DragonFly On-Line Manual Pages

Search: Section:  


SHA(3)		      DragonFly Library Functions Manual		SHA(3)

NAME

SHA_Init, SHA_Update, SHA_Final, SHA_End, SHA_File, SHA_FileChunk, SHA_Data, SHA1_Init, SHA1_Update, SHA1_Final, SHA1_End, SHA1_File, SHA1_FileChunk, SHA1_Data -- calculate the FIPS 160 and 160-1 ``SHA'' message digests

LIBRARY

Message Digest (MD4, MD5, etc.) Support Library (libmd, -lmd)

SYNOPSIS

#include <sys/types.h> #include <sha.h> void SHA_Init(SHA_CTX *context); void SHA_Update(SHA_CTX *context, const void *data, size_t len); void SHA_Final(unsigned char digest[20], SHA_CTX *context); char * SHA_End(SHA_CTX *context, char *buf); char * SHA_File(const char *filename, char *buf); char * SHA_FileChunk(const char *filename, char *buf, off_t offset, off_t length); char * SHA_Data(const void *data, unsigned int len, char *buf); void SHA1_Init(SHA_CTX *context); void SHA1_Update(SHA_CTX *context, const void *data, size_t len); void SHA1_Final(unsigned char digest[20], SHA_CTX *context); char * SHA1_End(SHA_CTX *context, char *buf); char * SHA1_File(const char *filename, char *buf); char * SHA1_FileChunk(const char *filename, char *buf, off_t offset, off_t length); char * SHA1_Data(const void *data, unsigned int len, char *buf);

DESCRIPTION

The SHA_ and SHA1_ functions calculate a 160-bit cryptographic checksum (digest) for any number of input bytes. A cryptographic checksum is a one-way hash function; that is, it is computationally impractical to find the input corresponding to a particular output. This net result is a ``fingerprint'' of the input-data, which does not disclose the actual input. SHA (or SHA-0) is the original Secure Hash Algorithm specified in FIPS 160. It was quickly proven insecure, and has been superseded by SHA-1. SHA-0 is included for compatibility purposes only. The SHA1_Init(), SHA1_Update(), and SHA1_Final() functions are the core functions. Allocate an SHA_CTX, initialize it with SHA1_Init(), run over the data with SHA1_Update(), and finally extract the result using SHA1_Final(). SHA1_End() is a wrapper for SHA1_Final() which converts the return value to a 41-character (including the terminating '\0') ASCII string which represents the 160 bits in hexadecimal. SHA1_File() calculates the digest of a file, and uses SHA1_End() to return the result. If the file cannot be opened, a null pointer is returned. SHA1_FileChunk() is similar to SHA1_File(), but it only calcu- lates the digest over a byte-range of the file specified, starting at offset and spanning length bytes. If the length parameter is specified as 0, or more than the length of the remaining part of the file, SHA1_FileChunk() calculates the digest from offset to the end of file. SHA1_Data() calculates the digest of a chunk of data in memory, and uses SHA1_End() to return the result. When using SHA1_End(), SHA1_File(), or SHA1_Data(), the buf argument can be a null pointer, in which case the returned string is allocated with malloc(3) and subsequently must be explicitly deallocated using free(3) after use. If the buf argument is non-null it must point to at least 41 characters of buffer space.

SEE ALSO

md2(3), md4(3), md5(3), ripemd(3), sha256(3)

HISTORY

These functions appeared in FreeBSD 4.0.

AUTHORS

The core hash routines were implemented by Eric Young based on the pub- lished FIPS standards.

