NAME

       OSSL_DECODER_from_data, OSSL_DECODER_from_bio, OSSL_DECODER_from_fp - Routines to perform a decoding

SYNOPSIS

        #include <openssl/decoder.h>

        int OSSL_DECODER_from_bio(OSSL_DECODER_CTX *ctx, BIO *in);
        int OSSL_DECODER_from_fp(OSSL_DECODER_CTX *ctx, FILE *fp);
        int OSSL_DECODER_from_data(OSSL_DECODER_CTX *ctx, const unsigned char **pdata,
                                   size_t *pdata_len);

       Feature availability macros:

       OSSL_DECODER_from_fp() is only available when OPENSSL_NO_STDIO is undefined.

DESCRIPTION

       OSSL_DECODER_from_data()  runs  the  decoding process for the context ctx, with input coming from *pdata,
       *pdata_len bytes long.  Both *pdata and  *pdata_len  must  be  non-NULL.   When  OSSL_DECODER_from_data()
       returns,  *pdata  is updated to point at the location after what has been decoded, and *pdata_len to have
       the number of remaining bytes.

       OSSL_DECODER_from_bio() runs the decoding process for the context ctx, with the input coming from the BIO
       in.  Should it make a difference, it's recommended to have the BIO set in binary mode  rather  than  text
       mode.

       OSSL_DECODER_from_fp()  does  the  same thing as OSSL_DECODER_from_bio(), except that the input is coming
       from the FILE fp.

RETURN VALUES

       OSSL_DECODER_from_bio(), OSSL_DECODER_from_data() and OSSL_DECODER_from_fp() return 1 on success, or 0 on
       failure.

EXAMPLES

       To decode an RSA key encoded with PEM from a bio:

        OSSL_DECODER_CTX *dctx;
        EVP_PKEY *pkey = NULL;
        const char *format = "PEM";   /* NULL for any format */
        const char *structure = NULL; /* any structure */
        const char *keytype = "RSA";  /* NULL for any key */
        const unsigned char *pass = "my password";

        dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, format, structure,
                                             keytype,
                                             OSSL_KEYMGMT_SELECT_KEYPAIR,
                                             NULL, NULL);
        if (dctx == NULL) {
            /* error: no suitable potential decoders found */
        }
        if (pass != NULL)
            OSSL_DECODER_CTX_set_passphrase(dctx, pass, strlen(pass));
        if (OSSL_DECODER_from_bio(dctx, bio)) {
            /* pkey is created with the decoded data from the bio */
        } else {
            /* decoding failure */
        }
        OSSL_DECODER_CTX_free(dctx);

       To decode an EC key encoded with DER from a buffer:

        OSSL_DECODER_CTX *dctx;
        EVP_PKEY *pkey = NULL;
        const char *format = "DER";   /* NULL for any format */
        const char *structure = NULL; /* any structure */
        const char *keytype = "EC";   /* NULL for any key */
        const unsigned char *pass = NULL
        const unsigned char *data = buffer;
        size_t datalen = sizeof(buffer);

        dctx = OSSL_DECODER_CTX_new_for_pkey(&pkey, format, structure,
                                             keytype,
                                             OSSL_KEYMGMT_SELECT_KEYPAIR
                                             | OSSL_KEYMGMT_SELECT_DOMAIN_PARAMETERS,
                                             NULL, NULL);
        if (dctx == NULL) {
            /* error: no suitable potential decoders found */
        }
        if (pass != NULL)
            OSSL_DECODER_CTX_set_passphrase(dctx, pass, strlen(pass));
        if (OSSL_DECODER_from_data(dctx, &data, &datalen)) {
            /* pkey is created with the decoded data from the buffer */
        } else {
            /* decoding failure */
        }
        OSSL_DECODER_CTX_free(dctx);

SEE ALSO

       provider(7), OSSL_DECODER_CTX(3)

HISTORY

       The functions described here were added in OpenSSL 3.0.

COPYRIGHT

       Copyright 2020-2023 The OpenSSL Project Authors. All Rights Reserved.

       Licensed under the Apache License 2.0 (the "License").  You may not use this file  except  in  compliance
       with  the  License.   You  can  obtain  a  copy  in  the  file  LICENSE  in the source distribution or at
       <https://www.openssl.org/source/license.html>.

3.0.13                                             2025-02-05                        OSSL_DECODER_FROM_BIO(3SSL)