X-Git-Url: https://bearssl.org/gitweb//home/git/?p=BearSSL;a=blobdiff_plain;f=inc%2Fbearssl_rsa.h;h=7c79d33e7e7579df96bfe5fe4e8e22b388721d46;hp=3d5c26a3222602ae658d168cfcc0001e4b958f34;hb=491a45337de8dc0a4c100abf33f5c0e187a08afd;hpb=7f343eedfc0ef1b3eab8ded1d60e2abc82324a5e diff --git a/inc/bearssl_rsa.h b/inc/bearssl_rsa.h index 3d5c26a..7c79d33 100644 --- a/inc/bearssl_rsa.h +++ b/inc/bearssl_rsa.h @@ -84,7 +84,7 @@ extern "C" { * random masking, but "true" constant-time code. * * - They support only private keys with two prime factors. RSA private - * key with three or more prime factors are nominally supported, but + * keys with three or more prime factors are nominally supported, but * rarely used; they may offer faster operations, at the expense of * more code and potentially a reduction in security if there are * "too many" prime factors. @@ -92,7 +92,7 @@ extern "C" { * - The public exponent may have arbitrary length. Of course, it is * a good idea to keep public exponents small, so that public key * operations are fast; but, contrary to some widely deployed - * implementations, BearSSL has no problem with public exponent + * implementations, BearSSL has no problem with public exponents * longer than 32 bits. * * - The two prime factors of the modulus need not have the same length @@ -170,7 +170,7 @@ typedef struct { /** * \brief RSA private key. * - * The structure references the primvate factors, reduced private + * The structure references the private factors, reduced private * exponents, and CRT coefficient. It also contains the bit length of * the modulus. The big integers use unsigned big-endian representation; * extra leading bytes of value 0 are allowed. However, the modulus bit @@ -277,6 +277,57 @@ typedef uint32_t (*br_rsa_pkcs1_vrfy)(const unsigned char *x, size_t xlen, const unsigned char *hash_oid, size_t hash_len, const br_rsa_public_key *pk, unsigned char *hash_out); +/** + * \brief Type for a RSA encryption engine (OAEP). + * + * Parameters are: + * + * - A source of random bytes. The source must be already initialized. + * + * - A hash function, used internally with the mask generation function + * (MGF1). + * + * - A label. The `label` pointer may be `NULL` if `label_len` is zero + * (an empty label, which is the default in PKCS#1 v2.2). + * + * - The public key. + * + * - The destination buffer. Its maximum length (in bytes) is provided; + * if that length is lower than the public key length, then an error + * is reported. + * + * - The source message. + * + * The encrypted message output has exactly the same length as the modulus + * (mathematical length, in bytes, not counting extra leading zeros in the + * modulus representation in the public key). + * + * The source message (`src`, length `src_len`) may overlap with the + * destination buffer (`dst`, length `dst_max_len`). + * + * This function returns the actual encrypted message length, in bytes; + * on error, zero is returned. An error is reported if the output buffer + * is not large enough, or the public is invalid, or the public key + * modulus exceeds the maximum supported RSA size. + * + * \param rnd source of random bytes. + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param pk RSA public key. + * \param dst destination buffer. + * \param dst_max_len destination buffer length (maximum encrypted data size). + * \param src message to encrypt. + * \param src_len source message length (in bytes). + * \return encrypted message length (in bytes), or 0 on error. + */ +typedef size_t (*br_rsa_oaep_encrypt)( + const br_prng_class **rnd, const br_hash_class *dig, + const void *label, size_t label_len, + const br_rsa_public_key *pk, + void *dst, size_t dst_max_len, + const void *src, size_t src_len); + /** * \brief Type for a RSA private key engine. * @@ -362,6 +413,47 @@ typedef uint32_t (*br_rsa_pkcs1_sign)(const unsigned char *hash_oid, #define BR_HASH_OID_SHA512 \ ((const unsigned