SSL_CIPHER_get_name(3) — Subroutines

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(
        SSL_CIPHER ∗cipher ); int SSL_CIPHER_get_bits(
        SSL_CIPHER ∗cipher, int ∗alg_bits ); char ∗SSL_CIPHER_get_version(
        SSL_CIPHER ∗cipher ); char ∗SSL_CIPHER_description(
        SSL_CIPHER ∗cipher, char ∗buf, int size );

DESCRIPTION

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

The SSL_CIPHER_get_bits() function 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.

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

The SSL_CIPHER_description() function returns a textual description of the cipher used into the buffer (buf) of length (len) provided. The 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 the OPENSSL_malloc() function. 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, such as EXP-RC4-MD5, has 40 secret bits. The algorithm uses the full 128 bits (which would be returned for alg_bits), of which 88 bits are fixed. The search space is 40 bits.

The string returned by the SSL_CIPHER_description() function 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.

RESTRICTIONS

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

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

RETURN VALUES

See Description

EXAMPLES

The following examples show output for the SSL_CIPHER_description()function:

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

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