BUGS

No method is known to exist which finds two files having the same hash value, nor to find a file with a specific hash value. There is on the other hand no guarantee that such a method does not exist. The IA32 (Intel) implementation of SHA-1 makes heavy use of the `bswapl' instruction, which is not present on the original 80386. Attempts to use SHA-1 on those processors will cause an illegal instruction trap. (Arguably, the kernel should simply emulate this instruction.) DragonFly 5.3 February 25, 1999 DragonFly 5.3 sha(3) OpenSSL sha(3)

NAME

SHA1, SHA1_Init, SHA1_Update, SHA1_Final, SHA224, SHA224_Init, SHA224_Update, SHA224_Final, SHA256, SHA256_Init, SHA256_Update, SHA256_Final, SHA384, SHA384_Init, SHA384_Update, SHA384_Final, SHA512, SHA512_Init, SHA512_Update, SHA512_Final - Secure Hash Algorithm

SYNOPSIS

#include <openssl/sha.h> int SHA1_Init(SHA_CTX *c); int SHA1_Update(SHA_CTX *c, const void *data, size_t len); int SHA1_Final(unsigned char *md, SHA_CTX *c); unsigned char *SHA1(const unsigned char *d, size_t n, unsigned char *md); int SHA224_Init(SHA256_CTX *c); int SHA224_Update(SHA256_CTX *c, const void *data, size_t len); int SHA224_Final(unsigned char *md, SHA256_CTX *c); unsigned char *SHA224(const unsigned char *d, size_t n, unsigned char *md); int SHA256_Init(SHA256_CTX *c); int SHA256_Update(SHA256_CTX *c, const void *data, size_t len); int SHA256_Final(unsigned char *md, SHA256_CTX *c); unsigned char *SHA256(const unsigned char *d, size_t n, unsigned char *md); int SHA384_Init(SHA512_CTX *c); int SHA384_Update(SHA512_CTX *c, const void *data, size_t len); int SHA384_Final(unsigned char *md, SHA512_CTX *c); unsigned char *SHA384(const unsigned char *d, size_t n, unsigned char *md); int SHA512_Init(SHA512_CTX *c); int SHA512_Update(SHA512_CTX *c, const void *data, size_t len); int SHA512_Final(unsigned char *md, SHA512_CTX *c); unsigned char *SHA512(const unsigned char *d, size_t n, unsigned char *md);

DESCRIPTION

Applications should use the higher level functions EVP_DigestInit(3) etc. instead of calling the hash functions directly. SHA-1 (Secure Hash Algorithm) is a cryptographic hash function with a 160 bit output. SHA1() computes the SHA-1 message digest of the n bytes at d and places it in md (which must have space for SHA_DIGEST_LENGTH == 20 bytes of output). If md is NULL, the digest is placed in a static array. Note: setting md to NULL is not thread safe. The following functions may be used if the message is not completely stored in memory: SHA1_Init() initializes a SHA_CTX structure. SHA1_Update() can be called repeatedly with chunks of the message to be hashed (len bytes at data). SHA1_Final() places the message digest in md, which must have space for SHA_DIGEST_LENGTH == 20 bytes of output, and erases the SHA_CTX. The SHA224, SHA256, SHA384 and SHA512 families of functions operate in the same way as for the SHA1 functions. Note that SHA224 and SHA256 use a SHA256_CTX object instead of SHA_CTX. SHA384 and SHA512 use SHA512_CTX. The buffer md must have space for the output from the SHA variant being used (defined by SHA224_DIGEST_LENGTH, SHA256_DIGEST_LENGTH, SHA384_DIGEST_LENGTH and SHA512_DIGEST_LENGTH). Also note that, as for the SHA1() function above, the SHA224(), SHA256(), SHA384() and SHA512() functions are not thread safe if md is NULL. The predecessor of SHA-1, SHA, is also implemented, but it should be used only when backward compatibility is required.

RETURN VALUES

SHA1(), SHA224(), SHA256(), SHA384() and SHA512() return a pointer to the hash value. SHA1_Init(), SHA1_Update() and SHA1_Final() and equivalent SHA224, SHA256, SHA384 and SHA512 functions return 1 for success, 0 otherwise.