char *)"\x09\x60\x86\x48\x01\x65\x03\x04\x02\x03") +/** + * \brief Type for a RSA decryption engine (OAEP). + * + * Parameters are: + * + * - A hash function, used internally with the mask generation function + * (MGF1). + * + * - A label. The `label` pointer may be `NULL` if `label_len` is zero + * (an empty label, which is the default in PKCS#1 v2.2). + * + * - The private key. + * + * - The source and destination buffer. The buffer initially contains + * the encrypted message; the buffer contents are altered, and the + * decrypted message is written at the start of that buffer + * (decrypted message is always shorter than the encrypted message). + * + * If decryption fails in any way, then `*len` is unmodified, and the + * function returns 0. Otherwise, `*len` is set to the decrypted message + * length, and 1 is returned. The implementation is responsible for + * checking that the input message length matches the key modulus length, + * and that the padding is correct. + * + * Implementations MUST use constant-time check of the validity of the + * OAEP padding, at least until the leading byte and hash value have + * been checked. Whether overall decryption worked, and the length of + * the decrypted message, may leak. + * + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param sk RSA private key. + * \param data input/output buffer. + * \param len encrypted/decrypted message length. + * \return 1 on success, 0 on error. + */ +typedef uint32_t (*br_rsa_oaep_decrypt)( + const br_hash_class *dig, const void *label, size_t label_len, + const br_rsa_private_key *sk, void *data, size_t *len); + /* * RSA "i32" engine. Integers are internally represented as arrays of * 32-bit integers, and the core multiplication primitive is the @@ -501,7 +593,7 @@ uint32_t br_rsa_i31_pkcs1_sign(const unsigned char *hash_oid, * * This function is defined only on architecture that offer a 64x64->128 * opcode. Use `br_rsa_i62_public_get()` to dynamically obtain a pointer - * to that functiom. + * to that function. * * \see br_rsa_public * @@ -518,7 +610,7 @@ uint32_t br_rsa_i62_public(unsigned char *x, size_t xlen, * * This function is defined only on architecture that offer a 64x64->128 * opcode. Use `br_rsa_i62_pkcs1_vrfy_get()` to dynamically obtain a pointer - * to that functiom. + * to that function. * * \see br_rsa_pkcs1_vrfy * @@ -539,7 +631,7 @@ uint32_t br_rsa_i62_pkcs1_vrfy(const unsigned char *x, size_t xlen, * * This function is defined only on architecture that offer a 64x64->128 * opcode. Use `br_rsa_i62_private_get()` to dynamically obtain a pointer - * to that functiom. + * to that function. * * \see br_rsa_private * @@ -555,7 +647,7 @@ uint32_t br_rsa_i62_private(unsigned char *x, * * This function is defined only on architecture that offer a 64x64->128 * opcode. Use `br_rsa_i62_pkcs1_sign_get()` to dynamically obtain a pointer - * to that functiom. + * to that function. * * \see br_rsa_pkcs1_sign * @@ -602,6 +694,22 @@ br_rsa_private br_rsa_i62_private_get(void); */ br_rsa_pkcs1_sign br_rsa_i62_pkcs1_sign_get(void); +/** + * \brief Get the RSA "i62" implementation (OAEP encryption), + * if available. + * + * \return the implementation, or 0. + */ +br_rsa_oaep_encrypt br_rsa_i62_oaep_encrypt_get(void); + +/** + * \brief Get the RSA "i62" implementation (OAEP decryption), + * if available. + * + * \return the implementation, or 0. + */ +br_rsa_oaep_decrypt br_rsa_i62_oaep_decrypt_get(void); + /* * RSA "i15" engine. Integers are represented as 15-bit integers, so * the code uses only 32-bit multiplication (no 64-bit result), which @@ -706,6 +814,26 @@ br_rsa_pkcs1_vrfy br_rsa_pkcs1_vrfy_get_default(void); */ br_rsa_pkcs1_sign br_rsa_pkcs1_sign_get_default(void); +/** + * \brief Get "default" RSA implementation (OAEP encryption). + * + * This returns the preferred implementation of RSA (OAEP encryption) + * on the current system. + * + * \return the default implementation. + */ +br_rsa_oaep_encrypt br_rsa_oaep_encrypt_get_default(void); + +/** + * \brief Get "default" RSA implementation (OAEP decryption). + * + * This returns the preferred implementation of RSA (OAEP decryption) + * on the current system. + * + * \return the default implementation. + */ +br_rsa_oaep_decrypt br_rsa_oaep_decrypt_get_default(void); + /** * \brief RSA decryption helper, for SSL/TLS. * @@ -736,6 +864,326 @@ br_rsa_pkcs1_sign br_rsa_pkcs1_sign_get_default(void); uint32_t br_rsa_ssl_decrypt(br_rsa_private core, const br_rsa_private_key *sk, unsigned char *data, size_t len); +/** + * \brief RSA encryption (OAEP) with the "i15" engine. + * + * \see br_rsa_oaep_encrypt + * + * \param rnd source of random bytes. + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param pk RSA public key. + * \param dst destination buffer. + * \param dst_max_len destination buffer length (maximum encrypted data size). + * \param src message to encrypt. + * \param src_len source message length (in bytes). + * \return encrypted message length (in bytes), or 0 on error. + */ +size_t br_rsa_i15_oaep_encrypt( + const br_prng_class **rnd, const br_hash_class *dig, + const void *label, size_t label_len, + const br_rsa_public_key *pk, + void *dst, size_t dst_max_len, + const void *src, size_t src_len); + +/** + * \brief RSA decryption (OAEP) with the "i15" engine. + * + * \see br_rsa_oaep_decrypt + * + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param sk RSA private key. + * \param data input/output buffer. + * \param len encrypted/decrypted message length. + * \return 1 on success, 0 on error. + */ +uint32_t br_rsa_i15_oaep_decrypt( + const br_hash_class *dig, const void *label, size_t label_len, + const br_rsa_private_key *sk, void *data, size_t *len); + +/** + * \brief RSA encryption (OAEP) with the "i31" engine. + * + * \see br_rsa_oaep_encrypt + * + * \param rnd source of random bytes. + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param pk RSA public key. + * \param dst destination buffer. + * \param dst_max_len destination buffer length (maximum encrypted data size). + * \param src message to encrypt. + * \param src_len source message length (in bytes). + * \return encrypted message length (in bytes), or 0 on error. + */ +size_t br_rsa_i31_oaep_encrypt( + const br_prng_class **rnd, const br_hash_class *dig, + const void *label, size_t label_len, + const br_rsa_public_key *pk, + void *dst, size_t dst_max_len, + const void *src, size_t src_len); + +/** + * \brief RSA decryption (OAEP) with the "i31" engine. + * + * \see br_rsa_oaep_decrypt + * + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param sk RSA private key. + * \param data input/output buffer. + * \param len encrypted/decrypted message length. + * \return 1 on success, 0 on error. + */ +uint32_t br_rsa_i31_oaep_decrypt( + const br_hash_class *dig, const void *label, size_t label_len, + const br_rsa_private_key *sk, void *data, size_t *len); + +/** + * \brief RSA encryption (OAEP) with the "i32" engine. + * + * \see br_rsa_oaep_encrypt + * + * \param rnd source of random bytes. + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param pk RSA public key. + * \param dst destination buffer. + * \param dst_max_len destination buffer length (maximum encrypted data size). + * \param src message to encrypt. + * \param src_len source message length (in bytes). + * \return encrypted message length (in bytes), or 0 on error. + */ +size_t br_rsa_i32_oaep_encrypt( + const br_prng_class **rnd, const br_hash_class *dig, + const void *label, size_t label_len, + const br_rsa_public_key *pk, + void *dst, size_t dst_max_len, + const void *src, size_t src_len); + +/** + * \brief RSA decryption (OAEP) with the "i32" engine. + * + * \see br_rsa_oaep_decrypt + * + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param sk RSA private key. + * \param data input/output buffer. + * \param len encrypted/decrypted message