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RSA_public_encrypt(3)
NAME
  RSA_public_encrypt, RSA_private_decrypt - RSA public key cryptography

SYNOPSIS
  #include <openssl/rsa.h>

  int RSA_public_encrypt(
	  int flen,
	  unsigned char *from,
	  unsigned char *to,
	  RSA *rsa,
	  int padding );

  int RSA_private_decrypt(
	  int flen,
	  unsigned char *from,
	  unsigned char *to,
	  RSA *rsa,
	  int padding );

DESCRIPTION
  The RSA_public_encrypt() function encrypts the flen bytes at from (usually
  a session key) using the public key rsa and stores the ciphertext in to.
  The to must point to RSA_size(rsa) bytes of memory.

  The padding denotes one of the following modes:

  RSA_PKCS1_PADDING
	  PKCS #1 v1.5 padding. This currently is the most widely used mode.

  RSA_PKCS1_OAEP_PADDING
	  EME-OAEP as defined in PKCS #1 v2.0 with SHA-1, MGF1 and an empty
	  encoding parameter. This mode is recommended for all new
	  applications.

  RSA_SSLV23_PADDING
	  PKCS #1 v1.5 padding with an SSL-specific modification that denotes
	  that the server is SSL3 capable.

  RSA_NO_PADDING
	  Raw RSA encryption. This mode should only be used to implement
	  cryptographically sound padding modes in the application code.
	  Encrypting user data directly with RSA is insecure.

  The flen must be less than RSA_size(rsa) - 11 for the PKCS #1 v1.5 based
  padding modes, and less than RSA_size(rsa) - 41 for RSA_PKCS1_OAEP_PADDING.
  The random number generator must be seeded prior to calling the
  RSA_public_encrypt() function.

  The RSA_private_decrypt() function decrypts the flen bytes at from using
  the private key rsa and stores the plaintext in to. The to must point to a
  memory section large enough to hold the decrypted data , which is smaller
  than RSA_size(rsa). The padding is the padding mode that was used to
  encrypt the data.

  These functions conform to SSL, PKCS #1 v2.0.

NOTES
  The RSA_PKCS1_RSAref(3) method supports only the RSA_PKCS1_PADDING mode.

RETURN VALUES
  The RSA_public_encrypt() function returns the size of the encrypted data,
  RSA_size(rsa). The RSA_private_decrypt() function returns the size of the
  recovered plaintext.

  On error, -1 is returned; the error codes can be obtained by using the
  ERR_get_error() function.

HISTORY
  The padding argument was added in SSLeay 0.8. RSA_NO_PADDING is available
  since SSLeay 0.9.0, OAEP was added in OpenSSL 0.9.2b.

SEE ALSO
  Functions: err(3), rand_ssl(3), rsa(3), RSA_size(3)

Index for Section 3

Alphabetical listing for R

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