, EVP_md2, EVP_md5, EVP_sha, EVP_sha1, +EVP_sha224, EVP_sha256, EVP_sha384, EVP_sha512, EVP_dss, EVP_dss1, EVP_mdc2, +EVP_ripemd160, EVP_get_digestbyname, EVP_get_digestbynid, EVP_get_digestbyobj \- +EVP digest routines +.SH "SYNOPSIS" +.IX Header "SYNOPSIS" +.Vb 1 +\& #include <openssl/evp.h> +\& +\& void EVP_MD_CTX_init(EVP_MD_CTX *ctx); +\& EVP_MD_CTX *EVP_MD_CTX_create(void); +\& +\& int EVP_DigestInit_ex(EVP_MD_CTX *ctx, const EVP_MD *type, ENGINE *impl); +\& int EVP_DigestUpdate(EVP_MD_CTX *ctx, const void *d, size_t cnt); +\& int EVP_DigestFinal_ex(EVP_MD_CTX *ctx, unsigned char *md, +\& unsigned int *s); +\& +\& int EVP_MD_CTX_cleanup(EVP_MD_CTX *ctx); +\& void EVP_MD_CTX_destroy(EVP_MD_CTX *ctx); +\& +\& int EVP_MD_CTX_copy_ex(EVP_MD_CTX *out,const EVP_MD_CTX *in); +\& +\& int EVP_DigestInit(EVP_MD_CTX *ctx, const EVP_MD *type); +\& int EVP_DigestFinal(EVP_MD_CTX *ctx, unsigned char *md, +\& unsigned int *s); +\& +\& int EVP_MD_CTX_copy(EVP_MD_CTX *out,EVP_MD_CTX *in); +\& +\& #define EVP_MAX_MD_SIZE 64 /* SHA512 */ +\& +\& int EVP_MD_type(const EVP_MD *md); +\& int EVP_MD_pkey_type(const EVP_MD *md); +\& int EVP_MD_size(const EVP_MD *md); +\& int EVP_MD_block_size(const EVP_MD *md); +\& +\& const EVP_MD *EVP_MD_CTX_md(const EVP_MD_CTX *ctx); +\& #define EVP_MD_CTX_size(e) EVP_MD_size(EVP_MD_CTX_md(e)) +\& #define EVP_MD_CTX_block_size(e) EVP_MD_block_size((e)\->digest) +\& #define EVP_MD_CTX_type(e) EVP_MD_type((e)\->digest) +\& +\& const EVP_MD *EVP_md_null(void); +\& const EVP_MD *EVP_md2(void); +\& const EVP_MD *EVP_md5(void); +\& const EVP_MD *EVP_sha(void); +\& const EVP_MD *EVP_sha1(void); +\& const EVP_MD *EVP_dss(void); +\& const EVP_MD *EVP_dss1(void); +\& const EVP_MD *EVP_mdc2(void); +\& const EVP_MD *EVP_ripemd160(void); +\& +\& const EVP_MD *EVP_sha224(void); +\& const EVP_MD *EVP_sha256(void); +\& const EVP_MD *EVP_sha384(void); +\& const EVP_MD *EVP_sha512(void); +\& +\& const EVP_MD *EVP_get_digestbyname(const char *name); +\& #define EVP_get_digestbynid(a) EVP_get_digestbyname(OBJ_nid2sn(a)) +\& #define EVP_get_digestbyobj(a) EVP_get_digestbynid(OBJ_obj2nid(a)) +.Ve +.SH "DESCRIPTION" +.IX Header "DESCRIPTION" +The \s-1EVP\s0 digest routines are a high level interface to message digests. +.PP +\&\fIEVP_MD_CTX_init()\fR initializes digest context \fBctx\fR. +.PP +\&\fIEVP_MD_CTX_create()\fR allocates, initializes and returns a digest context. +.PP +\&\fIEVP_DigestInit_ex()\fR sets up digest context \fBctx\fR to use a digest +\&\fBtype\fR from \s-1ENGINE \s0\fBimpl\fR. \fBctx\fR must be initialized before calling this +function. \fBtype\fR will typically be supplied by a functionsuch as \fIEVP_sha1()\fR. +If \fBimpl\fR is \s-1NULL\s0 then the default implementation of digest \fBtype\fR is used. +.PP +\&\fIEVP_DigestUpdate()\fR hashes \fBcnt\fR bytes of data at \fBd\fR into the +digest context \fBctx\fR. This function can be called several times on the +same \fBctx\fR to