CONFORMING TO

US Federal Information Processing Standard FIPS PUB 180-4 (Secure Hash Standard), ANSI X9.30

SEE ALSO

ripemd(3), hmac(3), EVP_DigestInit(3)

HISTORY

SHA1(), SHA1_Init(), SHA1_Update() and SHA1_Final() are available in all versions of SSLeay and OpenSSL. 1.0.2h 2016-05-03 sha(3) sha(3) OpenSSL sha(3)

NAME

SHA1, SHA1_Init, SHA1_Update, SHA1_Final, SHA224, SHA224_Init, SHA224_Update, SHA224_Final, SHA256, SHA256_Init, SHA256_Update, SHA256_Final, SHA384, SHA384_Init, SHA384_Update, SHA384_Final, SHA512, SHA512_Init, SHA512_Update, SHA512_Final - Secure Hash Algorithm

SYNOPSIS

#include <openssl/sha.h> int SHA1_Init(SHA_CTX *c); int SHA1_Update(SHA_CTX *c, const void *data, size_t len); int SHA1_Final(unsigned char *md, SHA_CTX *c); unsigned char *SHA1(const unsigned char *d, size_t n, unsigned char *md); int SHA224_Init(SHA256_CTX *c); int SHA224_Update(SHA256_CTX *c, const void *data, size_t len); int SHA224_Final(unsigned char *md, SHA256_CTX *c); unsigned char *SHA224(const unsigned char *d, size_t n, unsigned char *md); int SHA256_Init(SHA256_CTX *c); int SHA256_Update(SHA256_CTX *c, const void *data, size_t len); int SHA256_Final(unsigned char *md, SHA256_CTX *c); unsigned char *SHA256(const unsigned char *d, size_t n, unsigned char *md); int SHA384_Init(SHA512_CTX *c); int SHA384_Update(SHA512_CTX *c, const void *data, size_t len); int SHA384_Final(unsigned char *md, SHA512_CTX *c); unsigned char *SHA384(const unsigned char *d, size_t n, unsigned char *md); int SHA512_Init(SHA512_CTX *c); int SHA512_Update(SHA512_CTX *c, const void *data, size_t len); int SHA512_Final(unsigned char *md, SHA512_CTX *c); unsigned char *SHA512(const unsigned char *d, size_t n, unsigned char *md);

DESCRIPTION

Applications should use the higher level functions EVP_DigestInit(3) etc. instead of calling the hash functions directly. SHA-1 (Secure Hash Algorithm) is a cryptographic hash function with a 160 bit output. SHA1() computes the SHA-1 message digest of the n bytes at d and places it in md (which must have space for SHA_DIGEST_LENGTH == 20 bytes of output). If md is NULL, the digest is placed in a static array. Note: setting md to NULL is not thread safe. The following functions may be used if the message is not completely stored in memory: SHA1_Init() initializes a SHA_CTX structure. SHA1_Update() can be called repeatedly with chunks of the message to be hashed (len bytes at data). SHA1_Final() places the message digest in md, which must have space for SHA_DIGEST_LENGTH == 20 bytes of output, and erases the SHA_CTX. The SHA224, SHA256, SHA384 and SHA512 families of functions operate in the same way as for the SHA1 functions. Note that SHA224 and SHA256 use a SHA256_CTX object instead of SHA_CTX. SHA384 and SHA512 use SHA512_CTX. The buffer md must have space for the output from the SHA variant being used (defined by SHA224_DIGEST_LENGTH, SHA256_DIGEST_LENGTH, SHA384_DIGEST_LENGTH and SHA512_DIGEST_LENGTH). Also note that, as for the SHA1() function above, the SHA224(), SHA256(), SHA384() and SHA512() functions are not thread safe if md is NULL. The predecessor of SHA-1, SHA, is also implemented, but it should be used only when backward compatibility is required.

RETURN VALUES

SHA1(), SHA224(), SHA256(), SHA384() and SHA512() return a pointer to the hash value. SHA1_Init(), SHA1_Update() and SHA1_Final() and equivalent SHA224, SHA256, SHA384 and SHA512 functions return 1 for success, 0 otherwise.

CONFORMING TO

US Federal Information Processing Standard FIPS PUB 180-4 (Secure Hash Standard), ANSI X9.30

SEE ALSO

ripemd(3), hmac(3), EVP_DigestInit(3)

HISTORY

SHA1(), SHA1_Init(), SHA1_Update() and SHA1_Final() are available in all versions of SSLeay and OpenSSL. 1.0.2f 2016-01-28 sha(3)

Search: Section: