SSL_CIPHER_get_name, SSL_CIPHER_get_bits, SSL_CIPHER_get_version, SSL_CIPHER_description - get SSL_CIPHER properties

 #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);

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.

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(5) or RSA(1)), DH (for export ciphers as DH(5) or DH(1)), 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(4), DES(5), 3DES(1), RC4(4), RC4(5), RC4(6), RC4(1), RC2(4), RC2(5), RC2(1), IDEA(1), 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.

Some examples for the output of SSL_CIPHER_description():

 EDH-RSA-DES-CBC3-SHA    SSLv3 Kx=DH       Au=RSA  Enc=3DES(1) Mac=SHA1
 EDH-DSS-DES-CBC3-SHA    SSLv3 Kx=DH       Au=DSS  Enc=3DES(1) Mac=SHA1
 RC4-MD5                 SSLv3 Kx=RSA      Au=RSA  Enc=RC4(1)  Mac=MD5
 EXP-RC4-MD5             SSLv3 Kx=RSA(5) Au=RSA  Enc=RC4(4)   Mac=MD5  export

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.

See DESCRIPTION

ssl(3), SSL_get_current_cipher(3), SSL_get_ciphers(3), ciphers(1)