hash additional data. +.PP +\&\fIEVP_DigestFinal_ex()\fR retrieves the digest value from \fBctx\fR and places +it in \fBmd\fR. If the \fBs\fR parameter is not \s-1NULL\s0 then the number of +bytes of data written (i.e. the length of the digest) will be written +to the integer at \fBs\fR, at most \fB\s-1EVP_MAX_MD_SIZE\s0\fR bytes will be written. +After calling \fIEVP_DigestFinal_ex()\fR no additional calls to \fIEVP_DigestUpdate()\fR +can be made, but \fIEVP_DigestInit_ex()\fR can be called to initialize a new +digest operation. +.PP +\&\fIEVP_MD_CTX_cleanup()\fR cleans up digest context \fBctx\fR, it should be called +after a digest context is no longer needed. +.PP +\&\fIEVP_MD_CTX_destroy()\fR cleans up digest context \fBctx\fR and frees up the +space allocated to it, it should be called only on a context created +using \fIEVP_MD_CTX_create()\fR. +.PP +\&\fIEVP_MD_CTX_copy_ex()\fR can be used to copy the message digest state from +\&\fBin\fR to \fBout\fR. This is useful if large amounts of data are to be +hashed which only differ in the last few bytes. \fBout\fR must be initialized +before calling this function. +.PP +\&\fIEVP_DigestInit()\fR behaves in the same way as \fIEVP_DigestInit_ex()\fR except +the passed context \fBctx\fR does not have to be initialized, and it always +uses the default digest implementation. +.PP +\&\fIEVP_DigestFinal()\fR is similar to \fIEVP_DigestFinal_ex()\fR except the digest +context \fBctx\fR is automatically cleaned up. +.PP +\&\fIEVP_MD_CTX_copy()\fR is similar to \fIEVP_MD_CTX_copy_ex()\fR except the destination +\&\fBout\fR does not have to be initialized. +.PP +\&\fIEVP_MD_size()\fR and \fIEVP_MD_CTX_size()\fR return the size of the message digest +when passed an \fB\s-1EVP_MD\s0\fR or an \fB\s-1EVP_MD_CTX\s0\fR structure, i.e. the size of the +hash. +.PP +\&\fIEVP_MD_block_size()\fR and \fIEVP_MD_CTX_block_size()\fR return the block size of the +message digest when passed an \fB\s-1EVP_MD\s0\fR or an \fB\s-1EVP_MD_CTX\s0\fR structure. +.PP +\&\fIEVP_MD_type()\fR and \fIEVP_MD_CTX_type()\fR return the \s-1NID\s0 of the \s-1OBJECT IDENTIFIER\s0 +representing the given message digest when passed an \fB\s-1EVP_MD\s0\fR structure. +For example EVP_MD_type(\fIEVP_sha1()\fR) returns \fBNID_sha1\fR. This function is +normally used when setting \s-1ASN1\s0 OIDs. +.PP +\&\fIEVP_MD_CTX_md()\fR returns the \fB\s-1EVP_MD\s0\fR structure corresponding to the passed +\&\fB\s-1EVP_MD_CTX\s0\fR. +.PP +\&\fIEVP_MD_pkey_type()\fR returns the \s-1NID\s0 of the public key signing algorithm associated +with this digest. For example \fIEVP_sha1()\fR is associated with \s-1RSA\s0 so this will +return \fBNID_sha1WithRSAEncryption\fR. Since digests and signature algorithms +are no longer linked this function is only retained for compatibility +reasons. +.PP +\&\fIEVP_md2()\fR, \fIEVP_md5()\fR, \fIEVP_sha()\fR, \fIEVP_sha1()\fR, \fIEVP_sha224()\fR, \fIEVP_sha256()\fR, +\&\fIEVP_sha384()\fR, \fIEVP_sha512()\fR, \fIEVP_mdc2()\fR