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(const 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 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.
RETURN VALUES¶
See DESCRIPTION
SEE ALSO¶
ssl(3),
SSL_get_current_cipher(3),
SSL_get_ciphers(3),
ciphers(1)