length. + * \return 1 on success, 0 on error. + */ +uint32_t br_rsa_i32_oaep_decrypt( + const br_hash_class *dig, const void *label, size_t label_len, + const br_rsa_private_key *sk, void *data, size_t *len); + +/** + * \brief RSA encryption (OAEP) with the "i62" engine. + * + * This function is defined only on architecture that offer a 64x64->128 + * opcode. Use `br_rsa_i62_oaep_encrypt_get()` to dynamically obtain a pointer + * to that function. + * + * \see br_rsa_oaep_encrypt + * + * \param rnd source of random bytes. + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param pk RSA public key. + * \param dst destination buffer. + * \param dst_max_len destination buffer length (maximum encrypted data size). + * \param src message to encrypt. + * \param src_len source message length (in bytes). + * \return encrypted message length (in bytes), or 0 on error. + */ +size_t br_rsa_i62_oaep_encrypt( + const br_prng_class **rnd, const br_hash_class *dig, + const void *label, size_t label_len, + const br_rsa_public_key *pk, + void *dst, size_t dst_max_len, + const void *src, size_t src_len); + +/** + * \brief RSA decryption (OAEP) with the "i62" engine. + * + * This function is defined only on architecture that offer a 64x64->128 + * opcode. Use `br_rsa_i62_oaep_decrypt_get()` to dynamically obtain a pointer + * to that function. + * + * \see br_rsa_oaep_decrypt + * + * \param dig hash function to use with MGF1. + * \param label label value (may be `NULL` if `label_len` is zero). + * \param label_len label length, in bytes. + * \param sk RSA private key. + * \param data input/output buffer. + * \param len encrypted/decrypted message length. + * \return 1 on success, 0 on error. + */ +uint32_t br_rsa_i62_oaep_decrypt( + const br_hash_class *dig, const void *label, size_t label_len, + const br_rsa_private_key *sk, void *data, size_t *len); + +/** + * \brief Get buffer size to hold RSA private key elements. + * + * This macro returns the length (in bytes) of the buffer needed to + * receive the elements of a RSA private key, as generated by one of + * the `br_rsa_*_keygen()` functions. If the provided size is a constant + * expression, then the whole macro evaluates to a constant expression. + * + * \param size target key size (modulus size, in bits) + * \return the length of the private key buffer, in bytes. + */ +#define BR_RSA_KBUF_PRIV_SIZE(size) (5 * (((size) + 15) >> 4)) + +/** + * \brief Get buffer size to hold RSA public key elements. + * + * This macro returns the length (in bytes) of the buffer needed to + * receive the elements of a RSA public key, as generated by one of + * the `br_rsa_*_keygen()` functions. If the provided size is a constant + * expression, then the whole macro evaluates to a constant expression. + * + * \param size target key size (modulus size, in bits) + * \return the length of the public key buffer, in bytes. + */ +#define BR_RSA_KBUF_PUB_SIZE(size) (4 + (((size) + 7) >> 3)) + +/** + * \brief Type for RSA key pair generator implementation. + * + * This function generates a new RSA key pair whose modulus has bit + * length `size` bits. The private key elements are written in the + * `kbuf_priv` buffer, and pointer values and length fields to these + * elements are populated in the provided private key structure `sk`. + * Similarly, the public key elements are written in `kbuf_pub`, with + * pointers and lengths set in `pk`. + * + * If `sk` is `NULL`, then `kbuf_pub` may be `NULL`, and only the + * private key is set. + * + * If `pubexp` is not zero, then its value will be used as public + * exponent. Valid RSA public exponent values are odd integers + * greater than 1. If `pubexp` is zero, then the public exponent will + * have value 3. + * + * The provided PRNG (`rng_ctx`) must have already been initialized + * and seeded. + * + * Returned value is 1 on success, 0 on error. An error is reported + * if the requested range is outside of the supported