and \fIEVP_ripemd160()\fR return \fB\s-1EVP_MD\s0\fR +structures for the \s-1MD2, MD5, SHA, SHA1, SHA224, SHA256, SHA384, SHA512, MDC2\s0 +and \s-1RIPEMD160\s0 digest algorithms respectively. +.PP +\&\fIEVP_dss()\fR and \fIEVP_dss1()\fR return \fB\s-1EVP_MD\s0\fR structures for \s-1SHA\s0 and \s-1SHA1\s0 digest +algorithms but using \s-1DSS \s0(\s-1DSA\s0) for the signature algorithm. Note: there is +no need to use these pseudo-digests in OpenSSL 1.0.0 and later, they are +however retained for compatibility. +.PP +\&\fIEVP_md_null()\fR is a \*(L"null\*(R" message digest that does nothing: i.e. the hash it +returns is of zero length. +.PP +\&\fIEVP_get_digestbyname()\fR, \fIEVP_get_digestbynid()\fR and \fIEVP_get_digestbyobj()\fR +return an \fB\s-1EVP_MD\s0\fR structure when passed a digest name, a digest \s-1NID\s0 or +an \s-1ASN1_OBJECT\s0 structure respectively. The digest table must be initialized +using, for example, \fIOpenSSL_add_all_digests()\fR for these functions to work. +.SH "RETURN VALUES" +.IX Header "RETURN VALUES" +\&\fIEVP_DigestInit_ex()\fR, \fIEVP_DigestUpdate()\fR and \fIEVP_DigestFinal_ex()\fR return 1 for +success and 0 for failure. +.PP +\&\fIEVP_MD_CTX_copy_ex()\fR returns 1 if successful or 0 for failure. +.PP +\&\fIEVP_MD_type()\fR, \fIEVP_MD_pkey_type()\fR and \fIEVP_MD_type()\fR return the \s-1NID\s0 of the +corresponding \s-1OBJECT IDENTIFIER\s0 or NID_undef if none exists. +.PP +\&\fIEVP_MD_size()\fR, \fIEVP_MD_block_size()\fR, \fIEVP_MD_CTX_size()\fR and +\&\fIEVP_MD_CTX_block_size()\fR return the digest or block size in bytes. +.PP +\&\fIEVP_md_null()\fR, \fIEVP_md2()\fR, \fIEVP_md5()\fR, \fIEVP_sha()\fR, \fIEVP_sha1()\fR, \fIEVP_dss()\fR, +\&\fIEVP_dss1()\fR, \fIEVP_mdc2()\fR and \fIEVP_ripemd160()\fR return pointers to the +corresponding \s-1EVP_MD\s0 structures. +.PP +\&\fIEVP_get_digestbyname()\fR, \fIEVP_get_digestbynid()\fR and \fIEVP_get_digestbyobj()\fR +return either an \fB\s-1EVP_MD\s0\fR structure or \s-1NULL\s0 if an error occurs. +.SH "NOTES" +.IX Header "NOTES" +The \fB\s-1EVP\s0\fR interface to message digests should almost always be used in +preference to the low level interfaces. This is because the code then becomes +transparent to the digest used and much more flexible. +.PP +New applications should use the \s-1SHA2\s0 digest algorithms such as \s-1SHA256.\s0 +The other digest algorithms are still in common use. +.PP +For most applications the \fBimpl\fR parameter to \fIEVP_DigestInit_ex()\fR will be +set to \s-1NULL\s0 to use the default digest implementation. +.PP +The functions \fIEVP_DigestInit()\fR, \fIEVP_DigestFinal()\fR and \fIEVP_MD_CTX_copy()\fR are +obsolete but are retained to maintain compatibility with existing code. New +applications should use \fIEVP_DigestInit_ex()\fR, \fIEVP_DigestFinal_ex()\fR and +\&\fIEVP_MD_CTX_copy_ex()\fR because they can efficiently reuse a digest context +instead of initializing and cleaning it up on each call and allow non default +implementations of digests to be specified. +.PP +In OpenSSL 0.9.7 and later if digest contexts are not cleaned up after use +memory leaks will occur. +.PP +Stack allocation of \s-1EVP_MD_CTX\s0 structures is common, for example: +.PP +.Vb 2 +\& EVP_MD_CTX mctx; +\& EVP_MD_CTX_init(&mctx); +.Ve +.PP +This will cause binary compatibility issues if the size of \s-1EVP_MD_CTX\s0 +structure changes (this will only happen with a major release of OpenSSL). +Applications wishing to avoid this should use \fIEVP_MD_CTX_create()\fR instead: +.PP +.Vb 2 +\& EVP_MD_CTX *mctx; +\& mctx = EVP_MD_CTX_create(); +.Ve +.SH "EXAMPLE" +.IX Header "EXAMPLE" +This example digests the data \*(L"Test Message\en\*(R" and \*(L"Hello World\en\*(R", using the +digest name passed on the command line. +.PP +.Vb 2 +\& #include <stdio.h> +\& #include <openssl/evp.h> +\& +\& main(int argc, char *argv[]) +\& { +\& EVP_MD_CTX *mdctx; +\& const EVP_MD *md; +\& char mess1[] = "Test Message\en"; +\& char mess2[] = "Hello World\en"; +\& unsigned char md_value[EVP_MAX_MD_SIZE]; +\& int md_len, i; +\& +\& OpenSSL_add_all_digests(); +\& +\& if(!argv[1]) { +\& printf("Usage: mdtest digestname\en"); +\& exit(1); +\& } +\& +\& md = EVP_get_digestbyname(argv[1]); +\& +\& if(!md) { +\& printf("Unknown message digest %s\en", argv[1]); +\& exit(1); +\& } +\& +\& mdctx = EVP_MD_CTX_create(); +\& EVP_DigestInit_ex(mdctx, md, NULL); +\& EVP_DigestUpdate(mdctx, mess1, strlen(mess1)); +\& EVP_DigestUpdate(mdctx, mess2, strlen(mess2)); +\& EVP_DigestFinal_ex(mdctx, md_value, &md_len); +\& EVP_MD_CTX_destroy(mdctx); +\& +\& printf("Digest is: "); +\& for(i = 0; i < md_len; i++) +\& printf("%02x", md_value[i]); +\& printf("\en"); +\& +\& /* Call this once before exit. */ +\& EVP_cleanup(); +\& exit(0); +\& } +.Ve +.SH "SEE ALSO" +.IX Header "SEE ALSO" +\&\fIdgst\fR\|(1), +\&\fIevp\fR\|(3) +.SH "HISTORY" +.IX Header "HISTORY" +\&\fIEVP_DigestInit()\fR, \fIEVP_DigestUpdate()\fR and \fIEVP_DigestFinal()\fR are +available in all versions of SSLeay and OpenSSL. +.PP +\&\fIEVP_MD_CTX_init()\fR, \fIEVP_MD_CTX_create()\fR, \fIEVP_MD_CTX_copy_ex()\fR, +\&\fIEVP_MD_CTX_cleanup()\fR, \fIEVP_MD_CTX_destroy()\fR, \fIEVP_DigestInit_ex()\fR +and \fIEVP_DigestFinal_ex()\fR were added in OpenSSL 0.9.7. +.PP +\&\fIEVP_md_null()\fR, \fIEVP_md2()\fR, \fIEVP_md5()\fR, \fIEVP_sha()\fR, \fIEVP_sha1()\fR, +\&\fIEVP_dss()\fR, \fIEVP_dss1()\fR, \fIEVP_mdc2()\fR and \fIEVP_ripemd160()\fR were +changed to return truly const \s-1EVP_MD\s0 * in OpenSSL 0.9.7. +.PP +The link between digests and signing algorithms was fixed in OpenSSL 1.0 and +later, so now \fIEVP_sha1()\fR can be used with \s-1RSA\s0 and \s-1DSA\s0; there is no need to +use \fIEVP_dss1()\fR any more. +.PP +OpenSSL 1.0 and later does not include the \s-1MD2\s0 digest algorithm in the +default configuration due to its security weaknesses. |
