Проект OpenNet: MAN SSL_CIPHER_description (3) Библиотечные вызовы (FreeBSD и Linux)

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SSL_CIPHER_description (3)

>> SSL_CIPHER_description (3) ( Разные man: Библиотечные вызовы )

NAME

SSL_CIPHER_get_name, SSL_CIPHER_get_bits, SSL_CIPHER_get_version, SSL_CIPHER_description - get SSL_CIPHER properties

SYNOPSIS

 #include <openssl/ssl.h>

 const char *SSL_CIPHER_get_name(const SSL_CIPHER *cipher);
 int SSL_CIPHER_get_bits(const SSL_CIPHER *cipher, int *alg_bits);
 char *SSL_CIPHER_get_version(const SSL_CIPHER *cipher);
 char *SSL_CIPHER_description(SSL_CIPHER *cipher, char *buf, int size);

DESCRIPTION

SSL_CIPHER_get_name() returns a pointer to the name of cipher. If the argument is the NULL pointer, a pointer to the constant value ``NONE'' is returned.

SSL_CIPHER_get_bits() returns the number of secret bits used for cipher. If alg_bits is not NULL, it contains the number of bits processed by the chosen algorithm. If cipher is NULL, 0 is returned.

SSL_CIPHER_get_version() returns the protocol version for cipher, currently ``SSLv2'', ``SSLv3'', or ``TLSv1''. If cipher is NULL, ``(NONE)'' is returned.

SSL_CIPHER_description() returns a textual description of the cipher used into the buffer buf of length len provided. len must be at least 128 bytes, otherwise a pointer to the the string ``Buffer too small'' is returned. If buf is NULL, a buffer of 128 bytes is allocated using OPENSSL_malloc(). If the allocation fails, a pointer to the string ``OPENSSL_malloc Error'' is returned.

NOTES

The number of bits processed can be different from the secret bits. An export cipher like e.g. EXP-RC4-MD5 has only 40 secret bits. The algorithm does use the full 128 bits (which would be returned for alg_bits), of which however 88bits are fixed. The search space is hence only 40 bits.

The string returned by SSL_CIPHER_description() in case of success consists of cleartext information separated by one or more blanks in the following sequence:

<ciphername>: Textual representation of the cipher name.
<protocol version>: Protocol version: SSLv2, SSLv3. The TLSv1 ciphers are flagged with SSLv3.
Kx=<key exchange>: Key exchange method: RSA (for export ciphers as RSA(512) or RSA(1024)), DH (for export ciphers as DH(512) or DH(1024)), DH/RSA, DH/DSS, Fortezza.
Au=<authentication>: Authentication method: RSA, DSS, DH, None. None is the representation of anonymous ciphers.
Enc=<symmetric encryption method>: Encryption method with number of secret bits: DES(40), DES(56), 3DES(168), RC4(40), RC4(56), RC4(64), RC4(128), RC2(40), RC2(56), RC2(128), IDEA(128), Fortezza, None.
Mac=<message authentication code>: Message digest: MD5, SHA1.
<export flag>: If the cipher is flagged exportable with respect to old US crypto regulations, the word "export" is printed.

EXAMPLES

Some examples for the output of SSL_CIPHER_description():

 EDH-RSA-DES-CBC3-SHA    SSLv3 Kx=DH       Au=RSA  Enc=3DES(168) Mac=SHA1
 EDH-DSS-DES-CBC3-SHA    SSLv3 Kx=DH       Au=DSS  Enc=3DES(168) Mac=SHA1
 RC4-MD5                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(128)  Mac=MD5
 EXP-RC4-MD5             SSLv3 Kx=RSA(512) Au=RSA  Enc=RC4(40)   Mac=MD5  export

BUGS

If SSL_CIPHER_description() is called with cipher being NULL, the library crashes.

If SSL_CIPHER_description() cannot handle a built-in cipher, the according description of the cipher property is unknown. This case should not occur.