key sizes, or + * if an invalid non-zero public exponent value is provided. Supported + * range starts at 512 bits, and up to an implementation-defined + * maximum (by default 4096 bits). Note that key sizes up to 768 bits + * have been broken in practice, and sizes lower than 2048 bits are + * usually considered to be weak and should not be used. + * + * \param rng_ctx source PRNG context (already initialized) + * \param sk RSA private key structure (destination) + * \param kbuf_priv buffer for private key elements + * \param pk RSA public key structure (destination), or `NULL` + * \param kbuf_pub buffer for public key elements, or `NULL` + * \param size target RSA modulus size (in bits) + * \param pubexp public exponent to use, or zero + * \return 1 on success, 0 on error (invalid parameters) + */ +typedef uint32_t (*br_rsa_keygen)( + const br_prng_class **rng_ctx, + br_rsa_private_key *sk, unsigned char *kbuf_priv, + br_rsa_public_key *pk, unsigned char *kbuf_pub, + unsigned size, uint32_t pubexp); + +/** + * \brief RSA key pair generation with the "i15" engine. + * + * \see br_rsa_keygen + * + * \param rng_ctx source PRNG context (already initialized) + * \param sk RSA private key structure (destination) + * \param kbuf_priv buffer for private key elements + * \param pk RSA public key structure (destination), or `NULL` + * \param kbuf_pub buffer for public key elements, or `NULL` + * \param size target RSA modulus size (in bits) + * \param pubexp public exponent to use, or zero + * \return 1 on success, 0 on error (invalid parameters) + */ +uint32_t br_rsa_i15_keygen( + const br_prng_class **rng_ctx, + br_rsa_private_key *sk, unsigned char *kbuf_priv, + br_rsa_public_key *pk, unsigned char *kbuf_pub, + unsigned size, uint32_t pubexp); + +/** + * \brief RSA key pair generation with the "i31" engine. + * + * \see br_rsa_keygen + * + * \param rng_ctx source PRNG context (already initialized) + * \param sk RSA private key structure (destination) + * \param kbuf_priv buffer for private key elements + * \param pk RSA public key structure (destination), or `NULL` + * \param kbuf_pub buffer for public key elements, or `NULL` + * \param size target RSA modulus size (in bits) + * \param pubexp public exponent to use, or zero + * \return 1 on success, 0 on error (invalid parameters) + */ +uint32_t br_rsa_i31_keygen( + const br_prng_class **rng_ctx, + br_rsa_private_key *sk, unsigned char *kbuf_priv, + br_rsa_public_key *pk, unsigned char *kbuf_pub, + unsigned size, uint32_t pubexp); + +/** + * \brief RSA key pair generation with the "i62" engine. + * + * This function is defined only on architecture that offer a 64x64->128 + * opcode. Use `br_rsa_i62_keygen_get()` to dynamically obtain a pointer + * to that function. + * + * \see br_rsa_keygen + * + * \param rng_ctx source PRNG context (already initialized) + * \param sk RSA private key structure (destination) + * \param kbuf_priv buffer for private key elements + * \param pk RSA public key structure (destination), or `NULL` + * \param kbuf_pub buffer for public key elements, or `NULL` + * \param size target RSA modulus size (in bits) + * \param pubexp public exponent to use, or zero + * \return 1 on success, 0 on error (invalid parameters) + */ +uint32_t br_rsa_i62_keygen( + const br_prng_class **rng_ctx, + br_rsa_private_key *sk, unsigned char *kbuf_priv, + br_rsa_public_key *pk, unsigned char *kbuf_pub, + unsigned size, uint32_t pubexp); + +/** + * \brief Get the RSA "i62" implementation (key pair generation), + * if available. + * + * \return the implementation, or 0. + */ +br_rsa_keygen br_rsa_i62_keygen_get(void); + +/** + * \brief Get "default" RSA implementation (key pair generation). + * + * This returns the preferred implementation of RSA (key pair generation) + * on the current system. + * + * \return the default implementation. + */ +br_rsa_keygen br_rsa_keygen_get_default(void); + #ifdef __cplusplus } #endif